游离脂肪酸对小鼠骨骼肌干细胞分化及功能的影响

Effects of free fatty acid on the differentiation and function of skeletal muscle stem cells in mice

目的 :观察棕榈酸(palmitic acid,PA)对小鼠骨骼肌干细胞分化及功能的影响,为治疗衰老相关的肌少症寻找新思路。方法:对小鼠骨骼肌干细胞诱导分化后,同时予PA(100μmol/L)干预,用荧光染色法、荧光定量PCR测定成肌基因肌球蛋白重链(myosin heavy chains,MyHC)表达;用seahorse能量代谢仪检测细胞的氧耗增加率,荧光定量PCR检测线粒体融合基因线粒体融合素基因1(mitofusin1,Mfn1)、视神经萎缩症蛋白基因(opticatrophy 1,Opa1)和裂解基因发动相关因子基因(dynamin 1-like,Drp1)、线粒体分裂素基因1(fission 1,Fis1)的相对表达量。结果 :PA刺激后,MyHC荧光表达量下降,肌小管融合率减低,同时seahorse能量代谢仪检测细胞的氧耗增加率(oxygen consumption rate,OCR)降低(P<0.05);线粒体融合基因无明显异常,但裂解基因表达增加,融合/裂解比值下降(P<0.05)。结论:游离脂肪酸抑制骨骼肌干细胞分化、影响线粒体氧耗功能,这可能是通过影响线粒体Drp1基因,增加线粒体裂解实现的。

Objective：The effects of palmitic acid （PA） on the differentiation and function of mouse skeletal muscle stem cells was detected for the new medicine-sarcopenia.Methods：One hundred μmol/L PA was added to skeletal muscle stem cells.The morphological changes of the cultured cells were observed,the myosin heavy chains（MyHC） of the culture cells was determined using immunocytochemistry and the expression of the gene was determined by real time PCR. Oxygen consumption rates （OCR） was measured by XFe24 extra cellular flux analyzer. Levels of mitochondrial fusion and fission marks such as Mfn1,Opa1,Drp1,Fis1 were measured. Results：When the cells treated with PA,fluorescent expression of MyHC was decreased and the fusion rate of myotube also reduced. The oxygen consumption rate （OCR） in the presence of PA was decreased（P〈0.05）. The fusion mark was not significantly changed,but mitochondrial fusion index（Mfn1-to-Drp1ratio） was significantly increased. Conclusion：The results showed that PA inhibited the differentiation of skeletal muscle stem cells and OCR of mitochondria. The effects of PA on myogenesis were carried out through decreasing the fusion of mitochondria.