Viruses take down massive algal blooms, with big implications for climate

Algae might seem easy to ignore, but they are the ultimate source of all organic matter that marine animals depend upon. Humans are increasingly dependent on algae, too, to suck up climate-warming carbon dioxide from the atmosphere and sink it to the bottom of the ocean. Now, by using a combination of satellite imagery and laboratory experiments, researchers have evidence showing that viruses infecting those algae are driving the life-and-death dynamics of the algae’s blooms, even when all else stays essentially the same, and this has important implications for our climate.

Location and Biophysical Characteristics of the Study Area

Caption: This is a location map. Black rectangle delineates the area shown in Figures 1B and 2. (B) Map of surface chlorophyll from June 22, 2012 (day 174), emphasizing the phytoplankton patch as a distinct area of high chlorophyll concentration. Thick black lines mark the main attracting Lagrangian coherent structures from calculation of finite-size Lyapunov exponents. To facilitate the presentation, we plotted only the highest 20 percent of FSLEs (for the entire FSLE field, see Figure 2C). Thin black contour outline region of strong Chl gradient is used to define patch boundaries. Magenta diamonds mark the position of Argo floats used for extracting the mixed layer depth in the patch vicinity. Green diamonds mark the location of the sampling stations. Continue reading “Viruses take down massive algal blooms, with big implications for climate”

Monsato GMO crops damage red blood cells, organs

гмо кукуруза генетически модифицированные организмы продовольствие

Photo: EPA

Studies are now showing that Monsanto crops damage red blood cells which are responsible for delivering oxygen to the body. And without functioning red blood cells, our bodies are in critical condition — desperate for life support.

 The bad news about Monsanto can seem like an overwhelming highway car pileup, but thankfully the news is leading to a larger response by activists.

 Movements like the Monsanto Video Revolt, announced by Anthony Gucciardi last week, are taking the fight to Monsanto following the major success of movements like March Against Monsanto. Studies like these only lend more aid towards the cause that we fight for each day.

 The study found that red blood cells suffer due to a bacterium commonly used as a pesticide in Monsanto’s crops, called Bacillus thuringenesis (Bt). Specifically, the Bt toxin affects mammals in ways that previously were not understood. Heretofore the Bt bacterium were only thought to harm insects, but this is proving to be grossly erroneous.

 Dr. Mezzomo and a team of scientists at the Department of Genetics and Morphology and the Institute of Biological Sciences, at University of Brasilia published their findings in a recent issue of the Journal of Hematology and Thromboembolic Diseases.

 Poisons known as Cry toxins are used for gene pyramiding (a method in which multiple genes are assembled to have desirable traits from parent genes for a new, altered, single genotype) in GMO foods.

 These Cry toxins specifically alter the hematoxic levels, which means they poison our blood. “Cry toxins are disruptive even at the lowest administered doses,” says Mezzomo.

 The number of red blood cells in Monsanto Cry-toxin-exposed mammals (in this study, unfortunately rats were used) was not only lowered through the destruction of the cells themselves, but the toxins also disrupted blood clotting and caused organ degeneration and tissue damage.

 Voice of Russia, ConsciousLifeNews

 

http://english.ruvr.ru/2013_06_27/Monsato-GMO-crops-damage-red-blood-cells-organs-5591/

Advanced Biological Computer Developed with ability to read and transform genetic information

Microprocessor with DNA (illustration). Scientists have developed and constructed an advanced biological transducer, a computing machine capable of manipulating genetic codes, and using the output as new input for subsequent computations (Credit: © Giovanni Cancemi / Fotolia)

May 23, 2013 — Using only biomolecules (such as DNA and enzymes), scientists at the Technion-Israel Institute of Technology have developed and constructed an advanced biological transducer, a computing machine capable of manipulating genetic codes, and using the output as new input for subsequent computations. The breakthrough might someday create new possibilities in biotechnology, including individual gene therapy and cloning.

The findings appear today (May 23, 2013) in Chemistry & Biology (Cell Press).

Interest in such biomolecular computing devices is strong, mainly because of their ability (unlike electronic computers) to interact directly with biological systems and even living organisms. No interface is required since all components of molecular computers, including hardware, software, input and output, are molecules that interact in solution along a cascade of programmable chemical events.

“Our results show a novel, synthetic designed computing machine that computes iteratively and produces biologically relevant results,” says lead researcher Prof. Ehud Keinan of the Technion Schulich Faculty of Chemistry. “In addition to enhanced computation power, this DNA-based transducer offers multiple benefits, including the ability to read and transform genetic information, miniaturization to the molecular scale, and the aptitude to produce computational results that interact directly with living organisms.”

The transducer could be used on genetic material to evaluate and detect specific sequences, and to alter and algorithmically process genetic code. Similar devices, says Prof. Keinan, could be applied for other computational problems.

“All biological systems, and even entire living organisms, are natural molecular computers. Every one of us is a biomolecular computer, that is, a machine in which all components are molecules “talking” to one another in a logical manner. The hardware and software are complex biological molecules that activate one another to carry out some predetermined chemical tasks. The input is a molecule that undergoes specific, programmed changes, following a specific set of rules (software) and the output of this chemical computation process is another well defined molecule.”

Also contributing to the research were postdoctoral fellows Dr. Tamar Ratner and Dr. Ron Piran of the Technion’s Schulich Faculty of Chemistry, and Dr. Natasha Jonoska of the Department of Mathematics at the University of South Florida.

http://www.sciencedaily.com/releases/2013/05/130523180318.htm

 

‘Defective’ virus surprisingly plays major role in spread of disease, UCLA life scientists report

Contact: Stuart Wolpert swolpert@support.ucla.edu 310-206-0511 University of California – Los Angeles

Defective viruses, thought for decades to be essentially garbage unrelated to the transmission of normal viruses, now appear able to play an important role in the spread of disease, new research by UCLA life scientists indicates.

Defective viruses have genetic mutations or deletions that eliminate their essential viral functions. They have been observed for many human pathogens and are generated frequently for viruses that have high mutation rates. However, for some 40 years, it was believed that they were unimportant in natural settings.

In findings published Feb. 28 in the journal PLoS Pathogens, UCLA scientists and their colleagues report for the first time a significant link between a defective virus and an increased rate of transmission of a major disease.

“The idea has always been that defective viruses are either meaningless or detrimental,” said James O. Lloyd-Smith, a UCLA assistant professor of ecology and evolutionary biology and the senior author of the research. “We have found the opposite of that — that the defective virus is actually helping the normal, functional virus. This finding is bizarre and hard to believe, but the data are the data.”

“We have shown that the defective virus not only transmits with the virus but increases the transmission of the functional virus,” said Ruian Ke, a UCLA postdoctoral scholar in the department of ecology and evolutionary biology and the lead author of the study.

Defective viruses cannot complete their life cycle on their own, but if they’re able to get into the same cell with a non-defective virus, they can “hitchhike” with the normal virus and propagate, Lloyd-Smith said. Biologists had thought that defective viruses interfered with normal versions of the virus, “clogging up the gears of viral replication,” he said.

The life scientists studied DENV-1, one of four known types of the dengue virus that infect humans. Dengue viruses are transmitted by several species of mosquitoes and cause dengue fever, which is characterized by fever, joint pain and a skin rash similar to measles. Dengue hemorrhagic fever, a more severe form of dengue infection, can cause death. The dengue virus infects between 50 million and 100 million people each year in Southeast Asia, South America, parts of the United States and elsewhere.

The life sciences team — which also included John Aaskov, a virologist and professor of health at Australia’s Queensland University of Technology in Brisbane, and Edward Holmes, a professor of biological sciences at Australia’s University of Sydney — found that the presence of a defective DENV-1 virus may have led to large increases in dengue fever cases in Myanmar in 2001 and 2002, when that country experienced its most severe dengue epidemics on record.

The scientists describe when and how the defective “lineage,” or series of very closely related defective DENV-1 viruses, emerged and was transmitted between humans and mosquitoes in Myanmar, as well as what the public health implications are.

For the study, Ke designed a mathematical model to analyze the data to learn how the defective DENV-1 virus interacted with the normal virus. Aaskov and Holmes collected genetic sequences from from 15 people in Myanmar sampled over an 18-month period, all of whom were infected with the DENV-1 virus and nine of whom were also infected with the defective version.

Ke discovered that the lineage of defective viruses emerged between June 1998 and February 2001 and that it was spreading in the population until at least 2002. (The following year, the lineage appeared on the South Pacific island of New Caledonia, carried there by either a mosquito or a person.) The scientists analyzed the genetic sequences of both the defective and normal dengue viruses to estimate how long the defective virus had been transmitting in the human population.

“We can see from the gene sequence of the defective version that it is the same lineage and is a continued propagation of the virus,” said Lloyd-Smith, who holds UCLA’s De Logi Chair in Biological Sciences. “From 2001 to 2002, it went from being quite rare to being in all nine people we sampled that year; everybody sampled who was getting dengue fever was getting the defective version along with the functional virus. It rose from being rare to being very common in just one year.”

Most surprisingly, Lloyd-Smith said, the combination of the defective virus with the normal virus was “more fit” than the normal dengue virus alone.

“What we have shown is that this defective virus, which everyone had thought was useless or even detrimental to the fitness of the functional virus, actually appears to have made it better able to spread,” he said. “Ruian [Ke] calculated that the defective virus makes it at least 10 percent more transmissible, which is a lot. It was spreading better with its weird, defective cousin tagging along than on its own.

“This study has shown that the functional virus and defective virus travel in unison. The two transmit together in an unbroken chain, and that’s not just a matter of getting into the same human or the same mosquito — they need to get into the same cell inside that human or mosquito in order to share their genes and for the defective version to continue ‘hitchhiking.’ We are gaining insights into the cellular-level biology of how dengue is infecting hosts. It must be the case that frequently there are multiple infections of single cells.

“Ruian showed the defective virus appeared one to three years before these major epidemics,” Lloyd-Smith added. “One could imagine that if you build an understanding of this mechanism, you could measure it, see it coming and potentially get ahead of it.”

Might defective viruses play a role in the transmission of influenza, measles and other diseases?

“There are a few signs that this phenomenon may be happening for other viruses,” Lloyd-Smith said. “We may be cracking open the book on the possible interactions between the normal, functional viruses and the defective ones that people thought were just dead-ends. These supposedly meaningless viruses may be having a positive impact — positive for the virus, not for us. There is great variation, year to year, in how large dengue epidemics are in various locations, and we don’t understand why. This is a possible mechanism for why there are large epidemics in some years in some places. We need to keep studying this question.”

The research points to implications for how mutations might allow a new non-human virus to become a human virus.

“Different strains of a virus with different genetic properties may be interacting more frequently than we thought,” said Lloyd-Smith, who studies how ecology, evolution and epidemiology merge to drive the emergence of new pathogens, including new strains with important properties like drug resistance.

Why would a defective virus increase transmission of a disease?

Lloyd-Smith offers two hypotheses. One is that the presence of the defective virus with the functional virus in the same cell makes the functional virus replicate better within the cell by some unknown mechanism. “It might give the virus a bit of flexibility in how it expresses its genes and may make it a bit more fit, a bit better able to reproduce under some circumstances,” he said.

A second idea is that the defective virus may be interfering with the disease-causing virus, making the disease less intense; people then have a milder infection, and because they don’t feel as sick, they are more likely to go out and spread the disease.

“Normally, biologists test for how well a virus can replicate in a cell, but what we have shown here is even a genotype that cannot replicate in a cell can have an impact on transmission,” Ke said.

In conducting the research, Lloyd-Smith and Ke combined genetic sequence analysis with sophisticated mathematical models and bioinformatics.

Genetic sequencing technology has “exploded,” Lloyd-Smith said, providing a wealth of data on genetic sequences of pathogens and the evolution of viruses, leading to major new insights into the transmission of viruses.

“We were able to show that this defective virus transmitted in an unbroken chain across this population for a year-and-a-half,” Lloyd-Smith said. “Without gene sequencing, we would not have been able to establish that.”

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The research was federally funded by the National Science Foundation.

Read more about Lloyd-Smith’s research.

UCLA is California’s largest university, with an enrollment of more than 40,000 undergraduate and graduate students. The UCLA College of Letters and Science and the university’s 11 professional schools feature renowned faculty and offer 337 degree programs and majors. UCLA is a national and international leader in the breadth and quality of its academic, research, health care, cultural, continuing education and athletic programs. Six alumni and six faculty have been awarded the Nobel Prize.

For more news, visit the UCLA Newsroom and follow us on Twitter.

Mood-modifying drugs for humans also alter fish behavior

Contact: Natasha Pinol npinol@aaas.org 202-326-6440 American Association for the Advancement of Science

Trace amounts of pharmaceuticals in rivers and streams inspire changes in wildlife

This release is available in Arabic, French, Japanese, Spanish, Swedish, and Chinese.

             IMAGE:   This is a perch (Perca fluviatilis).

Click here for more information.     

Pharmaceutical drugs that end up in the world’s waterways after being excreted, flushed and treated at wastewater treatment plants may lead to unexpected ecological impacts, according to a new study of wild European perch. Tomas Brodin and colleagues from Umeå University in Sweden discovered that the fish ate faster, became bolder and acted less social after being subjected to an anxiety-moderating drug, known as Oxazepam.

The psychiatric drug is used to treat anxiety in humans. But, Oxazepam residues often wind up in natural aquatic systems, downstream from sewage treatment plants, where their effects on ecosystems have been unknown. Now, Brodin and the other researchers have dosed wild perch with amounts of Oxazepam equivalent to those found in Sweden’s rivers and streams, and their results suggest that even small amounts of the drug can alter the behavior and the foraging rates of these fish.

The related report appears in the 15 February issue of the journal Science, which is published by AAAS, the nonprofit science society.

“While alone, fish that were exposed to Oxazepam dared to leave safe refuge and enter novel, potentially dangerous areas,” explained Brodin. “In contrast, unexposed fish stayed hidden in their refuge. The exposed fish seemed much less stressed and scared, behaving calmer and bolder.”

             IMAGE:   These are shoaling perch.

Click here for more information.     

Perch that were exposed to the drug also devoured their food quicker than unexposed fish—a behavioral quirk that the researchers say could alter the composition of species in the water and lead to ecological events, such as increased algal blooming, over time. Since fish are generally integral pieces of their food webs, changes in their eating patterns could disturb ecological balances, according to the researchers.

The fish that were given Oxazepam during the study also became anti-social, distancing themselves from other perch and putting themselves at greater risk of predation. “Perch that were exposed to Oxazepam lost interest in hanging out with the group, and some even stayed as far away from the group as possible,” explained Brodin.

The fish in the study accumulated concentrations of the drug in their muscle tissues that were comparable to those found in wild fish, according to the researchers. So it’s likely that the fish in Sweden’s surface waters, many of which are being exposed to similarly diluted doses of Oxazepam, may be experiencing changes in their behavior and feeding rates as well, they say.

             IMAGE:   This is the Umeå University research team in front of the mass spectrometer, where the water and fish samples were analyzed. From left to right: Micael Jonsson, Jonatan Klaminder, Tomas…

Click here for more information.     

This study by Brodin and his colleagues singled out a particular psychiatric drug that has been found in natural systems. But, a veritable cocktail of drugs can be found in waterways worldwide, making the discovery of Oxazepam’s effects on fish that much more important.

More comprehensive studies are needed before general conclusions can be drawn about how such pharmaceutically induced changes to behavior might affect ecosystems, but these current findings suggest that the concentrations of Oxazepam in Sweden’s surface waters could have unexpected ecological and evolutionary consequences over time.

“The solution to this problem isn’t to stop medicating people who are ill but to try to develop sewage treatment plants that can capture environmentally hazardous drugs,” concluded Jerker Fick, a co-author of the Science report, in a press release from Umeå University.

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The report by Brodin et al. was supported by a Young Researcher Award from Umeå University, the Swedish Research Council Vetenskapsrådet and FORMAS, and a small starting grant from the strong research environment “The environment’s chemistry—from molecules to the ecosystem.”

The American Association for the Advancement of Science (AAAS) is the world’s largest general scientific society, and publisher of the journal, Science as well as Science Translational Medicine and Science Signaling. AAAS was founded in 1848, and includes some 261 affiliated societies and academies of science, serving 10 million individuals. Science has the largest paid circulation of any peer-reviewed general science journal in the world, with an estimated total readership of 1 million. The non-profit AAAS is open to all and fulfills its mission to “advance science and serve society” through initiatives in science policy; international programs; science education; and more. For the latest research news, log onto EurekAlert!, www.eurekalert.org, the premier science-news Web site, a service of AAAS.

Auto-immune disease: the viral route is confirmed

19.12.2012 –  Press release

Europe           Health technologies

Why would our immune system turn against our own cells? This is the question that the combined Inserm/CNRS/ Pierre and Marie Curie University/Association Institut de Myologie  have strived to answer in their “Therapies for diseases of striated muscle”, concentrating in particular on the auto-immune disease known as myasthenia gravis. Through the project known as FIGHT-MG (Fight Myasthenia Gravis), financed by the European Commission and coordinated by Inserm, Sonia Berrih-Aknin and Rozen Le Panse have contributed proof of the concept that a molecule imitating a virus may trigger an inappropriate immune response, causing muscular function to deteriorate. These results have been published in Annals of Neurology, accessible on line.

Myasthenia, a rare auto-immune disease

Myasthenia gravis is a rare auto-immune disease (5,000 to 6,000 patients in France) that produces muscular weakness and exhaustion. It generally affects the facial muscles first, and may then become generalised through the muscles of the limbs or the respiratory muscles, causing respiratory distress.

This is due to the production of circulating auto-antibodies that block the acetylcholine receptors (RACh), these neurotransmitters being necessary for transmitting the motor nerve signal to the neuro-muscular junction.

Could a viral infection be the origin of myasthenia?

Myasthenia is a multi-factorial disease in which environmental factors seem to play a key triggering role. Viral infections are suspected but it is hard to prove the role of a virus in triggering the condition. In fact, diagnosis of myasthenia is often made months, or even years, after the actual start of the illness when the virus is no longer detectable, even though the signature left by the virus is visible long after the infection.

Proof of the concept of a viral origin contributed by researchers

Under the European FIGHT-MG project, the team of researchers managed to decode the trigger for the illness by using a molecule that mimics the RNA double viral strand (Poly(I:C)).

To do this, they concentrated on the organ that plays a central role in the disease – the thymus. It is in this gland located in the thorax that the T-lymphocytes mature, these being the key players in immune response that are normally programmed to avoid the development of any auto-immunity.

The researchers were thus able to show in vitro that the Poly(I:C) was capable of specifically inducing an over-expression of RACh through thymal epithelial cells, while activating three proteins (the “toll-like” receptor 3 (TLR3), the protein kinase R (PKR) and interferon-beta (IFN-â)); it is this last that produces inflammation in the thymus.

At the same time, they analysed pathological thymus glands of myasthenia sufferers in whom they observed over-expression of these same three proteins in the immune system, characteristic of a viral infection.

Finally, the researchers also managed to identify the same molecular changes in the thymus glands of mice, after they had been injected with Poly(I:C). After a prolonged injection period, they also observed a proliferation in the mice of B anti-RACh cells, the presence of auto-antibodies blocking the RACh receptors and clinical signs synonymous with the muscular weakness found in myasthenia.

These original results show that molecules that mimic a viral infection are capable of inducing myasthenia in the mouse, something that had never been demonstrated before.

 

This set of papers published in the Annals of Neurology provides proof of the concept that a viral infection can cause inflammation of the thymus and lead to the development of auto-immune myasthenia.

The next stages of the research will consist in determining which exogenous virus this may be or whether it is a case of the abnormal activation of an anti-viral response by endogenous molecules.

© Inserm / R. Le Panse 

 

The introduction of a double strand of RNA (Poly(I:C) into the thymal epithelial cell induces the over-expression of the acetylcholine receptors (RACh), via the activation of the “toll-like” receptor 3 (TLR3) and the protein kinase R (PKR),  as well as the production of interferon-beta (IFN-β)). These changes in the thymus gland cause the formation of B anti-RACh cells and the production of circulating auto-antibodies that block the acetylcholine receptors present in the neuromuscular junction.

 

 

FIGHT-MG (Fighting Myasthenia Gravis) – a European collaboration making giant leaps forward

The FIGHT-MG project seeks to determine the genetic and environmental risk factors associated with the occurrence of the illness and its development. The project aims also to identify the key immunological molecules associated with its appearance, and to study the pathogenic mechanisms at the neuromuscular junction, establish new diagnostic tests, as well as new treatments (cellular treatments, immuno-regulatory treatments, immuno-absorption of pathogenic auto-antibodies and other pharmacological treatments).

“When one is working on a rare disease, it is essential to work through networking, so as to be able to share our facilities and resources to promote fundamental and clinical research. It is also crucial to communicate permanently with patient associations. It is this combination that enables us to take giant steps in the treatment of rare conditions,” explains Sonia Berrih-Aknin.

 

 

FIGHT-MG : http://www.fight-mg.eu/ 

FIGHT-MG started in December 2009 and will last for four years, with a total budget of about six million euros funded by the European Union (FP7). The project involves 12 partners based in seven European countries:

The 12 partners:

Inserm (coordinator), France Hellenic Pasteur Institute (HPI), Greece Open University of Israel (OUI), Israel Fondazione Istituto Neurologico “Carlo Besta” (INNCB), Italy Oslo University Hospital (OUS), Norway Hadassah Hebrew University Medical Center (HMO), Israel Israel Institute of Technology (TECHNION), Israel University of Paris 6 Pierre and Marie Curie (UPMC), France University of Basel (UNIBAS), Switzerland ProteoSys (PSY), Germany Genopolis Consortium for Functional Genomics (GENOPOLIS), Italy INSERM TRANSFERT SA (IT), France

 

 

The “Myasthenia” team

The “Myasthenia” team, headed by Sonia Berrih-Aknin joined the Institute of Myology directed by Professor T. Voit, just over a year ago in order to get closer to the reference centre for neuromuscular diseases run by Prof B. Eymard, at the Pitié-Salpêtrière Hospital in Paris. The Institute of Myology is an international center of expertise on the muscle and its diseases, a member of the Institute of Biotherapy of rare diseases created by the AFM-Telethon. The Sonia Berrih-Aknin’s team is interested in the etiological and physio-pathological mechanisms of myasthenia and innovative treatments that could improve patients’ quality of life.

Even though winning a European project is very competitive, this team has exceptionally been granted three other projects since 2001, and was responsible for their coordination. Sonia Berrih-Aknin was the coordinator of the “Mechanisms of Myasthenia” project (2001-2005) under FP5, the MYASTAID (2006-2010) project under  le cadre du FP6, as well as the Euromyasthenia Project (2006-2009) through the European Public Health  Directorate. These projects brought a total of more than fifty teams of clinicians, researchers and associations of sufferers in Europe.

New form of cell division found

Contact: Dian Land dj.land@hosp.wisc.edu 608-261-1034 University of Wisconsin-Madison

MADISON — Researchers at the University of Wisconsin Carbone Cancer Center have discovered a new form of cell division in human cells.

They believe it serves as a natural back-up mechanism during faulty cell division, preventing some cells from going down a path that can lead to cancer.

“If we could promote this new form of cell division, which we call klerokinesis, we may be able to prevent some cancers from developing,” says lead researcher Dr. Mark Burkard, an assistant professor of hematology-oncology in the Department of Medicine at the UW School of Medicine and Public Health.

Burkard will present the finding on Dec. 17 at the annual meeting of the American Society for Cell Biology in San Francisco.

A physician-investigator who sees breast cancer patients, Burkard studies cancers in which cells contain too many chromosomes, a condition called polyploidy.

About 14 percent of breast cancers and 35 percent of pancreatic cancers have three or more sets of chromosomes, instead of the usual two sets. Many other cancers have cells containing defective chromosomes rather than too many or too few.

“Our goal in the laboratory has been to find ways to develop new treatment strategies for breast cancers with too many chromosome sets,” he says.  The original goal of the current study was to make human cells that have extra chromosomes sets. But after following the accepted recipe, they unexpectedly observed the new form of cell division.

Until now, Burkard and most cell biologists today accepted a century-old hypothesis developed by German biologist Theodor Boveri, who studied sea urchin eggs. Boveri surmised that faulty cell division led to cells with abnormal chromosome sets, and then to the unchecked cell growth that defines cancer. With accumulated evidence over the years, most scientists have come to accept the hypothesis.

Normal cell division is at the heart of an organism’s ability to grow from a single fertilized egg into a fully developed individual. More than a million-million rounds of division must take place for this to occur. In each division, one mother cell becomes two daughter cells.

Even in a fully grown adult, many kinds of cells are routinely remade through cell division.

The fundamental process of cells copying themselves begins with a synthesis phase, when a duplicate copy is made of cell components, including the DNA-containing chromosomes in the nucleus. Then during mitosis, the two sets are physically separated in opposite directions, while still being contained in one cell. Finally, during cytokinesis, the one cell is cut into two daughter cells, right at the end of mitosis.

Burkard and his team were making cells with too many chromosomes–to mimic cancer. The scientists blocked cytokinesis with a chemical and waited to see what happened.

“We expected to recover a number of cells with abnormal sets of chromosomes,” Burkard explains.

The researchers found that, rather than appearing abnormal, daughter cells ended up looking normal most of the time. Contrary to Boveri’s hypothesis, abnormal cell division rarely had long-term negative effects in human cells.

So the group decided to see how the human cells recovered normal sets of chromosomes by watching with a microscope that had the ability to take video images.

“We started with two nuclei in one cell,” Burkard says. “To our great surprise, we saw the cell pop apart into two cells without going through mitosis.”

Each of the two new cells inherited an intact nucleus enveloping a complete set of chromosomes. The splitting occurred, unpredictably, during a delayed growth phase rather than at the end of mitosis.

The scientists did a number of additional experiments to carefully make sure that the division they observed was different than cytokinesis.

“We had a hard time convincing ourselves because this type of division does not appear in any textbook,” Burkard says.

Over time, they found that only 90 percent of daughter cells had recovered a normal complement of chromosomes. Burkard would like to leverage that statistic up to 99 percent.

“If we could push the cell toward this new type of division, we might be able to keep cells normal and lower the incidence of cancer,” he says.

Burkard now thinks that among all those rounds of cell division an organism goes through, every once in a while cytokinesis can fail. And that this new division is a back-up mechanism that allows cells to recover from the breakdown and grow normally.

The group has dubbed the new type of division klerokinesis to distinguish it from cytokinesis. Burkard enlisted the help of Dr. William Brockliss, UW assistant professor of classics, to come up with the name; klero is a Greek prefix meaning “allotted inheritance.”

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Collaborators on the project include Dr. Beth Weaver, UW assistant professor of cell and regenerative biology; Dr. Alka Choudhary; Robert Lera; Dr. Melissa Martowicz and Dr. Jennifer Laffin.

To see a movie, go to: http://med.wisc.edu/files/smph/docs/for_media/movie_rpe_klerokinesis.mov.

Licorice root helps the body defend against Pseudomonas aeruginosa infection

Contact: Cody Mooneyhan cmooneyhan@faseb.org 301-634-7104 Federation of American Societies for Experimental Biology

A trip to the candy store might help ward off rare, but deadly infections

New research in the Journal of Leukocyte Biology shows that glycyrrhizin extracted from licorice root helps the body defend against Pseudomonas aeruginosa infection

As it turns out, children were not the only ones with visions of sugar plums dancing in their heads over this past holiday season. In a new research report published in the January 2010 issue of the Journal of Leukocyte Biology (http://www.jleukbio.org), a team of scientists from the University of Texas Medical Branch and Shriners Hospitals for Children show how a compound from licorice root (glycyrrhizin from Glycyrrhiza glabra) might be an effective tool in battling life-threatening, antibiotic-resistant infections resulting from severe burns. Specifically, they found that in burned mice, glycyrrhizin improved the ability of damaged skin to create small proteins that serve as the first line of defense against infection. These proteins, called antimicrobial peptides, work by puncturing the cell membranes of bacteria similar to how pins pop balloons.

“It is our hope that the medicinal uses of glycyrrhizin will lead to lower death rates associated with infection in burn patients,” said Fujio Suzuki, Ph.D., one of the researchers involved in the work. Suzuki also said that more research is necessary to determine if this finding would have any implications for people with cystic fibrosis, who can develop Pseudomonas aeruginosa infections in their lungs.

To make this discovery, Suzuki and colleagues used three groups of mice. The first group was normal, the second group was burned and untreated, and the third group was burned and treated with glycyrrhizin. The skin of the untreated burned mice did not have any detectable antimicrobial peptides that prevent bacteria from growing and spreading, but the normal mice did. The skin of the untreated burned mice also had immature myeloid cells, which indicate an inability of the skin to produce antimicrobial peptides needed to prevent infection. The mice treated with glycyrrhizin, however, were more like the normal mice as they had the antimicrobial peptides and no immature myeloid cells.

“Burns are the most painful of all injuries,” said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology, “and the deadly Pseudomonas infections that can result from severe burns do more than add insult to those injuries. This research should serve as an important stepping stone toward helping develop new drugs that help prevent or treat Pseudomonas.”

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The Journal of Leukocyte Biology (http://www.jleukbio.org) publishes peer-reviewed manuscripts on original investigations focusing on the cellular and molecular biology of leukocytes and on the origins, the developmental biology, biochemistry and functions of granulocytes, lymphocytes, mononuclear phagocytes and other cells involved in host defense and inflammation. The Journal of Leukocyte Biology is published by the Society for Leukocyte Biology.

Details: Tsuyoshi Yoshida, Shohei Yoshida, Makiko Kobayashi, David N. Herndon, and Fujio Suzuki. Glycyrrhizin restores the impaired production of β-defensins in tissues surrounding the burn area and improves the resistance of burn mice to Pseudomonas aeruginosa wound infection. J Leukoc Biol 2010 87: 35-41. http://www.jleukbio.org/cgi/content/abstract/87/1/35

New vitamin-based treatment that could reduce muscle degeneration in muscular dystrophy: Niacin pre-cursor NAD+

Contact: Bryan Ghosh bghosh@plos.org 44-122-344-2837 Public Library of Science

Boosting the activity of a vitamin-sensitive cell adhesion pathway has the potential to counteract the muscle degeneration and reduced mobility caused by muscular dystrophies, according to a research team led by scientists at the University of Maine.

The discovery, published 23 October in the open access journal PLOS Biology, is particularly important for congenital muscular dystrophies, which are progressive, debilitating and often lethal diseases that currently remain without cure. The researchers found that they could improve muscle structure and function in a zebrafish version of muscular dystrophy by supplying a common cellular chemical (or its precursor, vitamin B3) to activate a cell adhesion pathway.

Muscle cells are in themselves relatively delicate, but derive important additional mechanical strength from adhesion protein complexes; these anchor the muscle cells to an external framework known as the basement membrane, thereby helping to buffer the cells against the extreme forces that they experience during muscle contractions. Mutations in the genes that encode these adhesion proteins can weaken these attachments, making muscle cells more susceptible to damage and death.

The resulting muscle degeneration can eventually lead to progressive muscle-wasting diseases, such as muscular dystrophies. A major component of the basement membrane, a protein called laminin, binds to multiple different receptors on the muscle cell surface and forms a dense, organized network.

The study was led by UMaine Associate Professor of Biological Sciences, Clarissa Henry, whose laboratory focuses on understanding how cell adhesion complexes contribute to muscle development. The researchers discovered that a pathway involving a common cellular chemical called nicotinamide adenine dinucleotide (NAD+) plays a role in the formation of organized basement membranes in muscle tissue, during development of the fish embryo. As disordered basement membranes are seen in many different types of muscular dystrophies, the researchers wondered whether activating this pathway might reduce the severity of some muscular dystrophies.

In the current study, the researchers show that NAD+ improves the organization of laminin in a zebrafish version of muscular dystrophy. Zebrafish lacking either of the two main receptors for laminin have a disorganized basement membrane, causing muscle degeneration and difficulties with movement. However adding extra NAD+, or even a vitamin packet containing vitamin B3 (niacin, a precursor to NAD+), significantly reduced these symptoms.

The research team found that the main protective effects of NAD+ come from enhancing the organization of the laminin structure in the basement membrane, which helps to increase the resilience of diseased muscle fibers.

Because the same cell adhesion complexes are found in humans, the research team is optimistic that these findings may one day positively impact patients with muscular dystrophies. “Although there is a long way to go, I’m hopeful that our data could eventually lead to new adjuvant therapies,” says University of Maine Ph.D. student Michelle Goody, who led the research team with Prof. Henry.

Prof. Henry summarizes; “One of my favorite aspects of this study is that it is a poster child for how asking basic biological questions can lead to exciting discoveries that may have future therapeutic potential.”

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Funding: This research was supported by NIH grant RO1 HD052934-01A1. MFG and MWK would like to thank the Graduate School of Biomedical Sciences, University of Maine, for funding. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Citation: Goody MF, Kelly MW, Reynolds CJ, Khalil A, Crawford BD, et al. (2012) NAD+ Biosynthesis Ameliorates a Zebrafish Model of Muscular Dystrophy. PLoS Biol 10(10): e1001409. doi:10.1371/journal.pbio.1001409

CONTACT:

Clarissa Henry School of Biology and Ecology University of Maine 2988 Hitchner Hall Orono, ME 4469 UNITED STATES Tel: +1-207-581-2816 clarissa.henry@maine.edu

Zinc supplementation significantly increases activation of the cells (T cells) responsible for destroying viruses and bacteria

2009 study posted for filing


Contact: Cody Mooneyhan
cmooneyhan@faseb.org
301-634-7104
Federation of American Societies for Experimental Biology

Got zinc? New zinc research suggests novel therapeutic targets

New report in the Journal of Leukocyte Biology suggests that zinc activates a key protein on T cells needed to fight infections

Everyone knows that vitamins “from A to zinc” are important for good health. Now, a new research study in the August 2009 print issue of the Journal of Leukocyte Biology (http://www.jleukbio.org) suggests that zinc may be pointing the way to new therapeutic targets for fighting infections. Specifically, scientists from Florida found that zinc not only supports healthy immune function, but increases activation of the cells (T cells) responsible for destroying viruses and bacteria.

“It has been shown that zinc supplementation significantly reduces the duration and severity of childhood diarrhea, lower respiratory infections, and incidence of malaria in zinc-deficient children,” said report co-author, Robert Cousins, Ph.D., who also is the director of the Center for Nutritional Sciences within the Food Science and Human Nutrition Department at the University of Florida. “Age-related declines in immune function have also been related to zinc deficiency in the elderly.”

Scientists administered either a zinc supplement or a placebo to healthy volunteers to assess the effects of zinc on T cell activation. After isolating the T cells from the blood, scientists then simulated infection in laboratory conditions. Results showed that T cells taken from the zinc-supplemented group had higher activation than those from the placebo group. Specifically, cell activation stimulated the zinc transporter in T cells called “ZIP8,” which transports stored zinc into the cell cytoplasm where it then alters the expression of a T cell protein in a way needed to fight infections.

“As the debate over zinc supplementation in healthy individuals continues,” said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology, “studies like this help shed light on how zinc may enhance the ability of our immune systems to fight off foreign invaders. Equally important, this work points toward new possible targets for entirely new drugs to help augment immune function and prevent or stop infections that might be resistant to traditional antibiotics.”

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The Journal of Leukocyte Biology (http://www.jleukbio.org) publishes peer-reviewed manuscripts on original investigations focusing on the cellular and molecular biology of leukocytes and on the origins, the developmental biology, biochemistry and functions of granulocytes, lymphocytes, mononuclear phagocytes and other cells involved in host defense and inflammation. The Journal of Leukocyte Biology is published by the Society for Leukocyte Biology.

Details: Tolunay B. Aydemir, Juan P. Liuzzi, Steve McClellan, and Robert J. Cousins Zinc transporter ZIP8 (SLC39A8) and zinc influence IFN- expression in activated human T cells. J Leukoc Biol 2009 86: 337�. http://www.jleukbio.org/cgi/content/abstract/86/2/337

 

Reprogramming of Pericyte-Derived Cells of the Adult Human Brain into Induced Neuronal Cells

  • Reprogramming of somatic cells into neurons provides a new approach toward cell-based therapy of neurodegenerative diseases (Vierbuchen and Wernig, 2011). Previous studies have shown that postnatal astroglia from the mouse cerebral cortex can be directly converted into functional neuronal cells in vitro by forced expression of a single transcription factor (Heinrich et al., 2010, Heinrich et al., 2011; Heins et al., 2002) and that the synergistic action of three or four transcription factors can induce neurogenesis from rodent and human fibroblasts (Caiazzo et al., 2011; Pang et al., 2011; Qiang et al., 2011; Son et al., 2011; Vierbuchen et al., 2010; Yoo et al., 2011). However, a major challenge for the translation of neuronal reprogramming into therapy is whether direct conversion of somatic cells into neuronal cells can be achieved from cells residing within the adult human brain. To address this question, we prepared adherent cultures from 30 human specimens that were derived from surgical approaches through the cerebral cortex to deep-seated nontraumatic nonmalignant lesions, i.e., epileptic foci and nonruptured vascular lesions. In order to characterize the cellular composition of the cultures obtained from these specimens, we performed immunocytochemistry and fluorescence-activated cell sorting (FACS) analyses at different stages of culturing. Intriguingly, the majority of cells expressed platelet-derived growth factor receptor-β (PDGFRβ) (Daneman et al., 2010) (Figures 1C and 1D and Figure S1A available online), which is detected within the human brain tissue exclusively on microvessel-associated pericytes (Figure 1A), a cell type involved in the establishment and maintenance of the blood-brain barrier and regulation of local blood flow (Armulik et al., 2011). Consistent with a pericyte identity, we also observed expression of NG2 (Karram et al., 2005) (Figure 1B and S1B), smooth muscle actin (SMA) (Figures S1A and S1B) (Hellström et al., 1999), CD146 (Crisan et al., 2008), and CD13 (Crisan et al., 2008) (Figure 1E), though with some heterogeneity with regard to coexpression of these markers (Figures 1E, S1A, and SB). In contrast, the number of glial acidic fibrillary protein (GFAP)-positive cells was extremely low in these cultures (<1%), although astrocytes were readily detected within the human tissue (data not shown). Quantitative RT-PCR experiments confirmed the enriched expression of pericytic marker genes and the virtual absence of astroglial (gfap) and oligodendroglial cells (olig2) in these cultures compared to human brain tissue from which the cells had been isolated (Figure S1C). Importantly, βIII-tubulin could not be detected at any stage of culturing (assessed from 2 days to 8 weeks after plating), demonstrating that these cultures were devoid of neuroblasts or surviving neurons (data not shown). Furthermore, these cultures were completely devoid of expression of neural stem cell markers such as sox2 or prom1 or neurogenic fate determinants such as ascl1 or pax6 (Figure S1C). Moreover, Sox2, Mash1, Olig2, and Pax6 were also not detected on the protein level by immunocytochemistry (data not shown). The few CD34-positive cells (Figures 1D and S1C) of hematopoietic or endothelial origin were lost upon passaging. Thus, these cultures are enriched for cells exhibiting pericyte characteristics.
    • Figure 1 Characterization and In Vitro Conversion into Induced Neuronal Cells of Human and Mouse Adult Brain Pericyte-like Cells (A) PDGFRβ expression in microvessel-associated cells in the adult human cerebral cortex. Scale bar: 100 μm. (B) NG2 expression in microvessel-associated cells in the adult human cerebral cortex. Microvessels were visualized by CD31 (green) immunoreactivity and DAPI (blue). Scale bar: 100 μm. (C) Immunocytochemical analysis for pericyte marker PDGFRβ (red) in cell cultures obtained from human cerebral tissue; DAPI is in blue. Scale bar: 100 μm. See also Figures S1A and S1D. Scale bar: 100 μm. (D) Example of FACS analysis from an adult human brain culture. Depicted are the isotype controls (ctrl, left and middle panel) for establishing the gating conditions for sorting the PDGFRβ- and CD34-positive populations. See also Figure S1I. (E) Relative coexpression of pericyte markers as analyzed by FACS analysis. Each data point represents the relative coexpression of PDGFRβ and CD146 (mean 40.7% ± 28.1%) or CD13 (mean 46.4% ± 29.1%). (F) Quantification of the effect on βIII-tubulin expression and morphology following DsRed only for control, Sox2, Mash1, and combined Sox2 and Mash1 expression. Cells were categorized for exhibiting a flat polygonal morphology, round morphology without processes, or neuronal morphology with processes. Each value represents the mean of βIII-tubulin-positive cells from six different patients. For each patient and treatment, at least three experimental replicates were analyzed. For each condition >1,000 cells were analyzed. Error bars are SEM. (G) Live imaging of the conversion of a PDGFRβ-positive FACS-sorted cell (blue arrow, see also Figure S1I) into an induced neuronal cell following coexpression of Sox2 and Mash1. Pictures show phase contrast and fluorescence (Mash1-DsRed and Sox2-GFP) images at different time points (Days-Hours:Minutes) during the reprogramming process. Note the change of the cotransduced cell from a protoplasmic to a neuron-like morphology. See also Movie S1Download (20.51 MB)Movie S1. Direct Observation of Neuronal Reprogramming of PDGFRβ- Sorted Pericyte-Derived Cells from the Adult Human Brain by Continuous Live Imaging in Culture Note the change in morphology of a cell coexpressing Sox2 and Mash1 (blue arrow) during reprogramming. Postimaging immunocytochemistry for βIII-tubulin (white) confirms the neuronal identity of the reprogrammed cell at the end of live imaging (see also Figure 1F).. (G′) Depicted is the last recorded time point in phase contrast (LT) and the postimmunocytochemistry (Post IC) of the reprogrammed cell for GFP (green), DsRed (red), and βIII-tubulin (white). (H) Example of MAP2 and βIII-tubulin coexpression after 5 weeks following transduction. See also Figure S1G. (I) Specific β-galactosidase expression associated with CD31-positive blood vessels in the cerebral cortex of Tg:TN-AP-CreERT2:R26RNZG mice. β-galactosidase-positive cells express the pericyte marker PDGFRβ. Note the restricted expression around microvessels. β-galactosidase, green; PDGFRβ, red; CD31, blue. Scale bars: left panel, 50 μm; right panels, 10 μm. (J) Reprogramming of EYFP-positive cells isolated from the cerebral cortex of adult Tg:TN-AP-CreERT2:R26REYFP mice into induced neuronal cells. EYFP-positive cells (green) transduced with Mash1 (red) and Sox2 (without reporter) display a neuronal morphology and express βIII-tubulin; 14 days postinfection. Scale bar: 100 μm. For the efficiency of reprogramming of mouse pericytic cells, see Figures S1J–S1K.
  • Previous work has identified Mash1 (mammalian achaete-scute homolog 1, encoded by the gene ascl1) as a powerful reprogramming factor for direct conversion of somatic cells into neuronal cells (Berninger et al., 2007; Caiazzo et al., 2011; Vierbuchen et al., 2010). When we assessed the response of our cultures to retrovirus-mediated expression of Mash1 (CAG-ascl1-IRES-dsred), we observed the reduction of PDGFRβ expression to 23% (n[cells] = 219), indicating a loss of pericyte-specific protein expression (Figure S1D). Moreover, a subset of Mash1-transduced cells responded with the induction of βIII-tubulin, suggesting some degree of neuronal respecification (Figure 1F). Previous work has suggested that Sox2 expression may facilitate neuronal reprogramming of postnatal astrocytes by neurogenic fate determinants (Heinrich et al., 2010). As there was no endogenous Sox2 expression in these cultures (Figure S1C), we hypothesized that forced expression of sox2 may enhance the efficiency of neuronal reprogramming by Mash1. Expression of Sox2 (CAG-sox2-IRES-gfp) alone had no overt effect on βIII-tubulin expression (Figure 1F) or morphology of pericyte-like cells (Figure S1F). In contrast, coexpression of Sox2 and Mash1 significantly increased the proportion of βIII-tubulin-expressing cells to 48% ± 9% SEM (n[cells] = 1,500, analyzed after 4–5 weeks following transduction, cultures from six different patients; compared to 10% ± 4% SEM after Mash1 transduction alone, p = 0.0038, Figure 1F). Most strikingly, many of the double-transduced cells (28% ± 5% SEM) exhibited neuronal morphology (Figure S1F) and induced expression of MAP2 (46% ± 11% SEM, n[cells] = 296 from three different patients, analyzed after 5–6 weeks; Figures 1H and S1G) and NeuN (Figure S1H), indicating a high degree of reprogramming efficiency of cells from adult human tissue. Consistent with the acquisition of a neuronal phenotype and a loss of pericyte identity, Sox2- and Mash1-coexpressing cells downregulated PDGFRβ (Figure S1E). Of note, some cultures contained virtually only (97%) PDGFRβ-positive cells (Figure 1D), of which 46% of the Mash1 and Sox2 cotransduced cells differentiated into βIII-tubulin-positive cells, with 26% exhibiting neuronal morphology (n[cells] = 203). In the following we refer to these neuronal cells derived from human pericyte-like cells as human pericyte-derived induced neuronal cells (hPdiNs).
  • Despite the high frequency of PDGFRβ-positive cells infected by the retroviral vectors, the remainder of PDGFRβ-negative cells may still act as the main source of induced neuronal cells upon Mash1 and Sox2 transduction. Thus, we proceeded to follow the fate conversion of pericytes by live imaging (Rieger et al., 2009). Cultured cells were FACS-sorted for surface expression of PDGFRβ (Figure S1I), transduced 48 hr later with retroviral vectors encoding sox2 and ascl1, and subsequently imaged by time-lapse video microscopy (Movie S1Download (20.51 MB)Movie S1. Direct Observation of Neuronal Reprogramming of PDGFRβ- Sorted Pericyte-Derived Cells from the Adult Human Brain by Continuous Live Imaging in Culture Note the change in morphology of a cell coexpressing Sox2 and Mash1 (blue arrow) during reprogramming. Postimaging immunocytochemistry for βIII-tubulin (white) confirms the neuronal identity of the reprogrammed cell at the end of live imaging (see also Figure 1F).). Figure 1G shows an example of an anti-PDGFRβ FACS-sorted cell undergoing Sox2- and Mash1-induced neurogenesis. The cell acquired a polarized morphology within 12 days following transduction and could be shown to express βIII-tubulin at the end of the live imaging (Figure 1G′). Intriguingly, following the onset of reporter expression, this PDGFRβ-sorted cell did not undergo any cell division, providing evidence for direct conversion from an adult human nonneuronal somatic cell into an hPdiN. Likewise, only 1 of 36 (3%) Sox2- and Mash1-coexpressing cells that we followed over time underwent cell division, in sharp contrast to untransduced (n[cells] = 11/30; 36%], Mash1-only (n[cells] = 8/30; 26%), and Sox2-only transduced cells (n[cells] = 13/30; 46%), indicating that Sox2- and Mash1-induced reprogramming does not only not require cell division, but is accompanied by immediate cell cycle exit. Of all the tracked cells coexpressing Sox2 and Mash1, 36% endured cell death. This percentage was considerably higher than that of untransduced cells (3%) and Sox2-only transduced cells (7%). Of note, Mash1-only transduced cells also exhibited a higher rate of cell death (33%), suggesting that Mash1 or Sox2 and Mash1 coexpression can induce a catastrophic conflict of cell fates in pericyte-derived cells. Counting of βIII-tubulin-positive cells after imaging revealed that none of the Sox2-only cells (n[cells] > 300), 7% of Mash1-only (n[cells] = 88) cells, and 25% of double-positive cells (n[cells] = 786; two independent experiments) expressed βIII-tubulin. In an additional experiment, in which cells had been sorted simultaneously for PDGFRβ and CD146 and had been time-lapsed, a reprogramming efficiency of 37% was observed (n[cells] = 209). Combining all time-lapse experiments, the overall reprogramming efficiency was 19% of the coinfected cells, taking proliferation and cell death into account.
  • To unequivocally determine the origin of the reprogrammed cells from pericytes in vivo, we turned to genetic fate-mapping in mice. We took advantage of a transgenic mouse that expresses an inducible Cre recombinase (CreERT2) under control of the tissue-nonspecific alkaline phosphatase (TN-AP) promoter for genetic fate mapping of pericytes (Dellavalle et al., 2011). These mice were crossed to reporter lines (Tg:TN-AP-CreERT2:R26RNZG and Tg:TN-AP-CreERT2:R26REYFP) to aid identification of cells of pericytic origin either by β-galactosidase or yellow fluorescent protein (YFP) immunoreactivity following tamoxifen-induced Cre-mediated excision of the stop cassette. As expected β-galactosidase expression was confined to microvessel-associated cells coexpressing PDGFRβ (Figure 1I) and NG2 (data not shown) (Dellavalle et al., 2011) in the cerebral cortex of young adult mice following induction at postnatal stages, indicating that the TN-AP promoter allows reliable fate-mapping of pericyte-derived cells in the adult brain. Next we prepared cultures from the adult cerebral cortex of Tg:TN-AP-CreERT2:R26REYFP mice under the same culture conditions as used for human samples. As in the adult cerebral cortex, reporter-positive cells coexpressed the pericytic markers PDGFRβ, NG2, and CD146 and could be expanded in vitro (data not shown). In contrast to control vector-transduced reporter-positive pericyte-derived cells (data not shown), Sox2- and Mash1-expressing cells gave rise to βIII-tubulin-positive PdiNs (Figure 1J). Neuronal reprogramming of wild-type mouse pericyte-derived cells occurred at an even higher frequency compared to adult human pericyte-derived cells: coexpression of Sox2 and Mash1 significantly increased the proportion of βIII-tubulin-positive cells to 92% ± 3% SEM (compared to 41% ± 10% SEM after Mash1 transduction alone, p = 0.0028) (Figure S1K), and most of the double-transduced cells (73% ± 7% SEM) exhibited neuronal morphology (Figure S1J) and were capable of repetitive action potential firing (Figure S2F and Table S1).
  • We next analyzed whether the hPdiNs expressing neuron-specific proteins also acquire the functional membrane properties of neurons. In Mash1 (n[cells] = 7) and Sox2 (n[cells] = 6) singly transduced cells, step-current injection failed to elicit any action potentials (Figures S2A, S2A′, S2B, and S2B′), indicating that neither transcription factor alone induces neuronal electrical properties. In sharp contrast, a substantial proportion of cells (71% of 17 cells tested, cultures from five different patients) coexpressing both factors responded typically with the generation of a single action potential that could be blocked by the sodium channel antagonist tetrodotoxin (TTX) (Figures S2C and S2C′). Moreover, in voltage-clamp these cells exhibited clearly discernible sodium (Figure S2C″) and potassium (data not shown) currents. However, these hPdiNs exhibited immature properties, as reflected by the relatively high input resistances, low action potential, and peak sodium current amplitudes, even after prolonged time in culture, consistent with the slow maturation of human neurons (Table S1). In order to further promote maturation and to investigate whether hPdiNs can integrate into a neuronal network, we cocultured hPdiNs with neurons from the mouse embryonic neocortex. Under these conditions hPdiNs exhibited a more complex morphology (Figures 2A, 2B, and 2E) and were capable of repetitive action potential firing (Figure 2C), although input resistances were still high (Table S1). Importantly, hPdiNs were found to receive functional glutamatergic input from cocultured neurons (4 out of 12 cells analyzed, Figures 2D–2D″), demonstrating that they express functional transmitter receptors, are capable of assembling a postsynaptic compartment, and can be recognized by other neurons as functional targets. Consistent with functional glutamatergic input, dendrites of hPdiNs were decorated with presynaptic terminals containing vesicular glutamate transporters (Figure 2F). Of note, hPdiNs exhibited immunoreactivity for the inhibitory neurotransmitter β-aminobutyric acid (GABA, 14/14 hPdiNs analyzed) (Figure S2D). Moreover, qRT-PCR showed the expression of the interneuron calcium binding protein pvalb (Figure S2E), pointing toward acquisition of an interneuron-like phenotype. In contrast, none of the Sox2 and Mash1 cotransduced cells expressed the glutamatergic lineage marker tbr1 (T-box brain gene 1; data not shown) or slc17a7 (encoding the vesicular glutamate transporter [vGluT]-1; Figure S2E). However, a definitive proof for a GABAergic interneuron-like identity awaits the demonstration of functional GABAergic transmission.
    • Figure 2 Neuronal Morphology and Membrane Properties of hPdiNs (A) Bright-field micrograph depicts an hPdiN (red arrowhead) after 26 days of coculture with E14 mouse cerebral cortical neurons, 46 days following retroviral transduction. (B) DsRed fluorescence indicating transduction with ascl1 and dsred-encoding retroviruses. Inset: GFP fluorescence indicating transduction with sox2– and gfp-encoding retrovirus. (C) Step current injection in current-clamp results in repetitive action potential firing. For comparison with cells transduced with a single transcription factor or cotransduced, but cultured without mouse cortical neurons, see Figures S2A–S2C″. (D) The graph depicts spontaneous synaptic events recorded from the same hPdiN as shown in (C). The enlarged trace shows individual synaptic events. (D′) The synaptic events are blocked by the application of CNQX (10 μM). (D″) Recovery of spontaneous synaptic input following washout of CNQX. For a summary of the electrophysiological properties, see Table S1. (E) Micrograph depicting an hPdiN stained for DsRed and GFP, after 22 days of coculture with E14 neurons, 42 days following retroviral transduction. (F) High-magnification view of a single dendrite (magenta, GFP) from the same hPdiN as shown in (E), illustrating the high density and the distribution of vGluT1-immunoreactive puncta (green, Cy5).
  • Here we provide evidence for high-efficiency reprogramming of pericyte-derived cells of the adult human cerebral cortex into induced neuronal cells by coexpression of only two transcription factors. The fact that only coexpressing cells convert into neuronal cells provides direct evidence for a cell-autonomous effect. Different scenarios may account for the synergism of these two transcription factors. Sox2 may facilitate Mash1-induced reprogramming by rendering the somatic genome more susceptible to the neurogenic activity exerted by Mash1. Alternatively, Sox2 may be required to directly interact with Mash1 on common target genes. While we can currently not discern between these two modes of action, the fact that Neurog2 failed to reprogram cells in culture from the adult human cerebral cortex (data not shown) argues partially against the first mechanism as the solely important one. Recent studies on the role of Mash1 and Neurog2 during cortical development suggest that these factors activate distinct programs in neural progenitors (Castro et al., 2011). Mash1 also has been found as a key transcription factor in the direct reprogramming of fibroblasts (Pang et al., 2011; Vierbuchen et al., 2010) and hepatocytes (Marro et al., 2011) where it synergizes with Brn2 and Myt1l. This may suggest that Mash1 acts as a core factor in direct neuronal reprogramming. Interestingly, we observed a very slight induction of endogenous ascl1 mRNA expression (Figure S2E). It is noteworthy that, while fibroblasts coexpressing different combinations of transcription factors have been shown to give rise to induced neuronal cells of glutamatergic identity (Pang et al., 2011; Vierbuchen et al., 2010), dopaminergic (Caiazzo et al., 2011; Kim et al., 2011; Pfisterer et al., 2011) and cholinergic motor neuron identity (Son et al., 2011), the combination of Sox2 and Mash1 appears to favor a GABAergic phenotype in hPdiNs. It will be important to understand whether this is largely dependent on the factor combination used or the cellular context determined by the origin and nature of the reprogrammed cell.
  • Local CNS pericytes have been recently recognized as a major source of proliferating scar-forming cells following CNS injury (Göritz et al., 2011). A key finding of the present study is that progeny of brain pericytes represent a potential target for direct reprogramming. While much needs to be learned about adapting a direct neuronal reprogramming strategy to meaningful repair in vivo, e.g., by using a noninvasive approach to activate these transcription factors (Kormann et al., 2011), our data provide strong support for the notion that neuronal reprogramming of cells of pericytic origin within the damaged brain may become a viable approach to replace degenerated neurons

Why We Need Insects–Even “Pesky” Ones

Photo of yellow flowers of evening primrose in Ithaca, New York.

A large natural population of evening primrose (yellow flowers) in Ithaca, New York.

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October 4, 2012

View a video interview with Anurag Agrawal of Cornell University.

Image of Cornell University professor Anurag Agrawal.
View Video
Hard evidence of evolution.
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At first blush, many people would probably love to get rid of insects, such as pesky mosquitoes, ants and roaches. But a new study indicates that getting rid of insects could trigger some unwelcome ecological consequences, such as the rapid loss of desired traits in plants, including their good taste and high yields.

Specifically, the study–described in the Oct. 5, 2012 issue of Science and funded by the National Science Foundation showed that evening primroses grown in insecticide-treated plots quickly lost, through evolution, defensive traits that helped protect them from plant-eating moths. The protective traits lost included the production of insect-deterring chemicals and later blooms that gave evening primroses temporal distance from plant-eating larvae that peak early in the growing season.

These results indicate that once the plants no longer needed their anti-insect defenses, they lost those defenses. What’s more, they did so quickly–in only three or four generations.

Anurag Agrawal, the leader of the study and a professor of ecology and evolutionary biology at Cornell University, explains, “We demonstrated that when you take moths out of the environment, certain varieties of evening primrose were particularly successful. These successful varieties have genes that produce less defenses against moths.”

In the absence of insects, the evening primroses apparently stopped investing energy in their anti-insect defenses, and so these defenses disappeared through natural selection. Agrawal says that he was “very surprised” by how quickly this process occurred, and that such surprises, “tell us something about the potential speed and complexities of evolution. In addition, experiments like ours that follow evolutionary change in real-time provide definitive evidence of evolution.”

Agrawal believes that his team’s study results are applicable to many other insect-plant interactions beyond evening primroses and moths. Here’s why: The ubiquitous consumption of plants by insects represents one of the dominant species interactions on Earth. With insect-plant relationships so important, it is widely believed that many plant traits originally evolved solely as defenses against insects. Some of these anti-insect plant defenses, such as the bitter taste of some fruits, are desirable.

“This experimental demonstration of how rapid evolution can shape ecological interactions supports the idea that we need to understand feedbacks between evolutionary and ecological processes in order to be able to predict how communities and ecosystems will respond to change,” said Alan Tessier, a program director in NSF’s Directorate for Biological Sciences.

“One of the things farmers are trying to do is breed agricultural crops to be more resistant to pests,” said Agrawal. “Our study indicates that various genetic tradeoffs may make it difficult or impossible to maintain certain desired traits in plants that are bred for pest resistance.”

In addition, oils produced by evening primroses have been used medicinally for hundreds of years and are beginning to be used as herbal remedies. Agrawal’s insights about pests that attack these plants and about chemical compounds produced by these plants may ultimately be useful to the herbal and pharmaceutical industries.

Agrawal says that most previous real-time experiments on evolution have been conducted with bacteria in test tubes in laboratories. “One of things we were excited about is that we were able to repeat that kind of experiment in nature. You can expect to see a lot more of this kind of thing in future. We will keep our experiment running as a long-term living laboratory. ”

More information about this study is available from a Cornell University press release.

-NSF-

Cover of the October 5, 2012, issue of the journal Science.
The research results are described in the Oct. 5, 2012, issue of the journal Science.
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Persistent pollutant may promote obesity: Tributyltin shown to affect gene activity at extremely low concentrations

2008 study posted for filing

Contact: Jennifer Williams
jwilliams@aibs.org
202-628-1500 x209
American Institute of Biological Sciences

Persistent pollutant may promote obesity

Compound shown to affect gene activity at extremely low concentrations

Tributyltin, a ubiquitous pollutant that has a potent effect on gene activity, could be promoting obesity, according to an article in the December issue of BioScience. The chemical is used in antifouling paints for boats, as a wood and textile preservative, and as a pesticide on high-value food crops, among many other applications.

Tributyltin affects sensitive receptors in the cells of animals, from water fleas to humans, at very low concentrations—a thousand times lower than pollutants that are known to interfere with sexual development of wildlife species. Tributyltin and its relatives are highly toxic to mollusks, causing female snails to develop male sexual characteristics, and it bioaccumulates in fish and shellfish.

The harmful effects of the chemical on the liver and the nervous and immune systems in mammals are well known, but its powerful effects on the cellular components known as retinoid X receptors (RXRs) in a range of species are a recent discovery. When activated, RXRs can migrate into the nuclei of cells and switch on genes that cause the growth of fat storage cells and regulate whole body metabolism; compounds that affect a related receptor often associated with RXRs are now used to treat diabetes. RXRs are normally activated by signaling molecules found throughout the body.

The BioScience article, by Taisen Iguchi and Yoshinao Katsu, of the Graduate University for Advanced Studies in Japan, describes how RXRs and related receptors are also strongly activated by tributyltin and similar chemicals. Tributyltin impairs reproduction in water fleas through its effects on a receptor similar to the RXR. In addition, tributyltin causes the growth of excess fatty tissue in newborn mice exposed to it in utero. The effects of tributytin on RXR-like nuclear receptors might therefore be widespread throughout the animal kingdom.

The rise in obesity in humans over the past 40 years parallels the increased use of industrial chemicals over the same period. Iguchi and Katsu maintain that it is “plausible and provocative” to associate the obesity epidemic to chemical triggers present in the modern environment. Several other ubiquitous pollutants with strong biological effects, including environmental estrogens such as bisphenol A and nonylphenol, have been shown to stimulate the growth of fat storage cells in mice. The role that tributyltin and similar persistent pollutants may play in the obesity epidemic is now under scrutiny.

 

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After noon EST on 1 December and for the remainder of the month, the full text of the article will be available for free download through the copy of this Press Release available at http://www.aibs.org/bioscience-press-releases/.

BioScience, published 11 times per year, is the journal of the American Institute of Biological Sciences (AIBS). BioScience publishes commentary and peer-reviewed articles covering a wide range of biological fields, with a focus on “Organisms from Molecules to the Environment.” The journal has been published since 1964. AIBS is an umbrella organization for professional scientific societies and organizations that are involved with biology. It represents some 200 member societies and organizations with a combined membership of about 250,000.

 

Selenium may slow march of AIDS

2008 study posted for filing

Contact: Amitabh Avasthi
axa47@psu.edu
814-865-9481
Penn State

Increasing the production of naturally occurring proteins that contain selenium in human blood cells slows down multiplication of the AIDS virus, according to biochemists.

“We have found that increasing the expression of proteins that contain selenium negatively affects the replication of HIV,” said K. Sandeep Prabhu, Penn State assistant professor of immunology and molecular toxicology. “Our results suggest a reduction in viral replication by at least 10-fold.”

Selenium is a micronutrient that the body needs to maintain normal metabolism. Unlike other nutrients, which bind to certain proteins and modulate the protein’s activity, selenium gets incorporated into proteins in the form of an amino acid called selenocysteine.

These proteins – selenoproteins – are especially important in reducing the stress caused by an infection, thereby slowing its spread.

Upon infecting a person, the virus quickly degrades selenoproteins so that it can replicate efficiently. It is unclear just how the virus is able to silence these proteins but Prabhu and his colleagues believe that stress inflicted on cells by the rapidly dividing virus, which produces a key protein known as Tat, is the likely culprit.

Tat is one of about 14 odd proteins produced by HIV during the first stage of infection. The job of these proteins is to trigger the expression of all the other genes that the virus needs to sustain itself. In addition, Tat also plays a key role in helping the virus replicate.

One of the proteins that targets Tat is a selenoprotein known as TR1.

“Since HIV targets the selenoproteins, we thought that the logical way to deal with the virus is to increase the expression of such proteins in the body,” explained Prabhu, whose team’s findings are outlined this week (Nov. 28) in the Journal of Biological Chemistry.

Researchers first isolated blood cells from healthy human volunteers who did not have HIV, and infected those cells with the virus. Next, they added tiny amounts of a selenium compound – sodium selenite – into the cell culture to see the effect on viral replication.

Results from the tests indicate that the addition of selenium inhibits the replication of HIV at least 10-fold, compared to cell cultures in which no selenium is added. When the researchers selectively reduced production of the selenium containing TR1 protein, they observed a 3.5-fold increase in viral replication.

“This confirms that while increasing the expression of TR1 has a negative impact on the replication of HIV, reducing it helps the virus replicate more efficiently,” explained Prabhu. He believes that TR1 works by upsetting the chemical structure of Tat, which in turn reduces the virus’ ability to replicate.

“Once we fully understand the function of these selenium proteins, it will give us a handle to come up with more effective drugs,” said Prabhu, whose work is partly funded by the National Institutes of Health.

 

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Other researchers on the paper include Parisa Kalantari, post-doctoral scholar; Vivek Narayan, graduate student; Kambadur Muralidhar, visiting faculty; Ujjawal H. Gandhi, graduate student; and Hema Vunta, graduate student, all at Penn State; Satish K. Natarajan, research associate, University of Nebraska; and Andrew J. Henderson, associate professor of medicine and microbiology, Boston University.

 

Compelling evidence that brain parts evolve independently

Contact: Morwenna Grills Morwenna.Grills@manchester.ac.uk 44-161-275-2111 University of Manchester

An Evolutionary Biologist at The University of Manchester, working with scientists in the United States, has found compelling evidence that parts of the brain can evolve independently from each other. It’s hoped the findings will significantly advance our understanding of the brain.

The unique 15 year study with researchers at the University of Tennessee and Harvard Medical School also identified several genetic loci that control the size of different brain parts.

The aim of the research was to find out if different parts of the brain can respond independently of each other to evolutionary stimulus (mosaic evolution) or whether the brain responds as a whole (concerted evolution). Unlike previous studies the researchers compared the brain measurements within just one species. The findings have been published in the journal Nature Communications.

The brains of approximately 10,000 mice were analysed. Seven individual parts of each brain were measured by volume and weight. The entire genome, except the Y chromosome, was scanned for each animal and the gene set for each brain part identified.

Dr Reinmar Hager from the Faculty of Life Sciences compared variation in the size of the brain parts to variation in the genes. He found that the variation in the size of brain parts is controlled by the specific gene set for that brain part and not a shared set of genes.

He also compared the measurements for each mouse to the overall size of its brain. Surprisingly he found very little correlation between the sizes of the brain parts and the overall size of the brain.

Dr Hager says: “If all the different brain parts evolved as a whole we would expect that the same set of genes influences size in all parts. However, we found many gene variations for each different part of the brain supporting a mosaic scenario of brain evolution. We also found very little correlation between the size of the brain parts and the overall size of the brain. This again supports the mosaic evolutionary hypothesis.”

Using the data collected from the mice Dr Hager and colleagues analysed the genes that influence the size of the brain to the genes that control the size of the body. They wanted to find out how independent size regulation of the brain is to that of the body.

They found evidence that the size of the brain is governed by an independent gene set to the one that controls the size of the body. Again they found vey little correlation between variations in the size of the body and the brain.

The evidence means that overall brain size can evolve independently of body size.

Following this research more work will be carried out to identify the specific genes that underlie the size of different parts in the brain

Dr Hager says: “If we can identify the specific genes that cause variations in the size of brain parts then there will be big implications for researchers looking at neuronal disease and brain development. We hope this research will significantly advance our understanding of the brain.”

Understanding the brain by controlling behavior

Contact: Peter Reuell preuell@fas.harvard.edu 617-496-8070 Harvard University

Using precisely-targeted lasers, researchers manipulate neurons in worms’ brains and take control of their behavior

In the quest to understand how the brain turns sensory input into behavior, Harvard scientists have crossed a major threshold. Using precisely-targeted lasers, researchers have been able to take over an animal’s brain, instruct it to turn in any direction they choose, and even to implant false sensory information, fooling the animal into thinking food was nearby.

As described in a September 23 paper published in Nature, a team made up of Sharad Ramanathan, an Assistant Professor of Molecular and Cellular Biology, and of Applied Physics, Askin Kocabas, a Post-Doctoral Fellow in Molecular and Cellular Biology, Ching-Han Shen, a Research Assistant in Molecular and Cellular Biology, and Zengcai V. Guo, from the Howard Hughes Medical Institute were able to take control of Caenorhabditis elegans – tiny, transparent worms – by manipulating neurons in the worms’ “brain.”

The work, Ramanathan said, is important because, by taking control of complex behaviors in a relatively simple animal – C. elegans have just 302 neurons –we can understand how its nervous system functions..

“If we can understand simple nervous systems to the point of completely controlling them, then it may be a possibility that we can gain a comprehensive understanding of more complex systems,” Ramanathan said. “This gives us a framework to think about neural circuits, how to manipulate them, which circuit to manipulate and what activity patterns to produce in them “.

“Extremely important work in the literature has focused on ablating neurons, or studying mutants that affect neuronal function and mapping out the connectivity of the entire nervous system. ” he added. “Most of these approaches have discovered neurons necessary for specific behavior by destroying them. The question we were trying to answer was: Instead of breaking the system to understand it, can we essentially hijack the key neurons that are sufficient to control behavior and use these neurons to force the animal to do what we want?”

Before Ramanathan and his team could begin to answer that question, however, they needed to overcome a number of technical challenges.

Using genetic tools, researchers engineered worms whose neurons gave off fluorescent light, allowing them to be tracked during experiments. Researchers also altered genes in the worms which made neurons sensitive to light, meaning they could be activated with pulses of laser light.

The largest challenges, though, came in developing the hardware necessary to track the worms and target the correct neuron in a fraction of a second.

“The goal is to activate only one neuron,” he explained. “That’s challenging because the animal is moving, and the neurons are densely packed near its head, so the challenge is to acquire an image of the animal, process that image, identify the neuron, track the animal, position your laser and shoot the particularly neuron – and do it all in 20 milliseconds, or about 50 times a second. The engineering challenges involved seemed insurmountable when we started. But Askin Kocabas found ways to overcome these challenges”

The system researchers eventually developed uses a movable table to keep the crawling worm centered beneath a camera and laser. They also custom-built computer hardware and software, Ramanathan said, to ensure the system works at the split-second speeds they need.

The end result, he said, was a system capable of not only controlling the worms’ behavior, but their senses as well. In one test described in the paper, researchers were able to use the system to trick a worm’s brain into believing food was nearby, causing it to make a beeline toward the imaginary meal.

Going forward, Ramanathan and his team plan to explore what other behaviors the system can control in C. elegans. Other efforts include designing new cameras and computer hardware with the goal of speeding up the system from 20 milliseconds to one. The increased speed would allow them to test the system in more complex animals, like zebrafish.

“By manipulating the neural system of this animal, we can make it turn left, we can make it turn right, we can make it go in a loop, we can make it think there is food nearby,” Ramanathan said. “We want to understand the brain of this animal, which has only a few hundred neurons, completely  and essentially turn it into a video game, where we can control all of its behaviors.”

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Funding for the research was provided by the Human Frontier Science Program, the NIH Pioneer Award and the National Science Foundation.

TAU Researcher Says Plants Can See, Smell, Feel, and Taste

Re-posted for Filing

Monday, July 30, 2012

Unlocking the secrets of plant genetics could lead to breakthroughs in cancer research and food security

Increasingly, scientists are uncovering surprising biological connections between humans and other forms of life. Now a Tel Aviv University researcher has revealed that plant and human biology is much closer than has ever been understood — and the study of these similarities could uncover the biological basis of diseases like cancer as well as other “animal” behaviors.

In his new book What a Plant Knows (Farrar, Straus and Giroux) and his articles in Scientific American, Prof. Daniel Chamovitz, Director of TAU’s Manna Center for Plant Biosciences, says that the discovery of similarities between plants and humans is making an impact in the scientific community. Like humans, Prof. Chamovitz says, plants also have “senses” such as sight, smell, touch, and taste.

Ultimately, he adds, if we share so much of our genetic makeup with plants, we have to reconsider what characterizes us as human.

These findings could prompt scientists to rethink what they know about biology, says Prof. Chamovitz, pointing out that plants serve as an excellent model for experiments on a cellular level. This research is also crucial to food security, he adds, noting that knowledge about plant genetics and how plants sense and respond to their environment is central to ensuring a sufficient food supply for the growing population — one of the main goals of the Manna Center.

http://www.aftau.org/site/News2/1811415631?page=NewsArticle&id=17013&news_iv_ctrl=-1

Addictive properties of drug abuse may hold key to an HIV cure, Florida State University biologist believes

September 21, 2012

FRIDAY, SEPTEMBER 21, 2012

Addictive properties of certain drugs may hold key to an HIV cure

Tom Butler

09/12/2012 2:02 pm

A Florida State University researcher is on a mission to explore the gene-controlling effects of addictive drugs in pursuit of new HIV treatments.

Working under the support of a $1.8 million grant from the National Institutes of Health (NIH), Florida State biologist Jonathan Dennis is studying a unique ability shared between a promising class of HIV treatments known as histone deacetylase inhibitors (HDIs) and psychostimulant drugs such as cocaine.

“Current HIV treatments do just that — they treat the disease by preventing the spread of HIV in the body, rather than eliminating the disease entirely,” Dennis said. “I want to find out how to root out those dormant HIV cells that are evading the treatment, and I believe the gene-controlling functions shared by HDIs and psychostimulant drugs hold the key to helping us do that.”

HDIs and addictive drugs such as cocaine share the ability to control gene expression through changes in the chromatin structure within DNA. In the case of HDI treatment, the chromatin changes are used to wake up dormant HIV virus cells that are hiding in the body.

Dennis believes that addictive drugs do the same thing. Dennis’ work will focus on identifying and understanding the overlapping gene changes that occur between these two types of substances, ultimately providing other researchers with the foundational information they need to turn HDI treatments into HIV cures.

Florida State professor Jonathan Dennis is researching the similarities between addictive drugs and HIV treatments in hopes of finding a cure for the disease.Using the resources available through Florida State University’s unique Integrating Genotype and Phenotype research cluster, Dennis was able to lure the attention of the NIH and obtain the grant. Genotype is the genetic constitution of an organism while the phenotype is its appearance and functional properties.

This research cluster combines cross-disciplinary expertise in the areas of evolutionary biology, molecular biology, genomics and epigenetics to solve one of the most important problems facing biology in the 21st century — the relationship between genotype and phenotype.

“The Integrating Genotype and Phenotype cluster has been critical in my work to unravel the mysteries behind chromatin and gene expression through direct access to other researchers and their areas of expertise,” Dennis said. “Without it I would not have been able to obtain this grant and be able to focus my work on helping the scientific community find a cure for HIV.”

To learn more about the scope and purpose of Dennis’ NIH grant, visit the grant website. To learn more about Dennis, visit his Department of Biological Science Web page. To find out more about the work of the research cluster, visit Integrating Genotype and Phenotype.

Florida State University, rated RU/VH (“Research University/Very High” research activity) by the Carnegie Foundation for the Advancement of Teaching, is one of the nation’s leading research and creative-activity institutions. With nearly $204 million in external research funding in 2011 and a large collection of unique, cutting-edge scientific and performing arts facilities, Florida State offers faculty and students unparalleled opportunities to expand the frontiers of knowledge and discovery in their areas of expertise. To learn more about Florida State research, locate a subject matter expert or arrange an interview on a specific research or creative topic, contact Tom Butler at tbutler@admin.fsu.edu, or Florida State’s News and Research Communications Office at (850) 644-4030.

 

http://news.fsu.edu/Top-Stories/Addictive-properties-of-certain-drugs-may-hold-key-to-an-HIV-cure

 

A mother’s nutrition–before pregnancy–may alter the function of her children’s genes

Contact: cmooneyhan@faseb.org cmooneyhan@faseb.org 301-634-7104 Federation of American Societies for Experimental Biology

New research in The FASEB Journal shows that diet induces epigenetic changes in female mice before pregnancy that are inherited by her pups

Bethesda, MD—Everyone knows that what mom eats when pregnant makes a huge difference in the health of her child. Now, new research in mice suggests that what she ate before pregnancy might be important too. According to a new research report published online in The FASEB Journal, what a group of female mice ate—before pregnancy—chemically altered their DNA and these changes were passed to her offspring. These DNA alterations, called “epigenetic” changes, drastically affected the pups’ metabolism of many essential fatty acids. These results could have a profound impact on future research for diabetes, obesity, cancer, and immune disorders.

“As parents, we have to understand better that our responsibilities to our children are not only of a social, economical, or educational nature, but that our own biological status can contribute to the fate of our children, and this effect can be long-lasting,” said Mihai Niculescu, M.D., Ph.D., study author from Nutrition Research Institute at the University of North Carolina at Chapel Hill, in Chapel Hill, N.C.  “My hope is that, along with many other scientists, we will reveal this tight biological relationship between us as parents, and our children, and how we can improve the lives of our children using our own biological machinery.”

To make this discovery, Niculescu and colleagues split mouse females into two groups before gestation, and fed them either a control diet, or a diet deficient in alpha-linolenic acid or ALA. This was achieved by replacing the type of fats in the diet, while keeping the number of calories the same. The females were bred with mouse males kept on a control diet. Immediately after the moms delivered the pups, each of these two initial groups were further split in two, so that each half of the initial groups received a flaxseed oil supplemented diet (rich in ALA), while the other halves from each group remained on the same diet. Researchers used blood and liver to look at polyunsaturated fatty acid (PUFA) levels and the DNA methylation of a gene called Fads2, which regulates PUFA metabolism. They found that in both the moms and pups, flaxseed oil induced a change in this chemical modification in the Fads2 gene. Flaxseed oil supplementation increased the methylation of this gene, which, in turn, decreased the activation of the gene in pups. However, flaxseed oil was not the only factor with impact upon Fads2 methylation in pups. Results demonstrated that regardless of the flaxseed oil intake, there was a correlation between the methylation of this gene in moms and in their pups, which suggested that pups also inherit this methylation from their moms. The pups’ ability to transform PUFAs in their own livers was influenced by both the mother’s dietary intake, and also by maternal Fads2 methylation status.

“New York City may be laughed at by some for banning large, sugary sodas and for encouraging a healthy diet,” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, “This report shows that future generations might not find that funny at all. This report adds to the large body of evidence that an inappropriate diet can produce changes in the function of our DNA and the DNA of our children—a process called epigenetics. As we begin understand the effects of diet on epigenetics, New York may go from being considered a funny ‘nanny-state’ to becoming appreciated as a public health visionary.”

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Receive monthly highlights from The FASEB Journal by e-mail. Sign up at http://www.faseb.org/fjupdate.aspx. The FASEB Journal is published by the Federation of the American Societies for Experimental Biology (FASEB). It is among the most cited biology journals worldwide according to the Institute for Scientific Information and has been recognized by the Special Libraries Association as one of the top 100 most influential biomedical journals of the past century. FASEB is composed of 26 societies with more than 100,000 members, making it the largest coalition of biomedical research associations in the United States. Celebrating 100 Years of Advancing the Life Sciences in 2012, FASEB is rededicating its efforts to advance health and well-being by promoting progress and education in biological and biomedical sciences through service to our member societies and collaborative advocacy.

Details:  Mihai D. Niculescu, Daniel S. Lupu, and Corneliu N. Craciunescu.  Perinatal manipulation of α-linolenic acid intake induces epigenetic changes in maternal and offspring livers. FASEB J. doi:10.1096/fj.12-210724  ;  http://www.fasebj.org/content/early/2012/09/19/fj.12-210724.abstract

From vitro to vivo: Fully automated design of synthetic RNA circuits in living cells

From vitro to vivo: Fully automated design of synthetic RNA circuits in living cells

September 14, 2012 by Stuart Mason Dambrot

Schemes of methodology and designs. (A) Thermodynamic scheme of RNA interaction, showing the different free energies at play and the progression of the reaction. We define the reaction coordinate as the size of intermolecular pairs (d). (B) Optimization scheme followed to design the RNA devices. (C) Secondary structures specified for the single species to obtain different RNA devices. Nucleotides shown were maintained fixed; RBS sequence yellow colored. Different devices were designed by imposing different structures for the riboregulator. Copyright © PNAS, doi:10.1073/pnas.1203831109 (Phys.org)

Synthetic biology combines science and engineering in the pursuit of two general goals: to design and construct new biological parts, devices, and systems not found in nature; and redesign existing, natural biological systems for useful purposes. For synthetic biologists a key goal is to use RNA to automatically engineer synthetic sequences that encode functional RNA sequences in living cells. While earlier RNA design attempts have mostly been developed in vitro or needed fragments of natural sequences to be viable, scientists at Institut de biologie systémique et synthétique in France have recently developed a fully automated design methodology and experimental validation of synthetic RNA interaction circuits working in a cellular environment. Their results demonstrate that engineering interacting RNAs with allosteric behavior in living cells can be accomplished using a first-principles computation.

Drs. Alfonso Jaramillo, Guillermo Rodrigo, and Thomas E. Landrain had to address several challenges in their study. “It is common practice – and unavoidable – to use computational algorithms to aid in the design of RNA molecules,” Jaramillo tells Phys.org. For example, he illustrates, computing minimum energy conformation, since one single nucleotide can stabilize an alternative conformation. Until now researchers have used computer assisted design to design synthetic RNAs that could combine functional fragments from known RNAs.  “The combination of known fragments reduced the number of possible nucleotide sequences and would enable a human-driven iteration in reasonable time,” Jaramillo explains. This approach required a lot of significant human effort to design a single sequence, where the designer would combine the fragments with some educated guesses and random nucleotides to fill the gaps. At that point, other computational tools would be used to verify each possible prototype and improve it. “We wanted to go further, so we asked whether we could teach the computer to do all this design iterations automatically, such that it could suggest a solution that could be synthesized and transformed in living cells,” Jaramillo adds.  Jaramillo comments that if the computer performs all design iterations unsupervised, it can explore a larger search space, freeing researchers from having to use known sequence fragments, and thus attempt a full sequence design (where all of the nucleotides come from random suggestions followed by computer selection). “To instruct the computer to do this, we incorporated what we thought were the essential physical properties of interacting RNAs in living cells by employing the evolutionary computation techniques used in artificial intelligence to develop software that could code without human supervision. The computer could then explore millions of prototype sequences instead of a few.” This evolutionary computation technique relies on mimicking the relevant steps of natural evolution, that is, the iterative improvement of a given solution by using selection. “However, we don’t have to be slaves of analogy and are free to consider what we think is more relevant to our problem,” Jaramillo points out. “We would start from a random sequence and would randomly modify it by applying simulated annealing techniques, implemented by a Metropolis Monte Carlo algorithm,” which solves a problem by generating suitable random numbers and observing that fraction of the numbers obeying some property or properties. “Contrary to natural evolution, our walks would not be completely adaptive but we could allow a decrease in fitness. We aim at the engineering of an ensemble of RNA species that could interact in a predefined way. Our first challenge was that in living cells, such molecules are very prone to degradation if they do not have a stable structure.”

Schematic representation of the six different RNA devices we designed and engineered for riboregulation. Devices RAJ11 and RAJ12 were obtained by imposing the structure T4, device RAJ21 with T1, device RAJ22 with T2, device RAJ23 with T3, and device RAJ31 with T5. SI Appendix (Fig. S7) shows the helical structure of the different complexes together with the corresponding base-pairing probability matrixes. SI Appendix (Table S1) shows the sequences of species. SI Appendix (Table S4) shows the thermodynamic properties of the systems. Copyright © PNAS, doi:10.1073/pnas.1203831109

The scientists therefore imposed that all our RNA species would have such structure – but this produced another challenge. “Unlike unstructured RNAs, such structure prevents RNA molecules from mutually interacting. We approached this by including a nucleation site, allowing an initial intermolecular contact that could disassemble the folded structure of the interacting partners.” This nucleation site consisted of a small fragment of an unstructured sequence. “This stabilization could be seen in energetic terms as the lowering of the activation free energy barrier, where we lower the energy of a high energy intermediate state.” As they relied on structured RNAs that would undergo post-interaction conformational changes, the scientists tested it by exploring a challenging problem involving allosteric RNA p and so chose to work with Escherichia coli. “We selected the problem of designing positive riboregulators because, due to design challenges, only a handful of them have ever been engineered by humans. Such positive riboregulators are RNA that, once expressed, could activate translation machinery.” This problem was not only challenging, but also useful for biotechnology, where there are very few molecules genetically encoded able to activate gene expression (contrary to the relative ease of engineering gene expression repressors). “As our methodology relied on fixing the secondary structure of the interacting RNAs, we tested several possibilities as well as alternative interaction mechanisms where the initial hybridization could be done in different ways.” After publishing the PNAS manuscript, Jaramillo adds, the team further validated the orthogonality (the ability to selectively translate mRNA) of their RNAs in E. coli. They’re also constructing a XOR gate device working inside the cell – something never done in bacteria and just recently achieved in mammals1.  The researchers are planning to extend the methodology to include the RNA-small molecule interactions and the incorporation of known functional RNA sequence fragments (such as ribozyme sequences) to create complex RNA interactions never seen before. “We’ve already succeeded in experimentally validating in E. coli a new type of such an interaction, consisting of an inactivated riboregulator that could be activated by a ribozyme after the introduction of a small-molecule inducer.”In this type of reaction, the number of different species is not conserved, as after the introduction of the inducer we get a RNA cleavage. “We’ve named this new riboregulator-ribozyme chimera a regazyme, and have also validated the full design of a riboswitch. Jaramillo also notes that other research might benefit from their findings, including the high-throughput design of new regulators for large-scale engineering projects. “Also, we can foresee using allosteric RNAs to sense mRNAs by being subject to a conformational change after binding that could trigger a reporter.” This would open the way to genetically-encoded and non invasive monitoring of gene expression dynamics – an important and unmet challenge in biophysics. “We’re also exploring the use of RNA,” Jaramillo concludes, “to create artificial signal transduction cascades.” More information: De novo automated design of small RNA circuits for engineering synthetic riboregulation in living cells, PNAS September 4, 2012, doi:10.1073/pnas.1203831109  1Related: Programmable single-cell mammalian biocomputers, Nature 487, 123–127 (05 July 2012), doi:10.1038/nature11149Journal reference: Proceedings of the National Academy of Sciences Nature Copyright 2012 Phys.org  All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.

Read more at: http://phys.org/news/2012-09-vitro-vivo-fully-automated-synthetic.html#jCp

The good news in our DNA: Defects you can fix with vitamins and minerals

2008 Re-Post for filing

Contact: Robert Sanders
rsanders@berkeley.edu
510-643-6998
University of California – Berkeley

Personal genomes may lead to personalized vitamin supplements

Berkeley — As the cost of sequencing a single human genome drops rapidly, with one company predicting a price of $100 per person in five years, soon the only reason not to look at your “personal genome” will be fear of what bad news lies in your genes.

University of California, Berkeley, scientists, however, have found a welcome reason to delve into your genetic heritage: to find the slight genetic flaws that can be fixed with remedies as simple as vitamin or mineral supplements.

“I’m looking for the good news in the human genome,” said Jasper Rine, UC Berkeley professor of molecular and cell biology.

“Headlines for the last 20 years have really been about the triumph of biomedical research in finding disease genes, which is biologically interesting, genetically important and frightening to people who get this information,” Rine said. “I became obsessed with trying to decide if there is some other class of information that will make people want to look at their genome sequence.”

What Rine and colleagues found and report this week in the online early edition of the journal Proceedings of the National Academy of Sciences (PNAS) is that there are many genetic differences that make people’s enzymes less efficient than normal, and that simple supplementation with vitamins can often restore some of these deficient enzymes to full working order.

First author Nicholas Marini, a UC Berkeley research scientist, noted that physicians prescribe vitamins to “cure” many rare and potentially fatal metabolic defects caused by mutations in critical enzymes. But those affected by these metabolic diseases are people with two bad copies, or alleles, of an essential enzyme. Many others may be walking around with only one bad gene, or two copies of slightly defective genes, throwing their enzyme levels off slightly and causing subtle effects that also could be eliminated with vitamin supplements.

“Our studies have convinced us that there is a lot of variation in the population in these enzymes, and a lot of it affects function, and a lot of it is responsive to vitamins,” Marini said. “I wouldn’t be surprised if everybody is going to require a different optimal dose of vitamins based on their genetic makeup, based upon the kind of variance they are harboring in vitamin-dependent enzymes.”

Though this initial study tested the function of human gene variants by transplanting them into yeast cells, where the function of the variants can be accurately assessed, Rine and Marini are confident the results will hold up in humans. Their research, partially supported by the Defense Advanced Research Projects Agency (DARPA) and the U.S. Army, may enable them to employ U.S. soldiers to test the theory that vitamin supplementation can tune up defective enzymes.

“Our soldiers, like top athletes, operate under extreme conditions that may well be limited by their physiology,” Rine said. “We’re now working with the defense department to identify variants of enzymes that are remediable, and ultimately hope to identify troops that have these variants and test whether performance can be enhanced by appropriate supplementation.”

In the PNAS paper, Rine, Marini and their colleagues report on their initial analysis of variants of a human enzyme called methylenetetrahydrofolate reductase, or MTHFR. The enzyme, which requires the B vitamin folate to work properly, plays a key role in synthesizing molecules that go into the nucleotide building blocks of DNA. Some cancer drugs, such as methotrexate, target MTHFR to shut down DNA synthesis and prevent tumor growth.

Using DNA samples from 564 individuals of many races and ethnicities, colleagues at Applied Biosystems of Foster City, Calif., sequenced for each person the two alleles that code for the MTHFR enzyme. Consistent with earlier studies, they found three common variants of the enzyme, but also 11 uncommon variants, each of the latter accounting for less than one percent of the sample.

They then synthesized the gene for each variant of the enzyme, and Marini, Rine and their UC Berkeley colleagues inserted these genes into separate yeast cells in order to judge the activity of each variant. Yeast use many of the same enzymes and cofactor vitamins and minerals as humans and are an excellent model for human metabolism, Rine said.

The researchers found that four different mutations affected the functioning of the human enzyme in yeast. One of these mutations is well known: Nearly 30 percent of the population has one copy, and nine percent has two copies.

The researchers were able to supplement the diet of the cultured yeast with folate, however, and restore full functionality to the most common variant, and to all but one of the less common variants.

Since this experiment, the researchers have found 30 other variants of the MTHFR enzyme and tested about 15 of them, “and more than half interfere with the function of the enzyme, producing a hundred-fold range of enzyme activity. The majority of these can be either partially or completely restored to normal activity by adding more folate. And that is a surprise,” Rine said.

Most scientists think that harmful mutations are disfavored by evolution, but Rine pointed out that this applies only to mutations that affect reproductive fitness. Mutations that affect our health in later years are not efficiently removed by evolution and may remain in our genome forever.

The health effects of tuning up this enzyme in humans are unclear, he said, but folate is already known to protect against birth defects and seems to protect against heart disease and cancer. At least one defect in the MTHFR enzyme produces elevated levels in the blood of the metabolite homocysteine, which is linked to an increased risk of heart disease and stroke, conditions that typically affect people in their post-reproductive years.

“In those people, supplementation of folate in the diet can reduce levels of that metabolite and reduce disease risk,” Marini said.

Marini and Rine estimate that the average person has five rare mutant enzymes, and perhaps other not-so-rare variants, that could be improved with vitamin or mineral supplements.

“There are over 600 human enzymes that use vitamins or minerals as cofactors, and this study reports just what we found by studying one of them,” Rine said. “What this means is that, even if the odds of an individual having a defect in one gene is low, with 600 genes, we are all likely to have some mutations that limit one or more of our enzymes.”

The subtle effects of variation in enzyme activity may well account for conflicting results of some clinical trials, including the confusing data on the effect of vitamin supplements, he noted. In the future, the enzyme profile of research subjects will have to be taken into account in analyzing the outcome of clinical trials.

If one considers not just vitamin-dependent enzymes but all the 30,000 human proteins in the genome, “every individual would harbor approximately 250 deleterious substitutions considering only the low-frequency variants. These numbers suggest that the aggregate incidence of low-frequency variants could have a significant physiological impact,” the researchers wrote in their paper.

All the more reason to poke around in one’s genome, Rine said.

“If you don’t give people a reason to become interested in their genome and to become comfortable with their personal genomic information, then the benefits of much of the biomedical research, which is indexed to particular genetic states, won’t be embraced in a time frame that most people can benefit from,” Rine said. “So, my motivation is partly scientific, partly an education project and, in some ways, a partly political project.”

Marini and Rine credit Bruce Ames, a UC Berkeley professor emeritus of molecular and cell biology now on the research staff at Children’s Hospital Oakland Research Institute, with the research that motivated them to look at enzyme variation. Ames found in the 1970s that many bacteria that could not produce a specific amino acid could do so if given more vitamin B6, and in recent years he has continued exploring the link between micronutrients and health.

“Looked at in one way, Bruce found that you can cure a genetic disease in bacteria by treating it with vitamins,” Rine said. Because the human genome contains about 6 billion DNA base pairs, each one subject to mutation, there could be between 3 and 6 million DNA sequence differences between any two people. Given those numbers, he reasoned that, as in bacteria, “there should be people who are genetically different in terms of the amount of vitamin needed for optimal performance of their enzymes.”

This touches on what Rine considers one of the key biomedical questions today. “Now that we have the complete genome sequences of all the common model organisms, including humans, it’s obvious that the defining challenge of biology in the 21st century is not what the genes are, but what the variation in the genes does,” he said.

Rine, Marini and their colleagues are continuing to study variation in the human MTHFR gene as well as other folate utilizing enzymes, particularly with respect to how defects in these enzymes may lead to birth defects. Rine also is taking advantage of the 1,500 students in his Biology 1A lab course to investigate variants of a second vitamin B6-dependent enzyme, cystathionine beta-synthase.

He also is investigating how enzyme cofactors like vitamins and minerals fix defective enzymes. He suspects that supplements work by acting as chaperones to stabilize the proper folding of the enzyme, which is critical to its catalytic activity. “That is a new principle that may be applicable to drug design,” Rine said.

 

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Coauthors with Rine and Marini are UC Berkeley research assistant Jennifer Gin and Janet Ziegle, Kathryn Hunkapiller Keho, David Ginzinger and Dennis A. Gilbert of Applied Biosystems, which also funded part of the study. The work was supported by a University of California Discovery Grant, DARPA and the National Institutes of Health

FASEB opposes the Government Spending Accountability Act

Contact: Lawrence Green lgreen@faseb.org 301-634-7335 Federation of American Societies for Experimental Biology

Bethesda, MD – The Federation of American Societies for Experimental Biology (FASEB) wrote to all  members of the House of Representatives expressing its opposition to the Government Spending Accountability (GSA) Act (HR 4631). While strongly supporting the bill’s goal and the desire to ensure that federal agencies are using their resources responsibly and efficiently, FASEB urged Representatives to oppose the bill in its current form. FASEB President Judith S. Bond PhD expressed  concern that, “if adopted, HR 4631 would impede the professional development of government scientists, hamper the ability of research agency staff to monitor scientific developments and make appropriate funding decisions based on new research, and reduce communication among researchers.”

In addition, she pointed out that “this bill would also place new restrictions on the ability of federal agencies to support conferences aimed at advancing the national research agenda.”

The FASEB letter states that it is important for federal agencies to have the capacity to provide support for a variety of scientific meetings and conferences. Many volunteer-led organizations serving patients, the public, and the research community administer multiple conferences per year. Dr. Bond emphasized the value of these meetings to the government and the public. “These conferences facilitate the public dissemination of research findings and support the training and professional development of the next  generation of scientists. By partnering with private organizations, federal agencies are able to reach broader audiences at a lower cost while promoting the public private partnership that has been a key part of the successful research enterprise.”

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FASEB is composed of 26 societies with more than 100,000 members, making it the largest coalition of biomedical research associations in the United States. Celebrating 100 Years of Advancing the Life Sciences in 2012, FASEB is rededicating its efforts to advance health and well-being by promoting progress and education in biological and biomedical sciences through service to our member societies and collaborative advocacy.

Stem-cell-protecting drug could prevent the harmful side effects of radiation therapy: mTOR inhibitor rapamycin

Contact: Elisabeth Lyons elyons@cell.com 617-386-2121 Cell Press

Radiation therapy is one of the most widely used cancer treatments, but it often damages normal tissue and can lead to debilitating conditions. A class of drugs known as mammalian target of rapamycin (mTOR) inhibitors can prevent radiation-induced tissue damage in mice by protecting normal stem cells that are crucial for tissue repair, according to a preclinical study published by Cell Press in the September issue of the journal Cell Stem Cell.

“We can exploit the emerging findings for the development of new preventive strategies and more effective treatment options for patients suffering this devastating disease,” says senior study author J. Silvio Gutkind of the National Institute of Dental and Craniofacial Research.

In response to radiation therapy, cancer patients often develop a painful condition called mucositis—tissue swelling in the mouth that can leave these patients unable to eat or drink and force them to rely on opioid-strength pain killers. Radiation therapy may cause this debilitating condition by depleting normal stem cells capable of repairing damaged tissue.

In the new study, Gutkind and his team found that the mTOR inhibitor rapamycin protects stem cells taken from the mouths of healthy individuals (but not cancer cells) from radiation-induced death and DNA damage, dramatically extending the lifespan of these normal stem cells and allowing them to grow. Rapamycin exerted these protective effects by preventing the accumulation of harmful molecules called reactive oxygen species. Moreover, mice that received rapamycin during radiation treatment did not develop mucositis.

Because rapamycin is approved by the Food and Drug Administration and is currently being tested in clinical trials for the prevention and treatment of various types of cancer, the new findings could have immediate and important implications for a large proportion of cancer patients. “Mucositis prevention would have a remarkable impact on the quality of life and recovery of cancer patients and at the same time would reduce the cost of treatment,” Gutkind says. “Our study provides the basis for further testing in humans, and we hope that these findings can be translated rapidly into the clinic.”

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Iglesias-Bartolome et al.: “mTOR inhibition prevents epithelial stem cell senescence  and protects from radiation-induced mucositis.”

Finkel et al.: “Relief with Rapamycin: mTOR Inhibition Protects against Radiation-Induced Mucositis”(In Translation Article

New bacteria contaminate hairspray

Contact: Lucy Goodchild l.goodchild@sgm.ac.uk 44-011-898-81843 Society for General Microbiology

Scientists in Japan have discovered a new species of bacteria that can live in hairspray, according to the results of a study published in the March issue of the International Journal of Systematic and Evolutionary Microbiology.

“Contamination of cosmetic products is rare but some products may be unable to suppress the growth of certain bacteria,” says Dr Bakir from the Japan Collection of Microorganisms, Saitama, Japan. “We discovered a new species of bacteria called Microbacterium hatanonis, which we found contaminates hairspray.”

“We also found a related species, Microbacterium oxydans in hairspray which was originally isolated from hospital material. Microbacterium species have been identified in milk, cheese, beef, eggs and even in the blood of patients with leukaemia, on catheters and in bone marrow.”

The scientists looked at the appearance and diet of the bacterium, then analysed its genome to show that it is an entirely new species. “It has been named in honour of Dr Kazunori Hatano, for his contribution to the understanding of the genus Microbacterium,” says Dr Bakir. Microbacterium hatanonis is rod-shaped and grows best at 30°C and pH neutral.

Scientists now need to determine the clinical importance of the new species, as similar bacteria have been found to infect humans. “Further testing will establish whether the species is a threat to human health,” says Dr Bakir. “We hope our study will benefit the formulation of hairspray to prevent contamination in the future.”

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Reposted at request 2008 data

Binding sites for LIN28 protein found in thousands of human genes

Contact: Debra Kain ddkain@ucsd.edu 619-543-6163 University of California – San Diego

Protein expression also causes changes in gene splicing

IMAGE:This is Gene Yeo, Ph.D.

Click here for more information.

A study led by researchers at the UC San Diego Stem Cell Research program and funded by the California Institute for Regenerative Medicine (CIRM) looks at an important RNA binding protein called LIN28, which is implicated in pluripotency and reprogramming as well as in cancer and other diseases.  According to the researchers, their study – published in the September 6 online issue of Molecular Cell – will change how scientists view this protein and its impact on human disease.

Studying embryonic stem cells and somatic cells stably expressing LIN28, the researchers defined discrete binding sites of LIN28 in 25 percent of human transcripts.  In addition, splicing-sensitive microarrays demonstrated that LIN28 expression causes widespread downstream alternative splicing changes –variations in gene products that can result in cancer or other diseases.

“Surprisingly, we discovered that LIN28 not only binds to the non-coding microRNAs, but can also bind directly to thousands of messenger RNAs,” said first author Melissa Wilbert, a doctoral student in the UC San Diego Biomedical Sciences graduate program.

Messenger RNA or mRNA, are RNA molecules that encode a chemical “blueprint” for the synthesis of a protein.  MicroRNAs (miRNAs) are short snippets of RNA that are crucial regulators of cell growth, differentiation, and death.  While they don’t encode for proteins, miRNAs are important for regulating protein production in the cell by repressing or “turning off” genes.

“The LIN28 protein is linked to growth and development and is important very early in human development,” said principal investigator Gene Yeo, PhD, MBA, of the Department of Cellular and Molecular Medicine, the Stem Cell Research Program and the Institute for Genomic Medicine at UC San Diego. “It is usually turned off in adult tissue, but can be reactivated, for instance, in certain cancers or metabolic disorders, such as obesity.”

Using genome-wide biochemical methods to look at the set of all RNA molecules across the transcriptome, the researchers found that LIN28 recognizes and binds to a known hairpin-like structure found on the let-7 family of miRNA, but surprisingly, this same structure is also found on mRNAs, allowing LIN28 to directly regulate thousands of targets.

“One of these targets actually encodes for the LIN28 protein itself. In other words, LIN28 helps to make more of itself,” said Yeo.  This process, known as autoregulation, helps to maintain a so-called “steady-state” system in which a protein positively regulates its own production by binding to a regulatory element of the mRNA for the gene coding it.

“Since these mRNA targets include those known to be involved in gene splicing, we also implicate LIN28 in the regulation of alternative splicing,” said Wilbert, adding that abnormal variations in splicing are often implicated in cancer and other disorders.

In the splicing process, fragments that do not typically code for protein, called introns, are removed from gene transcripts, and the remaining sequences, called exons, are reconnected.  The splicing factor proteins themselves, as well as the location where these proteins bind, dictate which pieces of the RNA are included or excluded in the final gene transcript – in much the same way that removing and inserting scenes, or splicing, can alter the plot of a movie.

The discovery of thousands of precise binding sites for LIN28 within human genes offers a novel look at the role this protein plays in development and disease processes.  For example, scientists had looked at targeting a particular miRNA called let-7 to halt cancer growth.  “But we now see that LIN28 can, in essence, bypass let-7 and find many, many other binding sites – perhaps with the same adverse effect of uncontrolled cell overgrowth,” said Yeo.  “This suggests that LIN28 itself should be the therapeutic target for diseases, rather than let-7 or other miRNAs.”

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Additional contributors to the study include, Stephanie C. Huelga, Katannya Kapeli, Thomas J. Stark, Tiffany Y. Liang, Stella X. Chen, Bernice Y. Yan, Jason L. Nathanson, Kasey R. Hutt, Michael T. Lovci, and Anthony Q. Vu, UC San Diego; Hilal Kazan and Quaid Morris, University of Toronto; Katlin B. Massirer, UC San Diego and State University of Campinas, Brazil; and Shawn Hoon, A*Star and National University of Singapore.

This study was supported in part by the National Institutes of Health (HG004659, GM084317 and NS075449), the National Institute of General Medical Sciences (T32 GM008666), and the California Institute for Regenerative Medicine (RB1-01413).

EPA pesticide exposure test too short, overlooks long term effects: EPA only test Pesticides health effects over 4 days

Contact: Morgan Kelly mekelly@pitt.edu 412-624-4356 University of Pittsburgh

Pitt research suggests EPA pesticide exposure test too short, overlooks long term effects

PITTSBURGH—The four-day testing period the U.S. Environmental Protection Agency (EPA) commonly uses to determine safe levels of pesticide exposure for humans and animals could fail to account for the toxins’ long-term effects, University of Pittsburgh researchers report in the September edition of Environmental Toxicology and Chemistry.

The team found that the highly toxic pesticide endosulfan—a neurotoxin banned in several nations but still used extensively in U.S. agriculture—can exhibit a “lag effect” with the fallout from exposure not surfacing until after direct contact has ended. Lead author Devin Jones, a recent Pitt biological sciences graduate, conducted the experiment under Rick Relyea, an associate professor of biological sciences in Pitt’s School of Arts and Sciences, with collaboration from Pitt post-doctoral researcher John Hammond. The paper is available on Pitt’s Web site at www.pitt.edu/news2009/Endosulfan.pdf

The team exposed nine species of frog and toad tadpoles to endosulfan levels “expected and found in nature” for the EPA’s required four-day period, then moved the tadpoles to clean water for an additional four days, Jones reported. Although endosulfan was ultimately toxic to all species, three species of tadpole showed no significant sensitivity to the chemical until after they were transferred to fresh water. Within four days of being moved, up to 97 percent of leopard frog tadpoles perished along with up to 50 percent of spring peeper and American toad tadpoles.

Of most concern, explained Relyea, is that tadpoles and other amphibians are famously sensitive to pollutants and considered an environmental indicator species. The EPA does not require testing on amphibians to determine pesticide safety, but Relyea previously found that endosulfan is 1,000-times more lethal to amphibians than other pesticides. Yet, he said, if the powerful insecticide cannot kill one the world’s most susceptible species in four days, then the four-day test period may not adequately gauge the long-term effects on larger, less-sensitive species.

“When a pesticide’s toxic effect takes more than four days to appear, it raises serious concerns about making regulatory decisions based on standard four-day tests for any organism,” Relyea said. “For most pesticides, we assume that animals will die during the period of exposure, but we do not expect substantial death after the exposure has ended. Even if EPA regulations required testing on amphibians, our research demonstrates that the standard four-day toxicity test would have dramatically underestimated the lethal impact of endosulfan on even this notably sensitive species.”

Andrew Blaustein, a professor in Oregon State University’s nationally ranked Department of Zoology, who is familiar with the Pitt study, said the results raise concerns about standards for other chemicals and the delayed dangers that might be overlooked. Some of the frog eggs the Pitt team used had been collected by Blaustein’s students for an earlier unrelated experiment, but he had no direct role in the current research.

“The results are somewhat alarming because standards for assessing the impacts of contaminants are usually based on short-term studies that may be insufficient in revealing the true impact,” Blaustein said. “The implications of this study go beyond a single pesticide and its effect on amphibians. Many other animals and humans may indeed be affected similarly.”

Tadpoles in the Pitt project spent four days in 0.5 liters of water containing endosulfan concentrations of 2, 6, 7, 35, 60, and 296 parts-per-billion (ppb), levels consistent with those found in nature. The team cites estimates from Australia—where endosulfan is widely used—that the pesticide can reach 700 ppb when sprayed as close as 10 meters from the ponds amphibians typically call home and 4 ppb when sprayed within 200 meters. The EPA estimates that surface drinking water can have chronic endosulfan levels of 0.5 to 1.5 ppb and acute concentrations of 4.5 to 23.9 ppb.

Leopard frogs, spring peepers, and American toads fared well during the experiment’s first four days, but once they were in clean water, the death rate spiked for animals previously exposed to 35 and 60 ppb. Although the other six species did not experience the lag effect, the initial doses of endosulfan were still devastating at very low concentrations. Grey and Pacific tree frogs, Western toads, and Cascades frogs began dying in large numbers from doses as low as 7 ppb, while the same amount killed all green frog and bullfrog tadpoles.

The endosulfan findings build on a 10-year effort by Relyea to understand the potential links between the global decline in amphibians, routine pesticide use, and the possible threat to humans in the future.

A second paper by Relyea and Jones also in the current Environmental Toxicology and Chemistry expands on one of Relyea’s most notable investigations, a series of findings published in Ecological Applications in 2005 indicating that the popular weed-killer Roundup® is “extremely lethal” to amphibians in concentrations found in the environment. The latest work determined the toxicity of Roundup Original Max for a wider group of larval amphibians, including nine frog and toad species and four salamander species. The report is available on Pitt’s Web site at www.pitt.edu/news2009/Roundup.pdf

In November 2008, Relyea reported in Oecologia that the world’s 10 most popular pesticides—which have been detected in nature—combine to create “cocktails of contaminants” that can destroy amphibian populations, even if the concentration of each individual chemical is within levels considered safe to humans and animals. The mixture killed 99 percent of leopard frog tadpoles and endosulfan alone killed 84 percent.

A month earlier, Relyea published a paper in Ecological Applications reporting that gradual amounts of malathion—the most popular insecticide in the United States—too small to directly kill developing leopard frog tadpoles instead sparked a biological chain reaction that deprived them of their primary food source. As a result, nearly half the tadpoles in the experiment did not reach maturity and would have died in nature

Repost at request

Wormwood ( Artemesia ) may hold key to non-toxic Cancer and Leukemia treatment

Reposted at Request from 26-Nov-2001

Contact: Rob Harrill rharrill@u.washington.edu 206-543-2580 University of Washington

Two bioengineering researchers at the University of Washington have discovered a promising potential treatment for cancer among the ancient arts of Chinese folk medicine.

Research Professor Henry Lai and assistant research Professor Narendra Singh have exploited the chemical properties of a wormwood derivative to target breast cancer cells, with surprisingly effective results.  A study in the latest issue of the journal Life Sciences describes how the derivative killed virtually all human breast cancer cells exposed to it within 16 hours.

“Not only does it appear to be effective, but it’s very selective,” Lai said.  “It’s highly toxic to the cancer cells, but has a marginal impact on normal breast cells.”

The compound, artemisinin, isn’t new.  It apparently was extracted from the plant Artemesia  annua L., commonly known as wormwood, thousands of years ago by the Chinese, who used it to combat malaria.  However, the treatment was lost over time.  Artemisinin was rediscovered during an archaeological dig in the 1970s that unearthed recipes for ancient medical remedies, and has become widely used in modern Asia and Africa to fight the mosquito-borne disease.

The compound helps control malaria because it reacts with the high iron concentrations found in the malaria parasite.  When artemisinin comes into contact with iron, a chemical reaction ensues, spawning charged atoms that chemists call “free radicals.”  The free radicals attack cell membranes, breaking them apart and killing the single-cell parasite.

About seven years ago, Lai began to hypothesize that the process might work with cancer, too.

“Cancer cells need a lot of iron to replicate DNA when they divide,” Lai explained.  “As a result, cancer cells have much higher iron concentrations than normal cells.  When we began to understand how artemisinin worked, I started wondering if we could use that knowledge to target cancer cells.”

Lai devised a potential method and began to look for funding, obtaining a grant from the Breast Cancer Fund in San Francisco.  Meanwhile, the UW patented his idea.

The thrust of the idea, according to Lai and Singh, was to pump up the cancer cells with maximum iron concentrations, then introduce artemisinin to selectively kill the cancer.  To accommodate a rate of iron intake greater than normal cells, cancer cell surfaces feature greater concentrations of transferrin receptors – cellular pathways that allow iron into a cell.  Breast cancer cells are no exception.  They have five to 15 times more transferrin receptors on their surface than normal breast cells.

In the current study, the researchers subjected sets of breast cancer cells and normal breast cells to doses of holotransferrin (which binds with transferrin receptors to transport iron into cells), dihydroartemisinin (a more water-soluble form of artemisinin) and a combination of both compounds.  Cells exposed to just one of the compounds showed no appreciable effect.  Normal breast cells, exposed to both compounds, exhibited a minimal effect.  But the response by cancer cells when hit with first holotransferrin, then dihydroartemisinin, was dramatic.

After eight hours, just 25 percent of the cancer cells remained.  By the time 16 hours had passed, nearly all the cells were dead.

An earlier study involving leukemia cells yielded even more impressive results.  Those cells were eliminated within eight hours.  A possible explanation might be the level of iron in the leukemia cells.

“They have one of the highest iron concentrations among cancer cells,” Lai explained.  “Leukemia cells can have more than 1,000 times the concentration of iron that normal cells have.”

The next step, according to Lai, is animal testing.  Limited tests have been done in that area.  In an earlier study, a dog with bone cancer so severe it couldn’t walk made a complete recovery in five days after receiving the treatment.  But more rigorous testing is needed.

If the process lives up to its early promise, it could revolutionize the way some cancers are approached, Lai said.  The goal would be a treatment that could be taken orally, on an outpatient basis.

“That would be very easy, and this could make that possible,” Lai said.  “The cost is another plus – at $2 a dose, it’s very cheap.  And, with the millions of people who have already taken artemisinin for malaria, we have a track record showing that it’s safe.”

Whatever happens, Lai said, a portion of the credit will have to go to unknown medical practitioners, long gone now.

“The fascinating thing is that this was something the Chinese used thousands of years ago,” he said.  “We simply found a different application.”

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For more information, contact Lai at (206) 543-1071 or hlai@u.washington.edu.  For more information on the journal Life Sciences, check the Web at:http://www.elsevier.com/locate/lifescie

Study illuminates how the plague bacteria causes disease

Contact: Heidi Hardman hhardman@cell.com 617-397-2879 Cell Press

The bacteria responsible for the plague and some forms of food poisoning “paralyze” the immune system of their hosts in an unexpected way, according to a new study in the September 8, 2006 issue of the journal Cell, published by Cell Press.

The researchers found that these bacteria, which belong to the genus Yersinia, harbor a protein that mimics an apparently unrelated mammalian enzyme. That copycat protein blocks host cells’ capacity to change shape and move, abilities important for cells of the immune system to track down and “eat” foreign invaders, the researchers explained.

The discovery marks the second way in which this protein, called YpkA, compromises the immune system. Earlier studies suggested that another portion of YpkA–which may have been derived from a mammalian enzyme and later co-opted by Yersinia–has activity that also influences cell shape by a separate, though incompletely understood mechanism.

The findings offer important new insight into the factors that lend Yersinia their ability to spawn disease, the researchers said. The results might also contribute to new strategies for fighting the bug.

“Yersinia injects several virulence factors into its host,” said C. Erec Stebbins of Rockefeller University. “If we can discover which ones are critical, we might identify the pathogen’s Achilles heel–an attractive target for antibacterial or anti-virulence compounds.”

“We were quite excited to see such a critical and unexpected factor in the virulence of Yersinia–a bacteria historically responsible for some of the worst diseases,” he added. Although improvements in sanitation have eliminated acute problems from diseases caused by Yersinia, concerns remain about the possibility that an untreatable strain might arise or that the bacteria might come into use as a biological weapon, he said.

Nearly 200 million people are estimated to have died in the plague epidemics that devastated the ancient world, the researchers said. The successful weaponization of plague in the former Soviet Union bioweapons program also made the pathogen a primary biodefense concern. Additional medical concerns have arisen from the evolution of multidrug-resistant strains of the plague bacterium found in patients from several locations.

The plague bacterium Yersinia pestis is closely related to Y. enterocolitica and Y. pseudotuberculosis, which are food-borne agents that cause inflammation of the stomach and intestines. All Yersinia bacteria have a virulence plasmid, which is necessary to cause disease. Plasmids are extra DNA molecules frequently found in bacteria containing genes that can be passed from one bacterial strain to another and that may confer an evolutionary advantage, such as antibiotic resistance.

In the case of Yersinia, the plasmid harbors numerous genes, including a large number that contribute to the ability of diverse pathogens to deliver virulence factors into host cells. One of these genes is YpkA, a protein with multiple domains, including one closely related to an enzyme, a type of kinase, not typically found in bacteria. Earlier studies found that mutations that eliminate this activity reduce but do not eliminate YpkA’s ability to disrupt cell shape by modifying their cytoskeletal support system.

In the current study, the researchers solved the high-resolution crystal structure of a second YpkA domain, the “Rho-GTPase binding domain” along with the host protein, “Rac1,” with which it interacts.

“The Yersinia structure was doing things to Rac1 that the host proteins normally do,” Stebbins said, suggesting that the domain acted as a mimic.

Further examination confirmed the domain to be a mimic of mammalian “guanidine nucleotide dissociation inhibitor” (GDI) proteins with a critical role in the bacteria’s ability to disrupt cell structure. The domain paralyzes cells by acting as an “off-switch” for host proteins involved in modifying cell shape, Stebbins said.

Mutations that prevented the bacterial proteins’ interaction with the host protein significantly impaired YpkA’s ability to disrupt the cytoskeleton. Moreover, a mutant strain of Y. pseudotuberculosis that lacked the GDI activity caused significantly fewer problems for infected mice compared to normal bacteria.

“Earlier studies that focused only on the protein’s kinase activity had missed half the picture,” Stebbins said. “The GDI domain seems to have an even bigger effect on host cells in culture, and a significant impact on virulence.”

The results also add to broader themes in the evolution of bacterial diseases, the researchers added.

“It is becoming increasingly clear that a common strategy used by bacterial pathogens to manipulate host cell biology is the mimicry of their own biochemical processes,” Stebbins said.

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The researchers include Gerd Prehna and C. Erec Stebbins of Rockefeller University in New York, NY; Maya I. Ivanov and James B. Bliska and of Stony Brook University in Stony Brook, NY.

This work was funded in part by research funds to C.E.S. from the Rockefeller University and PHS grants 1U19AI056510 (to C.E.S) and RO1AI433890 (to J.B.B) from the National Institute of Allergy and Infectious Diseases.

Prehna et al.: “Virulence in Yersinia Is Dependent on a Bacterial Mimic of Host Rho-Family Nucleotide Dissociation Inhibitors.” Publishing in Cell 126, 869–880, September 8, 2006. DOI 10.1016/j.cell.2006.06.056 http://www.cell.com

Repost at Request 2006

Triphala and Its Active Constituent Chebulinic Acid Are Natural Inhibitors of Vascular Endothelial Growth Factor-A Mediated Angiogenesis

Triphala churna (THL) is a combination of three fruits that has been used for many years in India for the treatment of various diseases. There are now reports which indicate that THL can inhibit growth of malignant tumors in animals. However, the mechanisms by which THL mediates its anti-tumor actions are still being explored. Because vascular endothelial growth factor-A (VEGF) induced angiogenesis plays a critical role in the pathogenesis of cancer, we therefore investigated whether tumor inhibitory effects of THL or its active constituents are through suppression of VEGF actions. We herein report that THL and chebulinic (CI) present in THL can significantly and specifically inhibit VEGF induced angiogenesis by suppressing VEGF receptor-2 (VEGFR-2) phosphorylation. These results are of clinical significance as these inexpensive and non-toxic natural products can be used for the prevention and treatment of diseases where VEGF induced angiogenesis has an important role

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Results and Discussion

There are now studies which indicate the therapeutic efficacies of THL in tumor bearing animals [7][10]. However, there is still no report indicating the effects of THL on VEGF induced angiogenesis [7][10]. We at first determined whether single oral dose of 100 mg/kg of THL could inhibit VEGF (250 ng) mediated angiogenesis in vivo in a well established mouse matrigel plug assay model [14][17]. This dose of THL was particularly selected as this dose demonstrated the highest efficacy in human malignant tumor bearing mice [10]. In addition, we also did not observe any significant changes in the complete blood count, hepatic enzymes, cholesterol, blood sugar, blood urea nitrogen (BUN) and serum creatinine level with this dose of THL in mice when compared to normal controls (data not shown). On day 8, THL untreated plugs containing VEGF appeared dark red, Masson’s trichrome staining (endothelial cells stain red and the matrigel stain blue) and CD31 immunostaining demonstrated higher levels of endothelial cells in these VEGF containing THL untreated plugs (Fig. 2 A–D). In contrast, on Day 8, plugs containing VEGF removed from animals treated with THL for 7 days were pale in color and the endothelial cells were also significantly less in numbers (Fig. 2A–D). Similar results were observed in control plugs without VEGF removed from animals untreated with THL (Fig. 2A–D). These data confirmed that oral administration of THL could significantly inhibit VEGF induced angiogenesis in vivo.

Furthermore in vitro studies have indicated the anti-VEGF actions of GA and EA, two constituents of THL [26], [27]. Since the bioavailability of these two compounds following ingestion of either fruits containing these two acids or in pure forms is poor [11], [12], [28], [29], [30] and because we had observed significant suppression of VEGF induced angiogenesis following oral administration of THL in our in vivo model (Fig. 2), we therefore examined the plasma level of another major constituent of THL, CI following oral feeding of mice with THL. The plasma concentration of CI reached to 1952.67 ng/ml (2.04 μM) at 20 min after gavaging the mice with a single dose of THL (100 mg/kg) containing 6.8 mg of CI as detected by LC-MS/MS.

Because VEGF mediates its angiogenic actions by stimulating proliferation, migration, tube formation and endothelial cell permeability [1][4], therefore in order to investigate whether THL could specifically inhibit these functions of VEGF in endothelial cells, we initially determined the non-toxic concentration of THL to be used for our in vitro experiments in HUVEC by examining the cytotoxic effects of various concentrations of THL (20–80 μg/ml) that were previously reported to inhibit tumor cell growth in vitro [9], [10], [31]. In addition, we also determined the effect of 2 μM of CI on the viability of HUVEC as this concentration of CI was detected in the plasma of mice after orally feeding them with the VEGF inhibitory dose of THL (100 mg/kg). Our results indicated 40 μg/ml of THL to be the highest non-toxic concentration of THL and 2 μM CI had no effect on cell viability (Fig. 3A, B). Accordingly, we selected 40 μg/ml of THL and 2 μM of CI for further in vitro experiments.

We next examined the effects of non-toxic concentration of THL (40 μg/ml) and CI (2 μM) on VEGF induced proliferation, migration, tube formation and permeability in HUVEC. Our results indicated significant inhibition of VEGF (20 ng/ml) induced proliferation (Fig. 3 C, D), migration (Fig. 4 A–D) and tube formation (Fig. 5A–D) by these cells after treatment with THL or CI. In addition, THL and CI also significantly inhibited VEGF induced permeability in HUVEC (Fig. 5E). It is to be noted here that THL (40 μg/ml) or CI (2 μM) alone had no effects on proliferation, wound healing, tube formation and permeability of the endothelial cells (data not shown).

Furthermore as these actions of VEGF is mediated mainly through its VEGFR-2 [1][4], therefore to elucidate the molecular mechanisms by which THL or CI inhibited VEGF functions, we investigated the effects of THL (40 μg/ml) and CI (2 μM) on VEGF (20 ng/ml) induced VEGFR-2 phosphorylation in HUVEC. Our results demonstrated that THL or CI significantly inhibited VEGF induced phosphorylation of VEGFR-2 (Fig. 5F).

Since our previous in vitro data suggested that THL and CI could significantly inhibit the important steps of VEGF induced angiogenesis (Fig. 3, 4, 5), therefore, we determined the effects of THL (40 μg/ml) and CI (2 μM) on VEGF mediated angiogenesis in CAM assay [19], [24], [25]. All observations were made on Day 4 after addition of these compounds. There was no evidence of angiogenesis or inflammation on addition of the vehicle (PBS) in which THL or CI were dissolved (Fig. 6A, E). However, striking angiogenesis was evident after exposure to 250 ng of VEGF (Fig. 6B, E). On the contrary, significant inhibition of VEGF induced angiogenesis was observed following exposures to 40 μg/ml of THL or 2 μM of CI (Fig. 6C, D, E). THL or CI alone did not induce any inflammation nor had any effects on blood vessel formation (data not shown).

Taken together our results for the first time demonstrated that THL or CI present in THL can significantly inhibit VEGF induced angiogenesis via suppression of VEGFR-2 actions. Moreover unlike the other constituents of THL such as GA and EA, the plasma level of CI reached considerably after oral intake of THL and this level of CI in turn could significantly and specifically inhibit the actions of VEGF in vitro. These results thus suggest that CI present in THL mediate the anti-VEGF effects of THL in vivo and is also a potent inhibitor VEGF functions. However, there may be other untested constituents of THL, which may also possess anti-VEGF activities.

Finally, VEGF mediated neovascularization plays an important pathogenic role in various diseases [1][3]. The presently available anti-VEGF drugs not only have serious toxicities, but are also very expensive [32][34]. This necessitates development of newer and effective non-toxic and inexpensive anti-VEGF agents. Our present study suggests that THL or CI may fulfill this promise in future

LINK to Full Study

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0043934

Catch the fever: It’ll help you fight off infection

New research published in the Journal of Leukocyte Biology demonstrates that elevated body temperature plays a vital role on the generation of effective T-cell mediated immune response

Bethesda, MD—With cold and flu season almost here, the next time you’re sick, think twice before taking something for your fever. That’s because scientists have found more evidence that elevated body temperature helps certain types of immune cells to work better.  This research is reported in the November 2011 issue of the Journal of Leukocyte Biology (https://www.jleukbio.org).

“An increase in body temperature has been known since ancient times to be associated with infection and inflammation,” said Elizabeth A. Repasky, Ph.D., a researcher involved in the work from the Department of Immunology at the Roswell Park Cancer Institute in Buffalo, New York. “Since a febrile response is highly conserved in nature (even so-called cold blooded animals move to warmer places when they become ill) it would seem important that we immunologists devote more attention to this interesting response.”

Scientists found that the generation and differentiation of a particular kind of lymphocyte, known as a “CD8+ cytotoxic T-cell” (capable of destroying virus-infected cells and tumor cells) is enhanced by mild fever-range hyperthermia. Specifically, their research suggests that elevated body temperature changes the T-cells’ membranes which may help mediate the effects of micro-environmental temperature on cell function. To test this, researchers injected two groups of mice with an antigen, and examined the activation of T-cells following the interaction with antigen presenting cells. Body temperature in half of the mice was raised by 2 degrees centigrade, while the other half maintained a normal core body temperature.  In the warmed mice, results showed a greater number of the type of CD8 T-cells capable of destroying infected cells.

“Having a fever might be uncomfortable,” said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology, “but this research report and several others are showing that having a fever is part of an effective immune response. We had previously thought that the microbes that infect us simply can’t replicate as well when we have fevers, but this new work also suggests that the immune system might be temporarily enhanced functionally when our temperatures rise with fever. Although very high body temperatures are dangerous and should be controlled, this study shows that we may need to reconsider how and when we treat most mild fevers.”

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The Journal of Leukocyte Biology (http://www.jleukbio.org) publishes peer-reviewed manuscripts on original investigations focusing on the cellular and molecular biology of leukocytes and on the origins, the developmental biology, biochemistry and functions of granulocytes, lymphocytes, mononuclear phagocytes and other cells involved in host defense and inflammation. The Journal of Leukocyte Biology is published by the Society for Leukocyte Biology.

Details: Thomas A. Mace, Lingwen Zhong, Casey Kilpatrick, Evan Zynda, Chen-Ting Lee, Maegan Capitano, Hans Minderman, and Elizabeth A. Repasky. Differentiation of CD8+ T cells into effector cells is enhanced by physiological range hyperthermia. J. Leukoc Biol November 2011 90:951-962;   doi:10.1189/jlb.0511229 ;  http://www.jleukbio.org/content/90/5/951.abstract

Fish oil may hold key to leukemia cure

This is a Repost from 6 months ago. What is Evil about it, is that none of this information is being conveyed to patients…Hence a rare re-post for me…
A compound produced from fish oil that appears to target leukemia stem cells could lead to a cure for the disease, according to Penn State researchers. The compound — delta-12-protaglandin J3, or D12-PGJ3 — targeted and killed the stem cells of chronic myelogenous leukemia, or CML, in mice, said Sandeep Prabhu, associate professor of immunology and molecular toxicology in the Department of Veterinary and Medical Sciences. The compound is produced from EPA — Eicosapentaenoic Acid — an Omega-3 fatty acid found in fish and in fish oil, he said.

“Research in the past on fatty acids has shown the health benefits of fatty acids on cardiovascular system and brain development, particularly in infants, but we have shown that some metabolites of Omega-3 have the ability to selectively kill the leukemia-causing stem cells in mice,” said Prabhu. “The important thing is that the mice were completely cured of leukemia with no relapse.”

The researchers, who released their findings in the current issue of Blood, said the compound kills cancer-causing stem cells in the mice’s spleen and bone marrow. Specifically, it activates a gene — p53 — in the leukemia stem cell that programs the cell’s own death. “p53 is a tumor suppressor gene that regulates the response to DNA damage and maintains genomic stability,” Prabhu said.

IMAGE:Penn State researchers initially tested a compound produced from fish oil on a type of leukemia found in mice called the Friend Virus. This slide shows a Friend Virus Leukemia…Click here for more information.

Killing the stem cells in leukemia, a cancer of the white blood cells, is important because stem cells can divide and produce more cancer cells, as well as create more stem cells, Prabhu said.

The current therapy for CML extends the patient’s life by keeping the number of leukemia cells low, but the drugs fail to completely cure the disease because they do not target leukemia stem cells, said Robert Paulson, associate professor of veterinary and biomedical sciences, who co-directed this research with Prabhu.

“The patients must take the drugs continuously,” said Paulson. “If they stop, the disease relapses because the leukemia stem cells are resistant to the drugs.”

Current treatments are unable to kill the leukemia stem cells, Paulson noted. “These stem cells can hide from the treatment, and a small population of stem cells give rise to more leukemia cells,” said Paulson. “So, targeting the stem cells is essential if you want to cure leukemia.”

IMAGE:Penn State researchers Sandeep Prahbu (right) and Robert Paulson (left) sketch out a delta-12-protaglandin J3, or D12-PGJ3. The compound, derived from fish oil, targeted and killed the stem cells of…Click here for more information.

During the experiments, the researchers injected each mouse with about 600 nanograms of D12-PGJ3 each day for a week. Tests showed that the mice were completely cured of the disease. The blood count was normal, and the spleen returned to normal size. The disease did not relapse.

In previous experiments, the compound also killed the stem cells of Friend Virus-induced leukemia, an experimental model for human leukemia.

The researchers focused on D12-PGJ3 because it killed the leukemia stem cells, but had the least number of side effects. The researchers currently are working to determine whether the compound can be used to treat the terminal stage of CML, referred to as Blast Crisis. There are currently no drugs available that can treat the disease when it progresses to this stage.

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The researchers, who applied for a patent, are also preparing to test the compound in human trials