紫檀芪调节PLIN5／FGF21通路抑制棕榈酸诱导的L6肌管细胞脂质沉积

Pterostilbene inhibits palmitate-induced lipid deposition in L6 myotubes by modulating PLIN5/FGF21 pathway

目的探讨紫檀芪(pterostilbene,PTT)对棕榈酸(palmitate acid,PA)诱导的大鼠L6肌管细胞脂质沉积的影响及其相关分子机制。方法大鼠L6成肌细胞诱导分化为肌管后,采用PA处理建立骨骼肌细胞脂质沉积模型并进行PTT干预。CCK-8法检测细胞活力,油红O染色法观察细胞内脂滴形成,GPO-PAP酶法检测细胞内甘油三酯(triglyceride,TG)含量,荧光法检测细胞摄取葡萄糖能力,Western blot检测围脂滴蛋白5(perlipin 5,Plin5)、成纤维细胞生长因子21(fibroblast growth factor 21,FGF21)的蛋白表达。Plin5基因沉默采用siRNA转染。结果 PTT(10~80μmol/L)对L6肌管细胞活力无明显影响(P>0.05);PA可诱导L6肌管细胞内脂质沉积、TG含量升高,并显著降低葡萄糖摄取能力(P<0.05),同时明显下调Plin5和FGF21蛋白表达;PTT干预可明显抑制PA诱导的上述变化,而Plin5基因沉默后,PTT对PA诱导的FGF21表达下降、TG含量增加及葡萄糖摄取能力降低的抑制作用被显著削弱(P<0.05)。结论 PTT可通过调节Plin5/FGF21信号通路抑制棕榈酸诱导的L6肌管细胞脂质沉积及胰岛素抵抗。

Objective To investigate the effects of pterostilbene （PTT） on lipid deposition induced by palmitate （PA） in rat L6 myotubes and its underlying molecular mechanisms. Methods Rat L6 myoblasts were differentiated into myotubes and then treated with PA to establish lipid deposition model, and PTT intervention was performed. Cells viability was assessed by CCK-8 assay. The lipid deposition was evaluated by oil red O staining. The intracellular triglyceride （TG） content was measured by an enzymatic procedure （GPO-PAP）. The glucose uptake was measured by fluorescence assay. The protein levels of perlipin 5 （Plin5） and fibroblast growth factor 21 （FGF21） were detected by Western blotting. Plin5 gene was silenced by siRNA transfection. Results PTT （10~80 μmol/L） treatment did not affect cell viability of L6 myotubes （P〉0.05）. PA treatment resulted in lipid deposition, significant increase in TG content, reduced glucose uptake （P〈0.05）, as well as, obviously reduced protein levels of FGF21 and PLIN5 in L6 myotubes （P〈0.05）. However, PTT intervention markedly inhibited these changes induced by PA, while, Plin5 knock-down by siRNA significantly attenuated the inhibitory effects of PTT on the decreased FGF21 protein level, increased TG content and decreased glucose uptake induced by PA treatment （P〈0.05）. Conclusion PTT inhibits palmitateinduced lipid deposition and insulin resistance in L6 myotubes by Plin5/FGF21 pathway.