SIRT1/PGC-1α通路在断指再植大鼠皮瓣成活及皮瓣自噬中的作用机制

The mechanism of SIRT1/PGC-1α pathway on skin flap survival and autophagy in rat severed finger replantation

目的:探究沉默信息调节因子1(SIRT1)/过氧化物酶体增殖物激活受体γ共激活因子1α(PGC-1α)信号通路在断指再植大鼠皮瓣成活、自噬中的作用及可能机制。方法:构建断指再植大鼠模型,根据实验设计,将50只SD大鼠随机分为:对照组、SIRT1激动剂(SRT-1460)组、雷帕霉素(RAPA)组、RAPA+SIRT1抑制剂(EX527)组、SRT-1460+RAPA组,每组10只;观察各组断指再植大鼠的皮瓣存活率、皮瓣存活面积,Western blotting检测各组大鼠皮瓣SIRT1、PGC-1α、Beclin1、微管相关蛋白1轻链3Ⅱ型(LC3II)蛋白表达水平,RT-qPCR检测各组大鼠皮瓣SIRT1、PGC-1α、Beclin1、LC3II mRNA表达水平。结果:与对照组相比,SRT-1460组断指再植大鼠皮瓣的存活率(74.81±4.38)及皮瓣存活面积(6.22±1.15)显著增加,断指再植大鼠皮瓣中SIRT1、PGC-1α、Beclin1、LC3II蛋白及mRNA表达显著增加,RAPA组断指再植大鼠皮瓣的存活率(76.50±5.82)、皮瓣存活面积(6.94±2.61)增加,断指再植大鼠皮瓣中SIRT1、PGC-1α、Beclin1、LC3II蛋白及mRNA表达显著增加;与RAPA组相比,RAPA+EX527组断指再植大鼠皮瓣的存活率(67.23±6.28)及皮瓣存活面积(5.91±1.83)减少,断指再植大鼠皮瓣的SIRT1、PGC-1α、Beclin1、LC3II蛋白及mRNA表达显著减少。与SRT-1460组相比,SRT-1460+RAPA组断指再植大鼠皮瓣的存活率(89.71±7.13)、皮瓣存活面积(8.32±1.26)减少,断指再植大鼠皮瓣的SIRT1、PGC-1α、Beclin1、LC3II蛋白及mRNA表达显著减少。结论:SIRT1/PGC-1α信号通路在断指再植大鼠皮瓣的成活中发挥重要作用,该通路的抑制可通过下调自噬并降低断指再植大鼠皮瓣的成活,激活该通路可增强自噬并提高断指再植大鼠皮瓣的成活。

Objective To explore the role and possible mechanism of silencing information regulatory factor 1(SIRT1)/peroxisome proliferator-activated receptor-γ-coactivator 1α(PGC-1α)signaling pathway in replanted flaps survival and autophagy in rat finger replantation.Methods According to the experimental design,50 SD rats were randomly divided into control group,SIRT1 agonist(SRT-1460)group,rapamycin(RAPA)group,RAPA+SIRT1 inhibitor(EX527)group and SRT-1460+RAPA group,with 10 rats in each group.The survival rate and the survival area of the skin flap were observed in each group.The expression levels of SIRT1,PGC-1α,Beclin1,microtubule-associated protein 1 light chain 3II(LC3II)in the skin flap of the rats in each group were detected by Western blotting.The mRNA expression levels of SIRT1,PGC-1α,Beclin1 and LC3II in rat skin flap were detected by RT-qPCR.Results Compared with the control group,the survival rate(74.81±4.38)and the survival area(6.22±1.15)of the rat skin flap in SRT-1460 group were significantly increased,the protein and mRNA expressions of SIRT1,PGC-1α,Beclin1,LC3II were significantly increased in rat skin flap after severed finger replantation,the survival rate(76.50±5.82)and the survival area(6.94±2.61)were increased in RAPA group,the protein and mRNA expressions of SIRT1,PGC-1α,Beclin1,LC3II were significantly increased in rat skin flap after severed finger replantation.Compared with RAPA group,the survival rate(67.23±6.28)and the survival area(5.91±1.83)of the rat skin flap in RAPA+EX527 group were decreased,the protein and mRNA expressions of SIRT1,PGC-1α,Beclin1,LC3II were significantly decreased.Compared with SRT-1460 group,the survival rate(89.71±7.13)and the survival area(8.32±1.26)of rat skin flap in SRT-1460+RAPA group were decreased,the protein and mRNA expressions of SIRT1,PGC-1α,Beclin1,LC3II were significantly decreased.Conclusion SIRT1/PGC-1α signaling pathway plays an important role in the survival of rat skin flap after finger replantation.Inhibition of this pathway can reduce autophagy and the survival of rat skin flap after finger replantation.Activation of this pathway can enhance autophagy and improve the survival of rat skin flap after finger replantation.