Tag Archives: Parkinson’s disease

stem.cell

TGen-led study finds link to Parkinson’s disease

The absence of a protein called SMG1 could be a contributing factor in the development of Parkinson’s disease and other related neurological disorders, according to a study led by the Translational Genomics Research Institute (TGen).

The study screened 711 human kinases (key regulators of cellular functions) and 206 phosphatases (key regulators of metabolic processes) to determine which might have the greatest relationship to the aggregation of a protein known as alpha-synuclein, which has been previously implicated in Parkinson’s disease. Previous studies have shown that hyperphosphorylation of the α-synuclein protein on serine 129 is related to this aggregation.

“Identifying the kinases and phosphates that regulate this critical phosphorylation event may ultimately prove beneficial in the development of new drugs that could prevent synuclein dysfunction and toxicity in Parkinson’s disease and other synucleinopathies,” said Dr. Travis Dunckley, a TGen Assistant Professor and senior author of the study.

Synucleinopathies are neurodegenerative disorders characterized by aggregates of α-synuclein protein. They include Parkinson’s, various forms of dementia and multiple systems atrophy (MSA).

The study — SMG1 Identified as a Regulator of Parkinson’s disease-associated alpha-Synuclein Through siRNA Screening — was published today in the journal PLOS ONE.

By using the latest in genomic technologies, Dr. Dunckley and collaborators found that expression of the protein SMG1 was “significantly reduced” in tissue samples of patients with Parkinson’s and dementia.

“These results suggest that reduced SMG1 expression may be a contributor to α-synuclein pathology in these diseases,” Dr. Dunckley said.

TGen collaborators in this study included researchers from Banner Sun Health Institute and Mayo Clinic Scottsdale.

Tissue samples were provided by the Banner Brain and Body Donation Program. The study was funded by the Arizona Parkinson’s Disease Consortium, which includes Mayo Clinic Scottsdale, Sun Health Research Institute, Barrow Neurologic Institute, Banner Good Samaritan Medical Center, Arizona State University, and TGen.

The study is available at: http://dx.plos.org/10.1371/journal.pone.0077711.

medical.research

A Saliva Gland Test for Parkinson’s Disease?

Described as a “big step forward” for research and treatment of Parkinson’s disease, new research from Mayo Clinic in Arizona and Banner Sun Health Research Institute suggests that testing a portion of a person’s saliva gland may be a way to diagnose the disease.

The study was released Friday and will be presented at the American Academy of Neurology’s 65th Annual Meeting in San Diego, March 16–23.

“There is currently no diagnostic test for Parkinson’s disease,” says study author Charles Adler, MD, PhD., a neurologist with Mayo Clinic in Arizona. “We have previously shown in autopsies of Parkinson’s patients that the abnormal proteins associated with Parkinson’s are consistently found in the submandibular saliva glands, found under the lower jaw. This is the first study demonstrating the value of testing a portion of the saliva gland to diagnose a living person with Parkinson’s disease. Making a diagnosis in living patients is a big step forward in our effort to understand and better treat patients.”

The study involved 15 people with an average age of 68 who had Parkinson’s disease for an average of 12 years, responded to Parkinson’s medication and did not have known saliva gland disorders.

Biopsies were taken of two different saliva glands: the submandibular gland and the minor saliva glands in the lower lip. The surgical team was led by Michael Hinni, MD, and David Lott, MD, at Mayo Clinic in Arizona, and the biopsied tissues were tested for evidence of the abnormal Parkinson’s protein by study co-author Thomas Beach, MD, with Banner Sun Health Research Institute.

“This procedure will provide a much more accurate diagnosis of Parkinson’s disease than what is now available,” Dr. Beach says. “One of the greatest potential impacts of this finding is on clinical trials, as at the present time some patients entered into Parkinson’s clinical trials do not necessarily have Parkinson’s disease and this is a big impediment to testing new therapies.”

The abnormal Parkinson’s protein was detected in nine of the 11 patients who had enough tissue to study. While still being analyzed, the rate of positive findings in the biopsies of the lower lip glands appears much lower than for the lower jaw gland.

“This study provides the first direct evidence for the use of submandibular gland biopsies as a diagnostic test for living patients with Parkinson’s disease,” says Dr. Adler. “This finding may be of great use when needing definitive proof of Parkinson’s disease, especially when considering performing invasive procedures such as deep brain stimulation surgery or gene therapy.”

Parkinson’s disease is a progressive disorder of the nervous system that affects movement. It develops gradually, sometimes starting with a barely noticeable tremor in just one hand. But while tremor may be the most well-known sign of Parkinson’s disease, the disorder also commonly causes stiffness or slowing of movement. No tests exist to diagnose Parkinson’s disease. Now diagnosis is made based on medical history, a review of signs and symptoms, a neurological and physical examination, and by ruling out other conditions. Yet up to 30 percent of patients may be misdiagnosed early in the disease.

Although Parkinson’s disease can’t be cured, medications may markedly improve symptoms.This study was funded by the Michael J. Fox Foundation for Parkinson’s Research.