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oai:docta.ucm.es:20.500.14352/976382025-09-06T00:10:10Zcom_20.500.14352_14col_20.500.14352_15

Oxidative stress modulates KLF6Full and its splice variants Urtasun, Raquel Cubero Palero, Francisco Javier Nieto, Natalia Abstract Background: Induction of reactive oxygen species (ROS) is a central mechanism in alcohol hepatotoxicity. Krüppel-like factor 6 (KLF6), a transcription factor and a tumor-suppressor gene, is an early-responsive gene to injury; however, the effect of ROS and alcohol on KLF6 induction is unknown. The aim of this study is to investigate the contribution of 2 sources of ROS, cytochrome P450 2E1 (CYP2E1), NAD(P)H quinone oxidoreductase (NQO1), and alcohol on the modulation of KLF6(Full) expression, splicing to KLF6_V1 and KLF6_V2, and the effect on TNFα, a downstream target. Methods and results: Endogenous ROS production in CYP2E1-expressing HepG2 cells induced mRNA and protein expression of KLF6(Full) and its splice variants compared to control cells. Incubation with pro-oxidants such as arachidonic acid (AA), β-naphtoflavone, and H(2) O(2) further enhanced KLF6(Full) and its splice variants. The AA effects on KLF6(Full) and its splice forms were blocked by vitamin E-which prevents lipid peroxidation-and by diallylsulfide-a CYP2E1 inhibitor. Menadione and paraquat, 2 pro-oxidants metabolized via NQO1, induced KLF6(Full) mRNA in a thiol-dependent manner. Antioxidants and an NQO1 inhibitor suppressed the menadione-dependent increase in KLF6(Full) and its splice variants mRNA. Furthermore, primary hepatocytes and livers from chronic alcohol-fed rats, with elevated lipid peroxidation, H(2) O(2) and CYP2E1 but with low GSH, showed a ~2-fold increase in KLF6(Full) mRNA compared to controls. Inhibition of p38 phosphorylation further up-regulated the CYP2E1 and the AA effects on KLF6(Full) mRNA, whereas inhibition JNK and ERK1/2 phosphorylation decreased both. KLF6_V1 but not KLF6(Full) ablation markedly increased TNFα levels in macrophages; thus, TNFα emerges as a downstream target of KLF6_V1. Conclusions: The novel effect of ROS on modulating KLF6(Full) expression and its splice variants could play a relevant role in liver injury and in TNFα regulation. 2024-02-01T12:08:14Z 2024-02-01T12:08:14Z 2012 journal article Urtasun R, Cubero FJ, Nieto N. Oxidative stress modulates KLF6Full and its splice variants. Alcohol Clin Exp Res. 2012 Nov;36(11):1851-62. doi: 10.1111/j.1530-0277.2012.01798.x. Epub 2012 Apr 6. PMID: 22486562; PMCID: PMC3396787. 0145-6008 10.1111/j.1530-0277.2012.01798.x. https://hdl.handle.net/20.500.14352/97638 https://doi.org/10.1111/j.1530-0277.2012.01798.x 22486562 https://pubmed.ncbi.nlm.nih.gov/22486562/ eng Postdoctoral EX2006-0070 5R01 AA017733 R01 AA017733-01S1 5P20AA017067 5P20 AA017067-01S1 5P20 AA017067-03S1 http://creativecommons.org/licenses/by-nc-nd/4.0/ restricted access Attribution-NonCommercial-NoDerivatives 4.0 International Wiley