Diet-induced obesity alters skeletal muscle fiber types of male but not female mice.
Diet-induced obesity alters skeletal muscle fiber types of male but not female mice.
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DOI：
10.1002/phy2.204
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发表时间：
2014-01-01
影响因子：
2.5
通讯作者：
Medler, Scott
中科院分区：
文献类型：
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作者：
Denies, Maxwell S;Johnson, Jordan;Maliphol, Amanda B;Bruno, Michael;Kim, Annabelle;Rizvi, Abbas;Rustici, Kevyn;Medler, Scott
骨骼肌是高度可塑性的组织，能够响应于使用、废用、疾病和其他因素而急剧重塑。越来越多的证据表明，脂肪组织对骨骼肌的基本纤维类型组成产生显著影响。在目前的研究中，我们研究了高脂饮食和随后的肥胖对C57 BLK/6 J小鼠肌纤维类型的长期影响。在断奶时，将每窝小鼠随机分配至高脂肪饮食组或对照组，并在该饮食下维持约1年。从比目鱼肌和跖肌收获单纤维，并使用SDS-PAGE确定纤维类型。高脂饮食小鼠明显比对照小鼠重（39.17 ± 2.7 g vs. 56.87 ± 3.4 g; P < 0.0003），但肌肉质量无差异。在雄性小鼠中，高脂饮食与比目鱼肌中缓慢的I型纤维比例显著降低相关（40.4 ± 3.5% vs. 29.33 ± 2.6%; P < 0.0165）。雄性小鼠比目鱼肌中I型纤维的比例与雄性小鼠的相对肥胖度成反比（P < 0.003; r2 = 0.65），而雌性小鼠则无相关性。在雄性小鼠中，I型纤维的减少与I/IIA型杂交纤维的增加相关，这表明I型纤维主要转化为这些杂交体。报告的趋势表明，I型纤维最容易受到肥胖的影响，并且这些纤维类型的变化可能具有性别特异性。小鼠被喂食高脂肪饮食，随后变得肥胖。与对照组相比，肥胖的雄性小鼠比目鱼肌中的I型慢纤维显著减少。I型纤维的损失与体脂的测量成正比，表明对肌肉表型的“剂量”依赖性影响。
Skeletal muscles are highly plastic tissues capable dramatic remodeling in response to use, disuse, disease, and other factors. Growing evidence suggests that adipose tissues exert significant effects on the basic fiber‐type composition of skeletal muscles. In the current study, we investigated the long‐term effects of a high‐fat diet and subsequent obesity on the muscle fiber types in C57 BLK/6J mice. Litters of mice were randomly assigned to either a high‐fat diet or a control group at the time of weaning, and were maintained on this diet for approximately 1 year. Single fibers were harvested from the soleus and plantaris muscles, and fiber types were determined using SDS‐PAGE. The high‐fat diet mice were significantly heavier than the control mice (39.17 ± 2.7 g vs. 56.87 ± 3.4 g; P < 0.0003), but muscle masses were not different. In male mice, the high‐fat diet was associated with a significantly lower proportion of slow, type I fibers in the soleus muscle (40.4 ± 3.5% vs. 29.33 ± 2.6%; P < 0.0165). Moreover, the proportion of type I fibers in the soleus of male mice was inversely proportional to the relative fatness of the male mice (P < 0.003; r2 = 0.65), but no association was observed in female mice. In male mice, the decline in type I fibers was correlated with an increase in type I/IIA hybrid fibers, suggesting that the type I fibers were transformed primarily into these hybrids. The reported trends indicate that type I fibers are most susceptible to the effects of obesity, and that these fiber‐type changes can be sex specific. Mice were fed a high‐fat diet and subsequently became obese. Obese male mice exhibited a significant decline in slow type I fibers in the soleus muscles, compared with controls. The loss of type I fibers was directly proportional to measures of body fat, suggesting a “dose”‐dependent effect on muscle phenotype.