MicroRNAs: a novel promising therapeutic target for cerebral ischemia/reperfusion injury?

To determine the molecular mechanism of cerebral ischemia/reperfusion injury, we examined the microRNA (miRNA) expression profile in rat cortex after focal cerebral ischemia/reperfusion injury using miRNA microarrays and bioinformatic tools to systematically analyze Gene Ontology (GO) function classifications, as well as the signaling pathways of genes targeted by these differentially expressed miRNAs. Our results show significantly changed miRNA expression profiles in the reperfusion period after focal cerebral ischemia, with a total of 15 miRNAs up-regulated and 44 miRNAs down-regulated. Target genes of these differentially expressed miRNAs were mainly involved in metabolic and cellular processes, which were identified as hub nodes of a miRNA-GO-network. The most correlated pathways included D-glutamine and D-glutamate metabolism, the renin-angiotensin system, peroxisomes, the PPAR signaling pathway, SNARE interactions in vesicular transport, and the calcium signaling pathway. Our study suggests that miRNAs play an important role in the pathological process of cerebral ischemia/reperfusion injury. Understanding miRNA expression and function may shed light on the molecular mechanism of cerebral ischemia/reperfusion injury.