Study Links Alzheimer's Disease With Circular RNA

A study in Nature Neuroscience found circular RNAs in the brain are linked to the development of Alzheimer's disease, and their presence in cerebrospinal fluid and blood could potentially lead to lab tests to detect disease prior to symptom onset, reports the National Institute on Aging (NIA) . Scientists at Washington University in St. Louis analyzed the complete RNA content in brain samples and compared circular RNAs in people with and without Alzheimer's. RNA sequences from brain tissue donated by 83 people with Alzheimer's were initially compared with samples from 13 healthy donors. Then the sequences from brain tissue samples from 89 people with Alzheimer's — 66 probable or possible cases — were compared with those from 40 controls acquired from the NIA's Accelerating Medicines Partnership-Alzheimer's Disease Biomarkers Project. More than 3,500 circular RNAs were detected and analyzed in both datasets, and certain circular RNAs were strongly associated with Alzheimer's development. Analysis of circular RNAs in samples from 21 brains donated by people with early-onset Alzheimer's determined the magnitude of changes in RNA expression was even higher than in the first two datasets. The implication is that the correlation between certain circular RNAs and disease is significant, but not enough to suggest causation.