Neuroscience

Articles and news from the latest research reports.

Posts tagged parkinson

15 notes

Personalized medicine closer to reality: Study uses stem cells to study variants of Parkinson’s disease

July 16, 2012

A nationwide consortium of scientists at 20 institutions, led by a principal faculty member at the Harvard Stem Cell Institute (HSCI), has used stem cells to take a major step toward developing personalized medicine to treat Parkinson’s disease.

This study points the way to screening patients with Parkinson’s for their particular variation of the disease, and then treating them with drugs shown effective to work on that variation, rather than trying to treat all patients with the same drugs, as is generally done now, notes Ole Isacson, a leader of the study. Credit: B. D. Colen/Harvard Staff

In part supported by the Harvard Miller Consortium for the Development of Nervous System Therapies, the team of scientists created induced pluripotent stem cells (iPS cells) from the skin cells of patients and at-risk individuals carrying genetic mutations implicated in Parkinson’s disease, and used those cells to derive neural cells, providing a platform for studying the disease in human cells outside of patients.

In a paper published in the journal Science Translational Medicine, the researchers report that although approximately 15 genetic mutations are linked to forms of Parkinson’s, many seem to affect the mitochondria, the cell unit that produces most of its energy.

“This is the first comprehensive study of how human neuronal cells can be models of Parkinson’s, and how it might be treated,” said Ole Isacson, a leader of the study, an HSCI principal faculty member, and a Harvard Medical School professor of neurology, based at McLean Hospital’s Neuroregeneration Laboratory.

The researchers determined that certain compounds or drugs could reverse some signs of disease in the cultured cells with specific genetic mutations, and not in cells with other types of mutations, making real the concept of developing drugs that would be prescribed to patients or individuals at risk for Parkinson’s.

The study was launched with federal stimulus funding provided by the National Institutes of Health (NIH) and was continued with funding from HSCI.

“These findings suggest new opportunities for clinical trials of Parkinson’s disease, wherein cell reprogramming technology could be used to identify the patients most likely to respond to a particular intervention,” said Margaret Sutherland, a program director at NIH’s National Institute of Neurological Disorders and Stroke, in a press release.

The new research indicates that compounds that previously have shown promise in treating Parkinson’s in animal studies, including the antioxidant coenzyme Q10, together with the immunosuppressant rapamycin, have differing levels of effectiveness on various genetic forms of Parkinson’s.

Researchers hope that such findings can provide the basis for more specific drugs for individuals with sporadic forms of Parkinson’s.

As Isacson explained in an interview, this study points the way to screening patients with Parkinson’s for their particular variation of the disease, and then treating them with drugs shown effective to work on that variation, rather than trying to treat all patients with the same drugs, as is generally done now.

“We believe that using human stem cells to study the disease is the correct way to go,” Isacson said. “We have the cell type most vulnerable to the disease in a dish. We can study the most vulnerable cells and compare them to the least vulnerable cells. Traditionally, in neurology,” he said, “all patients with the same disease get the same drugs. But they may have the disease for different reasons. This gives us a way to tease out those different reasons, and find different ways to treat them.”

Provided by Harvard University

Source: medicalxpress.com

Filed under science neuroscience brain psychology stem cells parkinson

4 notes

Adult Stem Cells from Bone Marrow: Cell Replacement/Tissue Repair Potential in Adult Bone Marrow Stem Cells in Animal Model

ScienceDaily (July 3, 2012) — searchers from the University of Maryland School of Maryland report promising results from using adult stem cells from bone marrow in mice to help create tissue cells of other organs, such as the heart, brain and pancreas — a scientific step they hope may lead to potential new ways to replace cells lost in diseases such as diabetes, Parkinson’s or Alzheimer’s.

The research in collaboration with the University of Paris Descartes is published online in the June 29, 2012 edition of Comptes Rendus Biologies, a publication of the French Academy of Sciences.

"Finding stem cells capable of restoring function to different damaged organs would be the Holy Grail of tissue engineering," says lead author David Trisler, PhD, assistant professor of neurology at the University of Maryland School of Medicine.

He adds, “This research takes us another step in that process by identifying the potential of these adult bone marrow cells, or a subset of them known as CD34+ bone marrow cells, to be ‘multipotent,’ meaning they could transform and function as the normal cells in several different organs.”

University of Maryland researchers previously developed a special culturing system to collect a select sample of these adult stem cells in bone marrow, which normally makes red and white blood cells and immune cells. In this project, the team followed a widely recognized study model, used to prove the multipotency of embryonic stem cells, to prove that these bone marrow stem cells could make more than just blood cells. The investigators also found that the CD34+ cells had a limited lifespan and did not produce teratomas, tumors that sometimes form with the use of embryonic stem cells and adult stem cells cultivated from other methods that require some genetic manipulation.

"When taken at an early stage, we found that the CD34+ cells exhibited similar multipotent capabilities as embryonic stem cells, which have been shown to be the most flexible and versatile. Because these CD34+ cells already exist in normal bone marrow, they offer a vast source for potential cell replacement therapy, particularly because they come from a person’s own body, eliminating the need to suppress the immune system, which is sometimes required when using adults stem cells derived from other sources," explains Paul Fishman, MD, PhD, professor of neurology at the University of Maryland School of Medicine.

The researchers say that proving the potential of these adult bone marrow stem cells opens new possibilities for scientific exploration, but that more research will be needed to see how this science can be translated to humans.

Source: Science Daily

Filed under science neuroscience brain parkinson alzheimer

9 notes

Years Before Diagnosis, Quality of Life Declines for Parkinson’s Disease Patients

ScienceDaily (July 2, 2012) — Growing evidence suggests that Parkinson’s disease (PD) often starts with non-motor symptoms that precede diagnosis by several years. In the first study to examine patterns in the quality of life of Parkinson’ disease patients prior to diagnosis, researchers have documented declines in physical and mental health, pain, and emotional health beginning several years before the onset of the disease and continuing thereafter.

Their results are reported in the latest issue of Journal of Parkinson’s Disease.

"We observed a decline in physical function in PD patients relative to their healthy counterparts beginning three years prior to diagnosis in men and seven and a half years prior to diagnosis in women," says lead investigator Natalia Palacios, PhD, Department of Nutrition, Harvard School of Public Health. "The decline continues at a rate that is five to seven times faster than the average yearly decline caused by normal aging in individuals without the disease."

The study included 51,350 male health professionals enrolled in the Health Professionals Follow Up Study (HPFS) and 121,701 female registered nurses enrolled in the Nurses’ Health Study (NHS). In both ongoing studies, participants fill out biannual questionnaires about a variety of lifestyle characteristics and document the occurrence of major chronic disease. In the NHS study, questionnaires measured health-related quality of life in eight areas: physical functioning, role limitations due to physical problems, role limitations due to emotional problems, vitality, bodily pain, social functioning, mental health, and general health perceptions. In the HPFS, only physical functioning was assessed.

Researchers identified 454 men and 414 women with PD in the two cohorts. At 7.5 years prior to diagnosis, physical function among PD cases, in both men and women, was comparable to that in the overall cohort. A decline began approximately 3 years prior to diagnosis in men and approximately 7.5 years prior to diagnosis in women. Physical function continued to decline thereafter at a rate of 1.43 and 2.35 points per year in men and women, respectively. In comparison, the average yearly decline in individuals without PD was 0.23 in men and 0.42 in women. Other measures of quality of life, available only in women, declined in a similar pattern.

Dr. Palacios notes that a strength of the study is the availability of prospective data on both PD patients and a healthy comparison group, and the ability to chart the deterioration in functioning and quality of life over the whole study follow-up, which included many years prior to diagnosis.

"This result provides support to the notion that the pathological process leading to PD may start several years before PD diagnosis," says Dr. Palacios. "Our hope is that, with future research, biological markers of the disease process may be recognizable in this preclinical phase."

Source: Science Daily

Filed under science neuroscience brain psychology parkinson

10 notes

Finding Brings Scientists One Step Closer to Parkinson’s Drug

June 27th, 2012

Long-term aim is to develop new treatments to block the spread of damaged proteins in the brain.

Van Andel Institute announces that researchers at Lund University in Sweden have published a study detailing how Parkinson’s disease spreads through the brain. Experiments in rat models uncover a process previously used to explain mad cow disease, in which misfolded proteins travel from sick to healthy cells. This model has never before been identified so clearly in a living organism, and the breakthrough brings researchers one step closer to a disease-modifying drug for Parkinson’s.

“Parkinson’s is the second most common neurodegenerative disorder after Alzheimer’s disease,” said Patrik Brundin M.D., Ph.D., Jay Van Andel Endowed Chair in Parkinson’s Research at Van Andel Research Institute (VARI), Head of the Neuronal Survival Unit at Lund University and senior author of the study. “A major unmet medical need is a therapy that slows disease progression. We aim to better understand how Parkinson’s pathology progresses and thereby uncover novel molecular targets for disease-modifying treatments.”

Previous research demonstrates that a misfolded protein known as alpha-synuclein protein gradually appears in healthy young neurons transplanted to the brains of Parkinson’s patients. This discovery gave rise to the group’s hypothesis of cell-to-cell protein transfer, which has since been demonstrated in laboratory experiments.

In the current study, published this week in the Public Library of Science (PLoS ONE), researchers for the first time were able to follow events in the recipient cell as it accepts the diseased protein by allowing it to pass its outer cell membrane. The experiments also show how the transferred proteins attract proteins in the host cell leading to abnormal folding or “clumping” inside the cells.

Coronal section at the level of the gyrus diagonalis of a rat transplanted with VM tissue six weeks after AAV2/6-huαsyn injection and sacrificed four weeks after grafting. The immunohistochemical analysis with antibodies directed against huαsyn shows the overexpression of this protein in the axon terminals of the right striatum. The center of the bilateral grafts is marked with an asterisk. On the right, the graft is clearly located in the area devoid of signal. The image and description were adapted from a PLoS ONE research paper image credited at the end of this article. doi:10.1371/journal.pone.0039465.g001

“This is a cellular process likely to lead to the disease process as Parkinson’s progresses, and it spreads to an increasing number of brain regions as the patient gets sicker,” said Elodie Angot, Ph.D., of Lund University’s Neuronal Survival Unit, and lead co-author of the study.

“In our experiments, we show a core of unhealthy human alpha-synuclein protein surrounded by alpha-synuclein produced by the rat itself. This indicates that this misfolded protein not only moves between cells but also acts as a “seed” attracting proteins produced by the rat’s brain cells,” said Jennifer Steiner, Ph.D., of Lund University and Van Andel Institute’s Center for Neurodegenerative Science, the study’s other lead author.

These findings are consistent with results from previous laboratory cell models and for the first time extend this observation into a living organism. However, it remains unclear exactly how alpha-synuclein gains access from the extracellular space to the cytoplasm of cells to act as a template for naturally occurring alpha-synuclein, causing the naturally-occurring protein to, in turn, misfold. Further studies are needed to clarify this important step in the process.

The discovery does not reveal the root of Parkinson’s disease, but in conjunction with disease models developed by Lund University researchers and others, could enable scientists to develop new drug targets aimed at mitigating or slowing the effects of the disease, which currently strikes more than 1% of people over the age of 65.

Source: Neuroscience News

Filed under science neuroscience brain psychology parkinson

9 notes

Parkinson’s Disease Gene Identified With Help of Saskatchewan Mennonite Families

ScienceDaily (June 27, 2012) — An international team including scientists from the University of Saskatchewan-Saskatoon Health Region and University of British Columbia, with the help of Saskatchewan Mennonite families, has identified an abnormal gene which leads to Parkinson’s disease.

"This discovery paves the way for further research to determine the nature of brain abnormalities which this gene defect produces," says Dr. Ali Rajput, a world expert in Parkinson’s disease who has been studying the disease for 45 years and working with the main family in the study since 1983.

"It also promises to help us find ways to detect Parkinson’s disease early, and to develop drugs which will one day halt the progression of the disease."

The abnormal gene is a mutated version of a gene called DNAJC13, identified by UBC medical genetics professor Matthew Farrer, who led the study.

Thirteen of 57 members of one extended Saskatchewan family in the study had been previously diagnosed with Parkinson’s disease. Three other single cases from Saskatchewan and one family from British Columbia were also found to have the same mutation. All were of Mennonite background, a Christian group who share Dutch-German-Russian ancestry.

The findings were presented last week to the more than 5,000 delegates at the 16th International Congress of Parkinson’s Disease and Movement Disorders in Dublin, Ireland.

Rajput and his son, fellow neurologist and researcher Alex Rajput, are long-time collaborators of Farrer. The research drew on the Rajputs’ work over the past four decades. The research team also includes scientists from McGill University, the Mayo Clinic in Florida, and St. Olav’s Hospital in Norway.

A key contribution is the Rajputs’ collection of more than 500 brains and nearly 2,200 blood samples from Parkinson’s patients. Farrer explains that confirmation of the gene’s linkage with Parkinson’s disease required DNA samples from thousands of patients with the disease and healthy individuals. He adds that the contributions of the Saskatchewan Mennonite family, who have asked to remain anonymous, were critical.

"A breakthrough like this would not be possible without their involvement and support. They gave up considerable time, contributed clinical information, donated blood samples, participated in PET imaging studies and — on more than one occasion following the death of a family member — donated brain samples," says Farrer, who holds the Canada Excellence Research Chair in Neurogenetics and Translational Neuroscience.

"The whole-hearted and unselfish commitment of this family is remarkable," Rajput says. "They went out of their way in every conceivable manner to help solve this mystery. We, on behalf of all the Parkinson’s disease patients in this province, Canada, and around the world, are grateful to them for making this discovery possible."

In a Parkinson’s patient, cells in an area of the brain called the substantia nigra (black substance) die and there are abnormal, round clumps of protein known as Lewy bodies inside the brain cells. Examination of the brains from the Mennonite family revealed the same Lewy body Parkinson’s disease as seen in other patients.

Parkinson’s disease is a progressive condition that causes symptoms such as tremors, slowness of movement, stiffness, and mental impairment. In most cases, symptoms appear after age 40. It is estimated that about one million people in North America and more than four million people worldwide are affected by the disease.

Source: Science Daily

Filed under science neuroscience parkinson brain psychology genetics

7 notes

Tiny Magnetic Coils Modulate Neural Activity, May Be Safer for Deep-Brain Implants

ScienceDaily (June 26, 2012) — Magnetic fields generated by microscopic devices implanted into the brain may be able to modulate brain-cell activity and reduce symptoms of several neurological disorders. Micromagnetic stimulation appears to generate the kind of neural activity currently elicited with electrical impulses for deep brain stimulation (DBS) — a therapy that can reduce symptoms of Parkinson’s disease, other movement disorders, multiple sclerosis and chronic pain — and should avoid several common problems associated with DBS, report Massachusetts General Hospital investigators.

"We have shown that fields generated by magnetic coils small enough to be implanted into the central nervous system can be used to modulate the activity of neurons, potentially leading to a new generation of neural prosthetics that are safer and possibly more effective than conventional electrical stimulation devices," says Giorgio Bonmassar, PhD, of the Martinos Center for Biomedical Imaging at MGH, co-lead author of the report in the online journal Nature Communications.

DBS involves implantation of small electrodes called leads into structures deep within the brain. The leads, connected to a battery-operated power source implanted into the abdomen, generate electrical signals that modulate neural activity at sites that vary depending on the condition being treated. DBS has successfully alleviated symptoms in patients not helped by other therapies, but it does have limitations. Magnetic resonance imaging (MRI) can cause metallic DBS implants to heat up and damage adjacent brain tissue, which limits the use of MRI in these patients. In addition, the presence of DBS implants typically elicits an immune system response, leading to scarring around the implant that can block the electrical signal.

Magnetic stimulation has been used to diagnose and treat neurological disorders for two decades, but until now it has required the use of large hand-held coils that generate fields from outside the skull, limiting the brain structures that can be stimulated and the accuracy with which a signal can be delivered. The current study was designed to investigate the potential of much smaller magnetic coils to generate the kind of neural activity produced by DBS, exploring a concept first developed by Bonmassar. The investigators first developed a computational simulation that verified that magnetic coils 1 millimeter long and .5 mm in diameter would generate magnetic and electrical fields that should stimulate neuronal activity.

The research team then tested whether a commercially available coil of that size, coated with a plastic material, would activate neurons in retinal tissue. Positioned right above retinal tissue and either parallel or perpendicular to the tissue surface, the coil generated fields that successfully elicited neuronal signals in retinal cells. How the coil was positioned relative to the retinal surface produced significant differences in the physiologic responses. When the coil was oriented parallel to the retina, the induced field appeared to activate retinal bipolar cells, which transmit signals from the light-sensing photoreceptors to retinal ganglion cells. A coil oriented perpendicular to the retina produced responses indicative of ganglion cell activation.

"These differences suggest that, by modifying the geometry of the coil, we may be able to selectively target populations of neurons and minimize the effects on non-targeted cells," says Shelley Fried, PhD, of the MGH Department of Neurosurgery, corresponding author of the Nature Communications report. “By sizing and orienting the coil appropriately to any given population of central nervous system neurons, we should be able to either activate or avoid activation of that population.

"This study provides a proof of concept that small coils can activate neurons, and much work still needs to be done," he adds. "We need to explore how to optimize coil properties and then evaluate the devices in animal models. We also hope to explore the use of these coils in non-DBS applications, including cardiovascular procedures such as heart muscle pacing." Fried is an instructor in Surgery and Bonmassar an assistant professor of Radiology at Harvard Medical School.

Source: Science Daily

Filed under science neuroscience brain parkinson psychology

10 notes

Speech algorithm detects early Parkinson’s symptoms

26 June 12 | By Liat Clark

A UK mathematician has made a public appeal for people to phone a dedicated number so data can be gathered to hone a tool that can diagnose Parkinson’s disease by analysing voice patterns.

Image: Shutterstock

Max Little, a research fellow at the Massachusetts Institute of Technology, made the announcement during the opening of the TEDGlobal conference in Edinburgh, 25 June. While studying at Oxford University, Little developed an algorithm that identifies the unique characteristics present in the voice of a Parkinson’s Disease sufferer. He setup the Parkinson’s Voice Initiative in order to improve upon the machine learning system — the algorithm is built to adapt when new information is introduced and, by widening the pool (it’s hoped, with 10,000 phone calls form the public), it should become a more accurate diagnosis tool, able to identify specific symptoms amid numerous variants of speech.

"This raises a very interesting possibility," Little says in a promotional video. "If we could use the entire existing telephone network then we could scale up the screening of Parkinson’s disease to the entire population, and do it at very minimal cost."

Other than the UK, there are phone numbers on the Parkinson’s Voice Initiative website for people in the US, Brazil, Mexico, Spain, Argentina and Canada. Parkinson’s sufferers and non-sufferers are both encouraged to call in anonymously. The calls should only last around three minutes. By getting non-sufferers to call in, the system can learn to weed out and discard unnecessary voice patterns, such as those brought on by a cold or heavy smoking.

Around 70-90 percent of sufferers report instances of vocal impairment following the onset of the disease. Little’s proposal therefore presents opportunities for widespread remote diagnosis.

He first presented the diagnosis tool’s successful testing in a paper published earlier this year in the IEEE Transactions journal. Little and co-author Athanasios Tsanas explained how 43 candidates were asked to hold one sound frequency for as long as possible. They collected 263 data samples in this way, and from this extracted 132 different vocal impairments. Using only ten of these recorded impairments, the algorithm could diagnose Parkinson’s speech markers accurately 99 percent of the time. The system is trained to identify the anomalies in the speech.

By collating more data in the future, the range of these vocal features could be widened, lessening the margin of error even more.

The paper suggests that in the future, data could be collected using Intel’s At-Home Testing Device, a telemonitoring system. It would then be sent to a clinic where the algorithm processes it and maps out the speech, identifying markers on the Unified Parkinson’s Disease Rating Scale (UPDRS) so that the severity of the illness is known. In this way, the system could not only be used to diagnose, but to monitor the progression of the disease.

Voice recognition could be a cheap and efficient alternative to having patients’ head to their GP for a twenty-minute diagnosis session. There is currently no simple diagnosis tool — no blood test that can identify Parkinson’s — and vocal tremors, breathiness and reduced speech volume are some of the first symptoms recorded in nearly all patients. These can be very subtle at the start, however, and systems such as Little’s could conceivably pick up the slightest abnormal intonation.

Parkinson’s Disease is the second most common neurodegenerative disorder after Alzheimer’s and, since it can only be treated with drugs or surgery and cannot be cured, early diagnosis can massively effect an individual’s quality of life.

Source: wired.co.uk

Filed under brain neuroscience parkinson psychology science

11 notes

'Brain pacemaker' effective for years against Parkinson's disease

June 20, 2012

A “brain pacemaker” called deep brain stimulation (DBS) remains an effective treatment for Parkinson’s disease for at least three years, according to a study in the June 2012 online issue of Neurology, the medical journal of the American Academy of Neurology.

But while improvements in motor function remained stable, there were gradual declines in health-related quality of life and cognitive abilities.

First author of the study is Frances M. Weaver, PhD, who has joint appointments at Edward Hines Jr. VA Hospital and Loyola University Chicago Stritch School of Medicine.

Weaver was one of the lead investigators of a 2010 paper in the New England Journal of Medicine that found that motor functions remained stable for two years in DBS patients. The new additional analysis extended the follow-up period to 36 months.

DBS is a treatment for Parkinson’s patients who no longer benefit from medication, or who experience unacceptable side effects. DBS is not a cure, and it does not stop the disease from progressing. But in the right patients, DBS can significantly improve symptoms, especially tremors. DBS also can relieve muscle rigidity that causes decreased range of motion.

In the DBS procedure, a neurosurgeon drills a dime-size hole in the skull and inserts an electrode about 4 inches into the brain. A connecting wire from the electrode runs under the skin to a battery implanted near the collarbone. The electrode delivers mild electrical signals that effectively reorganize the brain’s electrical impulses. The procedure can be done on one or both sides of the brain.

Researchers evaluated 89 patients who were stimulated in a part of the brain called the globus pallidus interna and 70 patients who were stimulated in a different part of the brain called the subthalamic nucleus. (Patients received DBS surgery at seven VA and six affiliated university medical centers.) Patients were assessed at baseline (before DBS surgery) and at 3, 6, 12, 18, 24 and 36 months. Patients were rated on a Parkinson’s disease scale that includes motor functions such as speech, facial expression, tremors, rigidity, finger taps, hand movements, posture, gait, bradykinesia (slow movement) etc. The lower the rating, the better the function.

Improvements in motor function were similar in both groups of patients, and stable over time. Among patients stimulated in the globus pallidus interna, the score improved from 41.1 at baseline to 27.1 at 36 months. Among patients stimulated in the subthalamic nucleus, the score improved from 42.5 at baseline to 29.7 at 36 months.

By contrast, some early gains in quality of life and the abilities to do the activities of daily living were gradually lost, and there was a decline in neurocognitive function. This likely reflects the progression of the disease, and the emergence of symptoms that are resistant to DBS and medications.

Researchers concluded that both the globus pallidus interna and the subthalamic nucleus areas of the brain “are viable DBS targets for treatment of motor symptoms, but highlight the importance of nonmotor symptoms as determinants of quality of life in people with Parkinson’s disease.”

Source: medicalxpress.com

Filed under science neuroscience brain psychology parkinson

10 notes

Antioxidant Urate Could Protect Against Parkinson’s Disease

May 23rd, 2012

Study supports urate protection against Parkinson’s disease, hints at novel mechanism

In vitro study indicates urate protection extends beyond antioxidant effect

Use of the antioxidant urate to protect against the neurodegeneration caused by Parkinson’s disease appears to rely on more than urate’s ability to protect against oxidative damage. In the May issue of the open-access journal PLoS One, researchers from the MassGeneral Institute for Neurodegenerative Diseases (MGH-MIND) describe experiments suggesting the involvement of a novel mechanism in urate’s protection of cultured brain cells against Parkinson’s-like damage.

“Our experiments showed, unexpectedly, that urate’s ability to protect neurons requires the presence of neighboring cells called astrocytes,” says Michael Schwarzschild, MD, PhD, of MGH-MIND, the study’s senior author. “The results suggest there may be multiple ways that raising urate could help protect against neurodegeneration in diseases like Parkinson’s and further support the development of treatments designed to elevate urate in the brain.” Schwarzschild and colleagues in the Parkinson’s Study Group currently are conducting a clinical trial investigating one approach to that strategy.

Characterized by tremors, rigidity, difficulty walking and other symptoms, Parkinson’s disease is caused by destruction of brain cells that produce the neurotransmitter dopamine. Several epidemiological studies suggested that healthy people with elevated levels of urate, a normal component of the blood, may have a reduced risk of developing Parkinson’s disease, and investigations by Schwarzschild’s team found that Parkinson’s patients with higher naturally occuring urate levels had slower progression of their symptoms.

The current study was designed to investigate whether both added urate and urate already present within the cells protect cultured dopamine-producing neurons against Parkinson-like degeneration. In addition, since previous studies suggested that urate’s protective effects depended on the presence of astrocytes,  star-shaped cells of the central nervous system that provide both structural and metabolic support to neurons,  the MGH-MIND team explored how the presence of astrocytes affects the ability of urate to protect against damage induced by MPP+, a toxic molecule that produces the same kind of neurodegeneration seen in Parkinson’s and is widely used in research studies.

Raising urate levels could help to protect against neurodegenerative diseases like Parkinsons. Image adapted from Flickr user Niels_Olson.

The experiments showed that, while added urate reduced MPP+-induced cell death by about 50 percent in cultured dopamine-producing mouse neurons, urate treatment virtually eliminated neuronal death in cultures containing both neurons and astrocytes. They also showed that reducing intracellular urate levels by induced expression of the enzyme that breaks it down increased neuronal vulnerability to MPP+ toxicity significantly in cultures that included astrocytes but only slightly in neuron-rich cultures. The fact that the presence of astrocytes greatly increases the protection of both externally applied urate and urate produced within cells indicates that the effect depends on more than urate’s ability to directly protect neurons against oxidative stress.

“A valuable next step will be determining whether endogenous urate is protective in live animal models of Parkinson’s disease,” says Schwarzschild. “It also will be important to determine whether we can selectively increase urate levels in brain cells by targeting urate transporter molecules. The approach now in early clinical trials examines whether treatment with the urate precursor inosine, which increases urate levels throughout the body, can slow the progression of the disease. If we could raise urate levels in brain cells without changing them in the rest of the body, we could avoid the risks of of excessive urate, which when accumulated in joints can cause gout.”

Source: Neuroscience News

Filed under science neuroscience brain psychology parkinson

8 notes

Vitamin K2: New Hope for Parkinson’s Patients?

ScienceDaily (May 11, 2012) — Neuroscientist Patrik Verstreken, associated with VIB and KU Leuven, succeeded in undoing the effect of one of the genetic defects that leads to Parkinson’s using vitamin K2. His discovery gives hope to Parkinson’s patients.

Male fruit fly (Drosophila Melanogaster). Scientists have succeeded in undoing the effect of one of the genetic defects that leads to Parkinson’s using vitamin K2. The research was done in fruit flies. (Credit: © Studiotouch / Fotolia)

This research was done in collaboration with colleagues from Northern Illinois University (US) and was recently published in the journal Science.

"It appears from our research that administering vitamin K2 could possibly help patients with Parkinson’s. However, more work needs to be done to understand this better," says Patrik Verstreken.

Malfunctioning power plants are at the basis of Parkinson’s.

If we looked at cells as small factories, then mitochondria would be the power plants responsible for supplying the energy for their operation. They generate this energy by transporting electrons. In Parkinson’s patients, the activity of mitochondria and the transport of electrons have been disrupted, resulting in the mitochondria no longer producing sufficient energy for the cell. This has major consequences as the cells in certain parts of the brain will start dying off, disrupting communication between neurons. The results are the typical symptoms of Parkinson’s: lack of movement (akinesia), tremors and muscle stiffness.

The exact cause of this neurodegenerative disease is not known. In recent years, however, scientists have been able to describe several genetic defects (mutations) found in Parkinson’s patients, including the so-called PINK1 and Parkin mutations, which both lead to reduced mitochondrial activity. By studying these mutations, scientists hope to unravel the mechanisms underlying the disease process.

Paralyzed fruit flies

Fruit flies (Drosophila) are frequently used in lab experiments because of their short life spans and breeding cycles, among other things. Within two weeks of her emergence, every female is able to produce hundreds of offspring. By genetically modifying fruitflies, scientists can study the function of certain genes and proteins. Patrik Verstreken and his team used fruitflies with a genetic defect in PINK1 or Parkin that is similar to the one associated with Parkinson’s. They found that the flies with a PINK1 or Parkin mutation lost their ability to fly.

Upon closer examination, they discovered that the mitochondria in these flies were defective, just as in Parkinson’s patients. Because of this they generated less intracellular energy — energy the insects needed to fly. When the flies were given vitamin K2, the energy production in their mitochondria was restored and the insects’ ability to fly improved. The researchers were also able to determine that the energy production was restored because the vitamin K2 had improved electron transport in the mitochondria. This in turn led to improved energy production.

Conclusion

Vitamin K2 plays a role in the energy production of defective mitochondria. Because defective mitochondria are also found in Parkinson’s patients with a PINK1 or Parkin mutation, vitamin K2 potentially offers hope for a new treatment for Parkinson’s.

Source: Science Daily

Filed under science neuroscience brain psychology parkinson

free counters