Two studies released this week provide more insight into diagnosing and treating Parkinson’s disease.
One emerging area of study focuses on how the build-up of proteins in the brain may lead to neurodegenerative diseases. Interactions between two of those proteins, amyloid and tau, may distinguish Parkinson's disease from other degenerative brain diseases like Alzheimer’s.
The research is part of the Parkinson’s Progression Markers Initiative, a global research project to better understand the disease sponsored in part by the Michael J. Fox Foundation for Parkinson’s research.
As many as 10 million people worldwide are living with Parkinson’s disease, according to the Parkinson’s Disease Foundation.
Could a Test Diagnose Parkinson’s Early?
Protein levels in a person’s spinal fluid may soon be a diagnostic tool for people in the early stages of Parkinson’s disease, according to a study published in JAMA Neurology.
Researchers at the University of Pennsylvania’s Perelman School of Medicine studied 102 people—63 of whom had early, untreated Parkinson’s disease. Researchers took spinal fluid samples and examined them for the presence of five proteins: amyloid beta, total tau, phosphorylated tau, alpha synuclein, and the ratio of tau to amyloid beta.
Researchers found that Parkinson’s patients had lower levels of tau proteins than healthy patients, providing a clue to early diagnosis. In Alzheimer’s patients, tau levels are higher than normal.
The cerebrospinal fluid test is currently only being used in research studies, but scientists say they’ll continue to test it for reliability.
“Biomarkers for Parkinson's disease such as these could help us diagnose patients earlier, and we've now shown that the simultaneous measurement of a variety of neurodegenerative disease proteins is valuable," study senior author Leslie M. Shaw, Ph.D., professor of Pathology and Laboratory Medicine at Penn Medicine, said in a statement.
‘First Steps’ Toward New Parkinson’s Drug
Researchers at the Johns Hopkins University School of Medicine’s Institute for Cell Engineering (ICE) are also exploring proteins and their role in Parkinson’s. They believe they may have found a compound that can be used to stop the “messenger of death.”
Husband-and-wife team Valina and Ted Dawson have been studying the molecular changes that lead to Parkinson’s. Earlier, they discovered the function of an enzyme called parkin, which helps the brain tag proteins for destruction in its natural recycling process. In Parkinson’s disease, parkin malfunctions.
In their latest study, the Dawsons and colleagues experimented on mice genetically engineered with hyperactive levels of a protein AIMP2, one of the proteins parkin typically destroys. The mice developed symptoms similar to Parkinson’s disease, and cells in the brain that create dopamine—an important brain chemical—began to die.
The team found that AIMP2 triggered what they called parthanatos, named for the Greek word that means “messenger of death.” This type of cell death is typical in cases of stroke or violent head injury, but not disease.
The Dawsons and graduate student Yunjong Lee then gave the mice a compounded drug that’s being designed to protect cells during cancer treatment. They found favorable results.
“Not only did the compound protect dopamine-making neurons from death, it also prevented behavioral abnormalities similar to those seen in Parkinson's disease,” Lee said in a statement.
Their findings were published in the journal Nature Neuroscience.
“While there are still many things that need to happen before we have a drug for clinical trials, we've taken some very promising first steps,” Valina Dawson said.