RT Journal Article SR Electronic T1 Pancreatic Sirtuin 3 Deficiency Promotes Hepatic Steatosis by Enhancing 5-Hydroxytryptamine Synthesis in Diet-Induced Obese Mice JF Diabetes JO Diabetes FD American Diabetes Association SP db200339 DO 10.2337/db20-0339 A1 Ming, Xing A1 Chung, Arthur C.K. A1 Mao, Dandan A1 Cao, Huanyi A1 Fan, Baoqi A1 Wong, Willy K.K. A1 Ho, Chin Chung A1 Lee, Heung Man A1 Schoonjans, Kristina A1 Auwerx, Johan A1 Rutter, Guy A. A1 Chan, Juliana C.N. A1 Tian, Xiao Yu A1 Kong, Alice P.S. YR 2020 UL http://diabetes.diabetesjournals.org/content/early/2020/10/21/db20-0339.abstract AB Sirtuin 3 (SIRT3) is a protein deacetylase regulating beta cell function through inhibiting oxidative stress in obese and diabetic mice, but the detailed mechanism and potential effect of beta cell specific SIRT3 on metabolic homeostasis, and its potential effect on other metabolic organs are unknown. We found glucose tolerance and glucose stimulated insulin secretion (GSIS) were impaired in high fat diet (HFD)-fed beta cell selective Sirt3 knockout (Sirt3f/f;Cre/+) mice. In addition, Sirt3f/f;Cre/+ mice had more severe hepatic steatosis than Sirt3f/f mice upon HFD feeding. RNA sequencing (RNA-Seq) of islets suggested that Sirt3 deficiency over-activated 5-hydroxytryptamine (5-HT) synthesis as evidenced by up-regulation of tryptophan hydroxylase 1 (TPH1). 5-HT concentration was increased in both islets and serum of Sirt3f/f;Cre/+ mice. 5-HT also facilitated the effect of palmitate to increase lipid deposition. Treatment with TPH1 inhibitor ameliorated hepatic steatosis and reduced weight gain in HFD-fed Sirt3f/f;Cre/+ mice. These data suggested that under HFD feeding, SIRT3 deficiency in beta cells not only regulates insulin secretion but also modulates hepatic lipid metabolism via the release of 5-HT.