(PHILADELPHIA) - Although a number of treatments exist to alleviate the symptoms of Parkinson's disease, to date, none reliably slow the progression of the disease. In 2013, a molecule called GM1 ganglioside showed promise in patients for not only relieving symptoms but also slowing disease progression. However, GM1 ganglioside has been difficult to make and to deliver to patients for regular use. Now, researchers at Thomas Jefferson University have demonstrated a way to help the brain of mice produce more of its own GM1 ganglioside in a study published December 2nd in the open access journal PLOS ONE.
"GM1 ganglioside has shown great promise in Parkinson's patients," says lead author Jay Schneider, Ph.D., Professor in the Department of Pathology, Anatomy and Cell Biology at the Sidney Kimmel Medical College at Thomas Jefferson University. "However, considering the difficulties with the manufacture of GM1 and its delivery to the brain, we wanted to see if we could coax the brain to make more of its own GM1."
GM1 ganglioside is normally made by nerve cells in the brain, but the substance is made at much lower levels in patients with Parkinson's and other neurodegenerative diseases. Although earlier work showed that patients who were administered GM1 ganglioside showed improvement in symptoms and progression, the current industry standard for obtaining GM1 ganglioside is to extract the substance from cow brains, which presents a number of manufacturing and potential safety concerns. Also, the substance cannot be readily made synthetically. "We were thinking, 'there's got to be a way around this,'" says Dr. Schneider, "instead of putting more GM1 into the brain, why not try to get the brain to make more of it."
Through a search of existing literature, Dr. Schneider and colleagues found that an enzyme called sialidase was capable of converting other naturally occurring ganglioside molecules in the brain into GM1 ganglioside. They tested their idea in a mouse model of Parkinson's disease. After the researchers inserted a pump that continually injected the sialidase into the mouse brain, the researchers then simulated the onset of Parkinson's. In this mouse Parkinson's model, Dr. Schneider and colleagues saw neuronal protection at similar levels to those seen in mice injected directly with GM1 ganglioside.
"We were very excited to see that this could work in the mouse model," says Dr. Schneider. "As long-term delivery of sialidase enzymes to the brain would require implantation of a pump system, which might not be optimal, we are currently working on alternative gene therapy approaches to enhance GM1 levels in the brain," he added.
Creating better ways of enhancing GM1 ganglioside levels in the brain could prove beneficial in a number of diseases in addition to Parkinson's disease, such as in Huntington's disease and Alzheimer's disease. Dr. Schneider is currently investigating novel gene-therapy approaches that could enhance the GM1 ganglioside content of neurons and plans to investigate the neuroprotective potential of these approaches. Provisional patents on these technologies have been filed.
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This research was supported by the Michael J Fox Foundation. The authors report no conflicts of interest.
Article reference: J.S. Schneider et al., "Intraventricular Sialidase Administration Enhances GM1 Ganglioside Expression and is Partially Neuroprotective in a Mouse Model of Parkinson's Disease," PLOS ONE, DOI: 10.1371/journal.pone.0143351, 2015.
For more information, contact Edyta Zielinska, 215-955-5291, edyta.zielinska@jefferson.edu, or Colleen Cordaro, 215-955-2238, colleen.cordaro@jefferson.edu
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Our newly formed organization, Jefferson, encompasses Thomas Jefferson University and Jefferson Health, representing our academic and clinical entities. Together, the people of Jefferson, 19,000 strong, provide the highest-quality, compassionate clinical care for patients, educate the health professionals of tomorrow, and discover new treatments and therapies that will define the future of health care.
Jefferson Health comprises five hospitals, 13 outpatient and urgent care centers, as well as physician practices and everywhere we deliver care throughout the city and suburbs across Philadelphia, Montgomery and Bucks Counties in Pa., and Camden County in New Jersey. Together, these facilities serve more than 78,000 inpatients, 238,000 emergency patients and 1.7 million outpatient visits annually. Thomas Jefferson University Hospital is the largest freestanding academic medical center in Philadelphia. Abington Hospital is the largest community teaching hospital in Montgomery or Bucks counties. Other hospitals include Jefferson Hospital for Neuroscience in Center City Philadelphia; Methodist Hospital in South Philadelphia; and Abington-Lansdale Hospital in Hatfield Township.
Thomas Jefferson University enrolls more than 3,900 future physicians, scientists, nurses and healthcare professionals in the Sidney Kimmel Medical College (SKMC), Jefferson Colleges of Biomedical Sciences, Health Professions, Nursing, Pharmacy, Population Health and is home of the National Cancer Institute (NCI)-designated Sidney Kimmel Cancer Center.
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Journal
PLoS ONE