Shuyue Wang1,2, Chen Liang1, Huihan Ai1, Meiting Yang1, Jingwen Yi2, Lei Liu1, Zhenbo Song1, Yongli Bao1, Yuxin Li3,4, Luguo Sun5, Huiying Zhao6. 1. National Engineering Laboratory for Druggable Gene and Protein Screening, School of Life Sciences, Northeast Normal University, No. 5268, Renmin Road, Changchun, 130024, China. 2. Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun, 130024, China. 3. National Engineering Laboratory for Druggable Gene and Protein Screening, School of Life Sciences, Northeast Normal University, No. 5268, Renmin Road, Changchun, 130024, China. liyx486@nenu.edu.cn. 4. Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun, 130024, China. liyx486@nenu.edu.cn. 5. Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun, 130024, China. sunlg388@nenu.edu.cn. 6. Department of Geriatrics, The First Hospital of Jilin University, Changchun, 130021, China. zhaohuiying163@163.com.
Abstract
BACKGROUND/AIM: The miR-181 family plays an important role in the regulation of various cellular functions. However, whether miR-181b-5p mediates hepatic insulin resistance remains unknown. In this study, we investigated the effect of miR-181b-5p on the regulation of hepatic glycogen synthesis. METHODS: The miR-181b-5p levels in the livers of diabetic mice were detected by real-time PCR. The glycogen levels and AKT/GSK pathway activation were examined in human hepatic L02 cells and HepG2 cells transfected with miR-181b-5p mimic or inhibitor. The potential target genes of miR-181b-5p were evaluated using a luciferase reporter assay and Western blot analysis. EGR1-specific siRNA and pCMV-EGR1 were used to further determine the role of miR-181b-5p in hepatic glycogen synthesis in vitro. Hepatic inhibition of miR-181b-5p in mice was performed using adeno-associated virus 8 (AAV8) vectors by tail intravenous injection. RESULTS: The miR-181b-5p levels were significantly decreased in the serum and livers of diabetic mice as well as the serum of type 2 diabetes patients. Importantly, inhibition of miR-181b-5p expression impaired the AKT/GSK pathway and reduced glycogenesis in hepatocytes. Moreover, upregulation of miR-181b-5p reversed high-glucose-induced suppression of glycogenesis. Further analysis revealed that early growth response 1 (EGR1) was a downstream target of miR-181b-5p. Silencing of EGR1 expression rescued miR-181b-5p inhibition-reduced AKT/GSK pathway activation and glycogenesis in hepatocytes. Hepatic inhibition of miR-181b-5p led to insulin resistance in C57BL/6 J mice. CONCLUSION: We demonstrated that miR-181b-5p contributes to glycogen synthesis by targeting EGR1, thereby regulating PTEN expression to mediate hepatic insulin resistance.
BACKGROUND/AIM: The miR-181 family plays an important role in the regulation of various cellular functions. However, whether miR-181b-5p mediates hepatic insulin resistance remains unknown. In this study, we investigated the effect of miR-181b-5p on the regulation of hepatic glycogen synthesis. METHODS: The miR-181b-5p levels in the livers of diabeticmice were detected by real-time PCR. The glycogen levels and AKT/GSK pathway activation were examined in human hepatic L02 cells and HepG2 cells transfected with miR-181b-5p mimic or inhibitor. The potential target genes of miR-181b-5p were evaluated using a luciferase reporter assay and Western blot analysis. EGR1-specific siRNA and pCMV-EGR1 were used to further determine the role of miR-181b-5p in hepatic glycogen synthesis in vitro. Hepatic inhibition of miR-181b-5p in mice was performed using adeno-associated virus 8 (AAV8) vectors by tail intravenous injection. RESULTS: The miR-181b-5p levels were significantly decreased in the serum and livers of diabeticmice as well as the serum of type 2 diabetespatients. Importantly, inhibition of miR-181b-5p expression impaired the AKT/GSK pathway and reduced glycogenesis in hepatocytes. Moreover, upregulation of miR-181b-5p reversed high-glucose-induced suppression of glycogenesis. Further analysis revealed that early growth response 1 (EGR1) was a downstream target of miR-181b-5p. Silencing of EGR1 expression rescued miR-181b-5p inhibition-reduced AKT/GSK pathway activation and glycogenesis in hepatocytes. Hepatic inhibition of miR-181b-5p led to insulin resistance in C57BL/6 J mice. CONCLUSION: We demonstrated that miR-181b-5p contributes to glycogen synthesis by targeting EGR1, thereby regulating PTEN expression to mediate hepatic insulin resistance.
Authors: Mirko Trajkovski; Jean Hausser; Jürgen Soutschek; Bal Bhat; Akinc Akin; Mihaela Zavolan; Markus H Heim; Markus Stoffel Journal: Nature Date: 2011-06-08 Impact factor: 49.962
Authors: Tatiana D Saccon; Augusto Schneider; Cindi G Marinho; Allancer D C Nunes; Sarah Noureddine; Joseph Dhahbi; Yury O Nunez Lopez; Gage LeMunyan; Roberto Salvatori; Carla R P Oliveira; Alécia A Oliveira-Santos; Nicolas Musi; Andrzej Bartke; Manuel H Aguiar-Oliveira; Michal M Masternak Journal: Aging Cell Date: 2021-06-12 Impact factor: 9.304