Syncoilin is an intermediate filament protein in activated hepatic stellate cells

Histochem Cell Biol. 2014 Jan;141(1):85-99. doi: 10.1007/s00418-013-1142-5. Epub 2013 Sep 17.


Hepatic stellate cells (HSCs) play an important role in several (patho)physiologic conditions in the liver. In response to chronic injury, HSCs are activated and change from quiescent to myofibroblast-like cells with contractile properties. This shift in phenotype is accompanied by a change in expression of intermediate filament (IF) proteins. HSCs express a broad, but variable spectrum of IF proteins. In muscle, syncoilin was identified as an alpha-dystrobrevin binding protein with sequence homology to IF proteins. We investigated the expression of syncoilin in mouse and human HSCs. Syncoilin expression in isolated and cultured HSCs was studied by qPCR, Western blotting, and fluorescence immunocytochemistry. Syncoilin expression was also evaluated in other primary liver cell types and in in vivo-activated HSCs as well as total liver samples from fibrotic mice and cirrhotic patients. Syncoilin mRNA was present in human and mouse HSCs and was highly expressed in in vitro- and in vivo-activated HSCs. Syncoilin protein was strongly upregulated during in vitro activation of HSCs and undetectable in hepatocytes and liver sinusoidal endothelial cells. Syncoilin mRNA levels were elevated in both CCl4- and common bile duct ligation-treated mice. Syncoilin immunocytochemistry revealed filamentous staining in activated mouse HSCs that partially colocalized with α-smooth muscle actin, β-actin, desmin, and α-tubulin. We show that in the liver, syncoilin is predominantly expressed by activated HSCs and displays very low-expression levels in other liver cell types, making it a good marker of activated HSCs. During in vitro activation of mouse HSCs, syncoilin is able to form filamentous structures or at least to closely interact with existing cellular filaments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / pharmacokinetics
  • Animals
  • Carbon Tetrachloride / pharmacology
  • Cell Differentiation
  • Cell Line
  • Desmin / pharmacology
  • Fibrosis / pathology
  • HEK293 Cells
  • Hepatic Stellate Cells / cytology
  • Hepatic Stellate Cells / metabolism*
  • Hepatocytes / pathology
  • Humans
  • Intermediate Filament Proteins / genetics
  • Intermediate Filament Proteins / metabolism*
  • Intermediate Filament Proteins / pharmacokinetics
  • Liver / cytology
  • Liver / pathology*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Muscle Proteins / genetics
  • Muscle Proteins / metabolism*
  • Muscle Proteins / pharmacokinetics
  • RNA Interference
  • RNA, Messenger / biosynthesis
  • RNA, Small Interfering
  • Tubulin / pharmacokinetics


  • Actins
  • Desmin
  • Intermediate Filament Proteins
  • Muscle Proteins
  • RNA, Messenger
  • RNA, Small Interfering
  • Sync protein, mouse
  • Tubulin
  • alpha-smooth muscle actin, mouse
  • Carbon Tetrachloride