US researchers have developed a groundbreaking new diagnostic technique that will allow for faster and more accurate detection of neurodegenerative diseases Alzheimer's and Parkinson's, and chronic wasting disease in animals.
Neurodegenerative diseases such as Alzheimer's, Parkinson's, mad cow disease, and CWD (widely found in deer) share a common feature the buildup of misfolded proteins in the central nervous system. Detecting these misfolded proteins is crucial for understanding and diagnosing these devastating disorders.
However, existing diagnostic methods, like enzyme-linked immunosorbent assay and immunohistochemistry, can be expensive, time-consuming, and limiting in terms of antibody specificity. The novel method, developed by University of Minnesota researchers, dubbed Nano-QuIC (Nanoparticle-enhanced Quaking-Induced Conversion), significantly improves the performance of advanced protein-misfolding detection methods, such as the NIH Rocky Mountain Laboratories' Real-Time Quaking-Induced Conversion (RT-QuIC) assay.
"Testing for these neurodegenerative diseases in both animals and humans has been a major challenge to our society," said Peter Larsen, Assistant Professor in the University's Department of Veterinary and Biomedical Sciences.
"What we're seeing now is this really exciting time when new, next generation diagnostic tests are emerging for these diseases. The impact that our research has is that it's greatly improving upon those next generation tests, it's making them more sensitive, and it's making them more accessible," he added.
The RT-QuIC method, detailed in the journal Nano Letters, involves shaking a mixture of normal proteins with a small amount of misfolded protein, triggering a chain reaction that causes the proteins to multiply and allowing for the detection of these irregular proteins.
Using tissue samples from deer, the team demonstrated that adding 50-nanometre silica nanoparticles to RT-QuIC experiments dramatically reduces detection times from about 14 hours to only four hours and increases the sensitivity by a factor of 10.
A typical 14-hour detection cycle means that a lab technician can run only one test per normal working day. However, with a detection time of less than four hours, researchers can now run three or even four tests per day.
Having a quicker and highly accurate detection method is particularly important for understanding and controlling transmission of CWD, a disease that is spreading in deer across North America, Scandinavia, and South Korea.
The researchers believe that Nano-QuIC could eventually prove useful for detecting protein-misfolding diseases in humans, specifically Parkinson's, Creutzfeldt-Jakob Disease, Alzheimer's, and ALS.