MicroRNA 26a inhibits HMGB1 expression and attenuates cardiac ischemia-reperfusion injury

Ischemia reperfusion (ir) injury is a major issue in cardiac transplantation and inflammatory processes play a major role in myocardial ir injury. microrna 26a (mir-26a) plays important roles in cellular differentiation,cell growth,cell apoptosis and metastasis. mir-26a has been demonstrated to modulate regulatory t cells expansion and attenuates renal ir injury. however,the role of mir-26a in the cardiac ir injury has never been investigated. in our study,hearts of c57bl/6 mice were flushed and stored in cold bretschneider solution for 8 hours and then transplanted into syngeneic recipients. the results demonstrate a crucial role for mir-26a in inhibiting high mobility group box-1 (hmgb1) expression and attenuating cardiac ir injury. mir-26a overexpression results in attenuated cardiac ir injury and inhibited hmgb1 expression. mir-26a also inhibits inflammatory cells infiltration and cytokines expression. furthermore,the attenuated cardiac ir injury induced by mir-26a was abrogated by additional administration of recombinant hmgb1 (rhmgb1). in conclusion,mir-26a plays a protective role in cardiomyocyte ir injury and this is associated with inhibited hmgb1 expression. © 2015 the authors.