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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

Overexpression of miR-29a decreased GFAP, a marker of HSC, and increased expression in the acute response to injury and immunoreactivity in cholestasis.There was significantly higher expression of GFAP (green) in tissues from the BDL group than in tissues from the sham-operated group in WT mice. Moreover, miR-29a overexpression significantly downregulated GFAP protein expression in miR-29aTg mice with cholestasis compared with the WT littermates. Data are expressed as the mean ± SE of six samples per group. *indicates a p < 0.05 between the groups.
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pone.0136453.g002: Overexpression of miR-29a decreased GFAP, a marker of HSC, and increased expression in the acute response to injury and immunoreactivity in cholestasis.There was significantly higher expression of GFAP (green) in tissues from the BDL group than in tissues from the sham-operated group in WT mice. Moreover, miR-29a overexpression significantly downregulated GFAP protein expression in miR-29aTg mice with cholestasis compared with the WT littermates. Data are expressed as the mean ± SE of six samples per group. *indicates a p < 0.05 between the groups.

Mentions: GFAP is a type III intermediate filament protein originally identified in HSC-derived myofibroblasts [22]. It increases in the acute response to injury and decreases in the chronic response [23–25]; and GFAP has therefore been suggested as an early marker of HSC activation. Hence, GFAP expression levels reveal the overall number of HSC and can therefore be utilized as a specific HSC proliferation marker. Compared with the sham-operation group, the BDL group of WT and miR-29aTg mice had increased GFAP protein expression (p < 0.001 and p = 0.003, respectively).(Fig 2) Moreover, miR-29a overexpression significantly downregulated GFAP immunoreactivity in the miR-29aTg mice with cholestasis compared with the WT littermates (p < 0.001).


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)

Overexpression of miR-29a decreased GFAP, a marker of HSC, and increased expression in the acute response to injury and immunoreactivity in cholestasis.There was significantly higher expression of GFAP (green) in tissues from the BDL group than in tissues from the sham-operated group in WT mice. Moreover, miR-29a overexpression significantly downregulated GFAP protein expression in miR-29aTg mice with cholestasis compared with the WT littermates. Data are expressed as the mean ± SE of six samples per group. *indicates a p < 0.05 between the groups.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4549141&req=5

pone.0136453.g002: Overexpression of miR-29a decreased GFAP, a marker of HSC, and increased expression in the acute response to injury and immunoreactivity in cholestasis.There was significantly higher expression of GFAP (green) in tissues from the BDL group than in tissues from the sham-operated group in WT mice. Moreover, miR-29a overexpression significantly downregulated GFAP protein expression in miR-29aTg mice with cholestasis compared with the WT littermates. Data are expressed as the mean ± SE of six samples per group. *indicates a p < 0.05 between the groups.
Mentions: GFAP is a type III intermediate filament protein originally identified in HSC-derived myofibroblasts [22]. It increases in the acute response to injury and decreases in the chronic response [23–25]; and GFAP has therefore been suggested as an early marker of HSC activation. Hence, GFAP expression levels reveal the overall number of HSC and can therefore be utilized as a specific HSC proliferation marker. Compared with the sham-operation group, the BDL group of WT and miR-29aTg mice had increased GFAP protein expression (p < 0.001 and p = 0.003, respectively).(Fig 2) Moreover, miR-29a overexpression significantly downregulated GFAP immunoreactivity in the miR-29aTg mice with cholestasis compared with the WT littermates (p < 0.001).

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