title: Hepatitis B virus directly promotes collagen I expression of LX-2 cells without infection in vitro.
abstract: OBJECTIVE
  To investigate direct effects of hepatitis B virus (HBV) on collagen type I in vitro.
  
  
  METHODS
  Collagen type I were measured after LX-2 cell cultured with purified or serum HBV for 12, 24 and 48 h. Furthermore, evidence of HBV infection to LX-2 were detected, and different inhibitors were used to identify pathways regulating collagen I expression.
  
  
  RESULTS
  The 3 × 10(5)  IU/mL purified/serum HBV increased collagen type I mRNA expression by 2.2-/3.2- and 1.3-/1.5-fold at 24 and 48 h, respectively. Collagen type I protein in the supernatant of purified/serum HBV group also increased compared to the control group (408.0 ± 8.0/384.4 ± 6.8 vs 262.7 ± 15.7 ng/mL, P < 0.05). However, the 3 × 10(7)  IU/mL purified/serum HBV increased collagen type I expression similar to that of 3 × 10(5)  IU/mL, while 3 × 10(3)  IU/mL group showed no effect. Human HBV immunoglobulin alleviated HBV-induced collagen I expression, but no evidence of HBV infection was found. Neutralization of transforming growth factor beta, tumor necrosis factor alpha, platelet-derived growth factor, extracellular signal-regulated kinase and TGF-β receptor had no obvious inhibitory effects; only inhibition of p38 mitogen-activated protein kinase decreased collagen type I mRNA expression by 0.5-/0.4- and 0.4-/0.3-fold at 24 and 48 h, respectively. It reduced collagen type I protein in the purified/serum HBV group for 48 h (252.1 ± 14.1/251.7 ± 18.8 vs 403.9 ± 4.9/385.0 ± 4.2 ng/mL, P < 0.05).
  
  
  CONCLUSIONS
  HBV directly promotes collagen type I expression of LX-2 cells without infection in vitro.
authors.affiliation: Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing             Digestive Disease Department, General Hospital of Lanzhou Petrochemical Corporation, Lanzhou, China.
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Wu
authors.forename: Yu
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authors.lastname: Wang
authors.forename: Yan
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authors.lastname: Cui
authors.forename: Qixuan
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authors.lastname: Bai
authors.forename: Xingyu
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authors.lastname: Ze
authors.forename: Tianhui
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authors.lastname: Liu
authors.forename: Min
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authors.lastname: Cong
authors.forename: Ping
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authors.lastname: Wang
authors.forename: Xinmin
authors.initials: X
authors.lastname: Li
authors.forename: Gang
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authors.lastname: Yin
authors.forename: Xiaojuan
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authors.lastname: Ou
authors.forename: Hong
authors.initials: H
authors.lastname: You
authors.forename: Jidong
authors.initials: J
authors.lastname: Jia