Scientists at Purdue University have developed a urine test for early-stage Parkinson’s disease. The technology involves isolating extracellular vesicles of neural origin from urine samples and then assessing the proteins within the vesicles to detect biomarkers of the disease. The researchers have called their technology “EVtrap” (Extracellular Vesicles total recovery and purification) and it involves using magnetic beads to concentrate extracellular vesicles in urine, before subsequent proteomics analysis. The goal of the technique is to detect levels of LRRK2 (leucine-rich repeat kinase 2) proteins and related downstream signaling proteins, which have been reported as being linked to Parkinson’s disease, in urine samples. This type of technology may be poised to allow non-invasive diagnosis of a variety of diseases that can affect the protein content of extracellular vesicles in urine.
Early-stage Parkinson’s disease can take a while to diagnose. This process can involve cognitive tests and tests to assess a patient’s movements. The researchers behind this latest technology report that the process can take a year or even longer, so developing more objective biomarker-based molecular testing approaches for suspected early-stage patients would be very welcome. “We believe this is a logical and rational approach to move forward for diagnosing Parkinson’s disease,” said W. Andy Tao, professor of biochemistry at Purdue. “Diagnosis for this type of neurodegenerative disease is difficult.”
The researchers had developed the EVtrap system previously, but realized that it would be useful for Parkinson’s disease patients when Shalini Padmanabhan from The Michael J. Fox Foundation got in touch. “When I reviewed the data from their previous publication,” said Padmanabhan, “it was interesting to note the expression of an important Parkinson’s disease-linked protein, LRRK2. This piqued my interest since this approach provided us with an opportunity to determine if LRRK2 proteins or the downstream pathways they impact are actually altered in urinary samples from Parkinson’s patients who harbor a mutation in the gene.”
So far, the researchers have tested the system with urine samples from Parkinson’s disease patients and healthy controls and found that the technique has significant promise for early detection of Parkinson’s-related biomarkers.
“This kind of analysis opens a new frontier in noninvasive diagnostics development. It’s showing that biomarkers previously thought to be undetectable have become uncovered and do a really good job of differentiating disease from non-disease state,” said Anton Iliuk, another researcher involved in the study. “It’s not obvious that urine would be a source of brain-based chemicals or signatures, but it is. These EVs can penetrate the blood-brain barrier quite easily.”
See a video about the technique below.
Study in journal Communications Medicine: Quantitative proteomics and phosphoproteomics of urinary extracellular vesicles define putative diagnostic biosignatures for Parkinson’s disease