玉郎伞查尔酮调控 PI3K/Akt 信号通路抗心肌缺血／再灌注损伤的作用及机制研究

摘要

目的：探讨玉郎伞查尔酮（YLSC）调控 PI3K／Akt 信号通路抗心肌缺血／再灌注损伤的作用及机制。方法40只♂ SD 大鼠随机分为5组：假手术组、模型组、YLSC 组、YLSC＋PI3K 抑制剂 wortmannin 组（YLSC ＋WM组）、PI3K 抑制剂wortmannin 组（WM组），每组8只。除假手术组外，其它各组大鼠均结扎冠状动脉左前降支制备心肌缺血模型，缺血30 min，再灌注120 min。实验结束后，采用比色法测定大鼠血清中肌酸激酶同工酶（CKMB）、乳酸脱氢酶（LDH）及一氧化氮（NO）水平，ELISA 法测定血清肿瘤坏死因子（TNFα）的含量，Western blot 法检测心肌组织中总Akt（tAkt）、磷酸化Akt（pAkt）及自噬相关蛋白LC3Ⅱ的表达，FQPCR 法分析内皮型一氧化氮合酶（eNOS）、凋亡因子caspase3及自噬相关基因Beclin1的表达量变化。结果与I／R 组比较，YLSC 组CKMB、LDH 以及TNFα血清含量明显降低，NO 水平升高，Beclin1、caspase3及LC3Ⅱ的表达量均明显下降，同时Akt 的磷酸化水平与eNOS mRNA 表达增加，上述各项指标差异具有统计学意义（P ＜0.05），而上述变化能够被PI3K／Akt 信号通路的特异性阻断剂wortmannin 所阻断，且其差异具有统计学意义（P ＜0.05）。结论 YLSC 通过激活PI3K／Akt 信号通路抑制缺血／再灌注所致的心肌细胞凋亡和过度自噬，从而发挥对心肌缺血／再灌注损伤的保护作用。%Aim To investigate the effects of 1 7-me-thoxyl-7-hydroxyl-benzofuran chalcone(YLSC)on my-ocardial ischemia /reperfusion injury(MI /RI)by mod-ulating PI3K/Akt signaling pathway and the possible mechanisms.Methods Male SD rats were randomly divided into sham group,model group,YLSC group, wortmannin(WM)group and YLSC +WM group(n =8).The rat model of MI /RI was established by ligation of the left anterior descending artery for 30 min fol-lowed by loosening the ligature for 2 h.After reperfu- sion,blood samples were obtained to determine serum contents of CK-MB,LDH,NO and TNF-α.The pro-tein levels of total (t)-Akt,phosphorylated (p)-Akt and LC3-Ⅱ were detected by Western blot.Caspase-3,Beclin1 and eNOS mRNA expression was evaluated by FQ-PCR.Results YLSC pretreatment greatly re-duced serum levels of CK-MB,LDH and TNF-α,and elevated NO content.It also inhibited the expression of caspase-3,Beclin1 and LC3-Ⅱ,while enhanced p-Akt and eNOS expression.Conclusion YLSC protects the heart against MI /RI via inhibition of apoptosis and excessive autophagy,in which protective effect is regu-lated by activation of the PI3K/Akt pathway.