What are circular RNAs?
RNAs are a type of molecules present in all human cells. They usually have a linear conformation. However, some species with a ring-like structure have recently been described and named “circular RNAs”, but little is known about their function. Recent studies in the field have reported changes in the levels of some circular RNAs in brains from patients diagnosed with Alzheimer’s disease. Our main goal was to validate these findings and study whether these changes also occur in other neurodegenerative diseases, such as frontotemporal dementia.
Our recent study, in collaboration with the Neurological Tissue Bank in Barcelona, entitled “Assessing circular RNAs in Alzheimer’s disease and frontotemporal lobar degeneration”, has been published in the specialized journal Neurobiology of Aging.
What was done in this study?
In this study, we analyzed the levels of 8 circular RNAs in brain tissue from neuropathological confirmed cases with Alzheimer’s disease, frontotemporal dementia and from individuals without neurological diseases. We included a total of 69 samples from the Neurological Tissue Bank in Barcelona. Specifically, we compared the levels of these RNAs between the different disease groups, and analyzed their relationship with several neuropathological measurements.
Our work shows different levels of circular RNAs in cases with Alzheimer’s disease compared to other groups, thus confirming previous findings. These differences were more pronounced in familial cases of Alzheimer’s disease (bearing genetic mutations that cause the pathology), and they could be associated with the presence of pathological aggregates in the brain, typical of this disorder. Moreover, some of these changes were also observed in cases with frontotemporal dementia.
Relevance of the study
The results of this study are important to understand the biological basis of neurodegenerative diseases. Furthermore, our findings could contribute to the identification of novel peripheral biomarkers that can help improve the diagnosis of patients with these disorders.