Lo Emily K K, Chen Congjia, Ismaiah Marsena J, Zhang Fangfei, Leung Hoi Kit Matthew, El-Nezami Hani
School of Biological Sciences, University of Hong Kong, Pokfulam 999077, Hong Kong, China.
School of Biological Sciences, University of Hong Kong, Pokfulam 999077, Hong Kong, China; Institute of Public Health and Clinical Nutrition, School of Medicine, University of Eastern Finland, FI-70211 Kuopio, Finland.
Mol Metab. 2024 Dec;90:102059. doi: 10.1016/j.molmet.2024.102059. Epub 2024 Nov 1.
Elevated circulating branched-chain amino acids (BCAAs) have been associated with obesity, insulin resistance, and MASLD. Nonetheless, BCAA supplementation has been shown to provide protective outcomes towards the intervention of MASLD. Currently, there is a lack of study towards the contribution of the BCAA: valine on MASLD. Herein, the effect of low-dose valine supplementation was investigated for its role in the progression of MASLD.
C57BL/6J mice were fed a high-fat/high-cholesterol diet (HFD) to induce MASLD. Upon the establishment of MASLD, valine was supplemented via voluntary oral administration. Clinical and biochemical parameters associated with MASLD were measured, and molecular mechanism and gut microbiota modulation from the effect of valine were investigated.
Low-dose valine was found to attenuate the progression of MASLD, significantly reducing the gain in body weight, liver weight, and epididymal white adipose tissue (eWAT) weight, while also attenuating hyperglycemia and hyperleptinemia, and improving serum lipid profiles. Mechanistically, in the liver, genes related to hepatic lipogenesis and cholesterol biosynthesis were downregulated, while those associated with fatty acid oxidation, autophagy, and antioxidant capacity were upregulated, and AMPK pathway activity was enhanced. Liver and hypothalamic leptin resistance and inflammation were also attenuated, allowing better appetite control in mice fed a HFD and leading to reduced food intake. Additionally, metabolic flexibility in the eWAT was improved, and the gut microbiome was modulated by low-dose valine supplementation.
Low-dose valine supplementation attenuates MASLD by enhancing systemic leptin sensitivity and modulating the gut microbiome.
循环中支链氨基酸(BCAAs)水平升高与肥胖、胰岛素抵抗和代谢相关脂肪性肝病(MASLD)有关。尽管如此,补充BCAAs已被证明对MASLD的干预具有保护作用。目前,关于BCAA中的缬氨酸对MASLD的作用缺乏研究。在此,研究了低剂量缬氨酸补充对MASLD进展的影响及其作用机制。
给C57BL/6J小鼠喂食高脂/高胆固醇饮食(HFD)以诱导MASLD。在建立MASLD后,通过自愿口服给予缬氨酸。测量与MASLD相关的临床和生化参数,并研究缬氨酸作用的分子机制和肠道微生物群调节。
发现低剂量缬氨酸可减轻MASLD的进展,显著降低体重、肝脏重量和附睾白色脂肪组织(eWAT)重量的增加,同时还可减轻高血糖和高瘦素血症,并改善血脂谱。机制上,在肝脏中,与肝脏脂肪生成和胆固醇生物合成相关的基因被下调,而与脂肪酸氧化、自噬和抗氧化能力相关的基因被上调,并且AMPK途径活性增强。肝脏和下丘脑的瘦素抵抗和炎症也得到减轻,使喂食HFD的小鼠食欲控制更好,导致食物摄入量减少。此外,eWAT中的代谢灵活性得到改善,低剂量缬氨酸补充可调节肠道微生物群。
低剂量缬氨酸补充通过增强全身瘦素敏感性和调节肠道微生物群来减轻MASLD。