CAMBRIDGE, Mass.--Researchers at MIT and Harvard Medical School have identified a compound that interferes with the pathogenic effects of Huntington's disease, a discovery that could lead to development of a new treatment for the disease. There is no cure for Huntington's, a neurodegenerative disorder that now afflicts 30,000 Americans, with another 150,000 at risk. The fatal disease, which is genetically inherited, usually strikes in midlife and causes uncontrolled movements, loss of cognitive function and emotional disturbance. "There are now some drugs that can help with the symptoms, but we can't stop the course of the disease or its onset," said Ruth Bodner, lead author on a paper appearing online the week of Mar. 6 in the Proceedings of the National Academy of Sciences (PNAS). Bodner is a postdoctoral fellow in MIT's Center for Cancer Research. The compound developed by Bodner and others in the laboratories of MIT Professor of Biology David Housman, Harvard Medical School Assistant Professor Aleksey Kazantsev and Harvard Medical School Professor Bradley Hyman might lead to a drug that could help stop the deadly sequence of cellular events that Huntington's unleashes. "Depending on its target, any one compound will probably block only a subset of the pathogenic effects," Bodner said.

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Link ID: 8636 - Posted: 03.09.2006

Howard Florey Institute scientists in Melbourne have found that fluoxetine (commonly marketed as ProzacŪ) not only improves depression in Huntington's disease, but also improves learning and memory. Dr Anthony Hannan and his team also found that fluoxetine restores the brain's process of neurogenesis - the birth of new neurons - to normal levels, which helps delay the onset of the inherited fatal disease. People with Huntington's disease have progressive motor problems, cognitive deficits (dementia) and psychiatric symptoms (the most common is depression) that usually start to appear in mid-life. There is no cure and death usually results within 10 to 20 years of symptom onset, or faster in the childhood-onset form of the disease. The disease is caused by a mutation in a single gene and when this defective gene is passed from parent to child, 50 percent of the offspring will inherit the disorder, which can be detected by genetic testing. Dr Hannan said this discovery was an important step in developing effective treatments to delay the onset of symptoms and the progression of Huntington's disease. "Now that we've found fluoxetine improves memory problems, or dementia, as well as depression in mice with Huntington's disease, further research can be conducted to see if the drug has the same benefits in humans with the disease," Dr Hannan said.

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Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 12: Psychopathology: The Biology of Behavioral Disorders
Link ID: 8007 - Posted: 10.07.2005

CHAPEL HILL -- New research from the University of North Carolina at Chapel Hill School of Medicine points to the possible molecular origin of at least nine human diseases of nervous system degeneration. The findings are currently in PLoS Computational Biology, an open-access journal published by the Public Library of Science (PloS) in partnership with the International Society for Computational Biology. These neurodegenerative diseases, including Huntington's disease, share an abnormal deposit of proteins inside nerve cells. This deposition of protein results from a kind of genetic stutter within the cell's nucleus asking for multiple copies of the amino acid glutamine, a building block of protein structure. These disorders are collectively known as polyglutamine diseases. Along with Huntington's, these diseases include spinobulbar muscular atrophy; spinocerebellar ataxia types 1, 2, 3, 6, 7 and 17; and dentatorubral-pallidoluysian atrophy, or Haw River Syndrome. Haw River Syndrome is a genetic brain disorder first identified in 1998 in five generations of a family having ancestors born in Haw River, N.C. The disorder begins in adolescence (between ages 15 and 30 years) and is characterized by progressive and widespread damage to brain function, leading to loss of coordination, seizures, paranoid delusions, dementia and death within 15 to 20 years.

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Link ID: 7944 - Posted: 09.24.2005

Clioquinol, an antibiotic that was banned for internal use in the United States in 1971 but is still used in topical applications, appears to block the genetic action of Huntington's disease in mice and in cell culture, according to a study reported by San Francisco VA Medical Center (SFVAMC) researchers. The study, led by principal investigator Stephen M. Massa, MD, PhD, a neurologist at SFVAMC, was reported in the August 16, 2005 issue of Proceedings of the National Academy of Sciences. Huntington's disease is a hereditary, degenerative, and ultimately fatal disease of the brain that causes changes in personality, progressive loss of memory and cognitive ability, and a characteristic uncontrolled jerking motion known as Huntington's chorea. There is no known cure or effective treatment. A person who carries the mutant Huntington's gene may pass it on unknowingly because the disease often manifests in early to late middle age after the carrier's children have already been born. During the course of the disease, the Huntington's gene causes the production of a toxic protein, mutant huntingtin, in neurons (brain cells). Eventually the protein kills the neurons, causing the disease's degenerative effects. In Massa's study, Clioquinol appeared to interrupt the production of mutant huntingtin. In the first part of his study, Massa and his research team tested the effect of Clioquinol on neurons in cell culture that contained a form of the mutant Huntington's gene.

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Link ID: 7884 - Posted: 09.12.2005

Pig brain cells wrapped in a seaweed derivative could be implanted into human brains by next year to treat Huntington's disease, if approved. Researchers at New Zealand's Living Cell Technologies in Auckland have already had good results in monkeys. They told New Scientist they were seeking approval to do the same in humans in the US. The Food and Drugs Administration has already approved trials with animal tissue for Parkinson's disease. However, there is concern that using animal cells in humans could spread infections from animals to humans. Huntington's Disease is an inherited condition caused by a single faulty gene and affects one in 100,000 people. Although present from birth, symptoms normally appear when the person is between 30 and 50. Cells start to die in an area of the brain which helps control the movement of the body's muscles. Patients experience gradually worsening twitches, loss of muscle control, and memory loss and eventually die from the condition. In an attempt to minimise this damage in primates, the New Zealand team used pig brain cells taken from the lining of a brain structure known as the choroid plexus. These cells have a nurturing role, mopping up toxins and secreting a range of chemicals that are reduced in Huntington's and are essential for brain cell function. (C)BBC

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Link ID: 7770 - Posted: 08.11.2005

MADISON-Boosting levels of two critical proteins that normally shut down during Huntington's disease, researchers at the University of Wisconsin-Madison and the Cold Spring Harbor Laboratory have cured fruit flies of the genetic, neurodegenerative condition. Forms of the same proteins-known in short form as CREB and HSP-70--exist in all cells, including those of humans. The study results, published online today by the Proceedings of the National Academy of Sciences, were a "logical finding" because of a growing body of work in the area, says senior author Jerry Yin, a UW-Madison molecular geneticist. Scientists previously knew, for example, that hiking the activity of either CREB or HSP-70 lessened symptoms in mice or flies with Huntington's disease. Completely reversing a disease by targeting a combination of proteins or genetic pathways, however, reflects the growing need to embrace a broader treatment paradigm in the realm of genetic disorders, says Yin. In working with a disorder such as Fragile X Syndrome, for example, conventional therapies might focus all their efforts on repairing the genetic pathways that cause neurons to go awry. Meanwhile, "the defective gene is not just in one type of tissue," says Yin. "And we are not yet sensitive to detecting the defects in those other tissues."

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Link ID: 7632 - Posted: 07.12.2005

Researchers have discovered a key regulatory molecule whose overactivation by the abnormal protein produced in Huntington's disease (HD) causes the central pathologies of the disease. The abnormal HD protein activates the regulatory protein called p53, which in turn switches on a host of other genes. This abnormal gene activation damages the cells' power plants, called the mitochondria, and kills brain cells. The researchers also speculated that disturbances in p53 may also play a role in some forms of Parkinson's disease and amyotrophic lateral sclerosis, or Lou Gehrig's disease. Ironically, p53 is the same regulatory protein that is inactivated in a large fraction of cancers. This inactivation allows abnormal cancer cells to escape the cell's protective "suicide program" that would normally kill them. The researchers theorize that the lower incidence of cancer in HD patients could be caused by the protective effect of overactive p53. In the July 7, 2005, issue of Neuron, Akira Sawa and colleagues at Johns Hopkins University School of Medicine reported experiments ranging from molecular studies in cultured brain cells to analysis of the brains of human HD patients that demonstrated the central role of p53 in the pathologies of HD.

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Link ID: 7602 - Posted: 07.07.2005

The symptoms of Huntington's disease (HD)--severe loss of muscle control, emotional disturbance, and cognitive decline--are not just due to the toxic effects on brain cells of the mutant protein that causes the disorder, researchers, led by X. William Yang at Neuropsychiatric Institute of David Geffen School of Medicine at UCLA, have found. Their studies with genetically altered mice have revealed evidence for a new effect of the protein--triggering pathological interactions among brain cells. The researchers said their findings could not only shed new light on the underlying causes of HD pathologies, but also those of other similar "polyglutamine repeat" (polyQ) diseases, in which mutant genes produce proteins with abnormally long strings of the amino acid glutamine. They said their findings also suggest that abnormal cell-cell interactions could also play a role in Alzheimer's and Parkinson's diseases. In their studies, the researchers genetically engineered mice in which they could selectively trigger production of the mutant, toxic HD protein either throughout the brain or just in one restricted set of neurons. If only the toxic protein were required to produce the disease pathology, the "restricted-production" mice should show significant HD-type pathologies, reasoned the researchers. However, if abnormal interactions among cells throughout the brain were required for HD, these mice should show few or no pathologies compared to the engineered mice in which the mutant protein was produced in multiple neuron types throughout the brain.

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Link ID: 7303 - Posted: 05.05.2005

Scientists at Melbourne's Howard Florey Institute have uncovered a clue about the causes of dementia in Huntington's disease, one of the disease's symptoms, by showing that mice susceptible to Huntington's disease have problems with learning and memory before the diseases' typical movement problems appear. The Florey scientists also discovered that in Huntington's diseased brains, information processing between neurons is disrupted, but the neurons do not die, which means the brain may respond to new anti-dementia drugs that can restore memory. Huntington's disease is an incurable, inherited disorder of the nervous system that affects specific brain regions and inevitably leads to death. Symptoms range from disrupted control of movements and thought processes, and emotional problems. These include: jerky arm or leg movements; difficulties with speech, swallowing, concentration, memory and learning; and depression and personality changes. Huntington's disease is caused by a mutation in a single gene. When this defective gene is passed from parent to child, 50 percent of the offspring will inherit the disorder, which can be detected by genetic testing. Research leader Dr Anthony Hannan said his team's investigations were significant as they could lead to the development of memory restoring drugs designed especially for people with Huntington's disease.

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Link ID: 7267 - Posted: 04.28.2005

EVANSTON, Ill. --- Alzheimer's. Parkinson's. Lou Gehrig's. Huntington's. These neurodegenerative diseases exhibit loss of nerve function in different ways, from memory lapses to uncontrollable muscular movements, but it is now believed that these diseases share many common molecular mechanisms. A team of Northwestern University scientists, led by Richard I. Morimoto, John Evans Professor of Biology, has made a key discovery toward understanding one of these mechanisms. In studying toxic proteins involved in Huntington's disease, they discovered that the disease-causing protein severely interferes with the working of the proteasome, the cellular machine responsible for eliminating damaged proteins within the cell. The findings, which could lead to an understanding of how to prevent neurodegenerative diseases and to the development of effective drugs, will be published Oct. 27 in The EMBO Journal, a publication of the European Molecular Biology Organization. The proteasome is responsible for cell homeostasis. In healthy cells, proteins perform their function and then, with the help of the proteasome, disappear. If idle and damaged proteins remain, their presence can affect cell behavior.

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Link ID: 6286 - Posted: 10.22.2004

Using a specially designed robotic microscope to study cultured cells, researchers have found evidence that abnormal protein clumps called inclusion bodies in neurons from people with Huntington's disease (HD) prevent cell death. The finding helps to resolve a longstanding debate about the role of these inclusion bodies in HD and other disorders and may help investigators find effective treatments for these diseases. The study was funded primarily by the NIH's National Institute of Neurological Disorders and Stroke (NINDS) and appears in the October 14, 2004, issue of Nature.1 Inclusion bodies are common to many neurodegenerative disorders, including HD, Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS). The role of inclusion bodies in these diseases has long been controversial. Some studies suggest that they may be a critical part of the disease process, while others indicate that they may help protect the cells from toxic proteins or that they are merely bystanders in the disease process. One problem in identifying how inclusion bodies influence disease is that researchers have been unable to track changes in individual neurons over time. "It was like viewing pictures of a football game and trying to imagine the score," says Steven Finkbeiner, M.D., Ph.D., of the Gladstone Institute of Neurological Disease and the University of California, San Francisco. "Much was happening that we couldn't see."

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Link ID: 6235 - Posted: 10.14.2004

University of Iowa researchers have shown for the first time that gene therapy delivered to the brains of living mice can prevent the physical symptoms and neurological damage caused by an inherited neurodegenerative disease that is similar to Huntington's disease (HD). If the therapeutic approach can be extended to humans, it may provide a treatment for a group of incurable, progressive neurological diseases called polyglutamine-repeat diseases, which include HD and several spinocerebellar ataxias. The study, conducted by scientists at the UI Roy J. and Lucille A. Carver College of Medicine and colleagues at the University of Minnesota and the National Institutes of Health (NIH), appears in the August issue of Nature Medicine and in the journal's advanced online publication July 4. "This is the first example of targeted gene silencing of a disease gene in the brains of live animals and it suggests that this approach may eventually be useful for human therapies," said senior study author Beverly Davidson, Ph.D., the Roy J. Carver Chair in Internal Medicine and UI professor of internal medicine, physiology and biophysics, and neurology. "We have had success in tissue culture, but translating those ideas to animal models of disease has been a barrier. We seem to have broken through that barrier."

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Link ID: 5751 - Posted: 07.05.2004

Scientists have found a drug which appears to slow the progress of the debilitating condition Huntington's Disease, which currently has no cure. Animal tests by Cambridge University researchers showed that rapamycin also delays the onset of the disease. The drug is already used in humans to prevent organ rejection after transplants. Huntington's Disease groups hailed the research, published in Nature Genetics, as a significant advance. The disease, caused by a mutation in the huntingtin protein which makes it become toxic, is an inherited condition. It affects the central nervous system and can lead to loss of muscle control, dementia and depression. Huntington's normally affects people in middle age, but it can strike at any time. It is estimated that around 50,000 people in the UK either suffer from the disease or are at risk of developing it. (C)BBC

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Link ID: 5496 - Posted: 05.19.2004

A brain chemical has been found that could improve the lives of people with Huntington's disease, scientists say. Mice tailored to develop the degenerative brain disease had fewer symptoms and declined at a slower rate when given Ciliary Neurotrophic Factor. The team at Portugal's Centre for Neuroscience in Coimbra used gene therapy to reprogramme the brain to produce the chemical. A UK team is now working to produce a tablet that has a similar effect. The research, published in the journal Experimental Neurology, is further evidence that the lack of certain "neurotrophic factors" are key to the progressive symptoms of Huntington's. (C) BBC

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Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: Development of the Brain
Link ID: 4788 - Posted: 01.10.2004

Decreasing meal frequency and caloric intake protects nerve cells from genetically induced damage, delays the onset of Huntington's disease-like symptoms in mice, and prolongs the lives of affected rodents, according to investigators at the National Institute on Aging (NIA) Intramural Research Program. This animal study* is the first to suggest that a change in diet can influence the course of Huntington's disease. "If reducing food intake has the same effects in humans as it does in mice, then it may be theoretically possible to delay the onset of the disease and extend the lives of Huntington's patients by prescribing low-caloric diets or diets with reduced meal frequency," says Mark Mattson, Ph.D., chief of the NIA's Laboratory of Neurosciences. The study will be published in the Proceedings of the National Academy of Sciences Online Early Edition the week of February 10 (doi:10.1073/pnas.0536856100). In the study, NIA scientists found that when mutant huntingtin, the abnormal human gene that causes Huntington's disease (HD), was introduced into mice, these mice exhibited clinical signs of the disease, including abnormal metabolism. This altered metabolism, a diabetes-like condition also found in humans with HD, caused the mice to progressively lose weight despite having good appetites. As the mice aged, they developed difficulties controlling their body movements, lost body weight, and eventually died.

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Link ID: 3430 - Posted: 02.11.2003

EVANSTON, Ill. -- Northwestern University scientists have made a key molecular discovery that has implications for a wide range of diseases characterized by the loss of nerve function, including Huntington's, Parkinson's, Alzheimer's and Lou Gehrig's diseases, cystic fibrosis and Creutzfeldt-Jakob disease, the human form of mad cow disease. The findings, which will be published in the Oct. 1 issue of Nature Cell Biology, could lead to an understanding of how to prevent these diseases and to the development of effective drugs. All human neurodegenerative diseases have two things in common. First, misfolded and damaged proteins clump together to form toxic species that aggregate, destroy cell function and cause disease. Second, studies have shown that special protective proteins, called molecular chaperones, can suppress these toxic effects. This question remained: How do the chaperones and aggregates interact with each other?

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Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 12: Psychopathology: The Biology of Behavioral Disorders
Link ID: 2734 - Posted: 09.30.2002

MINNEAPOLIS / ST. PAUL--University of Minnesota researchers have found that a nontoxic bile acid produced in the body prevents apoptosis, or programmed cell death, in mice with Huntington's disease. This finding, to be published July 29 in the Proceedings of the National Academy of Sciences USA (PNAS), may eventually lead to a treatment for Huntington's disease (HD) in humans. HD is an untreatable neurological disorder caused by selective and progressive degeneration of neural cells. In the study, led by Walter Low, Ph.D., professor of neurosurgery in the university's Medical School, a dose of tauroursodeoxycholic acid (TUDCA) was administered subcutaneously once every third day for six weeks in mice with the HD gene. Researchers found TUDCA was able to cross the blood / brain barrier, something many molecules are unable to do, resulting in decreased apoptosis in the section of the brain affected by HD and improving the neurological cell function in the mice. "We're extremely encouraged by the neuroprotective function of TUDCA in Huntington's disease and will be examining its potential in future studies," said Low.

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Link ID: 2403 - Posted: 07.30.2002

PAUL RECER AP Science Writer WASHINGTON (AP) - A bile acid the body produces in small amounts is able in laboratory studies to slow the progress of Huntington's disease, a fatal, inherited brain disorder that destroys the mind and has affected about 30,000 Americans. "We found in mouse studies that this compound protects the animals' neurons (brain cells) from the effects of the Huntington's disease gene," said C. Dirk Keene, first author of a study appearing this week in the Proceedings of the National Academy of Sciences. Keene, a researcher at the University of Minnesota, said many more laboratory studies are needed before the drug could be considered for testing in humans, but he said the research is important because it offers the hint of a future treatment for a lethal disorder that now has no treatment.

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Link ID: 2396 - Posted: 07.30.2002

STANFORD, Calif. - Stanford University Medical Center researchers have discovered a potential treatment for Huntington's disease. By enhancing the brain's natural protective response to the disease, researchers were able to alleviate the uncontrollable tremors and prolong the lives of mice with a neurological disorder that mimics Huntington's. Their finding suggests that a similar treatment strategy may be effective in humans. "This is exciting because it has implications for therapy," said Lawrence Steinman, MD, professor of neurological sciences and pediatrics and senior author of the study, published in the February issue of Nature Medicine. Huntington's disease is a hereditary disorder characterized by memory loss, abnormal movement and premature death. It affects 1 in 10,000 people, and children with an affected parent have a 50 percent chance of developing the disease.

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Link ID: 1453 - Posted: 02.01.2002

by Roberta Friedman So many diseases that destroy the aging brain have been linked with clumping proteins, yet the debate over cause and effect continues. Presented here today, recent findings bolster evidence that protein aggregates themselves may not damage nerve cells directly, or produce the clinical signs. The fibers and where they first appear cause the problem, contend researchers at the University of California, who presented a new way to visualize the process microscopically. Although diseases such as Huntington's and Alzheimer's are described collectively as neurodegeneration, some of their dysfunction may be due to the toxic effects of soluble forms of the affected proteins, says Steven Finkbeiner, assistant investigator at the Gladstone Insitute of Neurological Disease at UC San Francisco. They may actually precede the deposition of the protein in the brain as clumps. © Elsevier Science Limited 2000

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Link ID: 1059 - Posted: 11.27.2001