The Role of miRNA Expression Profiles in Different Biofluids in Aneurysm Rupture.

Objective: Intracranial aneurysm (IA) is a cerebrovascular disease in which the cerebral arteries become pathologically weakened. The molecular mechanisms behind the pathogenesis of IAs are poorly understood. MicroRNAs (miRNAs) are highly stable in body fluids and the expression signatures of specific circulating miRNAs may be associated with high rupture risk, severity, and clinical outcome of subarachnoid hemorrhage (SAH).

Methods: The presented study aimed to detect miRNA-based biomarkers and evaluating the usability of blood for a non-invasive approach. Blood samples from 24 patients with unruptured IA (group 1), blood and cerebrospinal fluid (CSF) samples collected on day 5 after aneurysmal SAH (aSAH) from 24 patients with ruptured IA (group 2), and both the blood and CSF samples from 24 individuals without any positive IA history (control group) were subjected to quantitative real time polymerase chain reaction for evaluating the expression profiles of eight miRNAs.

Results: miR-29a, miR-200a-3p, miR-451a, miR-1297, and miR-502-5p in blood and miR-29a, miR-200a-3p, miR-451a, miR-126, miR- 146a-5p, and miR-27b-3p in CSF were found to be differentially expressed in ruptured patients compared to controls. In both biofluids of ruptured cases, the differences in the expression profiles of miR-29a, miR-200a-3p, and miR-451a compared to controls were striking. The upregulation of miR-126, miR-200a-3p, miR-451a, and miR-502-5p in the ruptured group compared to unruptured patients suggesting that these miRNAs may be informative in predicting the risk of an aneurysmal rupture.

Conclusion: miR-29a, miR-200a-3p, and miR-451 were significantly altered in patients with aSAH compared to controls in both biofluids. These findings suggest that these miRNAs could be candidate non-invasive biomarkers for aSAH.