Downregulation of cardiac lineage protein-1 confers cardioprotection through the upregulation of redox effectors.

ABSTRACT

CLP-1, the mouse homologue of human Hexim1 protein, exerts inhibitory control on transcriptional elongation factor-b of RNA transcript elongation. Previously, we have demonstrated that downregulation of cardiac lineage protein-1 (CLP-1) in CLP-1(+/-) heterozygous mice affords cardioprotection against ischemia-reperfusion injury. Our current study results show that the improvement in cardiac function in CLP-1(+/-) mice after ischemia-reperfusion injury is achieved through the potentiation of redox signaling and their molecular targets including redox effector factor-1, nuclear factor erythroid 2-related factor, and NADPH oxidase 4 and the active usage of thioredoxin-1, thioredoxin-2, glutaredoxin-1 and glutaredoxin-2. Our results suggest that drugs designed to down regulate CLP-1 could confer cardioprotection through the potentiation of redox cycling.