8周有氧运动对高脂喂养肥胖小鼠血管内皮炎症及microRNA-126表达的影响

Effects of 8-Weeks' Aerobic Exercise on Vascular Endothelial Inflammation and microRNA-126 in Obese Mice

目的:探讨有氧运动对肥胖小鼠胸主动脉内皮细胞分子粘附、血管内皮炎症的影响。方法:SPF级雄性断乳C57BL/6小鼠37只,随机分为正常饮食组(Control Diet,CD,n=17)和高脂饮食组(High Fat Diet,HFD,n=20),分别进行普通饲料和高脂饲料喂养。12周后,筛选肥胖小鼠17只随机分为肥胖对照组(Obesity Control,OC,n=8)和肥胖运动组(Obesity Exercise,OE,n=9),筛选对照组小鼠17只随机分为正常对照组(Normal Control,NC,n=8)和正常运动组(Normal Exercise,NE,n=9),OE组和NE组进行为期8周的有氧跑台运动。跑台活动持续8周,每周6次,每次30 min,跑速20 m/min。测定小鼠体重及腹腔脂肪含量;采用透射电镜观察胸主动脉内皮细胞的形态学改变;ELISA测定血清TNF-α、insulin水平;分别采用real-time PCR和免疫组化技术检测胸主动脉microRNA-126(miR-126)、TNF-α、NF-κB、VCAM-1 m RNA含量和各蛋白表达。结果:与NC相比,OC小鼠体重和腹腔脂肪均显著增加(P<0.01),血清TNF-α水平显著上调(P<0.01),透射电镜结果显示,OC组小鼠内皮细胞形态上已造成相应损伤,胸主动脉miR-126水平显著下降(P<0.01),TNF-α、NF-κB、VCAM-1蛋白表达显著上升(P<0.01)。与OC相比,OE小鼠体重、lee’s指数均显著下降(P<0.01),血清TNF-α水平表达显著下调(P<0.01),炎症水平减轻,小鼠内皮细胞形态受损情况改善,OE小鼠血管内皮miR-126水平显著上升(P<0.01),小鼠胸主动脉TNF-α(P<0.01)、NF-κB(P<0.01)、VCAM-1(P<0.05)蛋白表达显著下调,运动前后miR-126与TNF-α(r=-0.60,P<0.05)、VCAM-1(r=0.69,P<0.05)表达变化呈显著相关。结论:8周有氧运动干预显著减少血清炎性因子,缓解肥胖小鼠内皮细胞分子粘附,改善血管内皮炎症,其作用可能与运动诱导miR-126增加相关。

Objective:To investigate the effect of aerobic exercise on vascular endothelial molecular adhesion and inflammation in obese mice.Methods:Thirty-seven SPF male C57BL/6 mice were randomly divided into control diet(CD,n=17)and high-fat diet(HFD,n=20),and separately fed ordinary food and high fat diet.After 12 weeks,17 obese mice were randomly divided into obesity control group(OC,n=8)and obese exercise group(OE,n=9).Seventeen control mice were randomly selected.Randomly divided into normal control group(NC,n=8),normal exercise group(NE,n=9).The OE group and the NE group performed aerobic exercise for 8 weeks.The treadmill exercise lasted 8 weeks,6 times a week,30 minutes each time,and the running speed was 20m/min.The body weight and abdominal fat content of mice were measured;Morphological changes of mouse thoracic aorta endothelial cells were observed by transmission electron microscopy;Serum TNF-αand insulin levels were measured by ELISA;Real-time PCR and immunohistochemistry were used to measure microRNA-126(miR-126),TNF-α,NF-κB,VCAM-1 mRNA.Results:Compared with NC group,mice in OC group’s body weight and peritoneal fat were increased(P<0.01),serum TNF-αlevel was significantly increased(P<0.01),transmission electron microscopy showed that the morphology of endothelial cells in obese mice corresponding injury,miR-126 levels in thoracic aorta decreased(P<0.01),TNF-α,NF-κB,and VCAM-1 protein expression increased(P<0.01).Compared with OC group,mice in OE group’s body weight and lee's index in the decreased(P<0.01),serum TNF-αlevels were down-regulated(P<0.01),inflammation levels decreased,and endothelial cell morphology was impaired in the OE group.MiR in the OE group Level of-126 increased(P<0.01),TNF-α(P<0.01),NF-κB(P<0.01),and VCAM-1(P<0.05)protein expression were down-regulated after exercise.There was a significant correlation with the expression changes of TNF-α(r=-0.60,P<0.05)and VCAM-1(r=0.69,P<0.05).Conclusion:8-weeks’exercise significantly reduced serum inflammatory factors,released endothelial cell molecular adhesion and improved vascular endothelial function in obese mice,which may be related to exercise-induced miR-126 expression.