Objective: Through aerobic exercise and diet intervention on obese mice, the effects of exercise and diet intervention on testicular oxidative stress and p38MAPK-NF-κB pathway were investigated in obese mice.
Methods: Seventeen C57BL/6J mice were randomly divided into a normal diet group (ND), and 37 mice were divided into a high-fat diet group (HFD), the high-fat diet accounted for 40% of fat. After 12 weeks of feeding, 3 obesity-resistant mice were excluded from the HFD group, and the remaining 34 were successfully modeled. The mice in ND group were then divided into normal diet control group (NC, n=8) and normal diet and exercise group (NE, n=9). The mice in HFD group were divided into obese high-fat diet control group (OC, n=8), obese high-fat diet and exercise group (OE, n=9), obese normal diet group (ONC, n=8), and obese normal diet and exercise group (ONE, n=9). Each group continued to feed for 8 weeks, and the NE, OE and ONE groups performed treadmill exercise for 8 weeks at a speed of 20 m/min, 60 min/d, 6 d/week. Blood and testicular tissue samples were collected 36～40 h after the last exercise. Serum testosterone and testicular oxidative stress (MDA, T-SOD, T-AOC) levels were detected by ELISA, and testicular p38MAPK-NF-κB levels were detected by RT-PCR and Western blot.
Results: Compared with the NC group, the body fat parameters, testicular MDA and testicular p38MAPK-NF-κB mRNA and protein levels in the OC group were increased significantly (P＜0.01), while the levels of testicular SOD, testis coefficient and blood testosterone were decreased significantly (P＜0.01); the body fat parameters of the mice in the NE group were decreased significantly (P＜0.05), and the serum level of testosterone was increased significantly (P＜0.01). Compared with the OC group, the body fat parameters, testicular MDA and testicular p38MAPK-NF-κB mRNA and protein levels were decreased significantly in the OE group (P＜0.05 or 0.01), and the testicular SOD and blood testosterone levels were increased significantly (P＜0.01); Body fat parameters, testicular MDA and testicular p38MAPK-NF-κB mRNA and protein levels were decreased significantly in ONC group (P＜0.01), while testicular SOD level and testis coefficient were increased significantly (P＜0.05); Body fat parameters, testicular MDA and testicular p38MAPK-NF-κB mRNA and protein levels of mice in ONE group were decreased significantly (P＜0.01), while testicular SOD, testis coefficient and blood testosterone levels were increased significantly (P＜0.01).
Conclusion: Obesity induces oxidative stress in the testis of mice, up-regulates the level of p38MAPK-NF-κB, and reduces the level of blood testosterone; exercise, diet and exercise*diet interventions can reduce testicular oxidative stress and down-regulate testicular p38MAPK-NF-κB levels by reducing body fat.
目的: 通过对肥胖小鼠施加有氧运动与饮食干预,探索运动与饮食干预对肥胖小鼠睾丸氧化应激和p38MAPK-NF-κB通路中的作用。方法: 随机将17只C57BL/6J小鼠分为正常饮食组(ND),37只分为高脂饮食组(HFD),高脂饮食脂肪占比40%,喂养12周后,HFD组剔除3只肥胖抵抗小鼠,其余34只肥胖造模成功;随后将ND组分为正常饮食对照组(NC,n=8),正常饮食运动组(NE,n=9),肥胖高脂饮食对照组(OC,n=8),肥胖高脂饮食运动组(OE,n=9),肥胖正常饮食组(ONC,n=8),肥胖正常饮食运动组(ONE,n=9),各组继续饲养8周,其中NE、OE和ONE组以速度20 m/min,60 min/d,6 d/week,进行8周跑台运动,末次运动后36～40 h取血和睾丸组织,ELISA检测血清睾酮和睾丸氧化应激(MDA、T-SOD、T-AOC)水平,RT-PCR和Western blot检测睾丸p38MAPK-NF-κB水平。结果: 与NC组比较,OC组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显升高(P＜0.01),睾丸SOD、睾丸系数和血睾酮明显降低(P＜0.01);NE组小鼠体脂参数明显降低(P＜0.05),血清睾酮明显升高(P＜0.01)。与OC组比较,OE组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P＜0.05或0.01),睾丸SOD和血睾酮水平明显升高(P＜0.01);ONC组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P＜0.01),睾丸SOD水平和睾丸系数明显升高(P＜0.05);ONE组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P＜0.01),睾丸SOD、睾丸系数和血睾酮水平明显升高(P＜0.01)。结论: 肥胖引起小鼠睾丸发生氧化应激,上调睾丸p38MAPK-NF-κB水平,并降低血睾酮水平;运动、饮食和运动×饮食干预均能通过降低体脂,改善睾丸氧化应激,下调睾丸p38MAPK-NF-κB水平。.
Keywords: exercise and dietary intervention; high-fat diet; mice; nuclear factor kappa-B (NF-κB); oxidative stress; p38 mitogen activated protein kinase (p38MAPK); testosterone.