Inflammatory skin damage in mice blocked by bleach solution, Stanford study finds

Contact: Krista Conger kristac@stanford.edu 650-725-5371 Stanford University Medical Center

STANFORD, Calif. — Processes that age and damage skin are impeded by dilute bleach solution, according to a new study by researchers at the Stanford University School of Medicine.

The study was conducted on mice. But if shown to work similarly in humans, the inexpensive, widely available household chemical could provide a new way to treat skin damage caused by radiation therapy, excess sun exposure or aging.

Dilute bleach baths have been used for decades to treat moderate to severe eczema in humans, but it has not been clear until now why they work. “Originally it was thought that bleach may serve an antimicrobial function, killing bacteria and viruses on the skin,” said Thomas Leung, MD, PhD, an instructor in dermatology at Stanford and a pediatric dermatologist at Lucile Packard Children’s Hospital. “But the concentrations used in clinic are not high enough for this to be the sole reason. So we wondered if there could be something else going on.”

Leung is the lead author of the study, which will be published online Nov. 15 in the Journal of Clinical Investigation. Seung Kim, MD, PhD, professor of developmental biology and a Howard Hughes Medical Institute investigator, is the study’s senior author.

“Dr. Leung relentlessly followed his hunch that an antimicrobial effect of dilute bleach wasn’t the whole story,” Kim said. “And his work has revealed new mechanisms for targeting inflammatory pathways with this versatile small molecule. It has also identified new possible clinical applications.”

Leung and his colleagues knew that many skin disorders, including eczema and radiation dermatitis, have an inflammatory component. When the skin is damaged, immune cells rush to the site of the injury to protect against infection. Because inflammation itself can be harmful if it spirals out of control, the researchers wondered if the bleach (sodium hypochlorite) solution somehow played a role in blocking this response.

To find out, they homed in on a molecule called nuclear factor kappa-light-chain-enhancer of activated B cells, or NF-kB, which is known to play a critical role in inflammation, aging and response to radiation. When activated by signaling molecules, it enters the cell’s nucleus and binds to DNA to control gene expression. When inactive, it is sequestered in the cytoplasm, away from the DNA.

Leung wondered if there could be a link between the effect of the dilute bleach solution and NF-kB’s role in skin. He exposed human keratinocytes, or skin cells, to 0.005 percent bleach for one hour before treating them with a signaling molecule that normally activates NF-kB function. He found that exposure to the solution blocked the expression of two genes known to be regulated by NF-kB. The effect was reversible, however — waiting 24 hours after the bleach treatment restored NF-kB’s ability to activate expression of the target genes.

Further investigation divulged how this happens.

“We found that the bleach solution oxidizes and inhibits an activator necessary for NF-kB to enter the nucleus, essentially blocking NF-kB’s effect,” Leung said. When the researchers mutated the activator to be oxidation-resistant, NF-kB’s gene targeting activity was unhindered.

Next, the researchers turned to potential clinical applications. Radiation dermatitis is a common side effect of radiation therapy for cancer. While radiation therapy is directed at cancer cells inside the body, the normal skin in the radiation therapy field is also affected. Radiation therapy often causes a sunburn-like skin reaction. In some cases, these reactions can be quite painful and can require interrupting the radiation therapy course to allow the skin to heal before resuming treatment. However, prolonged treatment interruptions are undesirable.

“An effective way to prevent and treat radiation dermatitis would be of tremendous benefit to many patients receiving radiation therapy,” said Susan Knox, MD, PhD, associate professor of radiation oncology and study co-author.

Leung and his colleagues tested the effect of daily, 30-minute baths in bleach solution on laboratory mice with radiation dermatitis. They found that the animals bathed in the bleach solution experienced less severe skin damage and better healing and hair regrowth than animals bathed in water.

They then turned their attention to old — but healthy — laboratory mice.

“Multiple research studies have linked increased NF-kB activity with aging,” Leung said. “We found that if we blocked NF-kB activity in elderly laboratory mice by bathing them in the bleach solution, the animals’ skin began to look younger. It went from old and fragile to thicker, with increased cell proliferation.” The effect diminished soon after the dilute-bleach baths were stopped, indicating that regular exposure is necessary to maintain skin thickness.

The researchers are now considering clinical trials in humans, and they are also looking at other diseases that could be treated by dilute-bleach baths. “It’s possible that, in addition to being beneficial to radiation dermatitis, it could also aid in healing wounds like diabetic ulcers,” Leung said. “This is exciting because there are so few side effects to dilute bleach. We may have identified other ways to use hypochlorite to really help patients. It could be easy, safe and inexpensive.”

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Other Stanford co-authors of the study were Lillian Zhang, a life sciences research assistant; senior researcher Jing Wang, MD; and research associate Shoucheng Ning, MD, PhD.

The study was supported by the Dermatology Foundation, the National Institutes of Health (training grant DK007217-38) and the Howard Hughes Medical Institute.

Information about Stanford’s Department of Dermatology, which also supported the work, is available at http://dermatology.stanford.edu.

The Stanford University School of Medicine consistently ranks among the nation’s top medical schools, integrating research, medical education, patient care and community service. For more news about the school, please visit http://mednews.stanford.edu. The medical school is part of Stanford Medicine, which includes Stanford Hospital & Clinics and Lucile Packard Children’s Hospital. For information about all three, please visit http://stanfordmedicine.org/about/news.html.

Print media contact: Krista Conger at (650) 725-5371 (kristac@stanford.edu) Broadcast media contact: M.A. Malone at (650) 723-6912 (mamalone@stanford.edu)

Study links intestinal bacteria to rheumatoid arthritis

Contact: Craig Andrews craig.andrews@nyumc.org 212-404-3511 NYU Langone Medical Center / New York University School of Medicine

Findings suggest bacterial disturbances in the gut may play a role in autoimmune attacks on the joints, point the way to novel treatments and diagnostics

Researchers have linked a species of intestinal bacteria known as Prevotella copri to the onset of rheumatoid arthritis, the first demonstration in humans that the chronic inflammatory joint disease may be mediated in part by specific intestinal bacteria. The new findings by laboratory scientists and clinical researchers in rheumatology at NYU School of Medicine add to the growing evidence that the trillions of microbes in our body play an important role in regulating our health.

Using sophisticated DNA analysis to compare gut bacteria from fecal samples of patients with rheumatoid arthritis and healthy individuals, the researchers found that P. copri was more abundant in patients newly diagnosed with rheumatoid arthritis than in healthy individuals or patients with chronic, treated rheumatoid arthritis. Moreover, the overgrowth of P. copri was associated with fewer beneficial gut bacteria belonging to the genera Bacteroides.

“Studies in rodent models have clearly shown that the intestinal microbiota contribute significantly to the causation of systemic autoimmune diseases,” says Dan R. Littman, MD, PhD, the Helen L. and Martin S. Kimmel Professor of Pathology and Microbiology and a Howard Hughes Medical Institute investigator.

“Our own results in mouse studies encouraged us to take a closer  look at patients with rheumatoid arthritis, and we found this remarkable and surprising association,” says Dr. Littman, whose basic science laboratory at NYU School of Medicine’s Skirball Institute of Biomolecular Medicine collaborated with clinical investigators led by Steven Abramson, MD, senior vice president and vice dean for education, faculty, and academic affairs; the Frederick H. King Professor of Internal Medicine; chair of the Department of Medicine; and professor of medicine and pathology at NYU School of Medicine.

“At this stage, however, we cannot conclude that there is a causal link between the abundance of P. copri and the onset of rheumatoid arthritis,” Dr. Littman says. “We are developing new tools that will hopefully allow us to ask if this is indeed the case.”

The new findings, reported today in the open-access journal eLife, were inspired by previous research in Dr. Littman’s laboratory, collaborating with Harvard Medical School investigators, using mice genetically predisposed to rheumatoid arthritis, which resist the disease if kept in sterile environments, but show signs of joint inflammation when exposed to otherwise benign gut bacteria known as segmented filamentous bacteria.

Rheumatoid arthritis, an autoimmune disease that attacks joint tissue and causes painful, often debilitating stiffness and swelling, affects 1.3 million Americans. It strikes twice as many women as men and its cause remains unknown although genetic and environmental factors are thought to play a role.

The human gut is home to hundreds of species of beneficial bacteria, including P. copri, which ferment undigested carbohydrates to fuel the body and keep harmful bacteria in check. The immune system, primed to attack foreign microbes, possesses the extraordinary ability to distinguish benign or beneficial bacteria from pathogenic bacteria. This ability may be compromised, however, when the gut’s microbial ecosystem is thrown off balance.

“Expansion of P. copri in the intestinal microbiota exacerbates colonic inflammation in mouse models and may offer insight into the systemic autoimmune response seen in rheumatoid arthritis,” says Randy S. Longman, MD, PhD, a post-doctoral fellow in Dr. Littman’s laboratory and a gastroenterologist at Weill-Cornell, and an author on the new study. Exactly how this expansion relates to disease remains unclear even in animal models, he says.

Why P. copri growth seems to take off in newly diagnosed patients with rheumatoid arthritis is also unclear, the researchers say. Both environmental influences, such as diet and genetic factors can shift bacterial populations within the gut, which may set off a systemic autoimmune attack. Adding to the mystery, P. copri extracted from stool samples of newly diagnosed patients appears genetically distinct from P. copri found in healthy individuals, the researchers found.

To determine if particular bacterial species correlate with rheumatoid arthritis, the researchers sequenced the so-called 16S gene on 44 fecal DNA samples from newly diagnosed patients with rheumatoid arthritis prior to immune-suppressive treatment; 26 samples from patients with chronic, treated rheumatoid arthritis; 16 samples from patients with psoriatic arthritis (characterized by red, flaky skin in conjunction with joint inflammation); and 28 samples from healthy individuals.

Seventy-five percent of stool samples from patients newly diagnosed with rheumatoid arthritis carried P. copri compared to 21.4% of samples from healthy individuals; 11.5% from chronic, treated patients; and 37.5% from patients with psoriatic arthritis.

Rheumatoid arthritis is treated with an assortment of medications, including antibiotics, anti-inflammatory drugs like steroids, and immunosuppressive therapies that tame immune reactions. Little is understood about how these medications affect gut bacteria. This latest research offers an important clue, showing that treated patients with chronic rheumatoid arthritis carry smaller populations of P. copri. “It could be that certain treatments help stabilize the balance of bacteria in the gut,” says Jose U. Scher, MD, director of the Microbiome Center for Rheumatology and Autoimmunity at NYU Langone Medical Center’s Hospital for Joint Diseases, and an author on the new study. “Or it could be that certain gut bacteria favor inflammation.”

The researchers plan to validate their results in regions beyond New York, since gut flora can vary across geographical regions, and investigate whether the gut flora can be used as a biological marker to guide treatment. “We want to know if people with certain populations of gut bacteria respond better to certain treatment than others,” says Dr. Scher. Finally, they hope to study people before they develop rheumatoid arthritis to see whether overgrowth of P. copri is a cause or result of autoimmune attacks.

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In addition to researchers from the NYU School of Medicine, investigators from Memorial Sloan Kettering Cancer Center and from the Harvard School of Public Health contributed to the study.  Funding for this research comes from the National Institutes of Health, the Howard Hughes Medical Institute, and the American Gastroenterological Association.

About NYU Langone Medical Center:

NYU Langone Medical Center, a world-class, patient-centered, integrated academic medical center, is one of the nation’s premier centers for excellence in clinical care, biomedical research, and medical education. Located in the heart of Manhattan, NYU Langone is composed of four hospitals—Tisch Hospital, its flagship acute care facility; Rusk Rehabilitation; the Hospital for Joint Diseases, the Medical Center’s dedicated inpatient orthopaedic hospital; and Hassenfeld Pediatric Center, a comprehensive pediatric hospital supporting a full array of children’s health services across the Medical Center—plus the NYU School of Medicine, which since 1841 has trained thousands of physicians and scientists who have helped to shape the course of medical history. The Medical Center’s tri-fold mission to serve, teach, and discover is achieved 365 days a year through the seamless integration of a culture devoted to excellence in patient care, education, and research. For more information, go to http://www.NYULMC.org, and interact with us on Facebook, Twitter, and YouTube.

There’s life after radiation for brain cells

Contact: Stephanie Desmon sdesmon1@jhmi.edu 410-955-8665 Johns Hopkins Medicine

Johns Hopkins researchers suggest neural stem cells may regenerate after anti-cancer treatment

Scientists have long believed that healthy brain cells, once damaged by radiation designed to kill brain tumors, cannot regenerate. But new Johns Hopkins research in mice suggests that neural stem cells, the body’s source of new brain cells, are resistant to radiation, and can be roused from a hibernation-like state to reproduce and generate new cells able to migrate, replace injured cells and potentially restore lost function.

“Despite being hit hard by radiation, it turns out that neural stem cells are like the special forces, on standby waiting to be activated,” says Alfredo Quiñones-Hinojosa, M.D., a professor of neurosurgery at the Johns Hopkins University School of Medicine and leader of a study described online today in the journal Stem Cells. “Now we might figure out how to unleash the potential of these stem cells to repair human brain damage.”

The findings, Quiñones-Hinojosa adds, may have implications not only for brain cancer patients, but also for people with progressive neurological diseases such as multiple sclerosis (MS) and Parkinson’s disease (PD), in which cognitive functions worsen as the brain suffers permanent damage over time.

In Quiñones-Hinojosa’s laboratory, the researchers examined the impact of radiation on mouse neural stem cells by testing the rodents’ responses to a subsequent brain injury. To do the experiment, the researchers used a device invented and used only at Johns Hopkins that accurately simulates localized radiation used in human cancer therapy. Other techniques, the researchers say, use too much radiation to precisely mimic the clinical experience of brain cancer patients.

In the weeks after radiation, the researchers injected the mice with lysolecithin, a substance that caused brain damage by inducing a demyelinating brain lesion, much like that present in MS. They found that neural stem cells within the irradiated subventricular zone of the brain generated new cells, which rushed to the damaged site to rescue newly injured cells. A month later, the new cells had incorporated into the demyelinated area where new myelin, the protein insulation that protects nerves, was being produced.

“These mice have brain damage, but that doesn’t mean it’s irreparable,” Quiñones-Hinojosa says. “This research is like detective work. We’re putting a lot of different clues together. This is another tiny piece of the puzzle. The brain has some innate capabilities to regenerate and we hope there is a way to take advantage of them. If we can let loose this potential in humans, we may be able to help them recover from radiation therapy, strokes, brain trauma, you name it.”

His findings may not be all good news, however. Neural stem cells have been linked to brain tumor development, Quiñones-Hinojosa cautions. The radiation resistance his experiments uncovered, he says, could explain why glioblastoma, the deadliest and most aggressive form of brain cancer, is so hard to treat with radiation.

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The research was supported by grants from the National Institutes of Health’s National Institute of Neurological Disorders and Stroke (RO1 NS070024), the Maryland Stem Cell Research Fund, the Robert Wood Johnson Foundation, the Howard Hughes Medical Institute, the PROMETEO grant, the Red de Terapia Celular (TerCel) from Instituto de Salud Carlos III, and the Consejo Nacional de Ciencia y Tecnología.

Other Johns Hopkins researchers involved in the study include Vivian Capilla-Gonzalez, Ph.D.; Hugo Guerrero-Cazares, M.D., Ph.D.; Janice Bonsu; Oscar Gonzalez-Perez, M.D.; Pragathi Achanta, Ph.D.; John Wong, Ph.D.; and Jose Manuel Garcia-Verdugo, Ph.D.

For more information: http://tinyurl.com/ofqkea3

JOHNS HOPKINS MEDICINE

Johns Hopkins Medicine (JHM), headquartered in Baltimore, Maryland, is a $6.7 billion integrated global health enterprise and one of the leading health care systems in the United States. JHM unites physicians and scientists of the Johns Hopkins University School of Medicine with the organizations, health professionals and facilities of The Johns Hopkins Hospital and Health System. JHM’s mission is to improve the health of the community and the world by setting the standard of excellence in medical education, research and clinical care. Diverse and inclusive, JHM educates medical students, scientists, health care professionals and the public; conducts biomedical research; and provides patient-centered medicine to prevent, diagnose and treat human illness. JHM operates six academic and community hospitals, four suburban health care and surgery centers, more than 38 primary health care outpatient sites and other businesses that care for national and international patients and activities. The Johns Hopkins Hospital, opened in 1889, was ranked number one in the nation for 21 years by U.S. News & World Report.

Johns Hopkins Medicine Media Relations and Public Affairs

Media Contact:

Stephanie Desmon 410-955-8665; sdesmon1@jhmi.edu

Helen Jones 410-502-9422, hjones49@jhmi.edu

Study finds vitamin C can kill drug-resistant TB

Contact: Kim Newman sciencenews@einstein.yu.edu 718-430-3101 Albert Einstein College of Medicine

May 21, 2013 — (Bronx, NY) — In a striking, unexpected discovery, researchers at Albert Einstein College of Medicine of Yeshiva University have determined that vitamin C kills drug-resistant tuberculosis (TB) bacteria in laboratory culture. The finding suggests that vitamin C added to existing TB drugs could shorten TB therapy, and it highlights a new area for drug design. The study was published today in the online journal Nature Communications.

TB is caused by infection with the bacterium M. tuberculosis. In 2011, TB sickened some 8.7 million people and took some 1.4 million lives, according to the World Health Organization. Infections that fail to respond to TB drugs are a growing problem: About 650,000 people worldwide now have multi-drug-resistant TB (MDR-TB), 9 percent of whom have extensively drug-resistant TB (XDR-TB).TB is especially acute in low and middle income countries, which account for more than 95 percent of TB-related deaths, according to the World Health Organization.

The Einstein discovery arose during research into how TB bacteria become resistant to isoniazid, a potent first-line TB drug. The lead investigator and senior author of the study was William Jacobs, Jr. Ph.D., professor of microbiology & immunology  and of genetics at Einstein. Dr. Jacobs is a Howard Hughes Medical Institute investigator and a recently elected member of the National Academy of Sciences.

Dr. Jacobs and his colleagues observed that isoniazid-resistant TB bacteria were deficient in a molecule called mycothiol. “We hypothesized that TB bacteria that can’t make mycothiol might contain more cysteine, an amino acid,” said Dr. Jacobs. “So, we predicted that if we added isoniazid and cysteine to isoniazid-sensitive M. tuberculosis in culture, the bacteria would develop resistance. Instead, we ended up killing off the culture— something totally unexpected.”

The Einstein team suspected that cysteine was helping to kill TB bacteria by acting as a “reducing agent” that triggers the production of reactive oxygen species (sometimes called free radicals), which can damage DNA.

“To test this hypothesis, we repeated the experiment using isoniazid and a different reducing agent— vitamin C,” said Dr. Jacobs. “The combination of isoniazid and vitamin C sterilized the M. tuberculosis culture. We were then amazed to discover that vitamin C by itself not only sterilized the drug-susceptible TB, but also sterilized MDR-TB and XDR-TB strains.”

To justify testing vitamin C in a clinical trial, Dr. Jacobs needed to find the molecular mechanism by which vitamin C exerted its lethal effect. More research produced the answer: Vitamin C induced what is known as a Fenton reaction, causing iron to react with other molecules to create reactive oxygen species that kill the TB bacteria.

“We don’t know whether vitamin C will work in humans, but we now have a rational basis for doing a clinical trial,” said Dr. Jacobs. “It also helps that we know vitamin C is inexpensive, widely available and very safe to use. At the very least, this work shows us a new mechanism that we can exploit to attack TB.”

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The paper is titled, “Mycobacterium tuberculosis is extraordinarily sensitive to killing by a vitamin C-induced Fenton reaction.” The other contributors are Catherine Vilcheze, Ph.D., Travis Hartman and Brian Weinrick, Ph.D., all at Einstein.

The study was supported by a grant (AI26170) from National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.

The authors declare no conflict of interest.

About Drug-Resistant TB

Multi-drug-resistant TB (MDR-TB): TB that does not respond to isoniazid and rifampicin, the two most potent anti-TB drugs.  Extensively drug-resistant TB (XDR-TB): TB that is resistant to rifampicin and isoniazid, as well as to any member of the quinolone family of antibiotics and at least one of four second-line injectable anti-TB drugs.

About Albert Einstein College of Medicine of Yeshiva University

Albert Einstein College of Medicine of Yeshiva University is one of the nation’s premier centers for research, medical education and clinical investigation. During the 2012-2013 academic year, Einstein is home to 742 M.D. students, 245 Ph.D. students, 116 students in the combined M.D./Ph.D. program, and 360 postdoctoral research fellows. The College of Medicine has more than 2,000 full-time faculty members located on the main campus and at its clinical affiliates. In 2012, Einstein received over $160 million in awards from the NIH. This includes the funding of major research centers at Einstein in diabetes, cancer, liver disease, and AIDS. Other areas where the College of Medicine is concentrating its efforts include developmental brain research, neuroscience, cardiac disease, and initiatives to reduce and eliminate ethnic and racial health disparities. Its partnership with Montefiore Medical Center, the University Hospital and academic medical center for Einstein, advances clinical and translational research to accelerate the pace at which new discoveries become the treatments and therapies that benefit patients. Through its extensive affiliation network involving Montefiore, Jacobi Medical Center –Einstein’s founding hospital, and five other hospital systems in the Bronx, Manhattan, Long Island and Brooklyn, Einstein runs one of the largest residency and fellowship training programs in the medical and dental professions in the United States. For more information, please visit http://www.einstein.yu.edu and follow us on Twitter @EinsteinMed.

Penn Study Finds that Antioxidant Found in Vegetables has Implications for Treating Cystic Fibrosis : Thiocyanate

2009 study posted for filing

 

Thiocyanate Reduces Damage by Inflammatory Molecules in Lung, Nerve, Pancreas, and Vessel-Lining Cells

 

PHILADELPHIA – Scientists at the University of Pennsylvania School of Medicine discovered that a dietary antioxidant found in such vegetables as broccoli and cauliflower protects cells from damage caused by chemicals generated during the body’s inflammatory response to infection and injury.  The finding has implications for such inflammation-based disorders as cystic fibrosis (CF), diabetes, heart disease, and neurodegeneration.

 

Through cell-culture studies and a synthesis of known antioxidant biochemistry, Zhe Lu, MD, PhD , Professor of Physiology, Yanping Xu , MD, PhD , Senior Research Investigator, and Szilvia Szép , PhD, postdoctoral researcher, showed that the antioxidant thiocyanate normally existing in the body protects lung cells from injuries caused by accumulations of hydrogen peroxide and hypochlorite, the active ingredient in household bleach. These potentially harmful chemicals are made by the body as a reaction to infection and injury. In addition, thiocyanate also protects cells from hypochlorite produced in reactions involving MPO, an enzyme released from germ-fighting white blood cells during inflammation. They published their finding this week in the Proceedings of the National Academy of Sciences.  Lu is also an Investigator of the Howard Hughes Medical Institute.

 

“Dr. Lu’s work throws new light on how the genetic defect underlying CF leads to the lung illnesses that are the leading cause of death,” said Bert Shapiro, Ph.D., who oversees membrane structure grants at the National Institutes of Health’s National Institute of General Medical Sciences (NIGMS). “His team’s findings suggest that the lungs of people with the disease are more susceptible to the damaging effects of cellular oxidants. While the idea is tantalizing and creative, further testing is needed to confirm it.”

 

The research team demonstrated that in three additional cell types used to extend their ideas to other inflammation-related conditions – cardiovascular disease, neurodegeneration, and diabetes – thiocyanate at blood concentrations of at least 100 micromolar (micromoles per liter) greatly reduces the toxicity of MPO in cells, including those lining blood vessels. Humans naturally derive thiocyanate from some vegetables and blood levels of thiocyanate in the general population vary from 10 to 140 micromolar.

 

This comparison raises the possibility, the authors point out, that without an adequate dietary supply of thiocyanate, hypochlorite produced by the body during inflammation would cause additional collateral damage to cells, thus worsening inflammatory diseases, and predisposing humans to diseases linked to MPO activity, including atherosclerosis.

 

Connection to CF

 

For over a decade Lu and colleagues have been exploring the inner workings of ion channels and how this knowledge relates to the pathology of such diseases as CF. The CF disease originates from mutations in the CF transmembrane conductance regulator (CFTR) protein, an ion channel protein in the cell membrane commonly thought to transport mainly chloride ions. It has, however, remained a mystery why a defect in a chloride-transporting channel leads to cystic fibrosis, a disease with exaggerated inflammation in both the lungs and the digestive system.

 

Lung injuries inflicted by excessive inflammation and recurring infection cause about ninety percent of CF patients’ symptoms and mortality. Although known as a chloride channel, CFTR also conducts thiocyanate ions, important because, in several ways, they can limit potentially harmful accumulations of hydrogen peroxide and hypochlorite, chemicals produced by the body to fight germs.

 

In CF patients, there is also a high incidence of diabetes, partly caused by damage to the pancreas. Type 2 diabetes is also associated with higher levels of MPO in the blood. The researchers found that the MPO-caused injuries to pancreas cells and endothelial cells used in their experiments can be greatly reduced by as little as 100 micromolar thiocyanate. Their finding raises the possibility that MPO, in the absence of adequate thiocyanate, contributes to diabetes.

 

In the cell-based experiments, thiocyanate at concentrations below 100 micromolar did not eliminate hypochlorite accumulation and did not fully protect against MPO toxicity. Conceivably, inadequate thiocyanate levels would aggravate MPO-produced injuries in patients suffering from inflammatory diseases, surmise the authors.

 

Links to Other Diseases

 

In other studies, MPO activity has been linked to lung cancers among smokers and also implicated in neurodegenerative diseases.  Intriguingly, people with congenital MPO deficiency are less likely to develop cardiovascular diseases.  The research team found that MPO-caused injuries to nerve cells, as well as to blood vessel-lining endothelial cells, can be greatly reduced by 100 micromolar thiocyanate.

 

Genetic defects in the CFTR predispose CF patients’ lungs to excessive inflammation entangled with recurring lung infection. Defective CFTR channels would be expected to result in lower thiocyanate concentrations in the affected regions within the respiratory, as well as the digestive systems, leaving tissues inadequately protected from accumulated hydrogen peroxide and overproduced hypochlorite.

 

Conceptually, delivering thiocyanate directly to the digestive and respiratory systems might be a therapy for CF disease, propose the researchers. As for the general population, individuals with low blood levels of thiocyanate may be at risk for chronic injuries by MPO, predisposing them to inflammatory or inflammation-mediated diseases. Many investigators have proposed developing drugs that specifically inhibit MPO-catalyzed hypochlorite production to combat these diseases, but natural thiocyanate not only decreases MPO-catalyzed formation of hypochlorite but also rapidly, once it is made, neutralizes it.

 

“In light of the obvious implications of this protective action of thiocyanate against the cell-damaging effect of MPO activity with regard to both CF disease and general population health, my colleagues and I will vigorously investigate the potential health benefit of thiocyanate,” says Lu. He emphasizes though, “until the research community acquires a better understanding of both positive and negative impacts of thiocyanate on human health, it would be unwise for anyone to self-administer thiocyanate because like many other chemicals, thiocyanate has adverse side effects at improper doses and/or under inappropriate conditions.”

 

The research was funded by NIGMS and the Howard Hughes Medical Institute.

UCLA/Pitt scientists uncover virus with potential to stop pimples in their tracks

Contact: Elaine Schmidt eschmidt@mednet.ucla.edu 310-794-2272 University of California – Los Angeles Health Sciences

Going viral to kill zits

Watch out, acne.  Doctors soon may have a new weapon against zits:  a harmless virus living on our skin that naturally seeks out and kills the bacteria that cause pimples.

The Sept. 25 online edition of the American Society for Microbiology’s mBio publishes the findings by scientists at UCLA and the University of Pittsburgh.

“Acne affects millions of people, yet we have few treatments that are both safe and effective,” said principal investigator Dr. Robert Modlin, chief of dermatology and professor of microbiology, immunology and molecular genetics at the David Geffen School of Medicine at UCLA.  “Harnessing a virus that naturally preys on the bacteria that causes pimples could offer a promising new tool against the physical and emotional scars of severe acne.”

The scientists looked at two little microbes that share a big name:  Propionibacterium acnes, a bacterium thriving in our pores that can trigger acne; and P. acnes phages, a family of viruses that live on human skin.  The viruses are harmless to humans, but programmed to infect and kill the aforementioned P. acnes bacteria.

When P. acnes bacteria aggravate the immune system, it causes the swollen, red bumps associated with acne.  Most effective treatments work by reducing the number of P. acnes bacteria on the skin.

“We know that sex hormones, facial oil and the immune system play a role in causing acne, however, a lot of research implicates P. acnes as an important trigger,” explained first author Laura Marinelli, a UCLA postdoctoral researcher in Modlin’s laboratory.  “Sometimes they set off an inflammatory response that contributes to the development of acne.”

Using over-the-counter pore cleansing strips from the drugstore, the researchers lifted acne bacteria and the P. acnes viruses from the noses of both pimply and clear-skinned volunteers.

When the team sequenced the bacteriophages’ genomes, they discovered that the viruses possess multiple features – such as small size, limited diversity and the broad ability to kill their hosts – that make them ideal candidates for the development of a new anti-acne therapy.

“Our findings provide valuable insights into acne and the bacterium that causes it,” observed corresponding author Graham Hatfull, Eberly Family Professor of Biotechnology, professor of biological sciences at the University of Pittsburgh and a Howard Hughes Medical Institute researcher.  “The lack of genetic diversity among the phages that attack the acne bacterium implies that viral-based strategies may help control this distressing skin disorder.”

“Phages are programmed to target and kill specific bacteria, so P. acnes phages will attack only P. acnes bacteria, but not others like E. coli,” added Marinelli.  “This trait suggests that they offer strong potential for targeted therapeutic use.”

Acne affects nearly 90 percent of Americans at some point in their lives, yet scientists know little about what causes the disorder and have made narrow progress in developing new strategies for treating it.  Dermatologists’ arsenal of anti-acne tools — benzoyl peroxide, antibiotics and Accutane – hasn’t expanded in decades.

“Antibiotics such as tetracycline are so widely used that many acne strains have developed resistance, and drugs like Accutane, while effective, can produce risky side effects, limiting their use,” explained coauthor Dr. Jenny Kim, director of the UCLA Clinic for Acne, Rosacea and Aesthetics.  “Acne can dramatically disfigure people and undermine their self-esteem, especially in teens.  We can change patients’ lives with treatment.  It’s time we identified a new way to safely treat the common disorder.”

The research team plans to isolate the active protein from the P. acnes virus and test whether it is as effective as the whole virus in killing acne bacteria. If laboratory testing proves successful, the researchers will study the compound’s safety and effectiveness in combating acne in people.

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The study was supported by grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases (R21AR060382, R01 AR053542 and F32AR060655) at the National Institutes of Health in Bethesda, Md.

Additional coauthors included Sorel Fitz-Gibbon, Megan Inkeles, Shawn Cokus, Matteo Pellegrini and Jeffrey F. Miller, all of UCLA; former UCLA researchers Clarmyra Hayes and Anya Loncaric, now of the California Institute of Technology and Solta Medical, respectively; and  Charles Bowman, Daniel Russell and Deborah Jacobs-Sera of the University of Pittsburgh.

The Clinic for Acne, Rosacea and Aesthetics at the UCLA Division of Dermatology at the David Geffen School of Medicine offers comprehensive care for acne and rosacea, as well as the scarring and discoloration that can result from these conditions.  The clinic’s goal is to educate the public and help patients develop habits leading to healthy skin.  Current research projects include studying the effect of Vitamin-D on immune response to acne, the effect of Omega-3 fatty acids on acne and its treatment, and the use of a mobile device application for acne management.  To schedule an appointment, call (310) 825-6911

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.

Nutritional supplement offers promise in treatment of unique form of autism

Contact: Scott LaFee
slafee@ucsd.edu
619-543-6163
University of California – San Diego

In mice, added amino acid reduced associated epilepsy, eased neurobehavioral symptom

An international team of researchers, led by scientists at the University of California, San Diego and Yale University schools of medicine, have identified a form of autism with epilepsy that may potentially be treatable with a common nutritional supplement.

The findings are published in the September 6, 2012 online issue of Science.

Roughly one-quarter of patients with autism also suffer from epilepsy, a brain disorder characterized by repeated seizures or convulsions over time. The causes of the epilepsy are multiple and largely unknown. Using a technique called exome sequencing, the UC San Diego and Yale scientists found that a gene mutation present in some patients with autism speeds up metabolism of certain amino acids. These patients also suffer from epileptic seizures. The discovery may help physicians diagnose this particular form of autism earlier and treat sooner.

The researchers focused on a specific type of amino acid known as branched chain amino acids or BCAAs. BCAAs are not produced naturally in the human body and must be acquired through diet. During periods of starvation, humans have evolved a means to turn off the metabolism of these amino acids. It is this ability to shut down that metabolic activity that researchers have found to be defective in some autism patients.

“It was very surprising to find mutations in a potentially treatable metabolic pathway specific for autism,” said senior author Joseph G. Gleeson, MD, professor in the UCSD Department of Neurosciences and Howard Hughes Medical Institute investigator. “What was most exciting was that the potential treatment is obvious and simple: Just give affected patients the naturally occurring amino acids their bodies lack.”

Gleeson and colleagues used the emerging technology of exome sequencing to study two closely related families that have children with autism spectrum disorder. These children also had a history of seizures or abnormal electrical brain wave activity, as well as a mutation in the gene that regulates BCAAs. In exome sequencing, researchers analyze all of the elements in the genome involved in making proteins.

In addition, the scientists examined cultured neural stem cells from these patients and found they behaved normally in the presence of BCAAs, suggesting the condition might be treatable with nutritional supplementation. They also studied a line of mice engineered with a mutation in the same gene, which showed the condition was both inducible by lowering the dietary intake of the BCAAs and reversible by raising the dietary intake. Mice treated with BCAA supplementation displayed improved neurobehavioral symptoms, reinforcing the idea that the approach could work in humans as well.

“Studying the animals was key to our discovery,” said first author Gaia Novarino, PhD, a staff scientist in Gleeson’s lab. “We found that the mice displayed a condition very similar to our patients, and also had spontaneous epileptic seizures, just like our patients. Once we found that we could treat the condition in mice, the pressing question was whether we could effectively treat our patients.”

Using a nutritional supplement purchased at a health food store at a specific dose, the scientists reported that they could correct BCAA levels in the study patients with no ill effect. The next step, said Gleeson, is to determine if the supplement helps reduce the symptoms of epilepsy and/or autism in humans.

“We think this work will establish a basis for future screening of all patients with autism and/or epilepsy for this or related genetic mutations, which could be an early predictor of the disease,” he said. “What we don’t know is how many patients with autism and/or epilepsy have mutations in this gene and could benefit from treatment, but we think it is an extremely rare condition.”

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Co-authors are Paul El-Fishawy, Child Study Center, Yale University School of Medicine; Hulya Kayserili, Medical Genetics Department, Istanbul University, Turkey; Nagwa A. Meguid, Rehab O. Khalil, Adel F. Hashish and Hebatalla S. Hashem, Department of Research on Children with Special Needs, National Research Centre, Cairo, Egypt; Eric M. Scott, Jana Schroth, Jennifer L. Silhavy, Neurogenetics Laboratory, Howard Hughes Medical Institute, Department of Neurosciences, UC San Diego; Majdi Kara, Pediatric Department, Tripoli Children’s Hospital, Libya; Tawfeq Ben-Omran, Clinical and Metabolic Genetics Division, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar; A. Gulhan Ercan-Sencicek, Stephan J. Sanders and Matthew W. State, Program on Neurogenetics, Child Study Center, Department of Psychiatry and Department of Genetics, Yale University School of Medicine; Abha R. Gupta, Child Study Center, Department of Pediatrics, Yale University School of Medicine; Dietrich Matern, Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic; Stacy Gabriel, Broad Institute of Harvard and Massachusetts Institute of Technology; Larry Sweetman, Institute of Metabolic Disease, Baylor Research Institute; Yasmeen Rahimi and Robert A. Harris, Roudebush VA Medical Center and Department of Biochemistry and Molecular Biology, Indiana University School of Medicine.

Funding for this research came, in part, from the National Institutes of Health (grants P1HD070494, R01NS048453, P30NS047101, RC2MH089956, K08MH087639, T32MH018268, U54HG003067), the Center for Inherited Disease Research, the Simons Foundation Research Initiative, Veterans Administration Merit Award, the German Research Foundation, the American Academy of Child and Adolescent Psychiatry Pilot Research Award/Elaine Schlosser Lewis Fund and the American Psychiatric Association/Lilly Research Fellowship.

Scientists create germ cell-supporting embryonic Sertoli-like cells from skin cells

Contact: Nicole Rura rura@wi.mit.edu 617-258-6851 Whitehead Institute for Biomedical Research

CAMBRIDGE, Mass. (September 6, 2012) – Using a stepwise trans-differentiation process, Whitehead Institute researchers have turned skin cells into embryonic Sertoli-like cells.

The main role of mature Sertoli cells is to provide support and nutrition to the developing sperm cells. Furthermore, Sertoli cells have been demonstrated to possess trophic properties, which have been utilized for the protection of non-testicular cellular grafts in transplantations. However, mature Sertoli cells are mitotically inactive, and the primary immature Sertoli cells during prolonged cultures degenerate in the petri dish. Therefore, finding an alternative source of these cells independent of the donor testis cells is of paramount interest both for basic research and clinical applications.

“The idea is if you could make Sertoli cells from a skin cell, they’d be accessible for supporting the spermatogenesis process when conducting in vitro fertilization assays or protecting other cell types such as neurons when co-transplanted in vivo,” says Whitehead Institute Founding Member Rudolf Jaenisch. “Otherwise, you could get proliferating cells only from fetal testis.”

Jaenisch lab researchers have seemingly overcome the supply and lifespan challenges through trans-differentiation, the process of reprogramming a cell directly from one mature cell type to another without first taking the cell in question all the way back to the embryonic stem-cell stage. Unlike other reprogramming methods that produce induced pluripotent stem cells (iPSCs), trans-differentiation does not rely on the use of genes that can cause cancer.

As reported in Cell Stem Cell‘s September issue, scientists trans-differentiated mouse skin cells into embryonic Sertoli-like cells by breaking the process into two main steps, mimicking Sertoli cells’ development in the testis. The first step in this progression transformed the skin fibroblasts from their mesenchymal state to a sheet-like epithelial state. In the second step the cells acquired the capability to attract each other to form aggregates as seen in vivo between embryonic Sertoli cells and germ cells.

Next the scientists devised a cocktail of five transcription factors that activate the epithelial cells’ embryonic Sertoli cell genetic program. The resulting cells exhibited many of the characteristics of embryonic Sertoli cells, including aggregating, forming tubular structures similar to the seminiferous tubules found in the testis, and secreting the typical Sertoli cell factors. When injected into a mouse fetal testis, the trans-differentiated cells migrated to the proper place and integrated into the endogenous tubules. Overall, the injected cells behaved like endogenous embryonic Sertoli cells, despite expressing a few genes differently.

“The injected trans-differentiated cells were closely interacting with the native germ cells, which shows that they definitely do not have any bad effect on the germ cells,” says Yossi Buganim, a postdoctoral researcher in the Jaenisch lab and first author of the Cell Stem Cell paper. “Instead, they enable those germ cells to survive.”

In fact, when the embryonic Sertoli-like cells were used to sustain other cells in a Petri dish, Buganim noted that the cells supported by the trans-differentiated cells thrived, living longer than cells sustained by actual native Sertoli cells.

Encouraged by these results in vitro, Buganim says he would like to investigate whether the embryonic Sertoli-like cells retain this enhanced supportive capacity after transplantation into the brain, where the cells could sustain ailing neurons. If so, they could have applications in the development of neuron-based therapies for neurodegenerative disorders such as ALS and Parkinson’s disease.

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This work was supported by the National Institutes of Health (NIH) grants R37-CA084198 and RO1-HD045022, and the Howard Hughes Medical Institute (HHMI).

Written by Nicole Giese Rura

Rudolf Jaenisch’s primary affiliation is with Whitehead Institute for Biomedical Research, where his laboratory is located and all his research is conducted. He is also a professor of biology at Massachusetts Institute of Technology.

Full Citation:

“Direct reprogramming of fibroblasts into embryonic Sertoli-like cells by defined factors”

Yosef Buganim (1), Elena Itskovich (1), Yueh-Chiang Hu (1,3), Albert W. Cheng (1,2), Kibibi Ganz (1), Sovan Sarkar (1), Dongdong Fu (1), Grant Welstead (1), David C. Page (1,2,3), and Rudolf Jaenisch (1,2).

Cell Stem Cell, September 7, 2012 print issue.

1. Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA 2. Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA 3. Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, MD 20815, USA

Scientists successfully awaken sleeping stem cells: ” might be possible to turn on the eye’s own resources to regenerate damaged retinas, without the need for transplanting outside retinal tissue or stem cells,”

Contact: Patti Jacobs pjacobs12@comcast.net 617-868-0077 Schepens Eye Research Institute

New hope for regenerating the human retina damaged by disease or injury

Boston, MA—Scientists at Schepens Eye Research Institute have discovered what chemical in the eye triggers the dormant capacity of certain non-neuronal cells to transform into progenitor cells, a stem-like cell that can generate new retinal cells. The discovery, published in the March issue of Investigative Ophthalmology and Visual Science (IOVS), offers new hope to victims of diseases that harm the retina, such as macular degeneration and retinitis pigmentosa.

“This study is very significant. It means it might be possible to turn on the eye’s own resources to regenerate damaged retinas, without the need for transplanting outside retinal tissue or stem cells,” says Dr. Dong Feng Chen, associate scientist at Schepens Eye Research Institute and Harvard Medical School, and the principal investigator of the study.  “If our next steps work in animal disease models, we believe that clinical testing could happen fairly quickly.”

Scientists have long been aware of Müller cells (which exist in great abundance in the eye) and have generally assumed that they were responsible for keeping retinal tissue protected and clear of debris. In recent years, however, researchers have reported that these cells sometimes exhibit progenitor cell behavior and re-enter the cell cycle (dividing and differentiating into other type of cells).  Progenitor cells are similar to stem cells but are more mature and are more limited in the number of cells types they can become.

But until this study, scientists have not understood what triggers the transformation. In their study, Chen and her team observed that when the naturally occurring chemicals known as glutamate and aminoadipate (which is a derivative of glutamate) were injected into the eye, the Müller cells began to divide and proliferate. Not certain if these chemicals directly signaled the transformation, they tested them in the laboratory and in mice.

They added each chemical separately to cultures of pure Müller cells and injected each into the space below the retina in healthy mice. In both cases, the cells became progenitor cells and then changed into retinal cells. And with aminoadipate, the newly minted retinal cells migrated to where they might be needed in the retina and turned into desirable cell types. Specifically, they showed that by injecting the chemical below the retina, the cells give rise to new photoreceptors – the type of cells that are lost in retinitis pigmentosa or macular degeneration, as a result, leading to blindness.

The team’s next step will be to test this process in animals that have been bred to have diseases that mimic macular degeneration and retinitis pigmentosa. The goal would be to learn if damaged retinas regenerate and vision improves. The team will likely use just aminoadipate because it only binds with Müller cells without the side effects of glutamate, which can actually harm retina cells in large doses.

“We believe that a drug created from the chemical aminoadipate or a similar compound has great potential for healing damaged retinas,” says Chen.

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Other authors of the study include:

Masumi Takeda 1,2,3 Akira Takamiya 1,2,3 Jian-wei Jiao 1,2 Kin-Sang Cho 1,2 Simon G. Trevino 1 Takahiko Matsuda 4  Dong F. Chen 1,2

1 The Schepens Eye Research Institute, Boston, Massachusetts 2 Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts  3 Department of Ophthalmology, Asahikawa Medical College,  Asahikawa, Japan 4 Department of Genetics, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts.

Schepens Eye Research Institute is an affiliate of Harvard Medical School and the largest independent eye research institute in the nation.

Repost 2008

Scientists create a virus that reproduces

By Elizabeth Weise, USA TODAY
It is the stuff of science fiction and bioethical debates: The creation of artificial life. Up until now, it’s largely been just that.

But an important technical bridge towards the creation of such life was crossed Thursday when genomics pioneer Craig Venter announced that his research group created an artificial virus based on a real one in just two weeks’ time.

When researchers created a synthetic genome (genetic map) of the virus and implanted it into a cell, the virus became “biologically active,” meaning it went to work reproducing itself.

Venter cautioned that the creation of artificial human or animal life is a long way off because the synthetic bacteriophage — the virus that was created — is a much simpler life form. Bacteriophages are viruses that infect bacteria.

The project was funded in part by the Department of Energy, which hopes to create microbes that would capture carbon dioxide in the atmosphere, produce hydrogen or clean the environment.

But the questions ethicists have raised about such work are numerous: Should we be playing God? Does the potential for good that new life forms may have outweigh the harm they could do?

Arthur Caplan, who heads the University of Pennsylvania’s Center for Bioethics, says yes. This technology “is impressive. It’s powerful and it should be treated with humility and caution,” Caplan says, “But we should do it.”

A genome is made up of DNA “letters,” or base pairs, that combine to “spell” an individual’s chromosomes. The human genome project was completed in April.

This summer, researchers at Venter’s Institute for Biological Energy Alternatives bought commercially available strands of DNA and, using a new technology, coaxed them together to form a duplicate of the genome of a bacteriophage called phi X.

“It’s a very important technical advance,” says Gerald Rubin, a molecular geneticist at the Howard Hughes Medical Institute. “You can envision the day when one could sit down at a computer, design a genome and then build it. We’re still inventing the tools to make that happen, and this is an important one.”

Venter notes the synthetic bacteriophage has 5,000 base pairs in its genome. The human genome has 3 billion, so similar work in human form probably won’t happen in this decade, he says.

To date, the largest genome that was synthesized was the 7,500-base-pair polio virus. But that was only semi-functional and took three years to complete.

The researchers chose to put the new technology into the public domain for all scientists to use. It will appear in the next few weeks on the Web site of the Proceedings of the National Academy of Sciences.

The technology raises safety issues, says David Magnus of Stanford’s Center for Biomedical Ethics. Even putting it in the public domain is “a double-edged sword,” he says. That presumes that allowing everyone access will keep the good guys ahead of the bad guys. “It’s a gamble. … It’s a bet that everyone has a stake in,” he says.

http://www.usatoday.com/news/science/2003-11-13-new-life-usat_x.htm

*Reposted for filing

Poxviruses defeat antiviral defenses by duplicating a gene – Engineered an E3L-deficient strain that was quickly able to increase infectious virus production by selectively increasing the number of copies of the K3L gene in its genome

Contact: Phil Sahm phil.sahm@hsc.utah.edu 801-581-2517 University of Utah Health Sciences

Study helps explain how large DNA viruses undergo rapid evolution

SALT LAKE CITY – Scientists have discovered that poxviruses, which are responsible for smallpox and other diseases, can adapt to defeat different host antiviral defenses by quickly and temporarily producing multiple copies of a gene that helps the viruses to counter host immunity. This discovery provides new insight into the ability of large double-stranded DNA viruses to undergo rapid evolution despite their low mutation rates, according to a study published by University of Utah researchers in the Aug. 17, 2012, issue of Cell.

Poxviruses are a group of DNA-containing viruses that are responsible for a wide range of diseases in both humans and animals, including smallpox. Unlike smaller RNA-containing viruses, such as those that cause influenza and HIV, which are able to evade host immune responses through rapid mutation, poxviruses have larger genomes and low mutation rates and little is known about their adaptive strategies against host defenses.

“Poxviruses encode a variety of genes that help them to counter host immune defenses and promote infection,” says Nels Elde, Ph.D., assistant professor of human genetics at the University of Utah School of Medicine and first author on the study. “Despite ample evidence that the poxvirus genome can undergo adaptive changes to overcome evolving host defenses, we still don’t know that much about the mechanisms involved in that adaptation.”

To determine mechanisms of adaptation, Elde and his colleagues studied the vaccinia virus, a type of poxvirus best known for its role as the vaccine used to eradicate smallpox.  Previous research has shown that vaccinia virus encodes two genes, known as K3L and E3L, which inhibit host defenses that normally block viral infection. In this study, Elde and his colleagues started with a strain of vaccinia virus that had been altered to delete the E3L gene and repeatedly propagated this E3L-deficient strain in human cells to see how well the virus would replicate. They found that this E3L-deficient strain was quickly able to increase infectious virus production by selectively increasing the number of copies of the K3L gene in its genome.

“This highly specific and rapid gene amplification was unexpected,” says Elde. “Our studies show that increasing K3L copy number leads to increased expression of K3L and enhanced viral replication, providing an immediate evolutionary advantage for those viruses that can quickly expand their genome.”

Elde and his colleagues also found that, in addition to K3L copy number amplification, some of the E3L-deficient vaccinia strains also acquired a mutation consisting of a single amino acid substitution in the K3L gene. Both the mutation-bearing and multicopy K3L viruses displayed improved viral fitness, or ability to replicate in the host environment, compared to wild-type vaccinia virus. The emergence of this beneficial amino acid substitution suggests that increasing K3L copy number facilitated the appearance of the variant by providing additional mutational targets, despite the virus’ otherwise low mutation rate.

“We were able to demonstrate at least two strategies by which poxviruses are able to adapt diverse mechanisms of host immunity,” says Elde. “Our observations reveal that, while poxviruses do undergo gene mutation, their first response to a new, hostile host environment can be rapid gene expansion. We also found evidence that the virus genome can contract after acquiring an adaptive mutation, thus alleviating the potential trade-off of having a larger genome, while leaving a beneficial mutation in place.”

Although smallpox was officially eradicated by the World Health Organization in 1980, concerns about the use of smallpox as a bioterrorism agent have spurred renewed interest in the study of vaccinia and other poxviruses. In addition, poxvirus infections, such as monkeypox, can be transmitted from animals to humans and the adaptive strategies of poxviruses may be relevant for other infectious organisms.

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The collaborative team of researchers involved in this study included scientists from the University of Utah, the Fred Hutchinson Cancer Research Center, the University of Washington, and the Howard Hughes Medical Institute

Environmental Risk Factors for Crohn’s Disease: Maltodextrin (MDX), a Ubiquitous Dietary Additive in Western Diets, Enhances Biofilm Formation and Adhesivness of E. coli (Abstract #Tu1844

Environmental Risk Factors for Crohn’s Disease: Maltodextrin (MDX), a Ubiquitous Dietary Additive in Western Diets, Enhances Biofilm Formation and Adhesivness of E. coli (Abstract #Tu1844)

Western diets that include significant amounts of the additive maltodextrin, a filler compound added to the sweeteners Splenda and Equal, may contribute to an increased susceptibility to Crohn’s disease, according to new research from the Cleveland Clinic Lerner Research Institute, OH. There is a clear link between bacteria and inflammatory bowel disease (IBD), with previous studies reporting differences in the types of bacteria and location of bacteria in the intestines of individuals with Crohn’s disease.

Investigators led by Christine McDonald, PhD, assistant staff, pathobiology department, Lerner Research Institute, looked at how bacteria were altered by components of the Western diet to better understand how diet affects bacteria associated with IBD, an area of research not well understood. They reviewed how certain components of this diet alter E. coli bacteria to increase their ability to form biofilms and adhere to intestinal epithelial cells  — features associated with the disease.

The investigators grew E. coli bacteria isolated from a Crohn’s disease patient in the lab with different substances found in a Western diet and tested their ability to form biofilm structures similar to those found in the gut of Crohn’s disease patients. Initially, they compared bacteria that were fed glucose (the simplest form of sugar) to bacteria that were fed artificial sweeteners. Surprisingly, Dr. McDonald’s group found that the sweeteners alone didn’t have an effect, but maltodextrin dramatically changed the bacteria.

When the researchers looked at how well the bacteria adhered to plastic or live intestinal cells, they found that bacteria grown in maltodextrin were stickier, resulting in thicker biofilms, and a greater number of bacteria piled up on the surface of intestinal cells. This finding is significant since maltodextrin is in a wide variety of products ranging from sweeteners and processed foods to medications and other products. Dr. McDonald cautioned that it is too early to conclude that maltodextrin promotes disease, though their results suggest that maltodextrin can cause E. coli to gain features associated with disease and therefore, potentially, increases an individual’s overall risk of developing IBD. Studies are planned to test this more directly in experimental mouse models of IBD. “While dietary additives like maltodextrin are generally considered safe, these findings suggest that perhaps people who are prone to develop IBD should consider limiting their maltodextrin intake,” Dr. McDonald said.

Previous research suggests that consumption of a Western diet — one that is high in fat, low in fiber and rich in processed foods — is associated with the development of Crohn’s disease. Other studies have observed striking differences between the bacteria found in healthy intestines and those affected by Crohn’s disease. In a healthy gut, the normal bacterial community is separated from direct contact with the intestinal cells, while in Crohn’s disease patients, gut bacteria form a dense structure (a biofilm) in close contact with the cells. Additionally, some studies have shown an increase in the amounts of E. coli and demonstrated that Crohn’s disease-associated E. coli has special features, making the strain more adhesive and invasive.

This study received no pharmaceutical funding. It was supported by the National Institutes of Health (R01DK082437) and the Howard Hughes Medical Institute “Med into Grad” Initiative.

Dr. McDonald will present these data on Tuesday, May 22 at noon PT in Halls C-G of the San Diego Convention Center.