高脂饮食干预父代C57BL/6小鼠对雄性子代过氧化物酶体增殖活化受体γ辅助活化因子1α启动子甲基化的影响

Paternal high-fat diet influences the high-fat diet-induced hypermethylation of the peroxisome proliferator-activated receptor gamma coactivator 1-alpha promoter in the offspring of C57BL/6mice

目的 观察高脂饮食干预的父代C57BL/6小鼠对其子代小鼠由高脂饮食诱导的肥胖及糖代谢异常的易感性及子代小鼠骨骼肌过氧化物酶体增殖活化受体γ辅助活化因子1α(Pgc-1α)基因启动子的甲基化状态,探讨父系高脂饮食引起的跨代遗传现象及其机制.方法 将20只雄性C57BL/6小鼠(F0)按随机数字表法分为正常对照组(C组,n=10)及高脂组(HF组,n=10),分别在12周正常饮食及12周高脂饮食干预后与同窝正常饮食、安静饲养的雌性小鼠交配.选取雄性子代小鼠(F1)为研究对象,根据F0干预方式不同将雄性F1小鼠分为安静对照组后代(CM组,n=8)、高脂饮食组后代(HFM组,n=9),两组小鼠均给予高脂饮食喂养4周.检测F1代小鼠骨骼肌Pgc-1α基因的表达情况及Pgc-1α启动子-260位点甲基化水平.两组间比较采用t检验.结果 与CM组相比,HFM组小鼠在4周高脂饮食干预后,体重较CM组增加3.27%(t=-3.924,P<0.01),腹腔白色脂肪总重量与体重比也明显增加[(2.26±0.24)%比(3.67±0.52)%,t=-3.906,P<0.01];与CM组相比,HFM组出现明显糖耐量异常,差异有统计学意义[分别为:15 min血糖值:(328±26)比(410±53)mg/dl、30 min:(318±43)比(412±48)mg/dl、60 min:(248±31)比(328±32)mg/dl,t=-2.291、-3.656、-4.759,均P<0.01];2组口服葡萄糖耐量实验曲线下面积差异有统计学意义[(374±39)比(388±33)mg/dl×120 min,t=-4.753,P<0.01];同时骨骼肌组织Pgc-1α基因表达较CM组明显减低,而Pgc-1α启动子-260位点甲基化水平明显增高[(36.8±4.7)%比(44.3±3.6)%,t=-4.453,P<0.01].结论 高脂饮食干预父代C57BL/6小鼠可以增加其雄性子代小鼠高脂饮食诱导的肥胖及糖代谢异常的易感性,这可能与HFM组小鼠骨骼肌组织Pgc-1α启动子-260位点高甲基化相关.

Objective To determine the effects of high-fat diet on metabolic health outcomes in their male offspring and methylated regulation of the metabolic master regulator, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1α) in C57BL/6 mice. Methods 8-week-old C57BL/6 male mice (n=20) were divided into two groups:the standard chow group (C, n=10) and the high fat diet group (HF, n=10) with random number table. After 12 weeks high fat diet (HFD) feed, each male mouse mated with a female sibling. Male pups were divided into two groups:male offspring from the control group (CM, n=8) and male offspring from HF group (HFM, n=9) were given HFD for 4 weeks until sacrifice at 8&nbsp;weeks of age. The experimental data were analyzed by t test between two groups. Results Compared with CM group, 4 weeks HFD resulted in a significantly increase in HFM in body weight 3.27%(t=-3.924, P<0.01), fat pad mass[ (2.26 ± 0.24)% vs (3.67 ± 0.52)%, t=-3.906, P<0.01] and impaired glucose tolerance. Blood glucose in 15 min were (328±26) vs (410±53) mg/dl, 30 min were (318±43) vs (412±48) mg/dl, 60 min were (248 ± 31) vs (328 ± 32) mg/dl and area under the curve were (374 ± 39) mg/dl × 120 min vs (388 ± 33) mg/dl×120 min (t=-2.291,-3.656,-4.759,-4.753, all P<0.01). Meanwhile, paternal HFD can increase the HFD-induced methylation of the Pgc-1α promoter were (36.8 ± 4.7)% vs (44.3 ± 3.6)% (t=-4.453, P<0.01) with a trend of decreased Pgc-1α mRNA expression in skeletal muscle. Conclusions The current study provides the evidence that paternal obesity can increase susceptibility to HFD-induced obesity and glucose tolerance dysfunction in male offspring with hypermethylation of the Pgc-1αpromoter at CpG site-260.