电针对运动大鼠腓肠肌组织代谢酶及自噬基因表达的影响

Effects of electroacupuncture on the expression of metabolic enzymes and autophagy genes in gastrocnemius muscle tissues of exercising rats

背景:急性运动易引起机体内骨骼肌组织损伤和体内脂代谢紊乱,但急性运动联合电针调控机体内代谢和自噬通路的机制尚不明确。目的:观察电针“足三里”和“环跳”穴对急性运动大鼠骨骼肌代谢酶及自噬水平的变化。方法:将50只雄性SD大鼠随机分为安静对照组(10只)、模型组(20只)、逆电针组(20只),后两组设2个时相点,即运动后即刻和运动后3 h组,每个时相点10只大鼠。后两组进行适应性跑台运动训练后,进行急性运动训练,逆电针组大鼠于每天跑台训练前先介入电针治疗(参数为电针大鼠两侧“足三里”和“环跳”穴,连续波、频率2 Hz、强度2 mA、留针30 min、1次/d、连续7 d),电针后休息10 min再进行急性运动。分别于运动后即刻和运动后3 h麻醉取大鼠双侧腓肠肌组织,苏木精-伊红染色观察大鼠骨骼肌组织病理学变化;ELISA法检测大鼠骨骼肌组织肝脂酶、脂肪酸合成酶、激素敏感脂肪酶、肉碱棕榈酰转移酶1活性;免疫组织化学和Western Blot法检测自噬基因表达变化。结果与结论:①苏木精-伊红染色后模型组大鼠运动后即刻和运动后3 h腓肠肌纤维排列出现紊乱、肿胀、破裂;逆电针组大鼠运动后即刻和运动后3 h腓肠肌纤维排列紧密,肿胀和破裂的细胞大为减少,与安静对照组比较无明显性差异;②模型组和逆电针组运动后3 h的肝脂酶和脂肪酸合成酶活性均低于安静对照组(P<0.05或P<0.01);模型组和逆电针组大鼠运动后3 h的脂蛋白酯酶、激素敏感脂肪酶和肉碱棕榈酰转移酶1活性高于安静对照组(P<0.05或P<0.01),激素敏感脂肪酶和肉碱棕榈酰转移酶1活性在逆电针组运动后即刻高于模型组同期(P<0.05);与模型组运动后3 h相比,逆电针组运动后3 h脂蛋白酯酶活性升高(P<0.05),激素敏感脂肪酶活性降低(P<0.01);③免疫组织化学结果显示,P62、自噬相关基因5和自噬相关基因7表达在模型组大鼠运动后即刻和运动后3 h及逆电针组运动后即刻均高于安静对照组(P<0.05或P<0.01),其中运动后即刻和运动后3 h逆电针组大鼠P62及自噬相关基因7表达均低于模型组(P<0.05);④Western Blot结果显示,运动后即刻逆电针组大鼠P62和自噬相关基因7蛋白表达均低于模型组(P<0.05);Parkin蛋白表达在模型组大鼠运动后即刻和运动后3 h均高于安静对照组(P<0.05),逆电针组大鼠运动后即刻和运动后3 h均低于模型组(P<0.05);⑤提示急性运动引起大鼠腓肠肌纤维排列出现紊乱、肿胀、破裂,电针两侧“足三里”和“环跳”穴可改善大鼠骨骼肌脂代谢水平及调控自噬细胞,防止急性运动引起大鼠机体内脂代谢紊乱和腓肠肌组织的损伤,其机制可能与调控自噬相关因子P62、自噬相关基因5、自噬相关基因7、Parkin蛋白表达来促进大鼠骨骼肌细胞自噬的发生或调节细胞自噬通路密切相关。

BACKGROUND:Acute exercise tends to cause skeletal muscle tissue damage and lipid metabolism disorders in vivo,but the mechanism by which acute exercise combined with electroacupuncture modulates metabolic and autophagic pathways in vivo is unclear.OBJECTIVE:To observe the changes in metabolic enzymes and autophagy levels in skeletal muscle of rats subjected to acute exercise by electroacupuncture at the acupoints of“Zusanli”and“Huantiao.”METHODS:Fifty male Sprague-Dawley rats were randomly divided into three groups:quiet control group(n=10),model group(n=20),and reverse electroacupuncture group(n=20).The latter two groups were set up with two time points,i.e.immediate and 3 hours after exercise groups(n=10 per time point).The model group and the reverse electroacupuncture group underwent acute exercise training after adaptive treadmill training.The rats in the reverse electroacupuncture group underwent electroacupuncture treatment(parameters:electroacupuncture on both sides of the rats at the acupoints of“Zusanli”and“Huantiao,”continuous wave,frequency of 2 Hz,intensity of 2 mA,leaving the needle in the body for 30 minutes,once a day for 7 consecutive days)before treadmill training.Bilateral gastrocnemius muscle tissues were taken under anesthesia immediately after exercise and 3 hours after exercise,and hematoxylineosin staining was used to observe the histopathological changes of rat skeletal muscle.ELISA kit was used to detect the activities of hepatic lipase,fatty acid synthase,hormone-sensitive lipase,and carnitine palmitoyltransferase 1 in rat skeletal muscle tissues.Immunohistochemistry and western blot were used to detect the changes in the expression of autophagy genes.RESULTS AND CONCLUSION:After hematoxylin-eosin staining,the arrangement of gastrocnemius muscle fibers in the model group was disturbed,swollen and ruptured immediately after exercise and 3 hours after exercise.In the reverse electroacupuncture group,gastrocnemius muscle fibers were tightly arranged and the number of swollen and ruptured cells was greatly reduced immediately after exercise and 3 hours after exercise,and there was no significant difference when compared with the quiet control group.Compared with the quiet control group,the activities of hepatic lipase and fatty acid synthase were lower while the activities of lipoprotein lipase,hormone-sensitive lipase,and carnitine palmitoyltransferase 1 were higher in the model group and the reverse electroacupuncture group 3 hours after exercise(P<0.05 or P<0.01).Compared with the model group,the activities of lipoprotein lipase and carnitine palmitoyltransferase 1 were higher in the reverse electroacupuncture group immediately after exercise(P<0.05),while the activity of lipoprotein lipase was higher and the activity of hormone-sensitive lipase was lower in the reverse electroacupuncture group 3 hours after exercise(P<0.01).Immunohistochemical results showed that compared with the quiet control group,the expression of P62,autophagy-related gene 5 and autophagy-related gene 7 was higher in the model group immediately and 3 hours after exercise,as well as in the reverse electroacupuncture group immediately after exercise(P<0.05 or P<0.01);compared with the model group,the expression of P62 and autophagy-related gene 7 was lower in the reverse electroacupuncture group immediately and 3 hours after exercise(P<0.05).Western blot results showed that the protein expression of P62 and autophagy-related gene 7 in the reverse electroacupuncture group was lower than that in the model group immediately after exercise(P<0.05);the protein expression of Parkin in the model group was higher than that in the quiet control group immediately and 3 hours after exercise(P<0.05);and the protein expression of Parkin in the reverse electroacupuncture group was lower than that in the model group immediately and 3 hours after exercise(P<0.05).To conclude,acute exercise induces disorders,swelling and rupture of gastrocnemius muscle fibers in rats and electroacupuncture on both sides of the acupoints of“Zusanli”and“Huantiao”can improve the level of lipid metabolism and regulate autophagy cells in rat skeletal muscle,preventing the disorders of lipid metabolism and damage of gastrocnemius muscle tissues caused by acute exercise.The mechanism may be closely related to the regulation of autophagy-related factor P62,autophagy-related gene 5,autophagyrelated gene 7,and Parkin protein expression to promote the occurrence of autophagy or regulate the autophagy pathway in rat skeletal muscle cells.