Apelin-13对葡萄糖剥夺乳鼠心肌细胞自噬的影响及机制

Effect of apelin-13 on glucose deprivation-induced autophagy of cardiomyocytes in suckling mice and its mechanism

  • 摘要: 目的 观察血管紧张素1型受体相关蛋白配体(apelin-13)对损伤心肌细胞自噬的影响,探讨其可能的作用机制。 方法 体外培养3 d龄内的SD乳鼠心肌细胞,通过葡萄糖剥夺(glucose deprivation,GD)方法建立心肌细胞损伤模型,将细胞随机分为5组:正常对照组(Control组)、葡萄糖剥夺组(GD组)、Apelin-13预处理组(GD+Apelin-13组)、Tricribine+Apelin-13预处理组(GD+Apelin-13+Tricribine组)和阻断剂组(Tricribine组)。采用透射电镜观察细胞内自噬体的变化,免疫沉淀脂质激酶分析法检测磷脂酰肌醇3-激酶(PI3K)的活性,Western-blotting法检测细胞内自噬相关蛋白-微管相关蛋白1轻链3(LC3)的表达,以及信号通路相关蛋白Akt、p-Akt、mTOR、p-mTOR的表达。 结果 葡萄糖剥夺可诱导乳鼠心肌细胞自噬体数量、LC3-Ⅱ/LC3-Ⅰ比值增加(P< 0.01);Apelin-13预处理能减轻葡萄糖剥夺引起的心肌细胞损伤,使自噬体数量、LC3-Ⅱ/LC3-Ⅰ比值下降,提高PI3K的活性,上调Akt、mTOR蛋白的磷酸化水平(P< 0.01);Akt特异性阻断剂Tricribine可以使Apelin-13的上述保护作用减弱(P< 0.01)。 结论 Apelin-13在一定程度上可以抑制GD诱导的心肌细胞自噬,机制可能与激活PI3K/Akt/mTOR信号通路有关。

     

    Abstract: Objective To observe the effect of angiotensin 1 receptor-related apelin-13 on glucose deprivation (GD)-induced autophagy of injured cardiomyocytes and its mechanism. Methods Cardiomyocytes from 3 days old SD suckling mice were incubated in vitro. A cardiomyocyte injury model was induced by GD. The cardiomyocytes were divided into control group, GD group, GD+apelin-13 group, GD+apelin-13+tricribine group, and tricribine group. Intracellular autophagosomes were observed under transmission electron microscope. Activity of phosphoinositide-3-kinase (PI3K) was tested by immunoprecipitation lipid kinase assay. Expressions of autophagy-related microtubule light chain protein 3 (LC3) and signal pathway-related proteins (Akt, p-Akt, mTOR and p-mTOR) were detected by Western blot. Results GD increased the number of autophagosomes and the LC3-II/LC3-I ratio(P< 0.01). Apelin-13 pretreatment attenuated the GD-induced injury of cardiomyocytes, reduced the number of autophagosomes and the LC3-II/LC3-I ratio, up-regulated the activity of PI3K and the phosphorylation levels of Akt and mTOR (P< 0.01). However, tricribine blocked the protective effect of apelin-13(P< 0.01). Conclusion Apelin-13 can inhibit GD-induced autophagy of cardiomyocytes at a certain extent by activating the signaling pathway of PI3K, Akt and mTOR.

     

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