Regulation of microRNAs miR-30a and miR-143 in cerebral vasculature after experimental subarachnoid hemorrhage in rats.

Background: microRNAs (miRNAs) are important regulators of translation and have been implicated in the pathogenesis of a number of cardiovascular diseases, including stroke, and suggested as possible prognostic biomarkers. Our aim was to identify miRNAs that are differentially regulated in cerebral arteries after subarachnoid hemorrhage (SAH), using a rat injection model of SAH and a qPCR-based screen of 728 rat miRNAs. Additionally, serum was analyzed for a possible spill-over to the circulation of regulated miRNAs from the vessel walls.

Results: We identified 482 different miRNAs expressed in cerebral arteries post-SAH. Two miRNAs, miR-30a and miR-143, were significantly upregulated in cerebral arteries after SAH when compared to sham-operated animals. However, none of these exhibited significantly altered serum levels after SAH versus post-sham surgery. The most robust upregulation was seen for miR-143, which has several predicted targets and is a strong regulator of vascular morphology. We hypothesize that miR-30a and miR-143 may play a role in the vascular wall changes seen after SAH.

Conclusions: We report that miR-30a and miR-143 in the cerebral arteries show significant changes over time after SAH, but do not differ from sham-operated rats at 24 h post-SAH. Although this finding suggests interesting novel possible mechanisms involved in post-SAH cerebrovascular changes, the lack of regulation of these miRNAs in serum excludes their use as blood-borne biomarkers for cerebrovascular changes following SAH.