BACKGROUND: Multiple mechanisms contribute to the liver fibrosis following cholestasis. Recent research has focused on the role of transforming growth factor β-1 (TGF-β1) in the progression of fibrosis. The aim of our study is to examine the role of epigenetic chromatin marks, such as histone H3 lysine methylation (H3Kme), in bile duct ligation (BDL)-induced TGF-β1 gene expression in rat liver. METHODS: Time course of methylated-histone H3 and SET7/9 recruitment were determined by chromatin immunoprecipitation in livers from BDL rats on days 1, 4, 9 and 14. Levels of TGF-β1 and SET7/9 were determined by western blots. The effect of SET7/9 knockdown on BDL-induced expression of TGF-β1, serum enzymes and liver collagen content was studied in vivo. RESULTS: Results showed that BDL increased the expression of the TGF β-1. Increased levels of active chromatin marks (H3K4me1, H3K4me2, and H3K4me3) and decreased levels of repressive marks (H3K9me2 and H3K9me3) in TGF-β1 promoter accompanied the changes in expression of the TGF β-1. BDL also increased expression of the H3K4 methyltransferase SET7/9 and recruitment to the promoter. SET7/9 gene knockdown with siRNAs significantly attenuated BDL-induced TGF-β1 gene expression, serum enzymes and liver collagen content. CONCLUSIONS: Taken together, these results show the functional role of epigenetic chromatin histone H3Kme in BDL-induced TGF-β1 expression. Pharmacologic and other therapies that reverse these modifications could have potential hepatoprotective effects for BDL-induced cirrhosis.
BACKGROUND: Multiple mechanisms contribute to the liver fibrosis following cholestasis. Recent research has focused on the role of transforming growth factor β-1 (TGF-β1) in the progression of fibrosis. The aim of our study is to examine the role of epigenetic chromatin marks, such as histone H3 lysine methylation (H3Kme), in bile duct ligation (BDL)-induced TGF-β1 gene expression in rat liver. METHODS: Time course of methylated-histone H3 and SET7/9 recruitment were determined by chromatin immunoprecipitation in livers from BDL rats on days 1, 4, 9 and 14. Levels of TGF-β1 and SET7/9 were determined by western blots. The effect of SET7/9 knockdown on BDL-induced expression of TGF-β1, serum enzymes and liver collagen content was studied in vivo. RESULTS: Results showed that BDL increased the expression of the TGF β-1. Increased levels of active chromatin marks (H3K4me1, H3K4me2, and H3K4me3) and decreased levels of repressive marks (H3K9me2 and H3K9me3) in TGF-β1 promoter accompanied the changes in expression of the TGF β-1. BDL also increased expression of the H3K4 methyltransferase SET7/9 and recruitment to the promoter. SET7/9 gene knockdown with siRNAs significantly attenuated BDL-induced TGF-β1 gene expression, serum enzymes and liver collagen content. CONCLUSIONS: Taken together, these results show the functional role of epigenetic chromatin histone H3Kme in BDL-induced TGF-β1 expression. Pharmacologic and other therapies that reverse these modifications could have potential hepatoprotective effects for BDL-induced cirrhosis.
Authors: Gerald U Denk; Shi-Ying Cai; Wen-Sheng Chen; Aiping Lin; Carol J Soroka; James L Boyer Journal: World J Gastroenterol Date: 2006-04-28 Impact factor: 5.742
Authors: T Niki; K Rombouts; P De Bleser; K De Smet; V Rogiers; D Schuppan; M Yoshida; G Gabbiani; A Geerts Journal: Hepatology Date: 1999-03 Impact factor: 17.425
Authors: P T Khaw; G S Schultz; S L MacKay; N Chegini; D S Rotatori; J L Adams; R W Shimizu Journal: Invest Ophthalmol Vis Sci Date: 1992-11 Impact factor: 4.799
Authors: Jelena Mann; David C K Chu; Aidan Maxwell; Fiona Oakley; Nian-Ling Zhu; Hidekazu Tsukamoto; Derek A Mann Journal: Gastroenterology Date: 2009-10-17 Impact factor: 22.682
Authors: I Dahlman; I Sinha; H Gao; D Brodin; A Thorell; M Rydén; D P Andersson; J Henriksson; A Perfilyev; C Ling; K Dahlman-Wright; P Arner Journal: Int J Obes (Lond) Date: 2015-03-18 Impact factor: 5.095