A new liquid biopsy method offers the potential for non-invasive Parkinson’s

A new liquid biopsy method offers potential for noninvasive testing of Parkinson’s disease

The EVtrap technology identifies proteins from brain cells in urine samples

LAFAYETTE BARAT, Ind. – A team led by researchers at Purdue University and Purdue spin-off company Tymora Analytical Operations have developed a technique that can reveal signs of Parkinson’s disease in urine samples.

This technique gave researchers the opportunity to see whether the protein LRRK2 (leucine-rich repeat kinase 2), which is associated with Parkinson’s disease, and its downstream pathways are altered in samples from Parkinson’s patients. This method could eventually lead to widespread non-invasive testing for other neurodegenerative conditions as well as cancer.

“We believe this is a logical and rational approach to move forward in diagnosing Parkinson’s disease,” said W. Andy Tao, professor of biochemistry at Purdue. “Diagnosis for this type of neurodegenerative disease is difficult.” Cognitive and movement testing can take a year or more to confirm a diagnosis, so molecular tests for early diagnosis and intervention can help people with Parkinson’s more quickly, he explained.

Tao and eight co-authors from Purdue, Tymora, The Michael J. Fox Foundation for Parkinson’s Research, and Columbia University published their findings in Communication Medicine journal.

“This will be a huge new area of ​​diagnostic development,” predicts co-author Anton Iliuk, Tymora’s president and chief technology officer, “especially for neurodegenerative diseases and cancer.”

Parkinson’s disease alone affects about 1% of the population over 60 years. Up to one million Americans are living with this disease, while 90,000 new cases are diagnosed each year.

The paper’s co-authors include Marco Hadisurya, a doctoral student in biochemistry; Kananart Kuwaranancharoen, a doctoral student in electrical and computer engineering; Xiaofeng Wu, who received his doctorate in chemistry at Purdue in 2022; Li Li, Tymora Analytical Operations; Zheng-Chi Lee, West Lafayette Middle/High School; Roy Alcalay, MD, Columbia University; and Shalini Padmanabhan of The Michael J. Fox Foundation, which funded the work.

This project started a few years ago after Padmanabhan read some of Iliuk and Tao’s work on the EVtrap (total restoration and purification of Extracellular Vesicles) method for urine analysis and proposed a collaboration.

“When I reviewed the data from their previous publications,” said Padmanabhan, “it was interesting to note the expression of the important Parkinson’s disease-associated protein, LRRK2. This piqued my interest because this approach gave us the opportunity to determine whether the LRRK2 protein or the downstream pathways it affects are actually altered in urine samples from Parkinson’s patients who have mutations in the gene.

In 2017, Tao led a team developing a blood test that can properly detect breast cancer. In that study, Tao and colleagues compared samples taken from breast cancer patients and healthy control groups.

“We identified a phosphorylated protein, which is a hallmark of cancer,” said Tao. And within those proteins, the team found extracellular vesicles, tiny packages that cells use as their delivery system for molecules. These findings suggest that blood samples containing phosphoproteins may serve as potential markers for early cancer diagnosis or for monitoring disease progression.

The team was able to quickly isolate the vesicles from a urine sample, using the EVtrap method developed by Tymora.

“We have used this method for a number of indications, especially focusing on different cancers for biomarker discovery and validation,” said Iliuk, who received his doctorate in biochemistry at Purdue in 2011. Iliuk and Tao founded Tymora Analytical, which specializes in technologies and services for detect disease biomarkers in biofluids.

“This kind of analysis opens new frontiers in the development of non-invasive diagnostics. This shows that biomarkers previously thought to be undetectable have been uncovered and do an excellent job of differentiating disease from non-disease states,” said Iliuk. “It’s not clear that urine would be a source of brain-based chemicals or signatures, but it is. This EV can cross the blood-brain barrier quite easily.”

After being excreted from the brain into the bloodstream, they become concentrated or filtered into urine. But sampling such biomarkers from the brain via a spinal tap is a highly invasive procedure.

“Especially for early diagnosis which is not the preferred sampling method,” said Tao. The urine sample contains proteins that can be markers of disease, but many perform household functions unrelated to disease.

“Extracellular vesicles provide a way to focus on disease markers as they are released by certain cell types,” he says.

Among the many ways to study the impact of LRRK2 is to trace its biological pathways, which can be done by analyzing urine, blood and cerebrospinal fluid. The EVtrap method provides an easy way to track urine changes, which are aggregated for many clinical studies.

The LRRK2 Biobanking Study at Columbia University has a large number of urine samples available for meaningful Parkinson’s disease research. Columbia University co-author Alcalay, who provided multiple samples, also helped correlate the EVtrap data with clinical data. For Communication Medicine study, the team studied samples from people with and without the LRRK2 gene mutation, and patients with and without the disease.

Padmanabhan notes, “This study also highlights that changes in urinary protein may serve as a proxy for protein signature changes that occur in brain diseases such as Parkinson’s disease.”

This study follows a 2021 paper published in the journal EMBO Molecular Medicine by an international team of researchers showing a link between LRRK2 and brain proteins in urine samples. The study, led by Matthias Mann of Germany’s Max Planck Institute of Biochemistry, included Padmanabhan and Alcalay of Columbia University as co-authors.

Writer: Steve Overcome