Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, QC H3A 1A3, Canada.
Cell Metab. 2022 Apr 5;34(4):564-580.e8. doi: 10.1016/j.cmet.2022.03.005.
Hepatokines, secretory proteins from the liver, mediate inter-organ communication to maintain a metabolic balance between food intake and energy expenditure. However, molecular mechanisms by which hepatokine levels are rapidly adjusted following stimuli are largely unknown. Here, we unravel how CNOT6L deadenylase switches off hepatokine expression after responding to stimuli (e.g., exercise and food) to orchestrate energy intake and expenditure. Mechanistically, CNOT6L inhibition stabilizes hepatic Gdf15 and Fgf21 mRNAs, increasing corresponding serum protein levels. The resulting upregulation of GDF15 stimulates the hindbrain to suppress appetite, while increased FGF21 affects the liver and adipose tissues to induce energy expenditure and lipid consumption. Despite the potential of hepatokines to treat metabolic disorders, their administration therapies have been challenging. Using small-molecule screening, we identified a CNOT6L inhibitor enhancing GDF15 and FGF21 hepatokine levels, which dramatically improves diet-induced metabolic syndrome. Our discovery, therefore, lays the foundation for an unprecedented strategy to treat metabolic syndrome.
肝脏分泌的蛋白因子——细胞溶质因子 6 样蛋白(CNOT6L)去腺苷酸化酶可调控机体的能量摄入和支出。然而,肝分泌因子水平在受到刺激后如何被快速调节的分子机制尚不清楚。本研究揭示了 CNOT6L 去腺苷酸化酶在响应刺激(如运动和进食)后如何关闭肝分泌因子的表达,以协调能量摄入和支出。机制上,CNOT6L 的抑制作用稳定了肝脏 Gdf15 和 Fgf21 的 mRNA,增加了相应的血清蛋白水平。由此引起的 GDF15 上调刺激后脑桥抑制食欲,而增加的 FGF21 则影响肝脏和脂肪组织以诱导能量消耗和脂质消耗。尽管肝分泌因子有治疗代谢紊乱的潜力,但它们的给药治疗一直具有挑战性。通过小分子筛选,我们发现了一种 CNOT6L 抑制剂,可提高 GDF15 和 FGF21 肝分泌因子的水平,显著改善饮食诱导的代谢综合征。因此,我们的发现为治疗代谢综合征的一种前所未有的策略奠定了基础。