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Waterborne copper exposure up-regulated lipid deposition through the methylation of GRP78 and PGC1α of grass carp Ctenopharyngodon idella

Research output: Contribution to journalArticle

Yi Huan Xu, Yi Chuang Xu, Christer Hogstrand, Tao Zhao, Li Xiang Wu, Mei Qin Zhuo, Zhi Luo

Original languageEnglish
Article number111089
JournalEcotoxicology and Environmental Safety
Volume205
DOIs
Published1 Dec 2020

King's Authors

Abstract

Early molecular events after the exposure of heavy metals, such as aberrant DNA methylation, suggest that DNA methylation was important in regulating physiological processes for animals and accordingly could be used as environmental biomarkers. In the present study, we found that copper (Cu) exposure increased lipid content and induced the DNA hypermethylation at the whole genome level. Especially, Cu induced hypermethylation of glucose-regulated protein 78 (grp78) and peroxisome proliferator-activated receptor gamma coactivator-1α (pgc1α). CCAAT/enhancer binding protein α (C/EBPα) could bind to the methylated sequence of grp78, whereas C/EBPβ could not bind to the methylated sequence of grp78. These synergistically influenced grp78 expression and increased lipogenesis. In contrast, DNA methylation of PGC1α blocked the specific protein 1 (SP1) binding and interfered mitochondrial function. Moreover, Cu increased reactive oxygen species (ROS) production, activated endoplasmic reticulum (ER) stress and damaged mitochondrial function, and accordingly increased lipid deposition. Notably, we found a new toxicological mechanism for Cu-induced lipid deposition at DNA methylation level. The measurement of DNA methylation facilitated the use of these epigenetic biomarkers for the evaluation of environmental risk.

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