A meta-analysis of differentially expressed circulatory micro-RNAs in chronic traumatic encephalopathy and other tauopathies: A significant role of miR-181c-5p.

Background: Micro-RNA (miRs) targeting kinases and phosphatases regulate the hyper-phosphorylation of tau protein, which is a characteristic feature of Chronic Traumatic Encephalopathy (CTE).

Primary Objective: Identification of lead dysregulated miR expressed in CTE, and other similar tauopathies.

Methods: A search strategy was devised using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to mine into multiple indexing databases such as Web of Science, Google Scholar, and PubMed spanning from 2005 to June 2022. Seven articles were screened out of 34,221 publications based on inclusion criteria and were categorized into two groups i.e., (1) CTE and its risk factors and (2) Age-related neurodegenerative disorders.

Results: Statistical analysis [RevMan 5.4.1] results showed that the overall risk ratio (RR) of the first group is significant (RR = 0.62, 95% CI = [0.38, 1.00], z = 1.95, p = 0.05) whereas, the second group favours the control population (RR = 1.64, 95% CI = [0.85, 3.16], z = 1.14, p = 0.14).

Conclusion: We observed that among all other dysregulated miRs, miR-181c-5p is significantly overexpressed in Alzhimers disease (AD) and CTE. Further, we found that miR-210-3p is also upregulated notably in all groups. In sum, we conclude that these miRs can be considered as potential target and biomarker in the diagnosis and treatment of various tauopathies.