槲皮素促进大鼠离心运动后骨骼肌线粒体自噬相关蛋白的表达

Quercetin elevates the expression of mitochondrial autophagy related proteins in rat skeletal muscle after eccentric exercise

【目的】观察槲皮素对骨骼肌氧化应激及线粒体自噬的影响,并探讨相关信号通路。【方法】大鼠分为对照组(control group,Con)、离心运动+生理盐水组(eccentric exercise+saline group,Ex+S)和离心运动+槲皮素组(eccentric exercise+quercetin group,Ex+Qu)。离心运动大鼠进行下坡跑,跑台速度为18～20 m/s,坡度-15°,90 min/d,连续5 d。槲皮素干预为运动后槲皮素生理盐水溶液灌胃(100 mg/kg)。分离骨骼肌,ELASA法检测白介素-1β(interleukin-1β,IL-1β)含量,比色法检测丙二醛(malondialdehyde,MDA)含量,Western blotting检测一磷酸腺苷依赖性蛋白激酶(adenosine monophosphate dependent protein kinas,AMPK)、叉形头转录因子O亚型3a(forkhead box transcription factor O subtype 3a,FOXO3a)和Bcl2/腺病毒E1B19kD相互作用蛋白3(Bcl2/adenovirus E1B19kD interacting protein 3,Bnip3)蛋白表达。【结果】与Con组比较,Ex+S组IL-1β和MDA含量均显著升高(P<0.01),AMPK、FOXO3a和Bnip3蛋白表达量显著降低(P<0.01);Ex+Qu组IL-1β含量、AMPK和Bnip3蛋白表达量显著升高(P<0.05～0.01)。与Ex+S组比较,Ex+Qu组IL-1β和MDA含量均显著降低(P<0.05～0.01),AMPK、FOXO3a和Bnip3蛋白表达量显著升高(P<0.01)。【结论】槲皮素可通过抑制离心运动后氧化应激,通过激活AMPK上调FOXO3a-Bnip3介导的线粒体自噬,从而抑制炎症反应,发挥保护效应。

【Objective】To observe the effect of quercetin on oxidative stress and mitochondrial autophagy in rat skeletal muscle after eccentric exercise,and explore the related signal pathway.【Methods】Rats were randomly divided into three groups:control group(Con),eccentric exercise+saline group(Ex+S),and eccentric exercise+quercetin group(Ex+Qu).The rats in the eccentric exercise groups were exercised on a motor-driven rodent treadmill at a speed of 18-20 m/min and a grade of-15°for 90 min/day.The rats in the quercetin group were administrated with quercetin(100mg/kg)immediately after exercise.All the interventions were lasted for 5 days.The content of IL-1βwas detected by ELASA.The content of MDA was determined by colorimetric method.The expression levels of AMPK,FOXO3a and Bnip3 were detected by Western blotting.【Results】Compared with the Con group,the contents of IL-1βand MDA increased significantly in the EX+S group(P<0.01),whereas the expressions of AMPK,FOXO3a and Bnip3 showed dramatic decrease(P<0.01).In addition,the IL-1βcontent and expressions of AMPK and Bnip3 showed dramatic increase in the EX+Qu groups(P<0.05~0.01).Compared with the EX+S group,the contents of IL-1βand MDA decreased significantly in the EX+Qu group(P<0.05~0.01),whereas the expressions of AMPK,FOXO3a and Bnip3 showed significantly increase(P<0.01).【Conclusion】Quercetin can inhibit oxidative stress,which in turn activates AMPK and FoxO3-Bnip3-mediated mitochondrial autophagy,then inhibits inflammation reactions in skeletal muscle after eccentric exercise.