不同禁食模式联合运动训练对小鼠白色脂肪棕色化的影响

Effects of Different Fasting Modes Combined with Exercise Training on Browning of White Adipose Tissue in Mice

为了探讨间歇性禁食联合运动训练对白色脂肪棕色化的影响,本实验将5~6周龄雄性C57BL/6小鼠随机分为6组:对照组、运动组、隔日禁食组、隔日禁食运动组、限时禁食组、限时禁食运动组。实验6周后测定小鼠血脂水平,并通过Western blot检测小鼠双侧腹股沟脂肪、肾周脂肪、附睾周脂肪、肩胛间棕色脂肪及左侧骨骼肌样本中磷酸化腺苷酸活化蛋白激酶(phosphorylated-adenosine monophosphate activated protein kinase,p-AMPK)、过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptor gamma,PPARγ)、氧化物酶体增殖物激活受体γ辅活化因子-1α(peroxisome proliferator-activated receptor gamma coactivator-1 alpha,PGC-1α)、解偶联蛋白1(uncoupling protein 1,UCP1)、特异性蛋白含Ⅲ型纤连蛋白域蛋白5(active fibronectin type Ⅲ domain containing protein 5,FNDC5)以及鸢尾素和PR结构域蛋白16(PR domain-containing 16,PRDM16)的表达水平,分析两种间歇性禁食模式联合运动训练对小鼠白色脂肪棕色化相关通路蛋白表达量的影响,以及不同脂肪组织中发生棕色化作用的程度。结果显示,各实验组总胆固醇水平与对照组相比均显著降低;限时禁食组和限时禁食运动组中的甘油三酯、低密度脂蛋白胆固醇水平与对照组相比均显著降低(P<0.05);隔日禁食组、隔日禁食运动组、限时禁食组和限时禁食运动组中的p-AMPK、PPARγ、PGC-1α、UCP1、FNDC5和PRDM16在不同脂肪组织和骨骼肌中的表达量与对照组相比均有不同程度的升高,其中限时禁食运动组中p-AMPK、PPARγ、PGC-1α和UCP1在棕色脂肪、腹股沟脂肪和肾周脂肪组织中的相对表达量与对照组相比均显著升高。上述结果表明,间歇性禁食及联合作用能够促进白色脂肪组织棕色化,其机制可能与PPARγ/PGC-1α/UCP1通路激活有关,其中限时禁食法联合运动的作用效果相对最佳。

To investigate the effect of intermittent fasting(IF)combined with exercise on browning of white adipose tissue(WAT),we randomly divided male C57BL/6 mice aged 5–6 weeks into six groups:control(Con),exercise(Ex),alternateday fasting(ADF),alternate-day fasting combined with exercise(ADFEx),time-restricted feeding(TRF),and time-restricted feeding combined with exercise(TRFEx).After the six-week experimental period,blood lipid levels of mice were tested.Next,Western blot was used to detect the expression levels of phosphorylated adenosine monophosphate activated protein kinase(p-AMPK),peroxisome proliferator-activated receptor gamma(PPARγ),peroxisome proliferator-activated receptor gamma coactivator-1 alpha(PGC-1α),uncoupling protein 1(UCP1),active fibronectin type III domain containing protein 5(FNDC5)and PR domain-containing 16(PRDM16)in the bilateral inguinal white adipose tissue(in-WAT),perirenal adipose tissue(pe-WAT),epididymal adipose tissue(ep-WAT),interscapular brown adipose tissue(BAT),and left hindlimb skeletal muscle of mice.The effect of IF combined with exercise on protein expression in WAT browning-related signaling pathways in mice was analyzed,and the degrees of browning in different adipose tissues were compared.The results showed that the level of total cholesterol(TC)in each experimental group was significantly lower than that of the Con group.The levels of triglycerides(TG)and low-density lipoprotein cholesterol(LDL-C)in the TRF and TRFEx groups were significantly lower than those in the Con group(P<0.05).The relative expression levels of p-AMPK,PPARγ,PGC-1α,UCP1,FNDC5 and PRDM16 in different adipose tissues and skeletal muscle increased to different extents in the ADF,ADFEx,TRF and TRFEx groups compared with the Con group;the relative expression levels of p-AMPK,PPARγ,PGC-1αand UCP1 in BAT,in-WAT and pe-WAT increased significantly in the TRFEx group compared with the Con group.These results suggested that the combination of IF and exercise promoted the browning of WAT,and the mechanism might be related to the activation of the PPARγ/PGC-1α/UCP1 signaling pathway.TRFEx was most effective among all treatments.