Zhenwen Zhang1, Penghua Fang2,3, Lili Guo2, Biao He2, Mingyi Shi2, Yan Zhu1, Ping Bo1,2. 1. Department of Endocrinology, Clinical Medical College, Yangzhou, China. 2. Key Rresearch Institute of Gerontology, Medical College, Yangzhou University, Yangzhou, China. 3. Department of Physiology, School of Hanlin, Nanjing University of Chinese Medicine, Taizhou, China.
Abstract
BACKGROUND/AIMS: Glucose uptake occurs via the activation of an insulin-signaling cascade, resulting in the translocation of glucose transporter 4 (GLUT4) to the plasma membrane of adipocytes and myocytes. Recent research found that galanin could boost insulin-induced glucose uptake. This study aimed to explore whether activation of Akt2 mediates the beneficial effects of galanin on insulin-induced glucose uptake in the adipocytes of diabetic rats. METHOD: In this experiment, insulin, galanin and MK-2206, an Akt inhibitor, were injected individually or in combination into diabetic rats once a day for ten days. Then, glucose uptake and pAkt2 and its downstream proteins were examined in adipocytes. RESULTS: Administration of galanin significantly enhanced insulin-induced 2-Deoxy-D-[3H]glucose uptake; GLUT4 and vesicle-associated membrane protein 2 contents in plasma membranes; and pAkt2Thr308/Ser473 and Akt2 mRNA expression levels in adipocytes. In addition, Akt2 downstream proteins including phosphorylated AS160 were increased, but the levels of phosphorylated forkhead box O1 and glycogen synthase kinase-3β were reduced. Treatment with MK-2206 may block the beneficial effects of galanin on these insulin-induced events. CONCLUSIONS: The results of this study suggest that phosphorylation of Akt2 mediates the beneficial effects of galanin on insulin-induced glucose uptake in the adipocytes of diabetic rats.
BACKGROUND/AIMS: Glucose uptake occurs via the activation of an insulin-signaling cascade, resulting in the translocation of glucose transporter 4 (GLUT4) to the plasma membrane of adipocytes and myocytes. Recent research found that galanin could boost insulin-induced glucose uptake. This study aimed to explore whether activation of Akt2 mediates the beneficial effects of galanin on insulin-induced glucose uptake in the adipocytes of diabeticrats. METHOD: In this experiment, insulin, galanin and MK-2206, an Akt inhibitor, were injected individually or in combination into diabeticrats once a day for ten days. Then, glucose uptake and pAkt2 and its downstream proteins were examined in adipocytes. RESULTS: Administration of galanin significantly enhanced insulin-induced 2-Deoxy-D-[3H]glucose uptake; GLUT4 and vesicle-associated membrane protein 2 contents in plasma membranes; and pAkt2Thr308/Ser473 and Akt2 mRNA expression levels in adipocytes. In addition, Akt2 downstream proteins including phosphorylated AS160 were increased, but the levels of phosphorylated forkhead box O1 and glycogen synthase kinase-3β were reduced. Treatment with MK-2206 may block the beneficial effects of galanin on these insulin-induced events. CONCLUSIONS: The results of this study suggest that phosphorylation of Akt2 mediates the beneficial effects of galanin on insulin-induced glucose uptake in the adipocytes of diabeticrats.
Authors: María Constanza Potilinski; Gustavo A Ortíz; Juan P Salica; Emiliano S López; Mariano Fernández Acquier; Eduardo Chuluyan; Juan E Gallo Journal: PLoS One Date: 2020-02-07 Impact factor: 3.240