Hypoxia induces microRNA miR‐210 in vitro and in vivo

Abstract

Shortage of oxygen is one of the prime stress conditions in tissues. In this study, we looked for microRNAs expressed during hypoxia and showed that miR-210 expression was upregulated in response to hypoxia in vitro and in vivo. An active form of the HIF-1alpha induced the expression of miR-210, showing the involvement of the HIF-1 signaling pathway in miR-210 gene transcription. Furthermore, miR-210 was shown to bind to the predicted target sites of ephrin-A3 or neuronal pentraxin 1, causing repression in luciferase reporter activity. Contrary to the microRNA-mediated repression hypothesis, ephrin-A3 was expressed at very high levels in post-ischemic mouse hippocampus in vivo. Thus, the regulatory effects of miR-210 on its targets in vivo need to be further characterized.