Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates.
Int J Mol Sci. 2022 Aug 23;23(17):9547. doi: 10.3390/ijms23179547.
Current information regarding the effects of a high-fat diet (HFD) on skeletal muscle is contradictory. This study aimed to investigate the effects of a long-term HFD on skeletal muscle in male and female mice at the morphological, cellular, and molecular levels. Adult mice of the C57BL/6 strain were fed standard chow or an HFD for 20 weeks. The tibialis anterior muscles were dissected, weighed, and processed for cellular and molecular analyses. Immunocytochemical and morphometric techniques were applied to quantify fiber size, satellite cells (SCs), and myonuclei. Additionally, PCR array and RT-qPCR tests were performed to determine the expression levels of key muscle genes. Muscles from HFD mice showed decreases in weight, SCs, and myonuclei, consistent with the atrophic phenotype. This atrophy was associated with a decrease in the percentage of oxidative fibers within the muscle. These findings were further confirmed by molecular analyses that showed significant reductions in the expression of Pax7, Myh1, and Myh2 genes and increased Mstn gene expression. Male and female mice showed similar trends in response to HFD-induced obesity. These findings indicate that the long-term effects of obesity on skeletal muscle resemble those of age-related sarcopenia.
目前关于高脂肪饮食（HFD）对骨骼肌影响的信息相互矛盾。本研究旨在从形态、细胞和分子水平上研究长期 HFD 对雄性和雌性小鼠骨骼肌的影响。将 C57BL/6 品系的成年小鼠用标准饲料或 HFD 喂养 20 周。解剖比目鱼肌，称重，并进行细胞和分子分析。免疫细胞化学和形态计量技术用于定量纤维大小、卫星细胞（SCs）和肌核。此外，还进行了 PCR 阵列和 RT-qPCR 测试，以确定关键肌肉基因的表达水平。HFD 小鼠的肌肉重量、SCs 和肌核减少，符合萎缩表型。这种萎缩与肌肉中氧化纤维的百分比下降有关。分子分析进一步证实了这一点，表明 Pax7、Myh1 和 Myh2 基因的表达显著降低，而 Mstn 基因的表达增加。雄性和雌性小鼠对 HFD 诱导的肥胖的反应表现出相似的趋势。这些发现表明，肥胖对骨骼肌的长期影响与与年龄相关的肌肉减少症相似。
