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Wnt Pathway Stabilizes MeCP2 Protein to Repress PPAR-γ in Activation of Hepatic Stellate Cells
- Source :
- PLoS ONE, PLoS ONE, Vol 11, Iss 5, p e0156111 (2016)
- Publication Year :
- 2016
- Publisher :
- Public Library of Science, 2016.
-
Abstract
- PPAR-γ is essential for differentiation of hepatic stellate cells (HSC), and its loss due to epigenetic repression by methyl-CpG binding protein 2 (MeCP2) causes HSC myofibroblastic activation mediated in part via Wnt pathway, the key cellular event in liver fibrosis. Decreased miR-132 was previously proposed to promote MeCP2 protein translation for Ppar-γ repression in activated HSC (aHSC). The present study aimed to test this notion and to better understand the mechanisms of MeCP2 upregulation in aHSC. MeCP2 protein is increased on day 3 to 7 as HSC become activated in primary culture on plastic, but this is accompanied by increased but not reduced miR-132 or miR-212 which is also expected to target MeCP2 due to its similar sequence with miR-132. The levels of these mRNAs are decreased 40~50% in aHSCs isolated from experimental cholestatic liver fibrosis but increased 6-8 fold in aHSC from hepatotoxic liver fibrosis in rats. Suppression of either or both of miR132 and miR212 with specific anti-miRNA oligonucleotides (anti-oligo), does not affect MeCP2 protein levels in aHSCs. The Wnt antagonist FJ9 which inhibits HSC activation, increases miR-132/miR-212, reduces MeCP2 and its enrichment at 5' Ppar-γ promoter, and restores Ppar-γ expression but the anti-oligo do not prevent Ppar-γ upregulation. The pan-NADPH oxidase (NOX) inhibitor diphenyleneiodonium (DPI) also reduces both MeCP2 and stabilized non-(S33/S37/Thr41)-phospho β-catenin and reverts aHSC to quiescent cells but do not affect miR-132/miR-212 levels. Wnt antagonism with FJ9 increases MeCP2 protein degradation in cultured HSC, and FJ9-mediated loss of MeCP2 is rescued by leupeptin but not by proteasome and lysozome inhibitors. In conclusion, canonical Wnt pathway increases MeCP2 protein due to protein stability which in turn represses Ppar-γ and activates HSC.
- Subjects :
- 0301 basic medicine
Liver Cirrhosis
Male
Methyl-CpG-Binding Protein 2
Protein Expression
lcsh:Medicine
Peroxisome proliferator-activated receptor
Biochemistry
Mechanical Treatment of Specimens
chemistry.chemical_compound
0302 clinical medicine
Fluorescence Microscopy
Medicine and Health Sciences
Serine
Amino Acids
lcsh:Science
Wnt Signaling Pathway
Cells, Cultured
chemistry.chemical_classification
Microscopy
Multidisciplinary
Organic Compounds
Protein Stability
Liver Diseases
Wnt signaling pathway
Light Microscopy
3. Good health
Nucleic acids
Chemistry
Electroporation
Specimen Disruption
030220 oncology & carcinogenesis
Physical Sciences
Liver Fibrosis
Epigenetics
Research Article
congenital, hereditary, and neonatal diseases and abnormalities
Gastroenterology and Hepatology
Biology
Epigenetic Repression
Research and Analysis Methods
03 medical and health sciences
Extraction techniques
Downregulation and upregulation
Hydroxyl Amino Acids
Genetics
Gene Expression and Vector Techniques
Hepatic Stellate Cells
Animals
Rats, Wistar
Non-coding RNA
Molecular Biology Techniques
Psychological repression
Molecular Biology
Molecular Biology Assays and Analysis Techniques
Biology and life sciences
Binding protein
lcsh:R
Leupeptin
Organic Chemistry
Chemical Compounds
Proteins
RNA extraction
nervous system diseases
Gene regulation
Rats
PPAR gamma
MicroRNAs
030104 developmental biology
Proteasome
chemistry
Specimen Preparation and Treatment
Cell Transdifferentiation
Cancer research
Hepatic stellate cell
RNA
lcsh:Q
Gene expression
Subjects
Details
- Language :
- English
- ISSN :
- 19326203
- Volume :
- 11
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- PLoS ONE
- Accession number :
- edsair.doi.dedup.....6583a492caa84bf90d0d8204b71afb72