Isoleucine increases muscle mass through promoting myogenesis and intramyocellular fat deposition
Isoleucine increases muscle mass through promoting myogenesis and intramyocellular fat deposition
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异亮氨酸通过促进肌肉生成和肌细胞内脂肪沉积来增加肌肉质量
DOI：
10.1039/d0fo02156c
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发表时间：
2021-01-07
期刊：
影响因子：
6.1
通讯作者：
Pang, Weijun
中科院分区：
文献类型：
--
作者：
Liu, Shuge;Sun, Yunmei;Pang, Weijun
异亮氨酸（Ile）是一种支链氨基酸（BCAA），在调节体重和肌肉蛋白质合成方面具有重要作用。然而，在高脂饮食（HFD）条件下，Ile对肌肉质量和肌细胞内脂质沉积的调节作用在很大程度上仍不清楚。在这项研究中，使用32只野生雄性C57 BL/6 J小鼠随机分为两组，进行了含或不含25 g L-1 Ile的HFD的喂养实验。结果显示，Ile显著增加肌肉和脂肪量，并引起胰岛素抵抗，同时上调关键脂肪形成和肌形成蛋白的水平。更重要的是，Ile通过腓肠肌（GAS）和胫骨前肌（TA）的空泡化、肿胀和嵴断裂损害线粒体功能，并下调线粒体功能相关基因。此外，Ile促进了肌细胞的形成和更多的脂滴在肌管中的积聚。与对照组相比，Ile组肌球蛋白重链（MyHC）、成肌细胞决定蛋白1（MyoD）、肌生成素（MyoG）、过氧化物酶体增殖物激活受体γ（PPARg）和脂肪酸合成酶（FAS）的蛋白水平上调，而脂肪甘油三酯脂肪酶（ATGL）和脂蛋白脂肪酶（LPL）的蛋白水平下调。总的来说，Ile通过肌生成和肌细胞内脂质沉积增加肌肉质量。我们的研究结果提供了一个新的视角，不仅提高瘦肉多汁的农场动物通过增加肌细胞内脂质积累，但也调节肌病肥胖。
Isoleucine (Ile), as a branched-chain amino acid (BCAA), has a vital role in regulating body weight and muscle protein synthesis. However, the regulatory effect of Ile on muscle mass under high-fat diet (HFD) conditions and intramyocellular lipid deposition remains largely unclear. In this study, a feeding experiment with HFD with or without 25 g L-1 Ile was performed using 32 wild male C57BL/6J mice randomly divided into two groups. The results showed that Ile significantly increased both muscle and fat mass, as well as causing insulin resistance and meanwhile upregulating the levels of key adipogenic and myogenic proteins. More importantly, Ile damaged the mitochondrial function by vacuolation, swelling and cristae fracture in the gastrocnemius (GAS) and tibialis anterior (TA) with downregulation of mitochondrial function-related genes. Furthermore, Ile promoted myogenesis and more lipid droplet accumulation in myotubes. Compared with the control, the protein levels of myosin heavy chain (MyHC), myoblast determination protein 1 (MyoD), myogenin (MyoG), peroxisome proliferator-activated receptor gamma (PPARg) and fatty acid synthase (FAS) were upregulated in the Ile group, whereas the protein levels of adipose triglyceride lipase (ATGL) and lipoprotein lipase (LPL) were downregulated. Collectively, Ile increased muscle mass through myogenesis and intramyocellular lipid deposition. Our findings provide a new perspective for not only improving the lean juiciness of farm animals by increasing intramyocellular lipid accumulation, but also modulating myopathies under obesity.