DNA methylation status influences insulin-induced glucose transport in 3T3-L1 adipocytes by mediating p53 expression

Masashi Kuroda; Rumi Onoyama; Waka Sasaki; Mayu Sebe; Tadahiro Kitamura; Saeko Masumoto; Rie Tsutsumi; Nagakatsu Harada; Hiroshi Sakaue

doi:10.1016/j.bbrc.2020.02.038

DNA methylation status influences insulin-induced glucose transport in 3T3-L1 adipocytes by mediating p53 expression

Biochem Biophys Res Commun. 2020 Feb 16:S0006-291X(20)30304-1. doi: 10.1016/j.bbrc.2020.02.038. Online ahead of print.

Authors

Masashi Kuroda¹, Rumi Onoyama¹, Waka Sasaki¹, Mayu Sebe¹, Tadahiro Kitamura², Saeko Masumoto³, Rie Tsutsumi¹, Nagakatsu Harada⁴, Hiroshi Sakaue⁵

Affiliations

¹ Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima-city, 770-8503, Tokushima, Japan.
² Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15, Showa-machi, Maebashi-city, 371-8512, Gunma, Japan.
³ Faculty of Food and Agricultural Sciences, Fukushima University, 1, Kanayagawa, Fukushima-city, 960-1296, Fukushima, Japan.
⁴ Department of Health and Nutrition, Faculty of Nursing and Nutrition, The University of Shimane, 151, Nishihayashigi, Izumo-city, 693-8550, Shimane, Japan.
⁵ Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima-city, 770-8503, Tokushima, Japan; Diabetes Therapeutics and Research Center, Tokushima University, 3-18-15, Kuramoto-cho, Tokushima-city, 770-8503, Tokushima, Japan. Electronic address: hsakaue@tokushima-u.ac.jp.

PMID: 32070490
DOI: 10.1016/j.bbrc.2020.02.038

Abstract

Researchers frequently use 3T3-L1 adipocytes as a fat cell line, but the capacity of this line for insulin-mediated glucose transport is lower than that of primary isolated fat cells. In this study, we found that 5-azacytidine (5-aza-C), DNA methyltransferase 1 inhibitor, enhanced insulin-stimulated 2-deoxyglucose (2-DG) transport in 3T3-L1 cells after adipogenic differentiation. We next examined the expression of the genes related to glucose transport and insulin signal transduction. The insulin independent glucose transporter, glucose transporter 1 (GLUT1), showed lower expression in 5-aza-C pre-treated 3T3-L1 adipocytes, than in un-treated control adipocytes, while the expression of insulin dependent transporter GLUT4 remained unchanged. In addition, insulin receptor substrate-1 (IRS-1) was highly expressed in 5-aza-C pre-treated adipocytes. Based on DNA microarray and functional annotation analysis, we noticed that 5-aza-C pretreatment activated the tumor suppressor p53 pathway. We confirmed that in 5-aza-C adipocytes, p53 expression was markedly higher, and the methylation level of CpGs in its promoter region was lower than in un-treated control adipocytes. Moreover, pharmacological inhibition of p53 restored GLUT1 and IRS-1 expression to the same level as in un-treated 3T3-L1 adipocytes, and significantly decreased insulin-mediated 2-DG uptake. These results suggest that glucose transport capacity in adipocytes is influenced by DNA methylation status, and demethylation induced by 5-aza-C increased it possibly through the p53 signaling pathway.

Keywords: Adipocyte; DNA methylation; Glucose transport; p53.