有氧耐力训练高脂诱导肥胖模型小鼠白色脂肪组织和血浆PPARγ的水平变化

Effect of aerobic endurance training on peroxisome proliferators activated receptor gamma expression in white adipose tissue and plasma of obese mice induced by high fat

背景:研究表明过氧化物酶体增殖物激活受体γ(peroxisome proliferators activated receptor γ,PPARγ)是调节脂肪细胞分化的关键基因。耐力运动训练是一种非常有效的减肥手段,但是耐力运动对营养性肥胖小鼠血浆中PPARγ水平及脂肪组织中PPARγ蛋白表达情况的影响尚无确切定论。目的:探索高脂诱导的肥胖小鼠经中等强度耐力跑台运动训练后,白色脂肪组织中PPARγ蛋白表达的变化及血浆中PPARγ水平的变化。方法:40只4周龄雄性C57BL/6J小鼠,购于北京维通利华实验动物技术有限公司。小鼠经过1周适应性饲养后,随机分为对照组(10只)和高脂诱导组(30只),高脂诱导组小鼠经过8周高脂食物喂养后,取体质量较大的20只小鼠按照S型分组分为肥胖模型组(10只)和耐力运动组(10只)。对照组小鼠普通饲料喂养,不运动,肥胖模型组和耐力运动组小鼠高脂饲料喂养,肥胖模型组小鼠不运动,耐力运动组小鼠先进行1周适应性运动后进行8周中等强度耐力跑台运动训练,每周5次,每次运动60 min。实验结束后,称量小鼠体质量,获取小鼠血浆并检测PPARγ水平,获取肾周和附睾白色脂肪组织并称质量,部分脂肪组织进行苏木精-伊红染色,其余通过蛋白免疫印迹检测PPARγ蛋白表达量。结果与结论:①高脂诱导能明显增加小鼠体质量,引起体内脂肪组织质量增加及脂肪细胞增大;②高脂诱导能够明显减少血浆中PPARγ水平及脂肪组织PPARγ蛋白表达;③中等强度耐力运动训练可以明显减轻高脂诱导的肥胖小鼠的体质量,明显减轻体内脂肪组织质量,明显减小脂肪细胞体积;④中等强度耐力运动训练可以明显增加血浆中PPARγ水平,明显增加脂肪组织PPARγ蛋白表达。表明中等强度耐力运动训练可能是通过增加小鼠血浆中PPARγ水平及脂肪组织中PPARγ蛋白的表达水平达到减轻体质量的目的。

BACKGROUND: Peroxisome proliferators activated receptor γ has been shown to be a key gene regulating adipocyte differentiation. Endurance exercise training is a very effective means of weight loss, but the effect of endurance exercise on the plasma peroxisome proliferators activated receptor γ content and the expression of peroxisome proliferators activated receptor γ protein in adipose tissue of nutritional obese mice remains to be determined. OBJECTIVE: To explore the changes of peroxisome proliferators activated receptor γ protein expression in white adipose tissue and plasma peroxisome proliferators activated receptor γ content in high fat-induced obese mice after moderate-intensity endurance exercise training. METHODS: Forty male C57BL/6 J mice of 4 weeks old were provided by Beijing Weitong Lihua Experimental Animal Technology Co., Ltd. and were randomly divided into control group(n=10) and high fat induction group(n=30) after 1 week of adaptive feeding. After high-fat-induced mice were fed with high-fat diet for 8 weeks, 20 mice with larger body weight were divided into obese model group(n=10) and endurance exercise group(n=10) according to S-type grouping. Control group mice were fed with normal diet, no exercise. Mice in the obese model and endurance exercise groups were fed with high fat diet. Mice in the obese model group did not exercise. Mice in the endurance exercise group were subjected to 1 week of adaptive exercise, and then for 8 weeks of moderate-intensity endurance exercise training, 5 times weekly, 60 min/time. At the end of the experiment, the body weight of the mice was weighed, and the plasma level of peroxisome proliferators activated receptor γ was detected. The peripheral and epididymal adipose tissue was obtained and weighed. Part of the adipose tissue was taken for hematoxylin-eosin staining, and the remaining adipose tissue was detected by western blotting for peroxisome proliferators activated receptor γ protein expression. RESULTS AND CONCLUSION:(1) High fat induction could significantly increase the body weight of mice, causing the increase of adipose tissue weight and fat cells in the body.(2) High fat induction could significantly reduce plasma peroxisome proliferators activated receptor γ content and adipose tissue peroxisome proliferators activated receptor γ protein expression.(3) Moderate-intensity endurance exercise training could significantly reduce the body weight of obese mice induced by high fat, significantly reduce the weight of adipose tissue, and significantly reduce the volume of fat cells.(4) Moderate-intensity endurance exercise training can significantly increase the content of peroxisome proliferators activated receptor γ in plasma and significantly increase the expression of peroxisome proliferators activated receptor γ protein in adipose tissue. It is indicated that moderate-intensity endurance exercise training may achieve the purpose of reducing body weight by increasing the content of peroxisome proliferators activated receptor γ in mouse plasma and the expression level of peroxisome proliferators activated receptor γ protein in adipose tissue.