c-myc protects mice from ischemia stroke through elevating microRNA-200b-5p-regulated SIRT1 expression

Abstract Objective c-myc has been reported to attenuate ischemia stroke (IS). We initiated the research to uncover the molecular mechanism of c-myc with regard to microRNA (miR)-200b-5p/Sirtuin1 (SIRT1) axis. Methods An IS mouse model was prepared by middle cerebral artery occlusion (MCAO). Measurements of c-myc, miR-200b-5p and SIRT1 levels in MCAO mice were conducted. c-myc, miR-200b-5p and SIRT1-related adenovirus or lentivirus were injected into mice. The neurological function, production of inflammatory cytokines, neuronal apoptosis, brain tissue pathology and neuronal survival of MCAO mice after injection were observed. Results c-myc and SIRT1 levels went downward while miR-200b-5p expression went upward in MCAO mice. Elevation of c-myc or suppression of miR-200b-5p improved neurological function, reduced inflammation and neuronal apoptosis, and attenuated brain tissue pathology and neuronal survival of MCAO mice. Enhancement of miR-200b-5p or knockdown of SIRT1 weakened c-myc-induced protection against MCAO-induced brain injury in mice. Conclusion Overall, c-myc protects mice from IS through elevating miR-200b-5p-targeted SIRT1 expression.