Fibrogenic actions of acetaldehyde are 尾-catenin dependent but Wingless independent: A critical role of nucleoredoxin and reactive oxygen species in human hepatic stellate cells

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• 作者：Jaime Arellanes-Robledo ; Karina Reyes-Gordillo ; Ruchi Shah ; Jos茅 Alfredo Dom铆nguez-Rosales ; Zamira Helena Hern谩ndez-Nazara ; Francesco Ramirez ; Marcos Rojkind ; M. Raj Lakshman
• 关键词：ACH ; acetaldehyde ; ACTA1 ; alpha-smooth muscle actin ; COL1A2 ; collagen type-1 alpha-2 ; DCFDA ; 2&prime ; 7&prime ; - dichorofluorescein diacetate ; DVL ; disheveled ; DTNB ; 5 ; 5&prime ; -dithiobis(2-nitrobenzoic acid) ; DMEM ; Dulbecco's modified Eagle's medium ; FBS ; fetal bovine serum ; GSH ; glutathione ; GAPDH ; glyceraldehyde-3-phosphate dehydrogenase ; GSK3B ; glycogen synthase kinase-3 beta ; HSC ; hepatic stellate cells ; 4-HNE ; 4-hydroxynonenal ; NXN ; nucleoredoxin ; PDGFRB ; platelet-derived growth factor recep
• 刊名：Free Radical Biology and Medicine
• 出版年：December, 2013
• 年：2013
• 卷：65
• 期：Complete
• 页码：1487-1496
• 全文大小：1785 K

文摘

We investigated whether the fibrogenic actions of acetaldehyde, the immediate oxidation product of ethanol, are mediated via Wingless (WNT) and/or 尾-catenin pathways in human hepatic stellate cells (HSC). First, we show that both 尾-catenin small inhibitory RNA and a dominant negative-MYC expression vector markedly down-regulated the expressions of fibrogenic genes in freshly isolated HSC. We further show that acetaldehyde up-regulated platelet-derived growth factor receptor beta mRNA and protein expressions ranging from 4.0- to 7.2-fold (P<0.001). Acetaldehyde induced MYC and collagen type-1 alpha-2 mRNA and protein expressions were WNT independent because DKK1, an antagonist of the canonical WNT/尾-catenin pathway, completely failed to block these inductions. Acetaldehyde increased phospho-glycogen synthase kinase-3 beta (GSK3B) protein by 31% (P<0.01), whereas phospho-尾-catenin protein decreased by 50% (P鈮?.01). Significantly, in contrast to 43% (P<0.01) inhibition of 尾-catenin nuclear translocation in nucleoredoxin (NXN)-overexpressed HSC, acetaldehyde profoundly stimulated 尾-catenin nuclear translocation by 51%, (P<0.01). Acetaldehyde also increased the cellular reactive oxygen species level 2-fold (P<0.001) with a concomitant 2-fold (P<0.001) increase in 4-hydroxynonenal adducts. Conversely, there was a 44% decrease (P<0.001) in glutathione levels with a concomitant 76% (P<0.001) decrease in the level of NXN/ disheveled (DVL) complex. Based on these findings, we conclude that actions of acetaldehyde are mediated by a mechanism that inactivates NXN by releasing DVL, leading to the inactivation of GSK3B, and thereby blocks 尾-catenin phosphorylation and degradation. Thus, the stabilized 尾-catenin translocates to the nucleus where it up-regulates the fibrogenic pathway genes. This novel mechanism of action of acetaldehyde has the potential for therapeutic interventions in liver fibrosis induced by alcohol.