Objective: To investigate the influence of high-fat diet (HFD) in paternal C57BL/6 mice on HFD-induced liver fat deposition in male offspring, as well as transgenerational inheritance caused by paternal HFD and related mechanisms. Methods: A total of 20 male C57BL/6 mice aged 3 weeks (F0) were randomly divided into normal control group (C, 10 mice) and HFD group (HF, 10 mice). After 12 weeks of HFD intervention, the male mice in the HFD group mated with female ones treated with normal diet and pups were obtained. Male pups (F1) were selected as study subjects. According to the intervention for F0 mice, male F1 mice were divided into control male offspring group (CM, 8 mice) and HFD male offspring group (HFM, 9 mice). All these mice were given normal diet after weaning until 4 weeks old, followed by HFD for 4 weeks. The body length and body weight were measured and recorded every week. Oil red O staining was used to observe fat deposition in the liver. Western blot and real-time PCR were used to measure the expression of related proteins and genes involved in the de novo synthesis and aerobic oxidation of fatty acid, mitochondriogenesis, and autophagy. Results: After 4 weeks of HFD intervention, the HFM group had a significantly higher body weight than the CM group (P < 0.05); the oil red O staining showed that compared with the CM group, the HFM had a significant increase in liver fat deposition and a significantly higher integral absorbance value in the oil red O staining-positive area (384 360±57 600 vs 236 754±12 607, P < 0.01). For related factors involved in the de novo synthesis of fatty acid in the liver, compared with the CM group, the HFM group had significant increases in the expression of sterol regulatory element-binding protein-1 and fatty acid synthase (P < 0.05); for related factors involved in the mitochondrial biosynthesis in the liver, the HFM group had significant reductions in the relative expression of peroxisome proliferator-activated receptor-γ coactivator-1α, nuclear respiratory factor 1, and mitochondrial transcription factor A compared with the CM group (P < 0.05). For autophagy-related factors in the liver in the F1 mice, compared with the CM group, the HFM group had a significant reduction in microtubule-associated protein I light chain 3 (LC3-II/I) (P < 0.05) and a significant increase in P62 (P < 0.05), suggesting a reduced autophagy function in the liver. Conclusion: HFD intervention for paternal C57BL/6 mice can increase HFD-induced liver fat deposition in male offspring, which may be related to the increased de novo synthesis of fatty acid and reduced mitochondriogenesis and autophagy function in the liver.
目的： 观察高脂饮食干预父代C57BL/6小鼠对其雄性子代小鼠高脂饮食诱导的肝脏脂肪沉积的影响，探讨父系高脂饮食引起的跨带继承现象及其机制。 方法： 20只3周龄C57BL/6雄性小鼠（F0）随机分为正常对照组（n = 10）与高脂组（n = 10），高脂组小鼠在干预12周后与同窝正常饮食、安静饲养的雌性小鼠交配，产仔。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雄性后代（CM, n = 8）、高脂饮食组雄性后代（HFM, n = 9）。两组小鼠自断乳后给予正常饮食喂养至4周龄，后全部换为高脂饮食喂养4周。每周检测身长、体质量，并记录，油红O染色检测各组肝脏中脂质沉积情况，并采用Western blot及实时PCR法检测肝组织脂肪酸从头合成、脂肪酸有氧氧化、线粒体生发及自噬相关蛋白及其基因的表达情况。对数据采用独定样本t检验分析。 结果： 4周高脂饮食干预后，HFM组小鼠的体质量明显高于CM组小鼠（P < 0.05）；肝脏油红O染色结果显示，HFM组小鼠较CM组小鼠肝脏脂肪沉积显著增多，油红O染色阳性区积分吸光度值较CM组显著增加，前者为384 360±57 600，后者为236 754±12 607（t = 7.960, P < 0.01）。HFM组小鼠肝脏脂肪酸从头合成相关因子：胆固醇调节元件结合蛋白-1及脂肪酸合酶表达较CM组明显增加（P < 0.05）；HFM组小鼠肝脏线粒体生物合成相关因子：过氧化物酶体增殖物激活受体γ辅激活因子1α、核呼吸因子1和线粒体转录因子A相对表达水平较CM组明显减低（P < 0.05）；F1代小鼠肝脏自噬功能相关因子的表达显示：与CM组比较，HFM组肝组织微管相关蛋白I轻链3明显减低（1.442±0.025与0.102±0.017，t = 7.261，P < 0.05），P62明显增高(0.747±0.015与1.172±0.056，t = 4.369，P < 0.05)，提示肝脏自噬功能减弱。 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肝脏脂肪沉积，这可能与HFM组小鼠肝脏脂肪酸从头合成增加，而线粒体生发以及肝脏自噬功能的减弱密切相关。.
Keywords: Fatty liver; Male pup; Paternal obesity.