Hepatic stellate cell transdifferentiation involves genome-wide remodeling of the DNA methylation landscape

详细信息    查看全文

• 作者：Agata Page ; Pier Paoli ; Eva Moran Salvador ; Steve White ; Jeremy French ; Jelena Mann ; ^{Jelena.Mann@ncl.ac.uk" class="auth_mail" title="E-mail the corresponding author}
• 关键词：5-hmC ; 5-hydroxymethylcytosine ; 5-mC ; 5-methylcytosine ; aHSC ; activated hepatic stellate cells ; ALD ; alcoholic liver disease ; DNMT ; DNA methyltransferase ; HSC ; hepatic stellate cells ; MeCP2 ; methyl-CpG binding protein 2 ; NHL ; normal human liver ; PSC ; primary sclerosing cholangitis ; qHSC ; quiescent hepatic stellate cells ; rHSC ; rat hepatic stellate cells ; siRNA ; small interfering RNA ; αSMA ; alpha smooth muscle actin ; TET ; ten-eleven translocation methylcytosine dioxygenase ; TGF-β1 ; transforming g
• 刊名：Journal of Hepatology
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：64
• 期：3
• 页码：661-673
• 全文大小：2633 K

文摘

DNA methylation (5-mC) is an epigenetic mark that is an established regulator of transcriptional repression with an important role in liver fibrosis. Currently, there is very little knowledge available as to how DNA methylation controls the phenotype of hepatic stellate cell (HSC), the key cell type responsible for onset and progression of liver fibrosis. Moreover, recently discovered DNA hydroxymethylation (5-hmC) is involved in transcriptional activation and its patterns are often altered in human diseases. The aim of this study is to investigate the role of DNA methylation/hydroxymethylation in liver fibrosis.

Methods

Levels of 5-mC and 5-hmC were assessed by slot blot in a range of animal liver fibrosis models and human liver diseases. Expression levels of TET and DNMT enzymes were measured by qRT-PCR and Western blotting. Reduced representation bisulfite sequencing (RRBS) method was used to examine 5-mC and 5-hmC patterns in quiescent and in vivo activated rat HSC.

Results

We demonstrate global alteration in 5-mC and 5-hmC and their regulatory enzymes that accompany liver fibrosis and HSC transdifferentiation. Using RRBS, we show exact genomic positions of changed methylation patterns in quiescent and in vivo activated rat HSC. In addition, we demonstrate that reduction in DNMT3a expression leads to attenuation of pro-fibrogenic phenotype in activated HSC.

Conclusions

Our data suggest that DNA 5-mC/5-hmC is a crucial step in HSC activation and therefore fibrogenesis. Changes in DNA methylation during HSC activation may bring new insights into the molecular events underpinning fibrogenesis and may provide biomarkers for disease progression as well as potential new drug targets.