HBV promotes the proliferation of hepatic stellate cells via the PDGF-B/PDGFR-β signaling pathway in vitro

Int J Mol Med. 2012 Dec;30(6):1443-50. doi: 10.3892/ijmm.2012.1148. Epub 2012 Oct 4.

Abstract

The activation of hepatic stellate cells (HSCs) is closely associated with liver fibrosis in chronic hepatitis B virus (HBV) infection. However, the molecular mechanisms leading to HSC activation remain unclear. It has been reported that the platelet-derived growth factor-B (PDGF-B)/PDGF receptor-β (PDGFR-β) signaling pathway is involved in this process. Thus, we investigated whether HBV and its protein contribute to HSC proliferation by the PDGF-B/PDGFR-β signaling pathway. HBV particles were purified from the supernatant of HepG2.2.15 cells by ultracentrifugation and the cell lines carrying HBV preS, e, c or x genes were obtained. After incubation with HBV particles or co-cultured with the cell lines expressed in the viral protein, the proliferation of LX-2 cells, an HSC cell line, were detected by flow cyto-metry and real-time PCR and the expression of molecules related to the PDGF-B/PDGFR-β signaling pathway were further measured. Our results indicated that HBV particles, c and x proteins promoted LX-2 proliferation and increased the mRNA levels of PDGF-B, PDGFR-β, collagen-I and α-smooth muscle actin (α-SMA), as well as the phosphorylation of PDGFR-β; however, the expression protein levels of PDGF-B and PDGFR-β remained unchanged. In conclusion, HBV particles and HBV c and x proteins promote HSC proliferation and fibrogenesis in vitro and the PDGF-B/PDGFR-β signaling pathway is important in this process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / genetics
  • Actins / metabolism
  • Becaplermin
  • Cell Proliferation
  • Coculture Techniques
  • Collagen Type I / genetics
  • Collagen Type I / metabolism
  • Hep G2 Cells
  • Hepatic Stellate Cells / physiology*
  • Hepatic Stellate Cells / virology
  • Hepatitis B virus / physiology*
  • Host-Pathogen Interactions
  • Humans
  • Liver Cirrhosis / virology
  • Phosphorylation
  • Protein Processing, Post-Translational
  • Proto-Oncogene Proteins c-sis / genetics
  • Proto-Oncogene Proteins c-sis / metabolism*
  • Receptor, Platelet-Derived Growth Factor beta / genetics
  • Receptor, Platelet-Derived Growth Factor beta / metabolism*
  • Signal Transduction
  • Up-Regulation
  • Viral Proteins / physiology

Substances

  • Actins
  • Collagen Type I
  • Proto-Oncogene Proteins c-sis
  • Viral Proteins
  • Becaplermin
  • Receptor, Platelet-Derived Growth Factor beta