Levels of histone modifications in activated primarily cultured rat hepatic stellate cells / 中国病理生理杂志

ABSTRACT

AIM:To investigate the changes of histone modifications during the activation of primarily cultured rat hepatic stellate cells ( HSCs) and the relationship between histone modification patterns andα-smooth muscle actin (α-SMA) expression, and to explore the roles of histone modifications in the activation of HSCs.METHODS:The rat HSCs were isolated by in situ perfusion of collagenase combined with density gradient centrifugation, cultured in vitro and identi-fied by immunofluorescence staining.The morphological features of the cells were observed under inverted microscope.The changes of desmin and α-SMA during the activation of HSCs were detected by immunofluorescence staining and Western blotting.The levels of histone 3 lysine 4 dimethylation (H3K4me2), histone 3 lysine 9 dimethylation (H3K9me2), his-tone 3 lysine 9 acetylation (acH3K9) and histone 4 lysine 12 acetylation (acH4K12) in quiescent HSCs and activated HSCs were determined by Western blotting.RESULTS: The morphology of HSCs shifted from a quiescent phenotype to highly activated myofibroblast during the culture.Immunofluorescence staining and Western blotting showed that the expres-sion levels of α-SMA and desmin were increased over time and reached maximum at 15 d.According to the results of cell morphology and immunofluorescence staining, the cells cultured for 24 h and 15 d were quiescent and activated HSCs, re-spectively.Compared with quiescent HSCs, there were higher H3K4me2 and lower H3K9me2, acH3K9 and acH4K12 modification levels in activated HSCs ( P<0.01 ) .CONCLUSION: Histone modifications show anomalous expression during the activation of primarily cultured rat HSCs.Histone modifications may contribute to the transdifferentiation of HSCs and the development of hepatic fibrosis.