780-P: Improved Mitochondrial Function by Luseogliflozin Prevents Pancreatic Beta-Cell Damage

Abstract

We previously showed a sodium glucose co-transporter 2 (SGLT2) inhibitor, luseogliflozin, increased beta cell mass and improved beta cell function in db/db mice, but the mechanism has remained unclear. The aim of this study is to investigate the mechanism of favorable effects of luseogliflozin on beta cells. Six-week-old db/db mice were fed to standard chow (control group) or standard chow containing 0.01% luseogliflozin (luseo group) for 4 weeks. DNA microarray analysis, real-time PCR analysis, measurement of mitochondrial respiratory capacity and reactive oxygen species (ROS) generation, and metabolome analysis were performed using isolated islets. Immunohistochemistry and electron microscopy were performed using pancreatic tissues. DNA microarray and real-time PCR analysis showed gene expressions of solute carrier family 2 member 2 (Slc2a2) related to glucose uptake, pyruvate carboxylase (Pcx) and enzymes related to the tricarboxylic acid (TCA) cycle, and cytochrome c oxidase subunit 6A2 (Cox6a2) related to electron transport chain were upregulated in the luseo group. The luseo group had a higher mitochondrial complex II-linked oxidative phosphorylation capacity, and had a lower mitochondrial ROS generation compared with the control group. Electron microscopy showed mitochondrial swelling in the control group, while the mitochondrial size was normally maintained in the luseo group. Immunohistochemistry showed the proportion of Nkx6.1 positive cells/beta cells was significantly higher in the luseo group compared with the control group (89.8 ± 1.8% vs. 75.3 ± 3.5%, P < 0.01). In metabolome analysis, the metabolites in the TCA cycle were greater in the luseo group compared with the control group. Relief of glucotoxicity by luseogliflozin may reduce mitochondrial ROS generation and elevate Nkx6.1 expression related to beta cell proliferation. The elevated expression of Nkx6.1 could improve glucose metabolism in the TCA cycle, resulting in protection of beta cells. Disclosure Y. Yamauchi: None. K. Cho: None. T. Anzai: None. S. Tanaka: None. Y. Terauchi: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Eli Lilly Japan K. K., Novo Nordisk, Sanofi, Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Eli Lilly Japan K. K., Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Novartis Pharmaceuticals Corporation, Novo Nordisk, Ono Pharmaceutical Co., Ltd., Sanofi, Sumitomo Dainippon Pharma Co., Ltd., Takeda Pharmaceutical Company Limited, Speaker’s Bureau; Self; Abbott, Astellas Pharma Inc., AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Eli Lilly Japan K. K., Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Novartis Pharmaceuticals Corporation, Novo Nordisk, Ono Pharmaceutical Co., Ltd., Sanofi, Sanwa Kagaku Kenkyusho, Sumitomo Dainippon Pharma Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited. H. Miyoshi: Research Support; Self; Abbott Japan Co., Ltd., Astellas Pharma Inc., Daiichi Sankyo, Eli Lilly Japan K. K., Kowa Company, Ltd., Mitsubishi Tanabe Pharma Corporation, Nippon Boehringer Ingelheim Co. Ltd., Novo Nordisk Pharma Ltd., Ono Pharmaceutical Co., Ltd., Sumitomo Dainippon Pharma Co., Ltd., Taisho Pharmaceutical Co., Ltd., Speaker’s Bureau; Self; Astellas Pharma Inc., Eli Lilly Japan K. K., Kowa Company, Ltd., Mitsubishi Tanabe Pharma Corporation, MSD K. K., Nippon Boehringer Ingelheim Co. Ltd., Novo Nordisk Pharma Ltd., Ono Pharmaceutical Co., Ltd., Sanofi K. K., Sumitomo Dainippon Pharma Co., Ltd. T. Atsumi: Research Support; Self; Alexion Pharmaceuticals, Inc., Astellas Pharma Inc., Bristol-Myers Squibb Company, Chugai Pharmaceutical Co., Ltd., Daiichi Sankyo, Eisai Co., Ltd., Eli Lilly Japan K. K., Gilead Sciences, Inc., Mitsubishi Tanabe Pharma Corporation, Otsuka Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co., UCB Japan Co. Ltd., Speaker’s Bureau; Self; AbbVie Inc., Astellas Pharma Inc., Chugai Pharmaceutical Co., Ltd., Eli Lilly Japan K. K., Mitsubishi Tanabe Pharma Corporation, Pfizer Inc., Takeda Pharmaceutical Co., UCB Japan Co. Ltd. A. Nakamura: Research Support; Self; Boehringer Ingelheim International GmbH, Kissei Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Corporation, MSD K. K., Taisho Pharmaceutical Co., Ltd. T. Yokota: None. K. Takahashi: None. S. Kawata: None. K. Tsuchida: None. K. Omori: None. H. Nomoto: None. H. Kameda: None.