Key Laboratory of Metabolism and Molecular Medicine of the Ministry of Education, Department of Biochemistry and Molecular Biology of School of Basic Medical Sciences, and Department of Endocrinology and Metabolism of Zhongshan Hospital, and Department of Clinical Laboratory, Shanghai Pudong Hospital, Fudan University, Shanghai, China.
Key Laboratory of Metabolism and Molecular Medicine of the Ministry of Education, Department of Biochemistry and Molecular Biology of School of Basic Medical Sciences, and Department of Endocrinology and Metabolism of Zhongshan Hospital, and Department of Clinical Laboratory, Shanghai Pudong Hospital, Fudan University, Shanghai, China.
J Biol Chem. 2022 Feb;298(2):101544. doi: 10.1016/j.jbc.2021.101544. Epub 2021 Dec 28.
Uncontrolled gluconeogenesis results in elevated hepatic glucose production in type 2 diabetes (T2D). The small ubiquitin-related modifier (SUMO)-specific protease 2 (SENP2) is known to catalyze deSUMOylation of target proteins, with broad effects on cell growth, signal transduction, and developmental processes. However, the role of SENP2 in hepatic gluconeogenesis and the occurrence of T2D remain unknown. Herein, we established SENP2 hepatic knockout mice and found that SENP2 deficiency could protect against high-fat diet-induced hyperglycemia. Pyruvate- or glucagon-induced elevation in blood glucose was attenuated by disruption of SENP2 expression, whereas overexpression of SENP2 in the liver facilitated high-fat diet-induced hyperglycemia. Using an in vitro assay, we showed that SENP2 regulated hepatic glucose production. Mechanistically, the effects of SENP2 on gluconeogenesis were found to be mediated by the cellular fuel sensor kinase, 5'-AMP-activated protein kinase alpha (AMPKα), which is a negative regulator of gluconeogenesis. SENP2 interacted with and deSUMOylated AMPKα, thereby promoting its ubiquitination and reducing its protein stability. Inhibition of AMPKα kinase activity dramatically reversed impaired hepatic gluconeogenesis and reduced blood glucose levels in SENP2-deficient mice. Our study highlights the novel role of hepatic SENP2 in regulating gluconeogenesis and furthers our understanding of the pathogenesis of T2D.
非受控的糖异生导致 2 型糖尿病(T2D)患者肝葡萄糖生成增加。小泛素相关修饰酶(SUMO)特异性蛋白酶 2(SENP2)已知可催化靶蛋白的 SUMO 去修饰,对细胞生长、信号转导和发育过程有广泛影响。然而,SENP2 在肝糖异生和 T2D 发生中的作用尚不清楚。在此,我们建立了 SENP2 肝敲除小鼠,发现 SENP2 缺失可预防高脂肪饮食诱导的高血糖。破坏 SENP2 表达可减轻丙酮酸或胰高血糖素诱导的血糖升高,而肝内过表达 SENP2 则促进高脂肪饮食诱导的高血糖。通过体外测定,我们表明 SENP2 调节肝葡萄糖生成。在机制上,SENP2 对糖异生的影响是通过细胞燃料传感器激酶 5'-AMP 激活蛋白激酶α(AMPKα)介导的,AMPKα 是糖异生的负调节剂。SENP2 与 AMPKα 相互作用并使其 SUMO 化,从而促进其泛素化并降低其蛋白稳定性。AMPKα 激酶活性的抑制可显著逆转 SENP2 缺失小鼠受损的肝糖异生并降低血糖水平。本研究强调了肝 SENP2 在调节糖异生中的新作用,并进一步了解了 T2D 的发病机制。