PI3K/Akt信号通路在Irisin抵抗阿霉素心肌毒性中的作用

Protective role of irisin against doxorubicin cardiotoxicity injury via PI3K/Akt signaling pathway

目的探究鸢尾素(Irisin)能否通过调控PI3K/Akt信号通路减轻阿霉素(Doxorubicin, Dox)心肌细胞毒性及其分子机制。方法将培养的H_9C_2细胞随机分为:对照组(Con)、Irisin处理组(Irisin)、Dox损伤组(Dox)、Dox+Akt抑制剂组(Dox+LY294002)、 Irisin保护组(Dox+Irisin)、 Dox+Irisin+Akt抑制剂组(Dox+Irisin+LY294002)。分别采用原位切口末端标记法(TUNEL)检测细胞凋亡率、Western Blot检测凋亡相关蛋白表达水平以及CCK-8试剂检测细胞活力,明确Irisin处理对Dox诱导的心肌凋亡的作用。结果体外实验证明,与Con组细胞相比,Dox处理后H_9C_2细胞凋亡率显著增加,并且凋亡相关蛋白Bax、Cleaved-caspase 3的表达显著增加,同时抗凋亡蛋白Bcl-2的表达量显著降低(P <0.05),而加入Irisin可显著逆转Dox导致的心肌细胞凋亡率增加和凋亡相关蛋白质的表达趋势。进一步的研究证实,Irisin通过促进Akt的磷酸化而上调PI3K/Akt信号通路,从而降低H_9C_2细胞的凋亡,而加入Akt抑制剂LY294002后,Irisin对Dox诱导的心肌细胞毒性的缓解作用被削弱,并且促凋亡相关蛋白的表达量也显著升高。结论 Irisin可能通过上调PI3K/Akt信号通路抑制细胞凋亡,降低Dox诱导的心肌细胞毒性,为临床治疗Dox心肌损伤提供潜在的药物靶点和治疗策略。

AIM To investigate whether irisin could regulate the PI3K/Akt signaling pathway to attenuate doxorubicin(Dox)-induced cardiotoxicity and its molecular mechanism.METHODS H9C2 cells were cultured and randomly divided into the following groups:control group(Con),irisin treatment group(Irisin),Dox injury group(Dox),Dox+Akt inhibitor group(Dox+LY294002),irisin protection group(Dox+Irisin),and Dox+Irisin+Akt inhibitor group(Dox+Irisin+LY294002).TUNEL(TdTmediated dUTP Nick-End Labeling),Western Blot and CCK-8 reagent were used to detect the apoptosis ratio,the expression of apoptotic related proteins and the cell viability respectively,which will further clarify the functions of irisin treatment against Dox-induced cardiotoxicity.RESULTS The apoptosis rate of H9C2 cardiomyocytes was significantly increased after Dox treatment compared with the Con group.The expressions of Bax and Cleaved-caspase3 were significantly increased while the expression of Bcl-2 was significantly decreased(P<0.05),which were reversed by irisin treatment.In vitro experiments further demonstrated that irisin had a protective role against doxorubicin cardiotoxicity injury by increasing the phosphorylation of Akt,which was impaired by the PI3K inhibitor,LY294002.CONCLUSION Irisin attenuates Dox-induced cardiotoxicity by the activation of PI3K/Akt signaling pathway,which may clinically provide new therapeutic targets and strategies against Dox-induced cardiotoxicity.