Ethanol-induced expression of ET-1 and ET-BR in liver sinusoidal endothelial cells and human endothelial cells involves hypoxia-inducible factor-1alpha and microrNA-199.
Chronic alcohol consumption leads to inflammation and cirrhosis of the liver. In this study, we observed that liver sinusoidal endothelial cells (LSEC) derived from ethanol-fed rats showed several fold increases in the mRNA expression of endothelin-1 (ET-1), hypoxia-inducible factor-1alpha (HIF-1alpha), and inflammatory cytochemokines compared with control rat LSEC. We also observed the same results in acute ethanol-treated LSEC from control rats and human dermal microvascular endothelial cells. Ethanol-mediated ET-1 expression involved NADPH oxidase and HIF-1alpha activation. Furthermore, ethanol increased the expression of the ET-1 cognate receptor ET-BR in Kupffer cells and THP-1 monocytic cells, which also involved HIF-1alpha activation. Promoter analysis and chromatin immunoprecipitation showed that hypoxia response element sites in the proximal promoter of ET-1 and ET-BR were required for the binding of HIF-1alpha to up-regulate their expression. We showed that microRNAs, miR-199 among several microRNAs, attenuated HIF-1alpha and ET-1 expression, while anti-miR-199 reversed the effects, suggesting that ethanol-induced miR-199 down-regulation may contribute to augmented HIF-1alpha and ET-1 expression. Our studies, for the first time to our knowledge, show that ethanol-mediated ET-1 and ET-BR expression involve HIF-1alpha, independent of hypoxia. Additionally, ethanol-induced ET-1 expression in rat LSEC is regulated by miR-199, while in human endothelial cells, ET-1 expression is regulated by miR-199 and miR-155, indicating that these microRNAs may function as novel negative regulators to control ET-1 transcription and, thus, homeostatic levels of ET-1 to maintain microcirculatory tone.
Department of Biochemistry and Molecular Biology, The Southern California Research Center for ALPD and Cirrhosis, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
Samantha
S
Yeligar
Hidekazu
H
Tsukamoto
Vijay K
VK
Kalra
D000818:Animals; D002460:Cell Line; D042783:Endothelial Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D019332:Endothelin-1 / Q000819:agonists / Q000096:biosynthesis* / Q000276:immunology; D000431:Ethanol / Q000633:toxicity*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000819:agonists / Q000276:immunology / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D019255:NADPH Oxidases / Q000276:immunology / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000276:immunology; D051381:Rats; D017208:Rats, Wistar; D044023:Receptor, Endothelin B / Q000819:agonists / Q000096:biosynthesis* / Q000276:immunology; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology
D019332:Endothelin-1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D035683:MicroRNAs; D044023:Receptor, Endothelin B; C531408:mirn199 microRNA, human; D000431:Ethanol; D019255:NADPH Oxidases