About Careers MedBlog Contact us
Medindia LOGIN REGISTER
Advertisement

Faulty Protein Digestion in Neurons may be the Cause of Familial Parkinson's

by Dr. Enozia Vakil on March 8, 2013 at 4:19 PM
Font : A-A+

 Faulty Protein Digestion in Neurons may be the Cause of Familial Parkinson's

Researchers at the CUMC reveal the link between common genetic mutations in familial Parkinson's disease and brain cell damage. The mutations block an intracellular system that normally prevents a protein called alpha-synuclein from reaching toxic levels in dopamine-producing neurons. The findings suggest that interventions aimed at enhancing this digestive system, or preventing its disruption, may prove valuable in the prevention or treatment of Parkinson's. The study was published March 3 in the online edition of the journal Nature Neuroscience.

Parkinson's disease is characterized by the formation of Lewy bodies (which are largely composed of alpha-synuclein) in dopamine neurons. In 1997, scientists discovered that a mutation in alpha-synuclein can lead to Lewy body formation. "But alpha-synuclein mutations occur in only a tiny percentage of Parkinson's patients," said co-lead author David L. Sulzer, PhD, professor of neurology, pharmacology, and psychiatry at CUMC. "This meant that there must be something else that interfered with alpha-synuclein in people with Parkinson's."

Advertisement

Dr. Sulzer and his colleagues suspected that a gene called leucine-rich repeat kinase-2 (LRRK2) might be involved. LRRK2 mutations are the most common mutations to have been linked to Parkinson's. The current study aimed to determine how these mutations might lead to the accumulation of alpha-synuclein.

"We found that abnormal forms of LRRK2 protein disrupt a critical protein-degradation process in cells called chaperone-mediated autophagy," said Dr. Sulzer. "One of the proteins affected by this disruption is alpha-synuclein. As this protein starts to accumulate, it becomes toxic to neurons." Delving deeper, the researchers found that LRRK2 mutations interfere with LAMP-2A, a lysosome membrane receptor that plays a key role in lysosome function.
Advertisement

(Chaperone-mediated autophagy, or CMA, is responsible for transporting old or damaged proteins from the cell body to the lysosomes, where they are digested into amino acids and then recycled. In 2004, Dr. Sulzer and the current paper's other co-lead author, Ana Maria Cuervo, MD, PhD, professor of developmental & molecular biology, of anatomy & structural biology, and of medicine at Albert Einstein College of Medicine of Yeshiva University, showed that alpha-synuclein is degraded by the CMA pathway.)

"Now that we know this step that may be causing the disease in many patients, we can begin to develop drug treatments or genetic treatments that can enhance the digestion of these disease-triggering proteins, alpha-synuclein and LRRK2, or that remove alpha-synuclein," said Dr. Sulzer.

While LRRK2 mutations are the most common genetic cause of Parkinson's, it is too early to tell whether these findings, and therapies that might stem from them, would apply to patients with non-familial Parkinson's, the more common form of the disease. "Right now, all we can say is that it looks as though we've found a fundamental pathway that causes the buildup of alpha-synuclein in people with LRRK2 mutations and links these mutations to a common cause of the disease. We suspect that this pathway may be involved in many other Parkinson's patients," said Dr. Sulzer.

The study involved mouse neurons in tissue culture from four different animal models, neurons from the brains of patients with Parkinson's with LRRK2 mutations, and neurons derived from the skin cells of Parkinson's patients via induced pluripotent stem (iPS) cell technology. All the lines of research confirmed the researchers' discovery.

Source: Eurekalert
Advertisement

Advertisement
Advertisement

Recommended Reading

Latest Mental Health News

Can the Heat Scorch Your Mental Health?
Hospitals have reported an increase in mental illnesses with the scorching temperatures this summer.
Hidden in Plain Sight: The Unseen Battle of Adolescent Depression in Canada
Undetected and untreated adolescent depression in Canada calls for improved care.
From Storm to Serenity: How to Transform Workplace Conflicts into Opportunities?
Within every workplace, conflicts are inevitable occurrences that can stem from diverse reasons and requires better measures to be settled.
The Unseen Effects of Childhood Physical Abuse: Psychologically Flourishing in Adulthood
People who have experienced physical abuse in their childhood move on to achieve increased levels of life satisfaction and psychological well-being.
Link Between Early Bipolar Diagnosis and Lower Suicide Rates Identified
The link between an increased number of population-adjusted bipolar diagnoses and reduced suicide rates among boys identified.
View All
This site uses cookies to deliver our services.By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use  Ok, Got it. Close
×

Faulty Protein Digestion in Neurons may be the Cause of Familial Parkinson's Personalised Printable Document (PDF)

Please complete this form and we'll send you a personalised information that is requested

You may use this for your own reference or forward it to your friends.

Please use the information prudently. If you are not a medical doctor please remember to consult your healthcare provider as this information is not a substitute for professional advice.

Name *

Email Address *

Country *

Areas of Interests