运动对高脂饮食性肥胖大鼠棕色脂肪组织线粒体形态和动力学的影响及可能机制的研究

Effect of exercise on adipose mitochondrial morphology and dynamics of high fat diet obese rat and its mechanism study

目的:探讨有氧运动对高脂饮食性肥胖大鼠脂肪线粒体形态和动力学的影响,并对其可能的机制进行探讨。方法:将三周龄SD健康雄性大鼠随机分为正常组和高脂饮食组,后者在第8周时选取体重超出正常对照组平均体重20%的大鼠为肥胖大鼠,再分为肥胖对照组、运动干预组,第16周时处死。采用透射电镜观察脂肪细胞的线粒体形态,采用荧光定量PCR技术检测脂肪细胞中NYGGF4基因的表达水平,采用Western blot方法检测Mfn1蛋白、Mfn2蛋白、Drp1蛋白的表达水平。结果:1)肥胖组大鼠脂肪细胞线粒体体积变小、数量明显减少,线粒体嵴断裂、减少、消失,部分线粒体肿胀,甚至呈空泡状;有氧运动干预后,肥胖组大鼠脂肪线粒体形态基本正常,与正常组接近,表现为线粒体嵴清晰可见,线粒体无明显肿胀、皱缩。2)肥胖组大鼠脂肪细胞NYGGF4mRNA、Mfn1蛋白表达水平均显著高于对照组;Mfn2、Drp1蛋白表达水平与对照组比较差异均无统计学意义;有氧运动干预后,肥胖组大鼠脂肪细胞NYG-GF4mRNA、Mfn1蛋白表达水平均显著降低,与对照组相比差异无统计学意义。结论:NYGGF4基因可能通过上调Mfn1蛋白表达水平,导致肥胖大鼠脂肪细胞线粒体形态发生变化、数量减少,影响细胞线粒体形态及动力学。

Objective ： To explore the effects of aerobic exercise on high - fat diet obese rats fat mito- chondrial morphology and dynamics effects, and the possible mechanism is discussed. Methods： Healthy male SD rats of 3 weeks old were randomly divided into normal group and high fat diet group, and in the eighth week ,of the high diet group those whose weight was over 20% of the aver- age weight of normal group were divided into control group and exercise intervention group. At the sixteenth week, all were killed. Using transmission electron microscopy to observe fat cell mitochon- drial morphology,using fluorescence quantitative PCR technique for the detection of fat cells in the expression level of NYGGF4 gene, using Western blot method for the detection of MFN1 protein,MFN2 protein expression level of Drpl. Results ： 1 ） Obese rat adipocytes mitochondria volume smal- ler, quantity significantly reduced, mitochondrial cristae reduction, fracture or disappearance, partial mitochondria swelling, or even becoming vacuoles;aerobic exercise intervention, obese rat adipose mitochondrial morphology were normal, approaching normal group, with mitochondrial cristae clearly visible, no obvious swelling or shrinking. 2 ）Obese rats fat cells NYGGF4mRNA, Mfnl protein expres- sion were significantly higher than those of the control group;Mfn2, Drpl protein expression level in comparison with the control group showed no significant differences;After aerobic exercise interven- tion, obese rats fat cells NYGGF4mRNA, Mfnlprotein expression were significantly reduced, com- pared with the control group, the difference was not of statistical significance. Conclusion：NYGGF4 gene up -regulation of Mfnlexpression levels leads to obesity rat adipocytes mitochondria morpholo- gy changes, reducing the number of affected cells and affecting mitochondrial morphology and dy- namics.