Abstract
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.