Disrupted redox status primarily contributes to myocardial ischemia/reperfusion injury(MIRI).NRF2,the endogenous antioxidant regulator,might provide therapeutic benefits.Dihydrotanshinone-Ⅰ(DT)is an active component ...Disrupted redox status primarily contributes to myocardial ischemia/reperfusion injury(MIRI).NRF2,the endogenous antioxidant regulator,might provide therapeutic benefits.Dihydrotanshinone-Ⅰ(DT)is an active component in Salvia miltiorrhiza with NRF2 induction potency.This study seeks to validate functional links between NRF2 and cardioprotection of DT and to investigate the molecular mechanism particularly emphasizing on NRF2 cytoplasmic/nuclear translocation.DT potently induced NRF2 nuclear accumulation,ameliorating post-reperfusion injuries via redox alterations.Abrogated cardioprotection in NRF2-deficient mice and cardiomyocytes strongly supports NRF2-dependent cardioprotection of DT.Mechanistically,DT phosphorylated NRF2 at Ser40,rendering its nuclear-import by dissociating from KEAP1 and inhibiting degradation.Importantly,we identified PKC-δ-(Thr505)phosphorylation as primary upstream event triggering NRF2-(Ser40)phosphorylation.Knockdown of PKC-δdramatically retained NRF2 in cytoplasm,convincing its pivotal role in mediating NRF2 nuclear-import.NRF2 activity was further enhanced by activated PKB/GSK-3βsignaling via nuclear-export signal blockage independent of PKC-δactivation.By demonstrating independent modulation of PKC-δand PKB/GSK-3β/Fyn signaling,we highlight the ability of DT to exploit both nuclear import and export regulation of NRF2 in treating reperfusion injury harboring redox homeostasis alterations.Coactivation of PKC and PKB phenocopied cardioprotection of DT in vitro and in vivo,further supporting the potential applicability of this rationale.展开更多
基金supported by the National Key R&D Program of China(No.2019YFC1711000)National Natural Science Foundation of China(81421005 and 81722048)+2 种基金111 Project(B16046,China)“Double First-Class”University Project(CPU2018GF04,China)the Qing Lan Project of Jiangsu Province(China)
文摘Disrupted redox status primarily contributes to myocardial ischemia/reperfusion injury(MIRI).NRF2,the endogenous antioxidant regulator,might provide therapeutic benefits.Dihydrotanshinone-Ⅰ(DT)is an active component in Salvia miltiorrhiza with NRF2 induction potency.This study seeks to validate functional links between NRF2 and cardioprotection of DT and to investigate the molecular mechanism particularly emphasizing on NRF2 cytoplasmic/nuclear translocation.DT potently induced NRF2 nuclear accumulation,ameliorating post-reperfusion injuries via redox alterations.Abrogated cardioprotection in NRF2-deficient mice and cardiomyocytes strongly supports NRF2-dependent cardioprotection of DT.Mechanistically,DT phosphorylated NRF2 at Ser40,rendering its nuclear-import by dissociating from KEAP1 and inhibiting degradation.Importantly,we identified PKC-δ-(Thr505)phosphorylation as primary upstream event triggering NRF2-(Ser40)phosphorylation.Knockdown of PKC-δdramatically retained NRF2 in cytoplasm,convincing its pivotal role in mediating NRF2 nuclear-import.NRF2 activity was further enhanced by activated PKB/GSK-3βsignaling via nuclear-export signal blockage independent of PKC-δactivation.By demonstrating independent modulation of PKC-δand PKB/GSK-3β/Fyn signaling,we highlight the ability of DT to exploit both nuclear import and export regulation of NRF2 in treating reperfusion injury harboring redox homeostasis alterations.Coactivation of PKC and PKB phenocopied cardioprotection of DT in vitro and in vivo,further supporting the potential applicability of this rationale.
