Gene Discovery Could Help ALS Patients

(Ivanhoe Newswire) -- Scientists are one step closer to understanding how to treat and repair diseases of the nervous system, such as amyotrophic lateral sclerosis (ALS), or Lou Gehrig’s disease.

According to a new study, researchers at the University of Rochester Medical Center and Harvard worked together to identify a gene in mice that plays a central role in the proper development of one of the nerve cells that degenerates in ALS.

The scientists focused on corticospinal neurons, nerve cells that connect the brain to the spinal cord. As the ends of these nerves go bad, patients lose the ability to control their muscles, the researchers said.

The team of scientists discovered a protein in mice known as Bhlhb5 is central to how stem cells in the brain ultimately become corticospinal motor neurons, one type of neuron that deteriorates in ALS. The researchers said understanding how the body determines the destiny of stem cells is crucial if doctors are going to use the cells to treat diseases like ALS, Parkinson’s and Huntington’s diseases and spinal cord injuries.

“We’re looking at how the most sophisticated portion of the brain, the neocortex, creates the right kind of neurons where and when they’re needed,” study author Jeffrey D. Macklis, M.D., D.HST of Harvard, was quoted as saying. “Understanding how our brain circuits are initially built is the first step to repairing or reversing many diseases of the nervous system.”

In lab tests, the study’s authors found when Bhlhb5 was knocked out in mice, cells that normally develop into neurons that connect the brain to the spinal cord did not do so. Those mice shared many traits with people afflicted with a neurological disease called hereditary spastic paraplegia. There is currently no cure or treatment for the disease, which affects about 10,000 to 20,000 Americans.

Scientists said they now plan to analyze the function of the human counterpart to the Bhlhb5 gene in patients.

SOURCE: Neuron, 2008; October 23, 2008

Focusing on glial cells to overcome an intractable disease, ALS

Amyotrophic lateral sclerosis (ALS) is a devastating disease, gradually causing paralysis of the muscles in the hand and leg. The discovery by Koji Yamanaka and colleagues at the Brain Science Institute that the glial cells cause damage to the nerve cells shows great promise in the development of new treatments to prevent the progression of ALS.

Amyotrophic lateral sclerosis (ALS) is a devastating disease. Once ALS develops, the motor neurons that control the movement of muscles gradually start to die off, causing paralysis of the muscles in the hand and leg.

The patient suffers from difficulty in using arms and legs, and in eating food and speaking. In about two to five years after the development of ALS, the muscles that control breathing are paralyzed, necessitating the support of a respirator. However, because the senses, memory, and cognitive functions remain normal, the patient is conscious of the progression of the disease.

Unfortunately, no effective treatment has been found. So far, research into understanding ALS has focused mainly on motor neurons. However, Koji Yamanaka, Unit Leader, and colleagues at the Brain Science Institute has focused on cells neighboring the motor neurons, and have met with success in their discovery that the glial cells cause damage to the nerve cells, thus accelerating the progression of the disease. This discovery shows great promise in the development of new treatments to prevent the progression of ALS.

ALS, an incurable disease that exclusively destroys motor neurons

In the spring of 1939, Lou Gehrig, a Major League Baseball player for the New York Yankees in the US, was mired in a prolonged batting slump. His fans and team-mates were very surprised because he was a real slugger, who enjoyed many seasons with high batting averages; his batting record included 23 grand slam home runs, a Major League record, and a consecutive game-playing streak of 2130. He was called "Iron Horse," but it was ALS that prevented him from continuing his playing streak. Lou Gehrig retired in June that year. Two years later he died young, at the age of 37 years.

In the US, ALS is known as 'Lou Gehrig's disease' and is one of the neurodegenerative diseases caused by the gradual death of nerve cells. In Alzheimer's disease, which is a well-known neurodegenerative disease, the patient develops dementia as a result of the gradual death of memory-related nerve cells. In ALS, in contrast, the patient becomes paralyzed because of the gradual death of the motor neurons in the brain and the spinal cord that control the muscles throughout the body.

There are about 6,000 patients with ALS and it is estimated that about 2,000 people may develop ALS every year in Japan. Patients with ALS develop the disease mostly at about 60 years of age, but young people can be affected, like Gehrig.

About 10% of patients with ALS develop the disease because they have inherited the causative genes, but no abnormal genes were found in the remaining 90%. "In other words, anybody can develop ALS," says Yamanaka, who has worked as a neurologist and has treated patients with ALS.

Neurologists are the medical doctors who have been trained in the diagnosis of diseases of brain, spinal cord, and muscle, and their treatment with drugs. In fact, however, there are many other diseases that cannot be treated with drugs because the causes are unknown. "I faced a big dilemma in clinical practice, seriously thinking, 'What can I provide for patients with ALS?' So, I thought I would like to elucidate the cause of the neurodegenerative disease to develop new cures."

Yamanaka trained and worked as a neurologist for four years. Then he devoted himself to basic research and started the study on ALS in 2001. Why did he select ALS as his subject of research? "I chose ALS because it is an incurable disease. ALS progresses quickly, and the symptoms of the patient worsen day by day. From the time the patient makes a clinical visit, he or she will be unable to walk within the first year, will be bed-ridden within the following year, and won’t be alive within three years from the first visit. I was greatly motivated by shocking experiences when I was responsible as a neurologist for treating patients with ALS."

TDP-43 expression in mouse models of amyotrophic lateral sclerosis and spinal muscular atrophy

Redistribution of nuclear TAR DNA binding protein 43 (TDP-43) to the cytoplasm and ubiquitinated inclusions of spinal motor neurons and glial cells is characteristic of amyotrophic lateral sclerosis (ALS) pathology. Recent evidence suggests that TDP-43 pathology is common to sporadic ALS and familial ALS without SOD1 mutation, but not SOD1-related fALS cases.

Furthermore, it remains unclear whether TDP-43 abnormalities occur in non-ALS forms of motor neuron disease. Here, we characterise TDP-43 localisation, expression levels and post-translational modifications in mouse models of ALS and spinal muscular atrophy (SMA).

Results: TDP-43 mislocalisation to ubiquitinated inclusions or cytoplasm was notably lacking in anterior horn cells from transgenic mutant SOD1G93A mice.

In addition, abnormally phosphorylated or truncated TDP-43 species were not detected in fractionated ALS mouse spinal cord or brain. Despite partial colocalisation of TDP-43 with SMN, depletion of SMN- and coilin-positive Cajal bodies in motor neurons of affected SMA mice did not alter nuclear TDP-43 distribution, expression or biochemistry in spinal cords.

Conclusions: These results emphasise that TDP-43 pathology characteristic of human sporadic ALS is not a core component of the neurodegenerative mechanisms caused by SOD1 mutation or SMN deficiency in mouse models of ALS and SMA, respectively.

Author: Bradley J Turner, Dirk Baumer, Nicholas J Parkinson, Jakub Scaber, Olaf Ansorge and Kevin Talbot
Credits/Source: BMC Neuroscience 2008, 9:104

Outnumbering Unhealthy Cells with Healthy Ones Helps Sustain Breathing in ALS Mice

GEN News Highlights

Scientists say that transplanting a new line of stem cell like cells into rat models shifts key signs of neurodegenerative disease in general and those of amyotrophic lateral sclerosis (ALS) in particular. They found that it slowed the animals' neuron loss and preserved limb strength and breathing, basically extending life.

Investigators found that it is most beneficial to inject the glial restricted precursors (GRPs) into parts of the cervical spinal cord that control the diaphragm muscles largely responsible for breathing. In ALS patients, the death of motor neurons in this region is known to lead to respiratory decline.

The researchers observed that 47% more motor neurons survived there than in untreated model animals. “While the added cells, in the long run, didn't save all of the nerves to the diaphragm, they did maintain its nerve's ability to function and stave off death significantly longer,” says neuroscientist Nicholas Maragakis, M.D., an associate professor of neurology at Johns Hopkins who led the research team.

The GRPs also cleared away the neurotransmitter glutamate, which is usually difficult to remove in people with ALS. The resultant excess glutamate overstimulates the motor neurons that spark muscle movement, causing death.

The researchers transplanted 900,000 GRPs to specific sites in the cervical spinal cord of each model rat in early stages of disease. These GRPs began life as astrocyte progenitor cells from healthy rat spinal cord tissue. Following transplant, they transformed into mature, healthy astrocytes, found living alongside sick motor neurons, the scientists note. The astrocytes maintained proper ion levels and nutrient support of nerve cells.

At least a third of the added GRPs functioned after their transplantation. With time, almost 90% of the GRPs had differentiated into astrocytes. Unlike the model rats' own astrocytes, the new ones continued to appear healthy. None of the GRPs damaged the spinal cord or formed tumors. Additionally, transplanting alternate GRPs - those that the team engineered to lack glutamate transporters - offered none of the protective properties.\

The team consisted of researchers from Johns Hopkins and Invitrogen. The article appears online this week in Nature Neuroscience.

Astrocyte replacement shows promise in a rat model of ALS

Stem cell approaches for the treatment of neurodegenerative diseases has become a very attractive option. In amyotrophic lateral sclerosis (ALS), the cells affected in the disease, the motor neurons, have extremely long processes that need to be appropriately connected with the muscles they innervate, making motor neuron transplantation a daunting task. Over the past years, however, increasing evidence supports the notion that not only are motor neurons affected in the disease, but their surrounding cells including astrocytes, important cells regulating glutamate concentrations (required for normal function but if abnormally increased become toxic to the cells). In a study published this week in Nature Neuroscience and led by The ALS Association-funded Nicholas Maragakis, M.D., investigators demonstrate in a rat model that a feasible approach to increase survival in these animals is to transplant astrocytes. Although a great deal still needs to be done to apply this approach in the clinic, these studies do provide compelling evidence that this may one day be feasible.

Investigators isolated astrocyte precursors from developing spinal cord and transplanted these into the cervical spinal cord of 90 day old rats carrying the G93A SOD1 mutation. Investigators chose the cervical region with the hope that these transplants would have benefit for motor neurons which project to the diaphragm muscle. Loss of these neurons ultimately effects the survival of people with ALS. These transplanted cells survived, differentiated into mature astrocytes, and interacted with motor neurons in the spinal cord. Interestingly, these transplanted astrocytes did not show any overt signs of damage related to their close proximity with neurons producing mutant SOD1 motor neurons. This is an interesting finding as one may have expected that toxic factors released from the mutant expressing cells may damage the transplanted cells. Transplanted astrocytes delayed disease onset as well as progression of disease by about two weeks.

Several contributors may have led to the increased survival. Increased levels of the glutamate transporter GLT1 (found exclusively on astrocytes) which have been previously shown to be decreased in people with ALS and is replicated in the animal models may account for the increased survival. Astrocytes also produce trophic factors which support the survival of motor neurons. However in these transplants, investigators could not find increased levels for a variety of tropic factors they measured in the spinal cord including IGF1, BDNF and VEGF. Instead the investigators identified that there was a reduction in microglia, the inflammatory cells in the brain which may have contributed to the increased survival.

“In this study, we have been trying to design a paradigm which could be eventually translated to ALS patients. That is why we focused on a region, the cervical spinal cord, where respiratory function is centered. Our findings suggest that targeted cell replacement of cells other than motor neurons may be promising, and targeting astrocyte-relevant pathways in other ways may be important in ALS therapeutics as well,” commented Nicholas Maragakis, M.D.

Gene find sheds light on motor neuron diseases like ALS

Scientists have identified a gene in mice that plays a central role in the proper development of one of the nerve cells that goes bad in amyotrophic lateral sclerosis, or Lou Gehrig's disease, and some other diseases that affect our motor neurons.

The study is the result of a collaboration by scientists at the University of Rochester Medical Center who normally focus on the eye, working together with a developmental neuroscientist at Harvard who focuses on the cerebral cortex. The work appears in the Oct. 23 issue of the journal Neuron.

The work centers on corticospinal neurons, crucial nerve cells that connect the brain to the spinal cord. These neurons degenerate in patients with ALS, and their injury can play a central role in spinal cord injury as well. These are the longest nerves in the central nervous system – nerves sometimes several feet long that run from the brain to the spinal cord. As the ends of the nerves degenerate, patients lose the ability to control their muscles.

The team led by Lin Gan, Ph.D., of Rochester and Jeffrey D. Macklis, M.D., D.HST, of Harvard showed that a protein known as Bhlhb5 is central to how the brain's progenitor cells ultimately become corticospinal motor neurons, one type of neuron that deteriorates in ALS. The same group of neurons also degenerates in patients with a rare neurological disease known as hereditary spastic paraplegia.

The work by the Harvard and Rochester scientists marks an important step in scientists' understanding of how stem cells in the brain eventually grow into the extraordinary network of circuits that make up the human nervous system. Understanding how the body determines the destiny of stem and progenitor cells is crucial if physicians are to ultimately use the cells to create new treatments for motor neuron diseases like ALS and HSP, as well as other conditions such as Parkinson's and Huntington's diseases and spinal cord injury.

Macklis' team is a world leader in discovering how the brain determines the destiny of its cells. The process is a bit like what happens on a construction site, where a foreman taps the expertise of a variety of workers – carpenters, plumbers, bricklayers, and so on – as needed to build a given structure. In the brain, teams of molecular signaling molecules are brought together to create nerve cells out of raw material where and when needed. Hundreds of such signaling molecules are brought together instantly and continually to allow the brain to create the nerve cells it needs for growth and development.

"How does the brain take a broad class of neurons and decide which ones to send to the spinal cord, or which will connect to our visual centers?" said Macklis, who is director of the Center for Nervous System Repair at Massachusetts General Hospital and at Harvard.

"We're looking at how the most sophisticated portion of the brain, the neocortex, creates the right kind of neurons where and when they're needed. Understanding how our brain circuits are initially built is the first step to repairing or reversing many diseases of the nervous system," added Macklis.

The team showed that the molecular interactions that help control the destiny of the brain's progenitor cells can take place a bit later than some scientists have considered. The team found that Bhlhb5 plays an important role in determining the fate of progenitor cells that that have already exited the cell cycle and are well on their way to being refined into more precise types of cells.

The team showed that when Bhlhb5 is knocked out in mice, cells that normally develop into neurons which connect the brain to the spinal cord don't do so. Those mice share many traits with people with hereditary spastic paraplegia, also known as familial spastic paralysis. Doctors estimate that approximately 10,000 to 20,000 Americans have some form of HSP. Symptoms vary widely, but generally patients have weakness or stiffness in their legs that often results in use of a walker or wheelchair. Most patients live full lives, but many experience a range of other difficulties, including blindness, skin problems, nerve damage in the fingers and toes, and deafness. Some patients are completely disabled, while others have little difficulty. No cure or treatment currently exists.

A next step, Gan said, would be to analyze the function of the counterpart to the Bhlhb5 gene in patients. Scientists reported recently that the gene itself is not mutated in patients with HSP, but it's possible that the effect of the gene is somehow changed, perhaps by a different genetic mutation, in some patients with HSP. Already, more than 20 gene mutations are known to cause various forms of HSP, offering an array of targets to try to treat or cure the disease.

"This is a perfect example illustrating why we study genetics in the mouse," said Gan, who is associate professor in the Department of Ophthalmology at the University of Rochester Eye Institute. "We've been able to pinpoint a gene that may play a role in a disease affecting thousands of people, and the work would have been impossible to do directly in people. We did the research in mice, and now we can go back to take a closer look in patients."

Last year, the Rochester team showed that Bhlhb5 plays a role in determining what types of neurons are created in the eye. The eye is the usual focal point for Gan, who is director of the De Stephano Laboratory for Retinal Genomics at the University of Rochester Medical Center. His team studies the genes that play a role in creating the eye, keeping it healthy, and which might play a role in blinding eye diseases such as retinitis pigmentosa, macular degeneration, and glaucoma.

Stem Cells May Act as “Trojan Horse” to Deliver Gene Therapy to Injured Central Nervous System

Newswise — Amyotrophic lateral sclerosis (ALS) researchers at The Methodist Hospital in Houston have shown that transplanted bone marrow stem cells can attach themselves to injured areas in the brain or spinal cord, possibly providing a way to deliver future gene therapy.

According to Dr. Stanley H. Appel’s study published in the Oct. 14, 2008, issue of Neurology®, the medical journal of the American Academy of Neurology, these "Trojan horse" cells may improve the ability to deliver gene therapy to the brain and spinal cord.

The original intent of this study focused on whether transplanted bone marrow stem cells in six patients with sporadic ALS would suppress neuroinflammation and improve the patients’ clinical outcomes, said Appel, co-founder and co-director of the Methodist Neurological Institute at The Methodist Hospital. While the results showed no benefit in fighting the disease, Appel’s research team found that transplanting bone marrow stem cells that are closely matched to the patients’ own bone marrow allowed for a significant percentage of those cells to travel to and reside in the brain or spinal cord. However, it is clear from the study that unless the bone marrow stem cells are engineered to secrete neuroprotective factors, such transplants are not likely to be beneficial in human ALS.

“Our courageous ALS patients committed themselves to helping search for meaningful therapies for this devastating disease,” said Appel, lead author and chairman of Neurology at Methodist. “With their help, we’ve shown that these transplanted stem cells can potentially be used to deliver future drugs. These findings open the window in terms of where we can go next.”

Appel and his research team have focused on bone marrow because of all stem cells, they offer a readily available source for potential use in the development of therapies, drug delivery and drug administration in ALS and other neurodegenerative diseases.

Commonly known as Lou Gehrig’s disease, ALS is a progressive neurodegenerative disease characterized by degeneration of the upper and lower motor neurons in the brain and spinal cord, which stimulate skeletal muscle movement. As more motor neurons die, muscle weakness becomes progressively worse. Sporadic (non-inherited) ALS affects 90 percent of the ALS population, and is representative of the patients at Methodist’s MDA/ALS Clinic, the first and one of the largest multi-disciplinary ALS clinics in the nation.

This study was supported by the Muscular Dystrophy Association, Dr. and Mrs. George Kozmetsky, and the Hungarian Scientific Research Fund.

Study details

Method: Six patients with definite ALS received total body irradiation followed by donor peripheral blood HSCT infusion. Disease progression and survival were assessed monthly and compared to matched, historical database patients.

Results: No clinical benefits were evident; however, tissue examination in two of the 100 percent engrafted patients demonstrated 16-38 percent donor-derived DNA at sites with motoneuron pathology. Neither donor DNA nor increased cell numbers were found in several unaffected brain regions. A third minimally engrafted patient had neither donor DNA nor increased infiltrating cells in the central nervous system (CNS).

Conclusions: This study demonstrates that peripheral cells derived from donor hematopoietic stem cells can enter the human CNS primarily at sites of motoneuron pathology and engraft as immunomodulatory cells. Although unmodified hematopoietic stem cells did not benefit these sALS patients, such cells may provide a cellular vehicle for future CNS gene therapy.

About the Methodist Neurological Institute

The Methodist Neurological Institute (NI) houses the practice and research activities of the departments of neurology, neurosurgery, neuroradiology, neurophysiology and physical medicine & rehabilitation at The Methodist Hospital. The mission of the NI is to advance the discovery of the origins, mechanisms and treatment of neurological disease and to provide comprehensive care for patients with disorders and injuries of the brain and spinal cord.

Methodist is primarily affiliated with Weill Cornell Medical College and New York Presbyterian Hospital. Methodist is also affiliated with the University of Houston. Methodist is ranked among the country’s top centers in 12 specialties in U.S News & World Report’s 2008 America’s Best Hospitals issue. Methodist is ranked in more specialties than any other hospital in Texas, and is 12th in the nation for neurology and neurosurgery.

For more on the Methodist Neurological Institute, visit http://www.methodistneuroinstitute.com, or call (713) 790-3333.

FDA: Statins don't increase ALS risk

Sept. 30 (UPI) -- The U.S. Food and Drug Administration says it has determined statins do not increase the incidence of amyotrophic lateral sclerosis, or Lou Gehrig's Disease.

The FDA's review began in 2007 after the agency received a higher-than-expected number of reports of ALS developing in patients taking statins, cholesterol-lowering drugs. But officials said subsequent data from 41 long-term controlled clinical trials showed no increased incidence of the disease in patients treated with a statin compared with placebo.

Statins are the most commonly prescribed medications that treat elevated cholesterol levels in the United States and have also been shown to reduce the risk of heart disease in many patients.

"Based on currently available information, healthcare professionals should not change their prescribing practices for statins and patients should not change their use of statins," the FDA said.

The agency's analysis is reported in the journal Pharmacoepidemiology and Drug Safety.

T-cells Show Promise for ALS, Neurodegenerative Disease Therapies

Newswise — A type of white blood cell that is important to the immune system may provide hope for future new therapies for amyotrophic lateral sclerosis (ALS), as well as other neurodegenerative diseases, according to a study published online today in the Proceedings of the National Academy of Sciences.

Researchers at The Methodist Hospital in Houston have shown that restoring functional T-cells, an immune system white blood cell, in a mouse model of ALS slows disease progression. T-cells play a critical role in protecting brain cells by enhancing the protective functions of supporting cells of the brain and spinal cord called glia.

Of the ALS cases caused by genetic factors, about 10 percent have a mutation in a gene called superoxide dismutase 1, or SOD1, which mops up the free radicals that damage cell function.

“In animal models of ALS, we and others have previously shown that reducing the levels of mutant SOD1 protein in glia slows the progression of the disease,” said Dr. Stanley H. Appel, last author and chairman of Neurology at Methodist. “However, in our current report, we demonstrate an alternative approach. In ALS mice with functional immune cells called CD4+ T-cells, the progression of the disease is again slowed and survival increased.”

Co-lead authors Drs. David R. Beers and Jenny S. Henkel head the team of Methodist neurodegenerative disease scientists working with Appel, who also leads Methodist’s MDA/ALS Clinic and Research Center. Their findings show the disease could be slowed in these mice if they received a bone marrow transplant and were able to produce T-cells again.

“It has been known for some time that T-cells are present at sites of injury in ALS patients as well as in mouse models of ALS, and until now, the role of these cells was unknown,” said Beers. “This study demonstrates that T-cells, possibly CD4+ T-cells, through their interaction with microglia and astroglia, are protecting the cells in the spinal cord that cause muscle movement. It is now critically important to understand how T-cells provide this neuroprotection.”

“We’re currently looking at the sub-population of CD4+ T-cells that are providing this protection,” said Henkel. “These cells may eventually provide a readily accessible target for therapeutic intervention not only for ALS but other neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases.”

ALS is a neurodegenerative disease caused by loss of the motor neurons that control all voluntary movement.

This study was supported by the National Institutes of Health and the Muscular Dystrophy Association. It will be published in the Oct. 7 print issue of PNAS.

Research sees new ALS hope

by Jim O'Connell
Wednesday, September 17, 2008

University of Wisconsin researchers have discovered a breakthrough in the treatment of amyotrophic lateral sclerosis, better known as Lou Gehrig’s Disease.

The team, led by associate scientist Masatoshi Suzuki and neurology professor Clive Svendsen, discovered that the use of certain stem cells in ALS-infected muscles of rats have drastically improved their lifespan.

“These rats have a paralysis they develop with ALS, their limbs get frozen, and [the stem cell] slows down that freezing of the limbs over time,” Svendsen said. “By doing this we have extended the length by which the rat can live by about 28 days. This, in the life of a rat, who only lives 120 days anyway, is about 25 percent lifetime extension.”

In previous research Suzuki and Svendsen had used the same stem cells, which come from the bone marrow of adult humans, but did not see the same success.

This was because they had previously placed the stem cells into the spine or brain of the animal instead of directly into the paralyzed muscle.

“We used a combination of the stem cells and delivered them directly into the muscle, which is a very new thing,” Suzuki said.

Due to this direct application, the enhanced stem cells helped secure neurons to the infected muscles. The separation of these neurons is what causes ALS.

Svendsen and Suzuki are trying to push their findings even further by using their genetically modified cells on larger animals.

According to Svendsen this scale problem might be overcome by only injecting the cells into a particular part of the muscle.

However difficult this may be, Svendsen is determined to take the next step.

“The first trial will be probably looking at whether we can slow down disease progression in men by injecting cells into the muscle tissue.” Svendsen said. “Obviously there are a number of steps, this is just an animal, and we hope to acquire data in order to explore how this would work in humans.”

Often the use of stem cells for medical advancement causes a moral and political dilemma, but Svendsen says there is very little controversy surrounding his research.

While use of embryonic stem cells for research has sparked the most debate on this topic, the stem cells used in this project are taken right from the bone marrow of an adult patient.

“Because it’s adult stem cells, it is not that controversial,” Svendsen said. “And it could be used as a new technique for improving function.”

Nerve cells grown from new-style stem cells

Ordinary skin cells taken from patients with a fatal and incurable nerve disease have been transformed into nerve cells in a first step toward treating them, US researchers reported. They transformed the cells from two patients with amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, into motor neurons—the cells that waste away and die in ALS. There is no immediate medical use for the cells, taken from two sisters aged 82 and 89, the researchers reported in the journal Science.

"Now we can make limitless supplies of the cells that die in this awful disease. This will allow us to study these neurons and ALS, in a lab dish, and figure out what's happening in the disease process," said Dr Kevin Eggan of Harvard Medical School in Boston, who helped lead the study. "We can generate hundreds of millions of motor neurons that are genetically identical to a patient's own neurons," added Chris Henderson of Columbia University in New York, who also worked on the study. "This will be an immense help as we try to uncover the mechanisms behind this disease and screen for drugs that can prolong life."

There is no cure for ALS. The causes are not clear and it kills by gradually paralysing patients. About 120,000 new cases are diagnosed each year, according to the International Alliance of ALS. "It is our lack of understanding of that disease process which is preventing us from developing more effective treatments," Henderson said. "There is no way we could go to an ALS patient and take a sample of their motor neurons," he added, because the affected cells are in the spinal cord.

Eggan and Henderson hope to grow and study these motor neurons and see if they can re-create the disease in a lab dish–and then try out various drugs to treat it. The two patients have a mild form of ALS caused by a single genetic mutation, and all of the cells in their body carry that mutation. The experiment helps fulfil one of the promises of embryonic stem cell research, Eggan said. The hope of the controversial research has always been to figure out ways to make ordinary cells into customised scientific experiments, and into tailor—made medical treatments.

Last year several teams of researchers reported they had genetically engineered ordinary skin cells to act like embryonic stem cells—the master cells of the body, which have the ability to morph into any cell or tissue type. Eggan said that this does not mean it is no longer necessary to use the controversial methods to get real embryonic stem cells by using human embryos from fertility clinics or by using cloning technology. For one thing, they used viruses to carry in the four genes that transformed the skin cells. These viruses integrate into the cells, making them far too dangerous to use in people, Eggan said. For another, the genetic defect that causes ALS would have to be corrected before the cells could be used in any treatment, the researchers said. Embryonic stem cell research is what allowed them to figure out how to do every step in their experiment, Eggan added. And if this one fails, the researchers will have to return to true embryonic stem cells.

Predicting patient survival from protein stability and aggregation propensity

Amyotrophic Lateral Sclerosis (ALS), also known in America as Lou Gehrig's disease, is a fatal neurodegenerative disease that has no effective treatment. While it is well known that specific genetic mutations can cause the condition, how the changed genes produce the symptoms has previously been a mystery. A new paper in this week's PLoS Biology, the online open access journal, is able to predict ALS patient longevity to an unprecedented degree based on two properties of the protein SOD1. Jeffrey Agar and colleagues at Brandeis and Harvard Universities show that both the stickiness of SOD1 and its decreased stability accounts for 69% of patient survival data, providing strong evidence that SOD1 protein stability and its aggregation propensity are the main toxic causes of ALS.

ALS can occur spontaneously in people with no family history of the condition, but about 10% of cases run in families, and it has been shown that in about 20% of this subset of cases the underlying mutation is a change in the gene for SOD1. SOD1 is an enzyme – a biological catalyst – that neutralises potentially dangerous molecules, but ALS-causing mutant enzymes gain an unknown toxic function – i.e. the disease occurs because SOD1 does something that it doesn't do in unaffected people.

SOD1 has been shown to be mutated in at least 119 different ways in different ALS patients. Some mutations will have a more dramatic effect on SOD1 structure than others. SOD1 – like all enzymes – is a string of different amino acids in a certain pattern. Mutations that switch an amino acid for one with very different properties, or which alter an amino acid crucial for the formation of certain structural regions of the enzyme, will have a large impact on SOD1 function. Agar et al. looked at the difference in disease progression for a large population of patients with differing mutations, and found that those mutations which made SOD1 more likely to unfold from its normal structure, and those mutations that made it more likely that SOD1 would stick to other unfolded SOD1 molecules, correlated with reduced survival times post disease onset. Thus Agar et al. conclude that in people with ALS, it is the sticking together of SOD1 that is toxic.

Harvard, Columbia Researchers Make Stem Cell Breakthrough

Advance will aid search for treatments to a variety of diseases, researchers say

By CLIFFORD M MARKS

Scientists from Harvard and Columbia announced Thursday the creation of the first patient-specific stem cell line from humans afflicted with a genetic disease, a key step in the push to create therapies for a wide variety of illnesses by replacing diseased tissue with tissue generated by stem cells.

The study's two principal authors said in a press conference Wednesday that such treatments remained years away and that the more immediate impact of the disease-specific stem cells will be the ability to study disease progression and test potential treatments in a lab setting.

"We now have in the culture dish cells which have the same genetic makeup as do the ALS patients, and they are the very cells that are affected by the disease." said Columbia professor Christopher Henderson, referring to Amyotrophic Lateral Sclerosis (ALS), a neurodegenerative often called Lou Gehrig's Disease. "This provides us with the opportunity...to study these motor neurons derived from the ALS cells."

The study, which was co-authored by Henderson and Harvard professor Kevin C. Eggan, was published Thursday in the journal Science.

The age of the cell donors—82 and 89—gave the findings added significance, as some scientists had predicted using cells from older patients would complicate the creation of stem lines, according to Eggan.

"This opens the door to being able to make patient-specific, stem cell lines from diseases which affect people very late in life like Parkinson's disease or Alzheimer's disease," Eggan said.

Though the researchers originally planned to produce disease and patient-specific stem cells using the controversial practice of therapeutic cloning, which requires both a supply of human egg cells and the destruction embryos created to produce the stem cell lines, they opted instead to use a newer technique called "direct reprogramming," which was first unveiled late last year.

This method takes regular human cells—in this case skin cells—and uses viruses to reprogram them into cells that can develop into any kind of human tissue, in theory providing all the benefits of embryonic stem cells.

The current reliance on viruses renders the stem cell lines unsafe for transplantation because the process genetically modifies the reprogrammed cells. But Eggan predicted that researchers would soon fix this shortcoming with a process that instead uses chemicals to reprogram cells.

"Future research is surely going to focus on ways to replace those viruses with chemicals," he said. "And I think we'll see that in a short amount of time."

Both scientists repeatedly said that research on therapeutic cloning should not be abandoned, in large part because they said it was necessary to test the utility of reprogrammed cells against an embryonic stem cell bench mark.

"We need to compare these cells we've generated to the gold-standard cells we've generated from human embryonic stem cells," Eggan said. "Until we can do that, we won't have complete confidence."

Despite their insistence, the breakthrough and continuing difficulty in getting the egg cells required for therapeutic cloning suggests that reprogramming may provide greater hope for stem cell therapies.

Eggan said that Massachusetts law prohibiting compensation of human egg donors had stymied his lab's efforts to study the disease.

"We've now spent roughly $100,000 on advertising," Eggan said. "We've only had one woman follow through and go through the considerable effort of donating oocytes [egg cells] for research. I would characterize the number of oocytes she donated as a handful. And the results we had from those very few initial experiments were encouraging, but there's no sign of additional donors in sight."

Though the researchers expressed optimism about their ability to use the reprogrammed stem cells to study the progression of Lou Gehrig's disease and test potential treatments, a number of hurdles remain to discovering such therapies.

The researchers have not yet shown that the stem-cells-derived neurons degenerate as diseased neurons do in the human body, but they added they hope to do so in a matter of months.

In addition, the stem cells are specific to only a certain type of the disease, which afflicts less than five percent of sufferers, Eggan said. But the study authors said research on this less-common variant could have broader applications, if, as they hope, the disease mechanism is similar for most or all types of Lou Gehrig's disease despite different initial triggers in the vast majority of ALS patients.

"Our real hope is that very similar events are occurring in these sporadic patients--the 90 percent of patients in which the trigger is different," Henderson said. "Since the diseases are so similar we believe that many of the mechanisms must be similar or the same."

Protein plays Jekyll and Hyde role in Lou Gehrig's disease

Brandeis study sheds light on ALS

Waltham, MA—Amyotrophic lateral sclerosis (ALS), more commonly known as Lou Gehrig's disease, is a fatal neurodegenerative disease caused by the death of motor neurons in the brain and spinal cord that control muscle movements from walking and swallowing to breathing. In a groundbreaking study this week in PLoS Biology, Brandeis and Harvard Medical School scientists report key findings about the cause and occurrence of the familial form of ALS.

For the past three years, Brandeis chemist Jeff Agar and his colleagues have studied the rare, familial form of ALS (fALS) as a window into the sporadic form of ALS, which accounts for 90 percent of all cases. Scientists discovered fifteen years ago that mutations in the gene that makes the protein, superoxide dismutase, are responsible for inherited ALS, but how these mutations cause ALS remain a mystery. Researchers believe deciphering the mechanisms at work in inherited ALS will clear the way to understanding and treating sporadic ALS, in large part because clinical symptoms are identical in both forms of the disease.

Agar's research demonstrated that fALS is caused by two synergistic properties of the protein superoxide dismutase, creating toxic levels of the protein in motor neurons. "We discovered that increased protein unfolding and the propensity of the proteins to aggregate, (to clump together) are the major factors in the familial form of ALS," explained Agar.

This propensity of proteins to unfold and clump together amounts to what scientists call a 'toxic gain of function.' Many diseases are caused by a loss of protein function, but some, like ALS, are linked to a gain of function in which a protein takes on a new role, unrelated to the one it is supposed to perform in healthy cells.

"The protein superoxide dismutase, normally a useful antioxidant, goes from Dr. Jekyll to Mr. Hyde when it clumps up," said Agar. This research indicates that protein aggregation is toxic in ALS, something that has not been proven for other neurodegenerative diseases such as Alzheimer's and Parkinson's, though researchers worldwide are studying the role of protein clumps in these conditions, as well.

Still, scientists disagree on the nature of the toxic gain of function because not all clumps are toxic, nor are they all the same size in patients with neurodegenerative disease, or healthy people, for that matter. But Agar says that large clumps cause cell death, literally exploding the thread-like axons on nerve cells that transmit impulses from the cell.

"Most people are familiar with the process of aggregation, which is what happens when you cook an egg. A fluid (the egg white) is full of proteins that are free to move about. Upon cooking, these proteins unfold and clump together. When this happens inside a cell, especially inside the long, narrow, tubes that connect neurons (axons), the cells essentially choke because they can't move proteins and nutrients to where they are needed. The loss of motor neurons then results in the death of ALS patients."

The next step, said Agar, is to develop drugs that target key proteins and prevent them from clumping together. "Our study used data from innumerous ALS researchers, and the field has been working toward this discovery for some time. My hope is that if our findings are validated by other research groups, molecules that prevent aggregation will be developed and used to treat ALS. We hope to contribute to this process and have initiated the lengthy process of developing such molecules in collaboration with the laboratories of Greg Pestko and Dagmar Ringe here at Brandeis."

Umbilical cord blood cell transplants may help ALS patients

Moderate dose proves most effective in mouse model

Tampa, FL (June 24, 2008) – A study at the University of South Florida has shown that transplants of mononuclear human umbilical cord blood (MNChUCB) cells may help patients suffering from Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's disease. A disease in which the motor neurons in the spinal cord and brain degenerate, ALS leaves its victims with progressive muscle weakness, paralysis and, finally, respiratory failure three to five years after diagnosis.

In this study, USF researchers transplanted human umbilical cord blood (HUCB) cells into mouse models with ALS. Cells were transplanted at three different dose strength levels -- low, moderate and high -- to determine the degree to which dose levels of transplanted cells might delay disease symptom progression and increase lifespan. In results published today online at PloS ONE (Public Library of Science), researchers determined that the moderate-strength dose of HUCB cells was most effective in increasing lifespan and reducing disease progression.

"Our results demonstrate that treatment for ALS with an appropriate dose of MNC hUBC cells may provide a neuroprotective effect for motor neurons through active involvement of these cells in modulating the host immune inflammatory system response," said the study's lead author Svitlana Garbuzova-Davis, PhD, DSc, of the Center of Excellence for Aging and Brain Repair at USF.

According to the research team, modulating immune and inflammatory effectors with HUCB cells could have a protective effect on dying motor neurons. The team had previously shown that hUBC cell transplants reduced inflammation and provided neuroprotection in models of stroke and Alzheimer's disease.

"This preclinical study indicates that MNC hUBC cells may protect motor neurons by inhibiting an immune inflammatory response by decreasing pro-inflammatory cytokines, signaling proteins in the brain and spinal cord that play a role in immune response," Garbuzova-Davis and colleagues wrote. "Proinflammatory cytokines may be indirect mediators for glial cells' contribution to motoneuron death and the decrease in these cytokines might be due to a reduction of activated microglia, the cells that form active immune defense in the central nervous system."

The research team noted, however, that the mechanism underlying the beneficial effect of hUBC cells for repairing diseased motor neurons in ALS still needs more clarification.

Suggesting that 'more is not better,' it was the moderate, not the high, dose of hUBC cells that proved most effective. Researchers speculated that the high dose may have been less effective because it induced an immunological conflict within the mouse model.

"Future studies should look at multiple injections of smaller doses over time, in order to help translate this research to clinical trials," according to co-author Paul R. Sanberg, PhD, DSc, director of the Center.

"Developing an effective treatment for ALS is complicated by the diffuse nature of motor neuron death," concluded Garbuzova-Davis. "However, cell therapy may offer a promising new treatment."

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The other co-authors of the study were Cyndy Davis Sanberg and Nicole Kuzmin-Nichols of Saneron CCELL Therapeutics, Inc., and Alison E. Willing, Carmelina Gemma, Paula C. Bickford, Christina Miller, and Robert Rossi from USF.

Lou Gehrig's Disease Protein Found Throughout Brain, Suggesting Effects Beyond Motor Neurons

PHILADELPHIA, June 16 (AScribe Newswire) -- Two years ago researchers at the University of Pennsylvania School of Medicine discovered that misfolded proteins called TDP-43 accumulated in the motor areas of the brains of patients with amyotropic lateral sclerosis (ALS), or Lou Gehrig's disease. Now, the same group has shown that TDP-43 accumulates throughout the brain, suggesting ALS has broader neurological effects than previously appreciated and treatments need to take into account more than motor neuron areas. Their article appeared in last month's issue of the Archives of Neurology.

"The primary implication for ALS patients is that we have identified a molecular target for new therapies," says co-author John Q. Trojanowski, MD, PhD, Director of Penn's Institute on Aging. "The other implication is that new therapies for ALS now need to go beyond treating only motor neurons."

Traditionally, ALS has been diagnosed based on muscle weakness and neurodegeneration of the upper and lower motor neurons that extend from the motor cortex to the spinal cord and brainstem motor neurons, which directly innervate voluntary muscles. For example, if you want to wiggle your big toe, the signal travels from the motor neuron in the cortex at the top of your head to a synapse on the lower spinal cord motor neurons in the lower back, which, in turn transmit the "wiggle" command by sending a signal to the muscles that move your big toe. Patients with ALS cannot wiggle their big toe or complete other voluntary muscle movements, including those carried out by their other extremities and eventually, by the diaphragm that moves air in and of their lungs.

The study was conducted by examining post-mortem brain tissue of 31 ALS patients. The accumulation of TDP-43 was imaged by detecting TDP-43 with an antibody specific for this protein. TDP-43 pathology was observed not only in the areas of the brain and spinal cord that control voluntary movements, as expected, but also in regions of the brain that involve cognition, executive functioning, memory, and involuntary muscle control. TDP-43 pathology was not observed in any of the controls that did not have ALS.

The pathological TDP-43 observed in ALS brains is different in two ways from normal TDP-43 that is found in most cells. The ALS-associated TDP-43 includes fragments of normal TDP-43 as well as other abnormally modified forms of TDP-43, and it is located in the cytoplasm of neurons; whereas, normal TDP-43 is found almost exclusively in the cell nucleus. In ALS, the pathological TDP-43 accumulates in large "globs," mainly in cell bodies.

"Our observation of TDP-43 in the brains of ALS patients suggests that ALS and two other neurodegenerative diseases called ALS- PLUS [ALS with cognitive impairments] and FTLD [frontotemporal lobar disease] may all have the same underlying molecular pathology involving abnormal TDP-43," says Trojanowski. "This constitutes a paradigm shift in the way we think about these diseases."

Current research is focused on understanding the basic biology of TDP-43 in cell culture systems. The research team is now trying to find out whether pathological TDP-43 causes nerve cells to lose their normal function or if they take on a toxic function. "The over-riding goal that drives our work is helping ALS patients," says Trojanowski.

Felix Geser, of Penn, was lead author on this study. Linda Wong, Maria Martinez-Lage, Lauren Elman, Leo McCluskey, Sharon Xie, and Virginia Lee, all of Penn, and Nicholas Brandmeir, of Albany Medical College, Albany, NY were co-authors. This research was supported by grants from the National Institute on Aging.

ABOUT PENN MEDICINE

PENN Medicine is a $3.5 billion enterprise dedicated to the related missions of medical education, biomedical research, and excellence in patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System.

Penn's School of Medicine is currently ranked #4 in the nation in U.S.News & World Report's survey of top research-oriented medical schools; and, according to most recent data from the National Institutes of Health, received over $379 million in NIH research funds in the 2006 fiscal year. Supporting 1,400 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.

The University of Pennsylvania Health System includes three hospitals - its flagship hospital, the Hospital of the University of Pennsylvania, rated one of the nation's "Honor Roll" hospitals by U.S.News & World Report; Pennsylvania Hospital, the nation's first hospital; and Penn Presbyterian Medical Center - a faculty practice plan; a primary-care provider network; two multispecialty satellite facilities; and home care and hospice.

Vancouver researchers pioneer safe pathway to slow ALS using stem cells

A unique pilot study has established a safe pathway for using bone-marrow stem cells to slow down and potentially treat Amyotrophic Lateral Sclerosis (ALS), a fatal neurodegenerative disease without cure.

The study, published in the journal, Muscle & Nerve and led by Dr. Neil Cashman, professor of neurology at The University of British Columbia and director of the ALS program at Vancouver Coastal Health and VCH Research Institute, tested the use of a growth factor stimulant in ALS patients and found that bone-marrow stem cells became activated with no adverse effects to patients.

“Our idea was to use a growth factor stimulant to increase the number of circulating stem cells from within the body’s bone marrow where they would have the potential to travel to the site of injury and begin repair, slowing down the progression of ALS,” says Cashman, who also holds the Canada Research Chair in Neurodegeneration and Protein Misfolding Diseases at UBC and is a member of the Brain Research Centre at UBC Hospital.

“This pathway, if one day successful, may provide a new therapy that will avoid the ethical debate surrounding embryonic stem cells,” says Cashman.

Growth factors are proteins that can stimulate cell division. They occur naturally in the human body and can also be developed in a laboratory. Stem cells serve as a “repair system” in the human body and have the potential to develop and divide into many different cell types.

“The project was complex because growth factors have the potential to activate the wrong cells in the brain and spinal cord, which could be harmful to ALS patients” says Cashman.

The researchers identified Granulocyte Colony Stimulating Factor (G-CSF) as the safest possible growth factor to use. They then conducted the pilot trial to establish safety and measure stem cell mobilization.

“We were able to measure a prominent effect on stem cell mobilization and found no adverse effects in the patients,” said Cashman. “There have been many misgivings in using stem cell stimulators in ALS patients but now we know we can safely do this. This is an important first step in providing a new treatment for ALS.”

The research team is now developing a larger scale multicentre trial to look at therapeutic effect. This trial is at least one year away from beginning.

ALS is a progressive and ultimately fatal neurodegenerative disease that produces weakness, atrophy – partial or complete wasting away of a part of the body, and spasticity – continuous contracting of certain muscles. It results from progressive degeneration of motor neurons in the brain, brainstem, and spinal cord. There is no cure for ALS and to date the only registered pharmacological treatment is riluzole, which slows the progression of the disease on average by 10-15 per cent. New effective therapies are greatly needed to slow or halt this disease.

The Webster Foundation in Montreal through the VGH & UBC Hospital Foundation in Vancouver, as well as the Temerty Family Foundation in Toronto provided funding for this study. The co-authors include Dr. Andy Eisen (senior author), professor Emeritus, Neurology, University of British Columbia and former director Vancouver Coastal Health ALS program; and Dr. Charles Krieger, associate professor of kinesiology, Simon Fraser University, professor, neurology, clinical associate professor, Neurology, University of British Columbia, and clinician researcher VCH ALS program.

VCHRI is the research body of Vancouver Coastal Health Authority. In academic partnership with UBC, the institute advances health research and innovation across B.C., Canada, and beyond. www.vchri.ca

The Faculty of Medicine at UBC provides innovative programs in the health and life sciences, teaching students at the undergraduate, graduate and postgraduate levels, and generates more than $200 million in research funding each year.

The Brain Research Centre at UBC Hospital is a multidisciplinary centre dedicated to improving understanding and finding new treatments for brain diseases. The centre is a partnership of the University of British Columbia and Vancouver Coastal Health Research Institute.

Support cells modify Lou Gehrig's Disease

By Deanna Chieco

Glial cells, the supporting cells of the nervous system, are present everywhere in your brain and spinal cord and help with communication between neurons.

Despite their supportive role in the healthy nervous system, these glial cells can undergo functional changes after a brain injury or during illness that make it harder for the nervous system to heal.

A group of Hopkins researchers led by Nicholas Maragakis, a neurologist at the School of Medicine, examined the role of glial cells in the neurodegenerative disease amyotrophic lateral sclerosis, known as ALS or Lou Gehrig's Disease.

ALS involves the progressive degeneration of motor neurons, which transmit signals from the brain that tell muscles what to do, and eventually leads to weakness, paralysis and death.

The researchers examined how the growth or proliferation of astrocytes, a type of glial cell found throughout the central nervous system, could play a role in the cause of ALS.

Following an injury, astrocytes undergo a process called reactive astrogliosis, in which they lose their normal functioning and exhibit altered gene expression.

In a healthy nervous system, astrocytes play a supporting role which consists of regulating neurotransmitter and ion uptake as well as preventing toxins in the blood from reaching the brain.

However, if astrocytes become reactive, they can lead to the death of their neighboring neurons because of the loss of vital functions.

Working from previous evidence that reactive astrogliosis was important in neurodegenerative disorders, this group of researchers investigated a connection between the proliferation of these reactive astrocytes and ALS.

They used two mouse models that were genetically modified to express either an acute or chronic form of motor neuron disease. Markers were used to label dividing astrocytes in tissue sections for each mouse model. Astrocytes and motor neurons in the lower region of the spinal cord were the main area of focus.

The acute model represents the immediate cellular changes following a traumatic brain or spinal cord injury. In this model, they found that astrocyte proliferation was reduced in the disease model as compared to a wild-type mouse.

However, if these proliferating astrocytes were ablated, or removed, there was not a significant decrease in the number of reactive glial cells.

They concluded that proliferating astrocytes were not a large component of the reactive astrocytes contributing to acute motor neuron disease.

The chronic mouse model, which implies a slower onset and progression of disease-like symptoms, is more representative of ALS. In this case, the number of proliferating astrocytes was also reduced but found not to be the main contributor to reactive astrogliosis.

Additionally, if the proliferating astrocytes were ablated, the disease-like symptoms were retained, indicating that cell death of motor neurons was still occurring.

In each of these models, there was an increase in the number of astrocytes present, though they may not have been actively dividing at the time.

For a chronic disease like ALS, if large numbers of astrocytes proliferate over a long period of time, there could still be a significant effect on astrogliosis.

Though the researchers did not find improved symptoms if proliferating astrocytes were ablated, they were able to better define the role of these astrocytes in terms of nervous system injury and degeneration.

They determined that proliferating astrocytes are a relatively small contributor to the symptoms of the disease, but that they are in fact present in reactive astrogliosis.

Scientists Develop Yeast-Based Genetic Screen for Protein Linked to ALS and FTD

Researchers from the University of Pennsylvania School of Medicine have developed a yeast model that can screen for proteins that combat certain neurodegenerative diseases.

Past research has found a number of mutations in a disease protein called TDP-43, which is implicated in amyotrophic lateral sclerosis (ALS) and certain types of frontotemporal dementia (FTD), the scientists comment.

Based on these studies suggesting TDP-43 as a cause of ALS and FTD, the Penn team created a yeast model to express this protein. They found that TDP-43 formed clumps in the yeast model in the same way that it does in human nerve cells. They also identified particular segments of the mutated TDP-43 protein that cause it to aggregate and which parts cause it to be toxic.

The scientists were able to replicate the clumping process of proteins, which takes decades in humans, within hours in yeast cells. This allows for visualization of the clumping, rapid genetic screening to identify proteins that can reverse the harmful effects of the disease protein, and testing molecules that could eliminate or prevent clumping.

The Penn team is now pursuing drug screens with their TDP-43 model. The current study also involved scientists from Johns Hopkins and the Whitehead Institute for Biomedical Research. Findings are published in this weeks advance online issue of the Proceedings of the National Academy of Sciences.

Formaldehyde Exposure May Increase Risk Of ALS Disease

People exposed to formaldehyde - a chemical used mostly in household products - have increased risk for developing amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease.

Researchers from Harvard School of Public Health examined the link between ALS and 12 types of chemicals. Study was initially focused on affect of pesticides and herbicides, but later they found formaldehyde to be increasing the risk for developing the disease.

The study examined 1100 people who were questioned about the levels of formaldehyde exposure. The study began in 1982 and followed the participants during 15 years. Those who were exposed to the chemical showed to be 34% more likely to develop amyotrophic lateral sclerosis than those exposed to other chemicals.

People with certain jobs - 'beautician, pharmacist, mortician, chemist, lab technician, dentist, fireman, photographer, printer, nurse, doctor and veterinarian' - are also at 30% more likely to develop ALS than people with other professions, because they are being exposed to chemicals constantly.

Formaldehyde is a chemical widely used in wood products. It's used in press fabrics, glues, shampoos, and cosmetics. Formaldehyde is also used in laboratories and mortuaries for preserving tissues and for disinfecting.

Amyotrophic lateral sclerosis is a disease also named as Lou Gehrig's disease, because in 1941 Lou Gehrig - New York Yankees baseball player - died of ALS. The disease kills nerve cells in brain and spinal cord called motor neurons. These cells are responsible for muscle movements. Annually, ALS affects about 5600 people in US.

Chemical Exposure May Increase Risk Of ALS, Study Shows

ScienceDaily (Apr. 17, 2008) — Preliminary results show that a common environmental chemical may increase the risk of developing amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, according to new research.

The study was based on the Cancer Prevention Study II of the American Cancer Society. Over one million people were asked to report their exposure to 12 types of chemicals. The participants were followed for 15 years, and the number of people who died during that time of ALS was tracked. A total of 617 men and 539 women died from ALS during the study.

Researchers found no significant link between ALS and exposure to most chemicals, including pesticides and herbicides. People who reported that they had regular exposure to formaldehyde, however, were 34 percent more likely to develop ALS than those with no exposure to formaldehyde.

"Although this finding could well be a chance observation, it merits further investigation, particularly because people with longer exposure to formaldehyde had a greater risk of developing ALS than those with shorter exposures," said study author Marc Weisskopf, PhD, of Harvard University in Boston. "People who reported 10 or more years of exposure were almost four times as likely to develop ALS as those with no exposure."

Weisskopf said the results are preliminary and more research needs to be done to test the results. "This finding was somewhat surprising, because formaldehyde has not been raised as an issue in ALS before," he said.

Formaldehyde is used in particle board and other wood products, permanent press fabrics, glues, and other household products, such as cosmetics and shampoo. It is also used as a preservative in medical laboratories and mortuaries, and as an industrial disinfectant.

Weisskopf noted that the participants were asked about their exposure to formaldehyde and other chemicals in 1982. In 1987, formaldehyde was classified as a probable human carcinogen at high exposure levels by the U.S. Environmental Protection Agency in 1987.

"Exposure since then has generally decreased, but it certainly isn't gone," he said.

This research was presented at the American Academy of Neurology 60th Anniversary Annual Meeting in Chicago, April 16, 2008.

The study was supported by a grant from the U.S. Department of Defense.

Leaky blood vessels open up nerve cells to toxic assault in Lou Gehrig's disease

Leaky blood vessels that lose their ability to protect the spinal cord from toxins may play a role in the development of amyotrophic lateral sclerosis, better known as ALS or Lou Gehrigs disease, according to research published in the April issue of Nature Neuroscience.

The results mark the first time that scientists have witnessed molecular changes occurring long before key nerve cells start dying. The unexpected finding opens up a new front in studies of ALS, a disease in which motor neurons in the spinal cord die off for unknown reasons, resulting in dramatically weakened muscles. Patients lose their strength, their ability to move or swallow, and eventually lose their ability even to breathe. Most patients live only a few years after diagnosis.

We believe these changes contribute to or possibly initiate the onset of ALS, said lead author Berislav Zlokovic, M.D., Ph.D., of the University of Rochester Medical Center. Its clear that these changes occur before the loss of neurons, and its well known that the types of changes we are seeing certainly injure or kill these types of cells, which are extremely sensitive to their biochemical environment.

The results, discovered by studying mutant mice that have an inherited form of the disease, were made by a collaboration of neuroscientists from the University of Rochester Medical Center working together with a team of ALS experts from the University of California at San Diego. Zlokovic, a pioneer in learning how the bodys vascular system plays a role in neurodegenerative diseases like Alzheimers disease and ALS, led the team, and the first author is post-doctoral researcher Zhihui Zhong, Ph.D.

While its unlikely the new findings will help ALS patients immediately, the results open up a new and unexpected way to think about the disease. Zlokovics team is currently testing in the laboratory a compound that may help seal up leaky vessels and protect the neurons targeted by ALS.

The team studied mice with a mutation in a gene for superoxide dismutase 1 (SOD-1), which in healthy people and mice plays an important role keeping cells safe from damaging molecules known as free radicals. Scientists estimate that SOD-1 mutations play a role in a small number of cases of ALS overall in people, about one-quarter of the 10 percent or so of cases that are inherited. But those cases provide a unique window to study the diseases initial steps.

In the Nature Neuroscience paper, the group from Rochesters Center for Neurodegenerative and Vascular Brain Disorders and UCSD showed that a breakdown in the natural barrier between the blood and the spinal cord breaks down early on in mice destined to get ALS, long before nerve cells appear sick or die.

In this work, the team showed that the barrier between the blood and the spinal cord weakens in all three types of genetically based ALS cases that involve SOD-1 mutations, allowing toxic substances to flood into the spinal cord and directly affect neurons.

That barrier is crucial for the health of our central nervous system, which is treated like the inner sanctum of the body. Like a high-performance race car that demands a choice fuel, our neurons work well only if the chemical environment in the brain and spinal cord is precisely maintained within a strict, narrow set of conditions.

To maintain that select environment, the body has strict barriers or gateways for substances entering or exiting the central nervous system. Blood vessels run through our brain and spinal cord and supply oxygen and other nutrients, and the lining of those blood vessels constitutes a biochemical barrier to protect the central nervous system from toxins, inflammatory cells, red blood cells, blood products, and a variety of other potential toxic insults.

The barrier between the blood and the spinal cord isnt some stand-alone structure that keeps all substances away from the spinal cord. Rather, the word barrier describes an elaborate molecular lattice that lines the insides of the blood vessels that weave throughout the spinal cord. The lattice controls which molecules can cross from the blood to the neurons in the spinal cord, and which cannot. Its a bit like netting with very small openings that line the inside of blood vessels.

Oxygen and many nutrients get the OK to pass through the barrier in measured amounts. And the barrier readily accepts waste products from the spinal cord, transporting them away from the central nervous system and eventually out of the body. But the netting should be taut and should bar substances in the blood that have no business being near neurons.

The team found that a SOD-1 mutation disrupted key building blocks in the barrier. Essentially, the mutations loosened the lattice, creating bigger holes in the barrier that allowed molecular interlopers to pass from the blood to the spinal cord.

Mice with the mutation had lower levels of three types of tight junction proteins that are key components of the barrier: ZO-1, occludin and claudin-5. In mice just two months old, the numbers of those important tight junction proteins in the linings of blood vessels were reduced by about half, by 40 to 60 percent, allowing the lattice to loosen abnormally.

The weakened barrier brought about several problems. Neurons were exposed directly to biochemical byproducts of hemoglobin, which forms reactive oxygen molecules that injure neurons. Where the barrier had weakened, tiny hemorrhages dotted the spinal column. The smallest blood vessels crucial to nerve health shrunk: Mice with the mutation had total capillary length in the spinal cord 10 to 15 percent less than healthy mice, and their blood flow in the spinal cord was reduced by 30 to 45 percent.

Scientists must investigate whether the same processes happen in forms of ALS that are not inherited. Zlokovic notes that from what is known so far, the disease progresses exactly in inherited forms and forms that are not inherited.

The vascular system is crucial to health its how oxygen and other nutrients are delivered to cells, and how toxins are removed, said Zlokovic, who is professor of Neurosurgery and Neurology and director of the Center for Neurodegenerative and Vascular Brain Disorders. Any damage to the vascular system is a serious threat to the organism. Its clear now that the vascular system is certainly involved in the development of ALS.

Zlokovic first began doing research on the disease in 2004, when a former classmate from medical school who had been diagnosed with ALS and was looking for new treatments contacted him. By the time his friend died two years later, Zlokovic was well underway in studies investigating the possible role of the vascular system.

During the last 15 years, Zlokovic has pioneered the view that the vascular system plays a central role in many neurodegenerative diseases. He has found that a breakdown in the barriers between the blood and the central nervous system may be at the root of diseases like Alzheimers. In January, Zlokovic reviewed the evidence for involvement of the barrier in diseases like Alzheimers, ALS, and multiple sclerosis in a 24-page review in Neuron.

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The research team included Zlokovic, Zhong, and Don Cleveland, Ph.D., a widely recognized ALS expert who is a researcher at the University of California at San Diego. Previously, Cleveland has shown that cells besides neurons in the spinal cord, such as astrocytes and microglia, have an effect on the course of the disease.

Other authors of the paper include Rashid Deane, Ph.D., associate professor; medical student Zarina Ali; technical associate Margaret Parisi; Kerry OBanion, M.D., Ph.D., associate professor of Neurobiology and Anatomy; graduate student Yuriy Shapovalov; former student Konstantin Stojanovic; post-doctoral researcher Abhay Sagare, Ph.D.; and post-doctoral fellow Sverine Boille of UCSD. The National Institutes of Health and the Muscular Dystrophy Association funded the work.

New Gene Responsible For Lou Gehrig's Disease Identified

ScienceDaily (Mar. 31, 2008) — A team of Canadian and French researchers has identified a novel gene responsible for a significant fraction of ALS (sporadic amyotrophic lateral sclerosis) cases. ALS is commonly referred to as Lou Gehrig's disease, an incurable neuromuscular disorder that affects motor neurons and leads to paralysis and death within one to five years.

The team identified several genetic mutations in the TDP-43 gene by studying ALS patients from France and Quebec. They established TDP-43 as the gene responsible for up to five percent of the ALS patients.

Published in Nature Genetics, the study on 200 human subjects with ALS was led by Doctors Guy Rouleau, Edor Kabashi, Paul Valdmanis of the Research Centre of the Centre hospitalier de l'Université de Montréal (CRCHUM).

The breakthrough is the result of teamwork with peers from the Waterloo and Laval universities in Canada and the Fédération des maladies du système nerveux and the Institute of Biology (Unité de Neurologie Comportementale et Dégénérative) in France.

Building on past studies

In 1993, Dr. Rouleau and his team also helped identify "superoxide dismutase" as the gene that causes the disease in 10 to 20 percent of all familial cases of ALS. This cornerstone study led to development of several mouse and rat models of ALS that closely resemble the motor neuron disorder observed in ALS patients. These models have been very useful to study molecular and cellular mechanisms of disease and to test treatments for ALS.

TDP-43's normal function is to bind and splice RNA. Two years ago, a team from the University of Pennsylvania discovered TDP-43 in abnormal protein clumps, referred to as aggregates, in motor neurons of ALS patients. However, it was not certain whether TDP-43 causes motor neuron disease or is just a pathological marker.

"The identification of additional mutations in TDP-43 in other ALS patients will confirm that this gene is a prominent cause of this type of disorder," said Dr. Rouleau, director of the Sainte-Justine Hospital Research Centre. "Animal models over-expressing the mutations identified in this study will provide crucial insight into how TDP-43 aggregate and ultimately kill motor neurons."

"This discovery is a step towards the development of therapies for people suffering from this terrible disease and possibly other neurodegenerative diseases," said Dr. Kabashi.

Drs. Rouleau and Kabashi are financially supported by the Canadian Institutes of Health Research (CIHR) and ALS Canada. Their research was also funded by the Muscular Dystrophy Association and the ALS Association.

Toxic organophosphates appear to contribute to motor neuron disease

Motor neuron disease is a rare, devastating illness in which nerve cells that carry brain signals to muscles gradually deteriorate.

One form of it, Lou Gehrig's disease or ALS (amyotrophic lateral sclerosis), is familiar to the public in the lives of scientist Stephen Hawking and Morrie Schwartz, about whom Mitch Albom's "Tuesdays with Morrie" was written.

For most MND patients, the cause is unknown. Figuring out why these people develop the disease, which causes muscles to weaken, atrophy and cease to function, is an important step in developing therapies to treat or prevent motor neuron disease.

Now a team of University of Michigan scientists has gotten a step closer:

• They have discovered mutations in one key gene (neuropathy target esterase, or NTE) that cause a previously unknown type of inherited motor neuron disease.
  
• The discovery paves the way for better diagnosis and research on treatments.
  Most intriguing, the scientists found the mutations caused changes in a protein already known to be involved when people develop neurologic disorders as a result of exposure to toxic organophosphates-chemicals commonly used in solvents and insecticides and also as "nerve gas" agents. This discovery points to a new lead in the search to understand MND.
  
• "We speculate there may be gene-environment interactions that cause some forms of motor neuron disease," says John K. Fink, M.D., professor of neurology at the U-M Medical School and senior author of the new study, which appears in the March issue of the American Journal of Human Genetics. He also is a researcher at the VA Ann Arbor Healthcare System.
  

"Our findings support the possibility that toxic organophosphates contribute to motor neuron disease in genetically vulnerable people," says Fink. He believes the results suggest that altered activity of the gene found in patients in the study may also contribute to other motor neuron disorders, possibly including ALS. Motor neuron disease affects five per 100,000 people.

The findings are an exciting first step in uncovering a possible link between the environment and motor neuron disease, says Shirley Rainier, a research assistant professor at the U-M Department of Neurology and the first author of the study. "Why does one person in a family get it, and another doesn't""

Piecing together a puzzle

In the 1930s, an estimated 50,000 people in the U.S. became lame or otherwise neurologically affected by neurotoxic organophosphates when they drank a contaminated batch of "ginger jake," an alcohol-containing potion that was legal during Prohibition.

Ginger jake suppliers substituted a lubricating oil for the oil usually used, castor bean oil, when castor bean prices went up. A 2003 article in the New Yorker detailed the sad results, which led bands like the Mississippi Sheiks to write songs about the "ginger jake blues."

More recently, there have been incidents in Fiji, India and Africa when accidental consumption of oils containing neurotoxic organophosphates (instead of cooking oil) caused death or nerve damage for tens of thousands of people. Although scientists don't yet know the exact manner in which toxic organophosphate exposure leads to progressive and permanent nerve damage, they have learned that this process involves disturbance of an enzyme, NTE, contained within nerves.

Fink examined members of two families who had progressive weakness and spasticity (tightness) in their legs, as well as muscle atrophy in their hands, shins and feet. James Albers, M.D., Ph.D., a U-M professor of neurology and an expert in neuromuscular disorders, studied nerve and motor function. Rainier performed genetic studies and determined that the gene for the condition was on a region of chromosome 19.

Mark Leppert, Ph.D., co-chair of human genetics at the University of Utah, and his team performed genetic analysis that confirmed this location and excluded other areas in the genome. Among the many genes in this region of chromosome 19, one gene stood out as particularly likely: the gene that encodes for NTE. Because of its known role in organophosphate-induced neurological disease, the NTE gene was considered an important candidate gene and was studied immediately.

Analysis showed that the affected people in each family had NTE gene mutations. These mutations altered a critical part of the NTE protein called the esterase domain. Fink has named the inherited condition "NTE motor neuron disease." It begins in childhood and progresses slowly, with symptoms of weakness and spasticity in the legs and muscle atrophy in the hands and lower legs.

Next, Fink and his team want to learn if mutations in the NTE gene happen in other types of motor neuron disease such as ALS, and if the mutations make a person more vulnerable to neurological damage from organophosphate exposure. Fink's lab is currently using fruit flies as a model to study the NTE mutations, with the goal of finding treatments for people with motor neuron disease.

Study shows ALS aggregates are composed of only one protein

Washington, Mar 23 (ANI): A new study has provided a big clue to help fight amyotrophic lateral sclerosis (ALS), by discovering that the dense protein aggregates that contribute to the nerve decay of ALS are composed of just one protein - superoxide dismutase (SOD1).

Usually familial ALS is characterised by the aggregation of mutated SOD1, a protein that normally protects cells from free radical damage. However, the exact composition of these aggregates is not clear. Thus, identifying the other proteins present and if they are modified in any way could help answer how they form and why they are so toxic.

The study, led by Julian Whitelegge, made use of mass spectrometry to uncover the components of these aggregates and to their surprise the researchers discovered that they were composed almost entirely of SOD1.

However, some samples contained trace amounts of random abundant nerve proteins that likely got there by happenstance.

Besides, after analysing ALS mouse spinal cords, it was shown that almost all the SOD1 was fully intact protein and not partial or damaged fragments. Similarly, no evidence was found for extensive chemical modifications (that were not readily removed by DTT treatment).

Though there are many questions still remaining about these aggregates, the study has given provided a starting point, indicating that aggregation is an intrinsic property of mutant SOD1, just like the amyloid plaques associated with Alzheimers.

ALS Aggregates Are Composed of Only One Protein

Researchers have provided a big new clue to help combat amyotrophic lateral sclerosis (ALS), deciphering that the dense protein aggregates that contribute to the nerve decay of ALS are composed of just one protein: superoxide dismutase (SOD1).

While the aggregation of mutated SOD1, a protein that normally protects cells from free radical damage, is a tell-tale sign of familial ALS, the exact composition of these aggregates has been unclear. Identifying the other proteins present and if they are modified in some way could help answer how they form and why they are so toxic.

In a study appearing online in JBC March 21, Julian Whitelegge and colleagues Joan S. Valentine and David Borchelt used mass spectrometry to uncover the components of these aggregates and discovered, somewhat surprisingly, that they were composed almost entirely of SOD1 (some samples contained trace amounts of random abundant nerve proteins that likely got there by happenstance).

In addition, their analysis of ALS mouse spinal cords showed almost all the SOD1 was fully intact protein and not partial or damaged fragments. Likewise, the researchers did not find evidence for extensive chemical modifications (that were not readily removed by DTT treatment).

While many questions about these aggregates still remain, this study has given scientists a starting point, suggesting that aggregation is an intrinsic property of mutant SOD1, very much like the amyloid plaques associated with Alzheimer’s.

Motor Neuron Disease and Toxic Exposure: Possible Link?

University of Michigan scientists have found that people with a form of inherited motor neuron disease have abnormalities in the same gene that appears to be affected in people who suffer nerve damage after exposure to harmful amounts of organophosphates, chemicals used in insecticides and nerve gas.

Motor neuron disease is a rare, devastating illness in which nerve cells that carry brain signals to muscles gradually deteriorate. One form of it, Lou Gehrig’s disease or ALS (amyotrophic lateral sclerosis), is familiar to the public in the lives of scientist Stephen Hawking and Morrie Schwartz, about whom Mitch Albom’s “Tuesdays with Morrie” was written.

For most MND patients, the cause is unknown. Figuring out why these people develop the disease, which causes muscles to weaken, atrophy and cease to function, is an important step in developing therapies to treat or prevent motor neuron disease.

Now a team of University of Michigan scientists has gotten a step closer:
* They have discovered mutations in one key gene (neuropathy target esterase, or NTE) that cause a previously unknown type of inherited motor neuron disease.
* The discovery paves the way for better diagnosis and research on treatments.
* Most intriguing, the scientists found the mutations caused changes in a protein already known to be involved when people develop neurologic disorders as a result of exposure to toxic organophosphates—chemicals commonly used in solvents and insecticides and also as “nerve gas” agents. This discovery points to a new lead in the search to understand MND.

“We speculate there may be gene-environment interactions that cause some forms of motor neuron disease,” says John K. Fink, M.D., professor of neurology at the U-M Medical School and senior author of the new study, which appears in the March issue of the American Journal of Human Genetics. He also is a researcher at the VA Ann Arbor Healthcare System.

“Our findings support the possibility that toxic organophosphates contribute to motor neuron disease in genetically vulnerable people,” says Fink. He believes the results suggest that altered activity of the gene found in patients in the study may also contribute to other motor neuron disorders, possibly including ALS. Motor neuron disease affects five per 100,000 people.

The findings are an exciting first step in uncovering a possible link between the environment and motor neuron disease, says Shirley Rainier, a research assistant professor at the U-M Department of Neurology and the first author of the study. “Why does one person in a family get it, and another doesn’t?”

Piecing together a puzzle

In the 1930s, an estimated 50,000 people in the U.S. became lame or otherwise neurologically affected by neurotoxic organophosphates when they drank a contaminated batch of “ginger jake,” an alcohol-containing potion that was legal during Prohibition.

Ginger jake suppliers substituted a lubricating oil for the oil usually used, castor bean oil, when castor bean prices went up. A 2003 article in the New Yorker detailed the sad results, which led bands like the Mississippi Sheiks to write songs about the “ginger jake blues.”

More recently, there have been incidents in Fiji, India and Africa when accidental consumption of oils containing neurotoxic organophosphates (instead of cooking oil) caused death or nerve damage for tens of thousands of people. Although scientists don’t yet know the exact manner in which toxic organophosphate exposure leads to progressive and permanent nerve damage, they have learned that this process involves disturbance of an enzyme, NTE, contained within nerves.

Fink examined members of two families who had progressive weakness and spasticity (tightness) in their legs, as well as muscle atrophy in their hands, shins and feet. James Albers, M.D., Ph.D., a U-M professor of neurology and an expert in neuromuscular disorders, studied nerve and motor function. Rainier performed genetic studies and determined that the gene for the condition was on a region of chromosome 19.

Mark Leppert, Ph.D., co-chair of human genetics at the University of Utah, and his team performed genetic analysis that confirmed this location and excluded other areas in the genome. Among the many genes in this region of chromosome 19, one gene stood out as particularly likely: the gene that encodes for NTE. Because of its known role in organophosphate-induced neurological disease, the NTE gene was considered an important candidate gene and was studied immediately.

Analysis showed that the affected people in each family had NTE gene mutations. These mutations altered a critical part of the NTE protein called the esterase domain. Fink has named the inherited condition “NTE motor neuron disease.” It begins in childhood and progresses slowly, with symptoms of weakness and spasticity in the legs and muscle atrophy in the hands and lower legs.

Next, Fink and his team want to learn if mutations in the NTE gene happen in other types of motor neuron disease such as ALS, and if the mutations make a person more vulnerable to neurological damage from organophosphate exposure. Fink’s lab is currently using fruit flies as a model to study the NTE mutations, with the goal of finding treatments for people with motor neuron disease.

Other authors include Melanie Bui, Erin Mark, Donald Thomas, Debra Tokarz, Lei Ming, Colin Delaney, and James W. Albers, M.D., Ph.D., of the U-M Department of Neurology; Rudy J. Richardson, D.Sc, associate professor of neurology at U-M Medical School and Dow Professor of Toxicology in Environmental Health Sciences at the U-M School of Public Health; and Nori Matsunami, Jeff Stevens, Hilary Coon and Mark Leppert, Ph.D. of the University of Utah.

A patent application for the use of the NTE gene and protein sequence for diagnosis and treatment is pending. The University of Michigan through its Office of Technology Transfer is actively seeking a licensing partner to help bring the technology to market.

Citation: American Journal of Human Genetics, Volume 82, Issue 3, 780-785, 3 March 2008

Funds for this research came from the National Institutes of Health, the Veterans Affairs Merit Review, the U-M Institute of Gerontology, the Spastic Paraplegia Foundation and the National Organization for Rare Disorders

Gene newly linked to inherited ALS may also play role in common dementia

By Michael Purdy

Feb. 20, 2008 -- Scientists at Washington University School of Medicine in St. Louis have linked a mutation in a gene known as TDP-43 to an inherited form of amyotrophic lateral sclerosis (ALS), the neurodegenerative condition often called Lou Gehrig's disease.

Researchers found the connection intriguing because studies by other groups have revealed abnormalities in the TDP-43 protein in both sporadic and inherited ALS, as well as in several other neurodegenerative disorders.

"The potential link to sporad