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Activation of Mir-29a in Activated Hepatic Stellate Cells Modulates Its Profibrogenic Phenotype through Inhibition of Histone Deacetylases 4.

Huang YH, Tiao MM, Huang LT, Chuang JH, Kuo KC, Yang YL, Wang FS - PLoS ONE (2015)

Bottom Line: In this study, we examined whether miR-29a was involved in the regulation of HDAC4 and modulation of the profibrogenic phenotype in HSCs.Overexpression of miR-29a and HDAC4 RNA-interference decreased the expression of fibrotic genes, HDAC4 signaling, and HSC migration and proliferation.In contrast, knockdown of miR-29a with an antisense inhibitor increased HDAC4 function, restored HSC migration, and accelerated HSC proliferation.

View Article: PubMed Central - PubMed

Affiliation: Departments of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.

ABSTRACT

Background: Recent studies have shown that microRNA-29 (miR-29) is significantly decreased in liver fibrosis and that its downregulation influences the activation of hepatic stellate cells (HSCs). In addition, inhibition of the activity of histone deacetylases 4 (HDAC4) has been shown to strongly reduce HSC activation in the context of liver fibrosis.

Objectives: In this study, we examined whether miR-29a was involved in the regulation of HDAC4 and modulation of the profibrogenic phenotype in HSCs.

Methods: We employed miR-29a transgenic mice (miR-29aTg mice) and wild-type littermates to clarify the role of miR-29a in cholestatic liver fibrosis, using the bile duct-ligation (BDL) mouse model. Primary HSCs from both mice were treated with a miR-29a mimic and antisense inhibitor in order to analyze changes in profibrogenic gene expression and HSC activation using real-time quantitative RT-PCR, immunofluorescence staining, western blotting, and cell proliferation and migration assays.

Results: After BDL, overexpression of miR-29a decreased collagen-1α1, HDAC4 and activated HSC markers of glial fibrillary acidic protein expression in miR-29aTg mice compared to wild-type littermates. Overexpression of miR-29a and HDAC4 RNA-interference decreased the expression of fibrotic genes, HDAC4 signaling, and HSC migration and proliferation. In contrast, knockdown of miR-29a with an antisense inhibitor increased HDAC4 function, restored HSC migration, and accelerated HSC proliferation.

Conclusions: Our results indicate that miR-29a ameliorates cholestatic liver fibrosis after BDL, at least partially, by modulating the profibrogenic phenotype of HSCs through inhibition of HDAC4 function.

No MeSH data available.


Related in: MedlinePlus

Effects of TLCA on HDAC4 expression in cultured primary HSCs.TLCA increased HDAC4 expression (A) and nuclear translocation (B) in HSCs of WT mice (white bar). HSCs of miR-29a transgenic mice (gray bar) exhibited significantly reduced upregulation and nuclear translation of HDAC4 in response to TLCA stimulation. Data are expressed as the mean ± SE of four independent experiments. *indicates a p < 0.05 between the groups.
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pone.0136453.g004: Effects of TLCA on HDAC4 expression in cultured primary HSCs.TLCA increased HDAC4 expression (A) and nuclear translocation (B) in HSCs of WT mice (white bar). HSCs of miR-29a transgenic mice (gray bar) exhibited significantly reduced upregulation and nuclear translation of HDAC4 in response to TLCA stimulation. Data are expressed as the mean ± SE of four independent experiments. *indicates a p < 0.05 between the groups.

Mentions: The activation of HSCs is known to result in increased expression of several profibrogenic genes, including collagen-1α1, collagen-3α1 and MCP-1. As shown in Fig 3, miR-29a overexpression significantly downregulated the expression of collagen-1α1, collagen-3α1, and MCP-1 in activated HSCs of miR-29aTg mice compared with WT littermates (all p < 0.001). We then treated primary HSCs with one of the hydrophobic bile acids, taurolithocholic acid (TLCA; Sigma), to explore whether miR-29a affects HDAC4 expression and nuclear translocation in response to cholestasis. As shown in Fig 4, we found that there was significant upregulation and nuclear translation of HDAC4 in the HSCs of WT mice following TLCA stimulation (p = 0.001 and p < 0.001, respectively). HSCs of miR-29aTg mice could significantly reduce the upregulation and nuclear translation of HDAC4 in response to TLCA stimulation in HSCs (p = 0.003 and p < 0.001, respectively).


Activation of Mir-29a in Activated Hepatic Stellate Cells Modulates Its Profibrogenic Phenotype through Inhibition of Histone Deacetylases 4.

Huang YH, Tiao MM, Huang LT, Chuang JH, Kuo KC, Yang YL, Wang FS - PLoS ONE (2015)

Effects of TLCA on HDAC4 expression in cultured primary HSCs.TLCA increased HDAC4 expression (A) and nuclear translocation (B) in HSCs of WT mice (white bar). HSCs of miR-29a transgenic mice (gray bar) exhibited significantly reduced upregulation and nuclear translation of HDAC4 in response to TLCA stimulation. Data are expressed as the mean ± SE of four independent experiments. *indicates a p < 0.05 between the groups.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4549141&req=5

pone.0136453.g004: Effects of TLCA on HDAC4 expression in cultured primary HSCs.TLCA increased HDAC4 expression (A) and nuclear translocation (B) in HSCs of WT mice (white bar). HSCs of miR-29a transgenic mice (gray bar) exhibited significantly reduced upregulation and nuclear translation of HDAC4 in response to TLCA stimulation. Data are expressed as the mean ± SE of four independent experiments. *indicates a p < 0.05 between the groups.
Mentions: The activation of HSCs is known to result in increased expression of several profibrogenic genes, including collagen-1α1, collagen-3α1 and MCP-1. As shown in Fig 3, miR-29a overexpression significantly downregulated the expression of collagen-1α1, collagen-3α1, and MCP-1 in activated HSCs of miR-29aTg mice compared with WT littermates (all p < 0.001). We then treated primary HSCs with one of the hydrophobic bile acids, taurolithocholic acid (TLCA; Sigma), to explore whether miR-29a affects HDAC4 expression and nuclear translocation in response to cholestasis. As shown in Fig 4, we found that there was significant upregulation and nuclear translation of HDAC4 in the HSCs of WT mice following TLCA stimulation (p = 0.001 and p < 0.001, respectively). HSCs of miR-29aTg mice could significantly reduce the upregulation and nuclear translation of HDAC4 in response to TLCA stimulation in HSCs (p = 0.003 and p < 0.001, respectively).

Bottom Line: In this study, we examined whether miR-29a was involved in the regulation of HDAC4 and modulation of the profibrogenic phenotype in HSCs.Overexpression of miR-29a and HDAC4 RNA-interference decreased the expression of fibrotic genes, HDAC4 signaling, and HSC migration and proliferation.In contrast, knockdown of miR-29a with an antisense inhibitor increased HDAC4 function, restored HSC migration, and accelerated HSC proliferation.

View Article: PubMed Central - PubMed

Affiliation: Departments of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.

ABSTRACT

Background: Recent studies have shown that microRNA-29 (miR-29) is significantly decreased in liver fibrosis and that its downregulation influences the activation of hepatic stellate cells (HSCs). In addition, inhibition of the activity of histone deacetylases 4 (HDAC4) has been shown to strongly reduce HSC activation in the context of liver fibrosis.

Objectives: In this study, we examined whether miR-29a was involved in the regulation of HDAC4 and modulation of the profibrogenic phenotype in HSCs.

Methods: We employed miR-29a transgenic mice (miR-29aTg mice) and wild-type littermates to clarify the role of miR-29a in cholestatic liver fibrosis, using the bile duct-ligation (BDL) mouse model. Primary HSCs from both mice were treated with a miR-29a mimic and antisense inhibitor in order to analyze changes in profibrogenic gene expression and HSC activation using real-time quantitative RT-PCR, immunofluorescence staining, western blotting, and cell proliferation and migration assays.

Results: After BDL, overexpression of miR-29a decreased collagen-1α1, HDAC4 and activated HSC markers of glial fibrillary acidic protein expression in miR-29aTg mice compared to wild-type littermates. Overexpression of miR-29a and HDAC4 RNA-interference decreased the expression of fibrotic genes, HDAC4 signaling, and HSC migration and proliferation. In contrast, knockdown of miR-29a with an antisense inhibitor increased HDAC4 function, restored HSC migration, and accelerated HSC proliferation.

Conclusions: Our results indicate that miR-29a ameliorates cholestatic liver fibrosis after BDL, at least partially, by modulating the profibrogenic phenotype of HSCs through inhibition of HDAC4 function.

No MeSH data available.


Related in: MedlinePlus