Category Archives: Ontario Genometrics

Chili Pepper Compound Can Bring Pain Relief

From the FMS News Desk of Jeanne Hambleton

COURTESY usnews.com Health Day – Monday March 16

Capsaicin works on nerves to ease joint discomfort, scientists say

(HealthDay News) – University of Buffalo scientists say they have found how capsaicin, the compound that gives chili peppers their fiery flavor, also works to relieve joint and muscle pain.

In a study appearing Tuesday in the journal PLoS Biology, researchers found that capsaicin flips on nerve-ending receptors that sense both pain and heat.

“The receptor acts like a gate to the neurons. When stimulated it opens, letting outside calcium enter the cells until the receptor shuts down, a process called desensitization,” study leader Feng Qin, an associate professor at the university’s School of Medicine and Biomedical Sciences, said in a news release issued by the institution.
The flood of calcium changes the levels at which the receptors detect pain signal. “In other words, the receptor had not desensitized per se, but its responsiveness range was shifted,” Qin said.

While capsaicin has been used in folk medicines for generations, knowing how it works in relation to PIP2 may lead to developing other analgesics that ease pain without first causing irritation on their own, the team said.

More information

The U.S. National Institute of Neurological Disorders and Stroke has more about capsaicin .
(http://health.usnews.com/articles/health/healthday/2009/02/25/chili-pepper-compound-can-bring-pain-relief.html)

Finding Effective Treatment for Your Chronic Pain

Studies are underway to look into the effectiveness of alternative ways of delivering pain medications

By January W. Payne

Chronic pain is a problem that—when healthcare, lost income, and lost productivity are taken into account—is estimated to cost about $100 billion in the United States each year. More than a quarter of Americans age 20 or older, or about 76.5 million people, say they’ve experienced pain that lasted longer than 24 hours, according to the American Pain Foundation—and 42 percent have endured pain lasting longer than a year. Nobody keeps good long-term national stats, but if North Carolina’s experience is any guide, the numbers are on the rise.

A just-published study in the Archives of Internal Medicine found that the prevalence of chronic low-back pain in the state more than doubled, to 10.2 percent, between 1992 and 2006. Paul J. Christo, assistant professor and director of the Multidisciplinary Pain Fellowship at the Johns Hopkins University School of Medicine, calls undiagnosed, untreated, or undertreated pain a “significant public-health problem.”

Chronic pain encompasses a multitude of ills, from back pain, headaches, neck pain, and conditions like arthritis and fibromyalgia to pain that develops as a result of cancer treatment and lingers for months or even years. Low-back pain, migraines, and joint pain (particularly in the knees) are among the most common complaints, according to the National Center for Health Statistics. knee pains,

Still, while it may have different origins, chronic pain “can be viewed as an illness in its own right because of its effect on function,” says Russell Portenoy, chairman of the department of pain medicine and palliative care at Beth Israel Medical Center in New York City.

Studies have shown that some people with chronic pain have brain abnormalities, though the connection between that and pain is not well understood. One recent study, for instance, showed that women with fibromyalgia had blood flow abnormalities in a region of the brain known to discriminate the intensity of pain that were not observed on CT scans done in healthy women.

Another study showed that chronic pain may harm the wiring of the brain, as demonstrated on functional MRIs. Chronic pain may also be caused by a problem with the “fight or flight” response, Christo says. “We believe that in certain pain conditions . . . the stress response can worsen pain because that stress response releases a chemical called noroepinephrine. . . . And noroepinephrine binds to certain receptors in the body that trigger pain.”

“Pain is essentially an alarm system that is designed to grab your attention, and when it works properly, it signals harm or healing,” says Scott Fishman, professor and chief of the division of pain medicine at the University of California-Davis School of Medicine. When the body heals, the pain should dissipate, but “the nervous system can become injured,” Fishman says. “That’s when the symptom of pain becomes the disease of chronic pain.”

Finding relief can take quite an effort, since the causes are often not immediately clear and there is not a sure-fire treatment. The battle can require a team of experts, so the multidisciplinary pain clinics or pain management programs that have sprouted up at hospitals, rehab centers, and in free-standing facilities over the past decade or so may be of particular help.

The clinics provide an all-in-one setting for care that, in addition to pain management specialists who may be trained as neurologists, psychiatrists, physiatrists, or anesthesiologists, may include physical therapists, family and vocational counselors, and massage therapists, for example. (The American Chronic Pain Association offers advice on selecting a pain clinic.)

After a full assessment, tailored treatment may include medications from anti-inflammatory drugs to antidepressants to opioids. Since commonly prescribed opioid medications such as oxycodone, fentanyl, and morphine can cause addiction, the American Pain Society and the American Academy of Pain Medicine have just released the first comprehensive clinical practice guidelines to help physicians make treatment decisions.

The guidelines, published in the Journal of Pain, suggest that physicians regularly assess people taking long-term opioids and do periodic drug screenings of patients who are considered to be at risk for abuse or addiction. Meanwhile, the Food and Drug Administration announced plans this month to require the brand-name and generic makers of morphine, oxycodone, fentanyl, and methadone to assist with a plan to reduce the risks associated with the drugs.

Other treatment options include injections of steroids or other medications, nerve blocks that interrupt pain signals, physical therapy, alternative therapies, and psychological interventions such as cognitive behavioral therapy, biofeedback, and guided imagery and other relaxation techniques. Acupuncture, which some people with pain find helpful, is thought to ease pain by raising the level of endorphins in the body, Christo says. “Endorphins are sort of like opioids. . . . They are natural pain relievers,” he says.

“They are released when the body experiences pain—when you sprain your ankle, cut your finger, in response to injury.” Still, research offers conflicting conclusions about the pain-relieving effects of acupuncture. A review of 13 studies published last month in British Medical Journal found that acupuncture offered only a small level of pain relief for people with low-back pain, migraines, knee osteoarthritis, and postoperative pain.

Jennifer Phillips, 41, of Providence Forge, Va., saw 54 doctors before the fibromyalgia that caused her pain was diagnosed in 1996. Finally, after seeing an internist whose nurse had fibromyalgia, she found a routine that works for her: a combination of proper sleep (achieved, in part, using the tricylic antidepressant amitriptyline), daily supplements of vitamins, magnesium, and potassium, plenty of water, and a low-carb diet.

The search is on for greater relief. Studies are underway to look into the safety and effectiveness of alternative ways of delivering pain medications, such as an inhaled form of fentanyl that would get the drug into the patient’s system more quickly. For older people who have fractures of the spine, vertebroplasty and kyphotlasty—two minimally invasive techniques in which bone cement is injected into the collapsed bone in the spine—can result in “significant pain reduction,”

Christo says. In the ongoing debate over how best to handle back pain, a study just published in the Journal of the American Academy of Orthopaedic Surgeons finds that the most effective way to treat most degenerative disc disease cases is to combine physical therapy and anti-inflammatory medications, rather than having surgery.
While it may seem counterintuitive, people with chronic pain should try to get exercise. Experts say it is important to keep moving, both for the usual cardiovascular reasons and in order to avoid muscle atrophy. A supervised, individually designed exercise program, incorporating stretching or strengthening, may improve pain and functioning in people with chronic low-back pain, according to a 2005 study published in Annals of Internal Medicine.

A physical therapist or personal trainer can offer the necessary advice. In fact, staying in bed for more than a day or two can make back pain worse, according to the National Library of Medicine’s MedlinePlus.

Jeff Nance of Indianapolis, whose chronic pain is caused by degenerative disc disease and spinal stenosis of his lower back, recalls that he barely wanted to leave his home three years ago. Then he discovered the Meridian Health Group pain clinic in Indianapolis. Now he is working full time again, and he recently participated in an annual bike ride across the state of Indiana. Nance goes back to the clinic every few months for a check of his medications, and he sees a psychologist a couple of times a month.

“What we try to do is really recognize that people can have pain for all kinds of reasons, [and we] find as many of those causes as possible and treat them in the most specific fashion as possible,” says Michael Clark, associate professor and director of the Chronic Pain Treatment Program in the Department of Psychiatry and Behavioral Sciences at Johns Hopkins Hospital. “Ultimately, you’d like to get somebody well.”

(http://health.usnews.com/articles/health/pain/2009/02/10//finding-effective-treatment-for-your-chronic-pain.html?loomia_ow=t0:a41:g2:r2:c0.160667:b22273524&s_cid=loomia:chili-pepper-compound)

Copyright © 2009 U.S.News & World Report LP All rights reserved.

Mouse genome will help identify causes of environmental disease

Research on the DNA of 15 mouse strains commonly used in biomedical studies is expected to help scientists determine the genes related to susceptibility to environmental disease. The body of data is now publicly available in a catalog of genetic variants, which displays the data as a mouse haplotype map, a tool that separates chromosomes in to many small segments, helping researchers find genes and genetic variations in mice that may affect health and disease. The haplotype map appearing online in the July 29th issue of Nature is the first published full descriptive analysis of the “Mouse Genome Resequencing and SNP Discovery Project” conducted by the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health.

“These data allow researchers to compare the genetic makeup of one mouse strain to another, and perform the necessary genetic analyses to determine why some individuals might be more susceptible to disease than another. This puts us one step closer to understanding individual susceptibility to environmental toxins in humans. We also hope that pharmaceutical companies developing new treatments for environmental diseases will find these data and this paper as a valuable resource,” said David A. Schwartz. M.D., NIEHS Director.

The paper describes in detail the laborious and technology-driven approaches that were used to identify 8.27 million high quality SNPs distributed among the genomes of 15 mouse strains. Single Nucleotide Polymorphisms, or SNPs (known as snips), are single genetic changes, or variations, that can occur in a DNA sequence.

Much of the project was conducted through a contract between the National Toxicology Program at NIEHS and Perlegen Sciences, Inc. of Mountain View Calif.

“The database of mouse genetic variation should facilitate a wide range of important biological studies, and helps demonstrate the utility of this array technology approach,” said David R. Cox, M.D., Ph.D., chief scientific officer at Perlegen Sciences, Inc.

The Perlegen scientists used C57BL/6J the first mouse strain to undergo DNA sequencing as their standard reference to conduct the re-sequencing on the four wild-derived and eleven classical mouse strains. The technology used, the oligonucleotide array, was also used to discover common DNA variation in the human genome.

The arrays looked at about 1.49 billion bases (58 percent) of the 2.57 billion base pair of their standard reference strain. The data were then used to develop the haplotype map which contains 40,898 segments.

“The data will be a valuable resource to many, including the National Toxicology Program,” Schwartz says. The National Toxicology Program (NTP) is an interagency program, headquartered at NIEHS, with the mission to coordinate, conduct and communicate toxicological research across the U.S. government.

“The NTP is looking forward to exploring the responses of these strains of mice to various environmental agents,” said John Bucher, Ph.D., the new associate director of the NTP.

Frank M. Johnson, Ph. D., an NTP research geneticist and one of the authors of the Nature paper, adds that systematically characterizing even more mouse strains for susceptibility to toxins will not only help with genetic analysis, but better position researchers to do intervention studies.

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The data are publicly available on the National Center for Biotechnology Information Web site at http://www.ncbi.nlm.nih.gov/SNP/ and at a Web site developed by Perlegen at http://mouse.perlegen.com which allows researchers to download SNPs, genotypes, and LR-PCR primer pairs, which are currently mapped to NCBI Build 36.

In addition to the NTP and Perlegen Sciences scientists, other key collaborators on the project include researchers from the Department of Computer Science and Department of Human Genetics, University of California, Los Angeles; the Department of Computer Science and Engineering, University of California, San Diego; The Jackson Laboratory, Bar Harbor, Maine; Broad Institute of Harvard and MIT; and the Center for Human Genetic Research, Massachusetts General Hospital.

Reference: Kelly A. Frazer, Eleazar Eskin, Hyun Min Kang, Molly A. Bogue, David A. Hinds, Erica J. Beilharz, Robert V. Gupta, Julie Montgomery, Matt M. Morenzoni, Geoffrey B. Nilsen, Charit L. Pethiyagoda, Laura L. Stuve, Frank M. Johnson, Mark J. Daly, Claire M. Wade, David R. Cox. A sequence-based variation map of 8.27 million SNPs in inbred mouse strains. Nature, 2007

The National Institute of Environmental Health Sciences (NIEHS), a component of the National Institutes of Health, supports research to understand the effects of the environment on human health. For more information on environmental health topics, please visit our website at http://www.niehs.nih.gov/.

The National Institutes of Health (NIH) — The Nation’s Medical Research Agency — includes 27 Institutes and Centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical, and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

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Source

Genetics of chronic pain states.

Buskila D.

Department of Medicine H, Soroka Medical Center and Faculty of Health Sciences, Ben Gurion University, Beer Sheva, P.O.B 151, Israel 84101.

Chronic pain states are common in the general population. Genetic factors can explain a significant amount of the variability in the perception of pain. Fibromyalgia syndrome (FMS) and related conditions are syndromes characterized by generalized pain sensitivity as well as a constellation of other symptoms. Family studies show a strong familial aggregation of FMS and related conditions, suggesting the importance of genetic factors in the development of these conditions. Recent evidence suggests a role for polymorphisms of genes in the serotoninergic, dopaminergic and catecholaminergic systems in the pathogenesis of FMS and related conditions. Environmental factors may trigger the development of these disorders in genetically predisposed individuals. Future large well-designed studies are needed to further clarify the role of genetic factors in FMS and related conditions. The knowledge of these gene polymorphisms may help with better subgrouping of FMS patients and in designing a more specific pharmacologic treatment approach.

PMID: 17602998 [PubMed - in process]

1: Best Pract Res Clin Rheumatol. 2007 Jun;21(3):535-47.

Genetics of chronic pain states.
Best Practice & Research Clinical Rheumatology, Volume 21, Issue 3, Pages 535-547
D. Buskila

Reference

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Cataloging the Structural Variations in Human Genetics

Contact: Jim Keeley
keeleyj@hhmi.org
301-215-8858
Howard Hughes Medical Institute

May 10, 2007

A major new effort to uncover the medium- and large-scale genetic differences between humans may soon reveal DNA sequences that contribute to a wide range of diseases, according to a paper by Howard Hughes Medical Institute investigator Evan Eichler and 17 colleagues published in the May 10, 2007, Nature. The undertaking will help researchers identify structural variations in DNA sequences, which Eichler says amount to as much as five to ten percent of the human genome.

Past studies of human genetic differences usually have focused on the individual “letters” or bases of a DNA sequence. But the genetic differences between humans amount to more than simple spelling errors. “Structural changes — insertions, duplications, deletions, and inversions of DNA — are extremely common in the human population,” says Eichler. “In fact, more bases are involved in structural changes in the genome than are involved in single-base-pair changes.”

“It’s a lot of work, because it’s essentially doing 62 additional human genome projects.”
Evan E. Eichler

In some cases, individual genes appear in multiple copies because of duplications of DNA segments. In other cases, segments of DNA appear in some people but not others, which means that the “reference” human genome produced by the Human Genome Project is incomplete. “We’re finding new sequence in the human genome that is not in the reference sequence,” Eichler says.

These structural changes can influence both disease susceptibility and the normal functioning and appearance of the body. Color-blindness, increased risk of prostate cancer, and susceptibility to some forms of cardiovascular disease result from deletions of particular genes or parts of genes. Extra copies of a gene known as CC3L1 reduce a person’s susceptibility to HIV infection and progression to AIDS. Lower than normal quantities of other genes can lead to intestinal or kidney diseases.

Variation in the number of genes or in gene regulation caused by structural rearrangements may also contribute to more common diseases. “The million dollar question is what is the genetic basis of diseases like diabetes, hypertension, and high cholesterol levels?” says Eichler. “ We know there is a genetic factor, but what is the role of single base pair changes versus structural changes?”

The project Eichler and his colleagues describe in their paper will help answer this question. Using DNA from 62 people who were studied as part of the International HapMap Project, they are creating bacterial “libraries” of DNA segments for each person. The ends of the segments are then sequenced to uncover evidence of structural variation. Whenever such evidence is found, the entire DNA segment is sequenced to catalog all of the genetic differences between the segment and the reference sequence.

The result, says Eichler, will be a tool that geneticists can use to associate structural variation with particular diseases. “It might be that if I have an extra copy of gene A, my threshold for disease X may be higher or lower.” Geneticists will then be able to test, or genotype, large numbers of individuals who have a particular disease to look for structural variants that they have in common. If a given variant is contributing to a disease, it will occur at a higher frequency in people with the disease.

Knowing about structural variation in the human genome will also allow geneticists to analyze single-base-pair changes more effectively, according to Aravinda Chakravarti, a geneticist at The Johns Hopkins University School of Medicine who was not a coauthor of the paper. “We have to look at structural variants from a different perspective, because they are adding or subtracting something from the genome,” Chakravarti says. By understanding the patterns of both structural variants and single-base-pair changes in the population, “we’ll learn a lot.” To use both kinds of information in tandem, Eichler and his colleagues plan to incorporate the structural information they gather into existing databases on single-base-pair changes.

The project, which is being funded by the National Human Genome Research Institute at the National Institutes of Health, is difficult and expensive, Eichler admits. “It’s a lot of work, because it’s essentially doing 62 additional human genome projects,” he says. “Having been involved in the first one, I swore I would never do it again. But in this case we’re looking at the coolest parts of the genome.”

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University of Pittsburgh discovers genetic ‘shut down’ trigger in healthy immune cells

Contact: Michele Baum
baummd@upmc.edu
412-647-3555
University of Pittsburgh Schools of the Health Sciences

Discovery could have significant implications for targeting cancer, infection treatments
PITTSBURGH, May 9 — A fundamental genetic mechanism that shuts down an important gene in healthy immune system cells has been discovered that could one day lead to new therapies against infections, leukemia and other cancers. Results of a University of Pittsburgh School of Medicine study on the mechanism, called a somatic stop-codon mutation, are being reported today in the online journal PLoS ONE, published by the Public Library of Science.

“This kind of loss-of-function mutation can be very dangerous, and it is the first such mutation that has been identified in normal immune cells in blood,” said Bora E. Baysal, M.D., Ph.D., assistant professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh School of Medicine. “We did control experiments for two years to make sure it was real and not a technical error.”

Dr. Baysal and his colleagues tested 180 samples, including blood from healthy individuals and other material from those with childhood leukemia, looking at specific portions of DNA in immune cells known as monocytes, natural killer cells and lymphocytes. These cells are key to the body’s immune response against infection and disease. The investigators found somatic stop-codon mutations in an average of 5.8 percent of crucial portions of genetic material that deliver instructions from DNA, called messenger RNA, in normal blood samples and in a quarter of leukemia samples.

“DNA is the blueprint for all living cells. It carries the genetic code for most biological functions and is passed virtually unchanged from generation to generation,” said Dr. Baysal, who also is an associate investigator at the university-affiliated Magee-Womens Research Institute. “Harmful alterations in the code – mutations – can produce genetic disorders and play an important role in the development of cancer. Normal cells such as monocytes, lymphocytes and natural killer cells have many mechanisms to recognize and repair mutations, but a stop-codon mutation is a kind of permanent “off” switch that has escaped DNA repair,” he added.

“We believe there is a good biological reason for this. It may allow the cells to survive in a low-oxygen environment, such as where there is cancer or infection,” said Dr. Baysal. “It is part of the process for immune cells to ‘armor up’ for battle against cancer cells and other diseases.”

Earlier research on the mutated gene suggests the stop-codon mutation might be part of the programmed adaptive response to oxygen deprivation. This mutation and its location is “unusual because it predicts loss-of-function, it targets a classical tumor-suppressor gene, and it occurs in (peripheral blood mononuclear cells),” Dr. Baysal wrote, adding that the mutation is present at much higher levels in messenger RNA compared to DNA.

“This may give us a tool to modify the immune cells’ survival in a low oxygen environment, which could help the cells to survive and fight infections and tumors,” said Dr. Baysal, calling the mutated gene a potential “therapeutic target.”

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CONTACT: Jim Swyers, SwyersJP@upmc.edu
PHONE: (412) 647-3555
FAX: (412) 624-3184

The study was funded by the National Cancer Institute.

For copies of the paper, visit http://www.plosone.org/home.action.

http://www.upmc.com/communications/newsbureau

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Scientists encourage cells to make a meal of Huntington’s disease

Contact: Craig Brierley
c.brierley@wellcome.ac.uk
44-207-611-7329
Wellcome Trust

Scientists have developed a novel strategy for tackling neurodegenerative diseases such as Huntington’s disease: encouraging an individual’s own cells to “eat” the malformed proteins that lead to the disease.

Huntington’s disease is one of a number of degenerative diseases marked by clumps of malformed protein in brain cells. Symptoms include abnormal movements, psychiatric disturbances like depression and a form of dementia. The gene responsible for the disease was discovered in 1993, leading to a better understanding of the condition and to improved predictive genetic testing, but it has yet to lead to any treatments that slow the neurodegeneration in Huntington’s patients.

Professor David Rubinsztein, a Wellcome Trust Senior Clinical Fellow at the University of Cambridge, has been studying the molecular biology underlying Huntington’s and other neurodegenerative diseases. Huntington’s occurs when a protein known as huntingtin builds up in the brain cells of patients, mainly in neurons in the basal ganglia and in the cerebral cortex. Normally, cells dispose of or recycle their waste material, including unwanted or mis-folded proteins, through a process known as autophagy, or “self-eating”.

“We have shown that stimulating autophagy in the cells – in other words, encouraging the cells to eat the malformed huntingtin proteins – can be an effective way of preventing them from building up,” says Professor Rubinsztein. “This appears to stall the onset of Huntington’s-like symptoms in fruit fly and mice, and we hope it will do the same in humans.”

Autophagy can be induced in mouse and fly models by administering the drug rapamycin, an antibiotic used as an immunosuppressant for transplant patients. However, administered over the long term, the drug has some side effects and Rubinsztein and colleagues are aiming to find safer ways of inducing autophagy long term.

Now, Professor Rubinsztein, together with Professor Stuart Schreiber’s lab at the Broad Institute of Harvard/MIT, Boston in the US, and Dr Cahir O’Kane’s group in the Department of Genetics at the University of Cambridge have found a way of identifying novel “small molecules” capable of inducing autophagy. The research is published today in the journal Nature Chemical Biology.

The screening process involves identifying small molecules that enhance or suppress the ability of rapamycin to slow the growth of yeast, though the selected molecules have no effects on yeast growth by themselves. Yeast is a single-celled organism and therefore less complex to study for initial screening purposes.

Three of the molecules that enhanced the growth-suppressing effects of rapamycin in yeast were also found to induce autophagy by themselves in mammalian cells independent of the action of rapamycin. These molecules enhanced the ability of the cells to dispose of mutant huntingtin in cell and fruit fly models and protect against its toxic effects.

“These compounds appear to be promising candidates for drug development,” says Professor Rubinsztein. “However, even if one of the candidates does prove to be successful, it will be a number of years off becoming available as a treatment. In order for such drugs to be useful candidates in humans, we will need to be able to get them into right places in the right concentrations, and with minimal toxicity. These are some of the issues we need to look at now.”

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Scripps research team sheds light on long-sought cold sensation gene

Contact: Marisela Chevez
mchevez@scripps.edu
858-784-2171
Scripps Research Institute

Discovery could lead to new treatments to ease pain

The discovery, reported in the May 3 issue of the journal Neuron, might one day lead to the development of drugs that induce cold sensation as an analgesic, or block it to prevent certain forms of chronic pain associated with cold sensation.

“This study represents the first demonstration that a single gene is responsible for most cool temperature sensation,” says team leader Ardem Patapoutian, who has joint appointments with the Department of Cell Biology at Scripps Research and the Genomics Institute of the Novartis Research Foundation. “Many previous candidates have been postulated to play a role in our ability to sense cool temperatures, but none have withstood the test of genetics,” he says.

TRPM8 was first discovered by Patapoutian’s group and proposed as a key gene controlling cold sensation. To test the hypothesis, the group observed the behavior of mice genetically altered to lack the gene in response to cold stimuli.

When placed in compartments with a temperature gradient, or in an enclosure where they could choose between two temperatures, mice without TRPM8 showed essentially no preference in the temperature range of 18 to 31°C, suggesting their ability to sense this range was completely disabled without the gene. Normal mice, on the other hand, found cold temperature unpleasant, reliably avoiding cold temperatures in favor of warmer areas.

“It’s pretty amazing that one gene could impact thermal sensation this much,” says Ajay Dhaka, a Scripps Research postdoctoral fellow in the Patapoutian lab and lead author on the Neuron paper. “It really highlights the importance of the peripheral nervous system and how temperature affects our behavior,” he says.

The altered mice also showed little response to the application of acetone to their hindpaw, which causes an unpleasant cold sensation, while the acetone caused normal mice to flick their paw and lick them.

TRPM8 codes for an ion channel found at the tips of sensory neurons, which innervate the skin. When opened, ions flowing through TRPM8 lead to the activation of the sensory neuron, which in turn sends a signal to the brain. The Patapoutian team’s results support the idea that activation of TRPM8 by temperature triggers cold sensation. “TRPM8 acts as a gate,” says Dhaka, “At warm temperature it remains closed, but opens when exposed to cool temperature.”

The TRPM8-deficient mice did not lose their ability to feel pain in response to extreme cold, as evidenced by responses similar to wild type mice when exposed to -1° C cold plates. This suggests that other genes are responsible for this facet of cold sensation.

Though cold can be unpleasant or painful under certain circumstances, it can also deaden pain, as illustrated by icing an injury to relieve pain. To test this side of cold sensation, the researchers injected the mice with small amounts of a pain-causing chemical, formalin, and then exposed the affected paw area to a cold plate.

Cold temperature clearly reduced the acute pain felt by control mice as shown by a reduction in the response to formalin injection when compared to the amount of time control mice spent flicking and licking their paws when placed on a room temperature plate. In contrast, TRPM8-deficient mice did not receive any acute pain relief from the cold plate suggesting that cold activation of TRPM8 can mediate some of the analgesic effects of cold.

Just how the same sensation can be interpreted as unpleasant under certain circumstances and pleasant in others is still not clear, but is a question the group plans to investigate. “It would be really interesting to find out how the brain takes essentially the same signal and, depending on context, interprets it differently,” says Dhaka.

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Other authors on the paper, entitled “TRPM8 Is Required for Cold Sensation in Mice,” were Amber Murray and Taryn Earley, from Scripps Research, and Jayanti Mathur and Matt Petrus, from the Novartis Research Foundation.

About The Scripps Research Institute

The Scripps Research Institute is one of the world’s largest independent, non-profit biomedical research organizations, at the forefront of basic biomedical science that seeks to comprehend the most fundamental processes of life. Scripps Research is internationally recognized for its discoveries in immunology, molecular and cellular biology, chemistry, neurosciences, autoimmune, cardiovascular, and infectious diseases, and synthetic vaccine development. Established in its current configuration in 1961, it employs approximately 3,000 scientists, postdoctoral fellows, scientific and other technicians, doctoral degree graduate students, and administrative and technical support personnel. Scripps Research is headquartered in La Jolla, California. It also includes Scripps Florida, whose researchers focus on basic biomedical science, drug discovery, and technology development. Currently operating from temporary facilities in Jupiter, Scripps Florida will move to its permanent campus in 2009.

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‘Insulator’ helps silence genes in dormant herpes virus

Contact: Franklin Hoke
hoke@wistar.org
215-898-3716
The Wistar Institute

(Philadelphia – May 2, 2007) – By adulthood, most people have suffered at least one bout of painful cold sores brought on by the Herpes simplex virus 1, also known as HSV-1. After the initial infection, the virus usually remains in the body, hiding out in nearby nerve cells where the victim’s immune defenses cannot reach it, causing no symptoms at all.

In order to escape detection by the body’s immune system, the latent virus works to silence genes that would cause it to replicate. In this dormant state, only a tiny fragment of the virus genome – a single gene called the Latency-Associated Transcript gene (LAT) – remains active. Scientists have long puzzled over the mechanism used to keep this small region of the genome going while nearby genes remain quiescent.

Now, scientists at The Wistar Institute have discovered a molecular mechanism that keeps HSV-1 activation restricted to a single gene for months or even years. The researchers have identified an “insulator” – a stretch of DNA about 800 base pairs long – that serves as a physical barrier between active and inactive regions of the virus genome. Base pairs are the nucleotides on each side of the rungs that connect the strands of the DNA ladder.

“By establishing an insulator in early latency, the Herpes virus can protect this one small region of the genome from silencing, allowing infected cells to survive,” says study senior author Jumin Zhou, Ph.D., an associate professor at The Wistar Institute.

The findings, appearing in the May issue of the Journal of Virology, mark the first time an insulator has been identified in a virus and may lead to ways to develop strategies to manipulate the virus.

Insulators, also known as boundary elements, are DNA segments that work to prevent a gene from being influenced by the activation or repression of its neighbors. About a dozen different insulator elements have been identified in organisms as varied as yeast, fruit flies, and humans.

Not simply passive barriers, insulators help organize and regulate gene activity by marking boundaries on chromatin, the condensed genetic material that forms chromosomes. By establishing chromatin boundaries, insulators can limit the range of action of other DNA elements that work to activate, or “turn on,” the genes.

Recent studies on the LAT region of the HSV-1 genome have shown that nearby regions of the genome contain modifications indicative of silenced chromatin. The patterns found resemble well-studied regions where insulators are found in both yeast and chicken, namely the yeast mating loci and chicken globin locus.

To see if insulators play a role in silencing viral genes during the latent phase, Zhou and his group studied cells infected with HSV-1. The studies showed that during a latent period, the virus binds to a host protein called CTCF, a protein known to act as an insulator in mammals and in fruit flies. What’s more, the findings revealed that the viral DNA binds to CTCF in the same manner as the host DNA binds to the protein.

“By binding in this manner, we believed the CTCF protein was interacting with other viral proteins to form a type of insulator in the virus structure,” Zhou says.

To verify that it was an insulator at work, the researchers then inserted copies of the structure into fruit fly embryos to see if they could block the activity driven by gene-activating elements called “enhancers” during development.

“If the element we were testing was an insulator, then only one enhancer would be affected, and that’s exactly what we found,” Zhou says. Further studies showed that the insulator element blocked enhancer activities in the eye tissue of fruit flies and in human cells in culture.

“Based on these findings, we were able to identify this element as a kind of chromatin insulator that helps HSV-1 maintain a balance in its life cycle.”

The study also showed that HSV-1 chromatin is organized in a manner very similar to the host chromatin, a similarity that may work to the virus’s advantage, says Shelley L. Berger, Ph.D., the Hilary Koprowski Professor at The Wistar Institute and co-author on the study.

“This means that the virus can take advantage of the many regulatory schemes that the host has worked out for its own chromatin and not have to reinvent the wheel by making its own proteins and unique structures,” she says.

The researchers now plan to study the HSV-1 insulator in mice to see how the mechanism works to block the communication of gene-activating elements such as enhancers and promoters. The group is also working to identify any additional proteins that may play a role in establishing the insulator.

Knowing what genes the virus uses to hide and re-emerge could give pharmaceutical companies targets for designing drugs that disrupt those mechanisms. The studies also have implications for treating and manipulating other types of viruses, Zhou says.

“This study provides one of first examples of how viral chromatin is organized in a very similar way to host chromatin,” Zhou says. “Learning more about the similarities and differences in these chromatin structures may help finding ways to develop therapies that can target the virus and not the host.”

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In addition to senior author Zhou and co-author Berger, the additional coauthors on the study are Qi Chen, Lan Lin, Sheryl Smith, and Jing Huang, all at The Wistar Institute. The research was supported by grants from the National Institutes of Health and the Commonwealth Universal Research Enhancement Program of the Pennsylvania Department of Health.

The Wistar Institute is an international leader in biomedical research, with special expertise in cancer research and vaccine development. Founded in 1892 as the first independent nonprofit biomedical research institute in the country, Wistar has long held the prestigious Cancer Center designation from the National Cancer Institute. Discoveries at Wistar have led to the creation of the rubella vaccine that eradicated the disease in the U.S., rabies vaccines used worldwide, and a new rotavirus vaccine approved in 2006. Wistar scientists have also identified many cancer genes and developed monoclonal antibodies and other important research tools. Today, Wistar is home to eminent melanoma researchers and pioneering scientists working on experimental vaccines against influenza, HIV, and other diseases threatening global health. The Institute works actively to transfer its inventions to the commercial sector to ensure that research advances move from the laboratory to the clinic as quickly as possible. The Wistar Institute: Today’s Discoveries – Tomorrow’s Cures. On the web at http://www.wistar.org.

FMS Global News

Tenderpoints

Scientists find new agent to fight genetic disorders — Zorro-Locked Nucleic Acid

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

A study to appear in the June 2007 issue of The FASEB Journal describes a new agent, called “Zorro-LNA,” which has the potential to stop genetic disorders in their tracks. In the study, researchers from the Karolinska Institute in Stockholm, Sweden, describe how they developed Zorro-LNA to bind with both strands of a gene’s DNA simultaneously, effectively disabling that gene. This development has clinical implications for virtually every human condition caused by or worsened by dominant defective genes. Examples include: Huntington’s disease, familial high cholesterol, polycystic kidney disease, some instances of glaucoma and colorectal cancer, and neurofibromatosis, among others.

“Zorro-LNA is a new substance that targets DNA and turns off genes,” said co-author Edvard Smith of the Karolinska Institute in Sweden. “It has the potential of becoming a new drug for the treatment of human genetic disease.”

The findings described in this article significantly raise the possibility that new therapies could arise where defective DNA is deactivated more completely and more thoroughly than ever before. For instance, Zorro-LNA could be used in combination with “RNA interference” (RNAi). Like Zorro-LNA, RNAi has the ability to deactivate genes, but does so by degrading the gene’s RNA. In addition, Zorro-LNA could be used to deactivate certain genes in stem cells, which could eventually lead to the development of new cells, tissues, or organs. The discovery of RNAi was recognized by a Nobel Prize award in 2006 to two American scientists.

“This is a major development in the treatment not only of genetic diseases, but also of acquired diseases when microbes or toxins cause genes to go awry” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. “One might say these researchers have found a gene-hunter’s Holy Grail for which scientists have been hunting for many years. Zorro-LNA should give us a new, safe way of blocking the effects of errors in our genetic repertoire.”

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The Editor-in-Chief of The FASEB Journal will be available for interviews about this or other articles at a press reception at this year’s Experimental Biology meeting in Washington, D.C., on Tuesday, May 1, 2007, between 1:30–3:00 PM in the Experimental Biology press lounge. (Refreshments will be provided.) For more information about the meeting, visit http://www.eb2007.org.

A fact sheet on this article is available at The FASEB Journal’s press room. Visit http://www.fasebj.org and click “Press Room” in the left column.

The FASEB Journal is published by the Federation of American Societies for Experimental Biology (FASEB) and is consistently ranked among the top three biology journals worldwide by the Institute for Scientific Information.

FASEB comprises 21 nonprofit societies with more than 80,000 members, making it the largest coalition of biomedical research associations in the United States. FASEB advances biological science through collaborative advocacy for research policies that promote scientific progress and education and lead to improvements in human health.

FMS Global News

Tenderpoints

Information processing in the central nervous system: the signalling system controlling movement

Contact: Melanie Thomson
melanie.thomson@oxon.blackwellpublishing.com
44-018-654-76270
Blackwell Publishing Ltd.

Research by Renee Theiss, Jason Kuo and C J Heckman, which has just been published in The Journal of Physiology, throws light on how information is processed in the Central Nervous System (CNS) to drive movement. The findings are relevant to understanding mechanisms underlying movement and disorders such as spinal cord injury and motor neurone disease (ALS).

Interneurones in the spinal cord integrate command signals from the brain, with information from the senses, and their own internal pattern generating activities to send appropriate instructions to motorneurones controlling movement. Spinal interneurones exhibit a remarkable variety of firing patterns in response to a pulse of injected current, with important implications for information processing. These patterns range from repetitive to delayed, to bursting and to single spiking.

In the ventral spinal cord, interneurones process both motor commands and sensory inputs. Steady firing interneurones integrate these inputs, while bursting neurons may emphasize input variations and single spiking neurons probably serve as coincidence detectors. Although these different processing modes suggest a diversity in ion channels, Robert Lee (now at Emory University) and C J Heckman hypothesized that a small component of the total current mediated by sodium channels plays a critical role in determining firing patterns. This component is persistent instead of transient and is essential for action potential initiation during prolonged input.

The research by Theiss et al. on slices of spinal cord taken from rats indicates that reducing persistent sodium current in ventral interneurones converted both steady firing and bursting patterns into a single spike pattern, and thus its modulation may provide the CNS with the capacity to mediate dramatic changes in neural computations. This result is an important step forward in our understanding of neuronal processing and should lead to more research on how persistent sodium currents interact with other currents to generate the full array of firing patterns of neurons throughout the CNS.

Dr. Theiss noted that “Abnormal regulation of persistent sodium currents in disease states like spinal injury and ALS could seriously impair the integration of motor commands with sensory inputs, which is essential for normal movement patterns”.

FMS Global News

Tenderpoints

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