Participation of miR-200a in TGF-β1-mediated hepatic stellate cell activation

Mol Cell Biochem. 2014 Mar;388(1-2):11-23. doi: 10.1007/s11010-013-1895-0. Epub 2013 Nov 16.

Abstract

Hepatic stellate cell (HSC) activation is a pivotal event in the initiation and progression of hepatic fibrosis since it mediates transforming growth factor beta 1 (TGF-β1)-driven extracellular matrix (ECM) deposition. MicroRNAs (miRNAs), small non-coding RNAs modulating messenger RNA (mRNA) and protein expression, have emerged as key factors to regulate cell proliferation, differentiation, and apoptosis. Although the function of miR-200a has been discussed in many cancers and fibrotic diseases, its role in hepatic fibrosis is still poorly understood. The aim of this study is to investigate whether miR-200a could attenuate hepatic fibrosis partly through Wnt/β-catenin and TGF-β-dependant mechanisms. Our study found that the expression of endogenous miR-200a was decreased in vitro in TGF-β1-induced HSC activation as well as in vivo in CCl4-induced rat liver fibrosis. Overexpression of miR-200a significantly inhibited α-SMA activity and further affected the proliferation of TGF-β1-dependent activation of HSC. In addition, we identified β-catenin and TGF-β2 as two functional downstream targets for miR-200a. Interestingly, miR-200a specifically suppressed β-catenin in the protein level, whereas miR-200a-mediated suppression of TGF-β2 was shown on both mRNA and protein levels. Our results revealed the critical regulatory role of miR-200a in HSC activation and implied miR-200a as a potential candidate for therapy by deregulation of Wnt/β-catenin and TGFβ signaling pathways, at least in part, via decreasing the expression of β-catenin and TGF-β2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / biosynthesis
  • Actins / genetics
  • Animals
  • Apoptosis / genetics
  • Carbon Tetrachloride
  • Cell Cycle / genetics
  • Cell Differentiation / drug effects
  • Cell Line
  • Cell Proliferation / drug effects
  • Extracellular Matrix
  • HEK293 Cells
  • Hepatic Stellate Cells / pathology*
  • Humans
  • Liver Cirrhosis / genetics
  • Liver Cirrhosis / pathology*
  • Male
  • MicroRNAs / biosynthesis
  • MicroRNAs / genetics*
  • RNA, Messenger / biosynthesis
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects
  • Transfection
  • Transforming Growth Factor beta1 / pharmacology*
  • Transforming Growth Factor beta2 / antagonists & inhibitors
  • Transforming Growth Factor beta2 / biosynthesis*
  • Transforming Growth Factor beta2 / genetics
  • Wnt Signaling Pathway / genetics
  • beta Catenin / biosynthesis
  • beta Catenin / genetics

Substances

  • Actins
  • MIRN200 microRNA, rat
  • MicroRNAs
  • RNA, Messenger
  • Transforming Growth Factor beta1
  • Transforming Growth Factor beta2
  • beta Catenin
  • smooth muscle actin, rat
  • Carbon Tetrachloride