摘要
OBJECTIVE In this study we explored the role of Epac1-Rap1 pathway in the acute myocardial ischemia/reperfusion injury(MIRI) in vitro and in vivo.METHODS An acute myocardial ischemia/reperfusion injury model was established by the ligation of left anterior descending coronary.Myocardial architecture,fibers and apoptosis was evaluated by the Masson trichrome staining,Sirius red staining and TUNEL assay.H9c2 cells were subjected to hypoxia for 5 h followed by 1-h reoxygen.ation in vitro.Cell viability was measured by MTT assay and cellular injury was evaluated by measuring the release of lactate dehydrogenase(LDH).Western blot,real-time PCR and immunofluorescence were used to detect the expressions of Epac1 and relative downstream molecules.RESULTS Myocardial IR-induced cardiac apoptosis and accumulation of Epac1 and Rap1 in rat IR injury model.Direct Epac activation by 8-CPT(8-(4-chlorophenylthio)-2′-O-methyl-cAMP) exacerbated cardiomyocyte death and dysfunction following hypoxia-reoxygenation(H/R),selective activation of Epac in response to H/R was evident which enriched for cytosolic/membrane proteins and mRNA.Harmacological inhibitor of Epac(ESI-09) significantly ameliorated myocardial injury with the decline of Epac expression.Epac inhibitor and agonist studies also implicated the effect of Rap1,which is downstream of Epac in this pathway.The expression of Rap1 elevated when activated by Epac agonist and was blocked by Epac inhibitor.The same result was true for myocyte CaMK-II and intracellular calcium ions activation.Moreover,ESI-09 also increased ERK1/2 phosphorylation.CONCLUSION Our study reveal that Epac1/Rap1 signaling pathway is involved in the pathogenesis of myocardial I/R injury in rats,which provides evidence on the development of therapeutic strategies target this pathway for myocardial I/R injury.
OBJECTIVE In this study we explored the role of Epacl-Rapl pathway in the acute myocardial ischemia/reperfusion injury （MIRI） in vitro and in vivo. METHODS An acute myocardial ischemia/reperfusion injury model was established by the ligation of left anterior descending coronary. Myocardial architecture, fibers and apoptosis was evaluated by the Masson trichrome staining, Sirius red staining and TUNEL assay. H9c2 cells were subjected to hypoxia for 5 h followed by 1-h reoxygen- ation in vitro. Cell viability was measured by MTT assay and cellular injury was evaluated by measuring the release of lactate dehydrogenase （LDH）. Western blot, real-time PCR and immunofluorescence were used to detect the expressions of Epacl and relative downstream molecules. RESULTS Myocardial IR-induced cardiac apoptosis and accumulation of Epacl and Rap1 in rat IR injury model. Direct Epac activation by 8-CPT （8-（4-chlorophenylthio）-2＇-O-methyl-cAMP） exacerbated cardiomyocyte death and dysfunction following hypoxia-reoxygenation （H/R）, selective activation of Epac in response to H/R was evident which enriched for cytosolic/membrane proteins and mRNA. Harmacological inhibitor of Epac （ESI-09） significantly ameliorated myocardial injury with the decline of Epac expression. Epac inhibitor and agonist studies also implicated the effect of Rap1, which is downstream of Epac in this pathway. The expression of Rap1 elevated when activated by Epac agonist and was blocked by Epac inhibitor. The same result was true for myocyte CaMK-II and intracellular calcium ions activation. Moreover, ESI-09 also increased ERK1/2 phosphorylation. CONCLUSION Our study reveal that Epacl/Rapl signaling pathway is involved in the pathogenesis of myocardial I/R injury in rats, which provides evidence on the development of therapeutic strategies target this pathway for myocardial I/R injury.
出处
《中国药理学与毒理学杂志》
CAS
CSCD
北大核心
2018年第4期309-310,共2页
Chinese Journal of Pharmacology and Toxicology
基金
This work supported by the National Natural Science Foundation of China (81470432)
and Natural Science Foundation of Anhui Province Education Department (KJ2016A357).
关键词
急性心肌缺血
冠状动脉
治疗方法
临床分析
myocardial ischemia/reperfusion injury
hypoxia/reoxygenation injury
Epacl
Rap1
Ca2＋
