Peering into red blood cells to diagnose Parkinson’s

Hélèna Denis, PhD candidate
Centre Hospitalier de l’Université Laval

At Laval University, PhD candidate Hélèna Denis is looking deep inside the blood cells of people with Parkinson’s disease. She is examining the connection between proteins linked to Parkinson’s and small pieces of cell membrane, called extracellular vesicles that can emerge from any cell. Her research is made possible through a Graduate Student Award from Parkinson Canada’s Research Program for $30,000 over 2 years. Eventually, her work could be used to accelerate diagnosis, identify the stages or progression of the disease, and test how well new treatments work.

With no diagnostic tests available to determine conclusively if someone has Parkinson’s or what stage of the disease they are experiencing, doctors diagnose the disease based on clinical assessments using scales. The scale considers how well someone functions, their symptoms, and the results of a combination of memory and motor tests.

Hélèna Denis is studying extracellular vesicles (EVs), structures that emerge from cells that carry molecules. They mediate cell-to-cell communication. Denis is focusing on EVs derived from red blood cells to see how they are involved in Parkinson’s disease.

When cells are activated or stressed, they can release a greater number of these vesicles, Denis says.

She is comparing the number of vesicles derived from red blood cells of people who don’t have Parkinson’s with the number of vesicles in people who have the disease. 

“We have found strong correlations between the number of extracellular vesicles derived from red cells and a clinical scale that clinicians use to score stages of Parkinson’s disease,” she says.

People who appear to be in the early stages of Parkinson’s, according to the scale, also have fewer EVs derived from their red blood cells than people in later stages of the illness.

Denis also focuses on differences in the types of proteins found in the EVs of people with Parkinson’s, compared to the proteins found in the EVs of healthy people. Her research is made possible through a Graduate Student Award from Parkinson Canada’s Research Program for $30,000 over 2 years.

“Protein content within these vesicles could also help us diagnose or predict the stages of disease,” she says. 

Eventually, Denis’ findings might be used to diagnose Parkinson’s disease, to gauge disease progression more accurately or to measure the effectiveness of treatments. For example, if a drug or a therapy reduced the number of EVs derived from red blood cells or their specific protein signature in a patient with Parkinson’s that would indicate the drug was working.

Denis began her career in the pharmaceutical industry, but she didn’t like the pressure to commercialize discoveries. So she chose to pursue a career in academic research, where she can devote herself to this necessary basic science.

“I very much enjoy my research project because I have the opportunity to work with both patients and clinicians,” she says.

She’s also driven by the need to personalize drugs to better treat the individual symptoms of people with Parkinson’s. Developing biomarkers would help. “Each patient with Parkinson’s disease presents with a different set of symptoms,” Denis says. “Some people have more severe motor symptoms, while others have more prominent cognitive disabilities. Biomarkers would help personalize drugs to treat the symptoms of each patient individually.”