热休克蛋白60对骨骼肌线粒体动力学稳态调控作用

Effect of heat shock protein 60 on skeletal muscle mitochondrial dynamic homeostasis

目的探讨热休克蛋白60(Hsp60)对骨骼肌线粒体动力学稳态的调控作用。方法选取5只8周龄雄性健康C57/BL小鼠(体质量20~25 g)为研究对象。在小鼠成肌细胞系C2C12中分别给予Hsp60干扰RNA与对照试剂处理,并设为siHsp60组与对照组。采用免疫荧光染色法检测骨骼肌线粒体中Hsp60的表达情况。通过透射电镜与MitoTracker染色法检测线粒体的形态与数量。应用Western blot法检测线粒体分裂与融合蛋白即动力相关蛋白1(DRP1)与线粒体融合蛋白(OPA1)的表达。结果免疫荧光染色法发现,在小鼠的腓肠肌中Hsp60和线粒体标记物TOMM20有共定位表达。与对照组比较,siHsp60组细胞中异常线粒体的数量显著增加,差异有统计学意义(P<0.05)。与对照组比较,siHsp60组细胞中OPA1表达量显著降低,而DRP1表达量显著升高,差异均有统计学意义(P<0.05)。结论Hsp60可通过调控线粒体分裂与融合发挥保护骨骼肌的重要作用。

Objective To investigate the regulation of heat shock protein 60(Hsp60)on skeletal muscle mitochondrial dynamic home⁃ostasis.Methods Five healthy 8⁃week⁃old male C57/BL mice(body mass 20⁃25 g)were selected as subjects.Mouse myoblast cell line C2C12 was treated with Hsp60 interfering RNA and control reagent,and siHsp60 group and control group.The expression of Hsp60 in skeletal muscle mitochondria was detected by immunofluorescence staining.The morphology and number of mitochondria were detected by transmission electron microscopy and MitoTracker staining.The expressions of mitochondrial division and fusion pro⁃teins,namely,dynamin⁃related protein 1(DRP1)and optic atrophy 1(OPA1)were detected by Western blot.Results The immunoflu⁃orescence staining showed that Hsp60 and mitochondrial marker TOMM20 were colocalized in the gastrocnemius of mice.Compared with the control group,the number of abnormal mitochondria in siHsp60 group was significantly increased,and the difference was sta⁃tistically significant(P<0.05).Compared with control group,the expression level of OPA1 in siHsp60 group was significantly de⁃creased,while the expression level of DRP1 was significantly increased,with statistical significance(P<0.05).Conclusion Hsp60 can play an important role in protecting skeletal muscle by regulating mitochondrial division and fusion.