Involvement of the nuclear high mobility group B1 peptides released from injured hepatocytes in murine hepatic fibrogenesis

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE

卷:1842

Article

Kao, Ying-Hsien¹  Lin, Yu-Chun²  Tsai, Ming-Shian²  Sun, Cheuk-Kwan³  Yuan, Shyng-Shiou^4,5  Chang, Chih-Yang⁶  Jawan, Bruno⁷  Lee, Po-Huang^2,8 

[1] E DA Hosp, Dept Med Res, Kaohsiung, Taiwan

[2] E DA Hosp, Dept Surg, Kaohsiung, Taiwan

[3] E DA Hosp, Dept Med Educ, Kaohsiung, Taiwan

[4] Kaohsiung Med Univ, Kaohsiung Med Univ Hosp, Translat Res Ctr, Kaohsiung, Taiwan

[5] Kaohsiung Med Univ, Kaohsiung Med Univ Hosp, Dept Obstet & Gynecol, Kaohsiung, Taiwan

[6] E DA Hosp, Dept Obstet & Gynecol, Kaohsiung, Taiwan

[7] Kaohsiung Chang Gung Mem Hosp, Dept Anesthesiol, Kaohsiung 833, Taiwan

[8] Natl Taiwan Univ Hosp, Dept Surg, Taipei 100, Taiwan

关键词: Hepatic stellate cells;    Oxidative stress;    TGF-beta 1 signaling;    Smad2 phosphorylation;    RAGE;    TLR4;   

DOI  :  10.1016/j.bbadis.2014.06.017

来源: Elsevier

【 摘 要 】

This study investigated the pro-fibrogenic role of high mobility group box 1 (HMGB1) peptides in liver fibrogenesis. An animal model of carbon tetrachloride (CCl4)-induced liver fibrosis was used to examine the serum HMGB1 levels and its intrahepatic distribution. The increased serum HMGB1 levels were positively correlated with elevation of transforming growth factor-beta 1 (TGF-beta 1) and collagen deposition during fibrogenesis. The cytoplasmic distribution of HMGB1 was noted in the parenchymal hepatocytes of fibrotic livers. In vitro studies confirmed that exposure to hydrogen peroxide and CCl4 induced an intracellular mobilization and extracellular release of nuclear HMGB1 peptides in clone-9 and primary hepatocytes, respectively. An uptake of exogenous HMGB1 by hepatic stellate cells (HSCs) T6 cells indicated a possible paracrine action of hepatocytes on HSCs. Moreover, HMGB1 dose-dependently stimulated HSC proliferation, up-regulated de nova synthesis of collagen type I and a-smooth muscle actin (alpha-SMA), and triggered Smad2 phosphorylation and its nuclear translocation through a TGF-beta 1 -independent mechanism. Blockade with neutralizing antibodies and gene silencing demonstrated the involvement of the receptor for advanced glycation end-products (RAGE), but not toll-like receptor 4, in cellular uptake of HMGB1 and the HMGB1-mediated Smad2 and ERK1/2 phosphorylation as well as alpha-SMA up-regulation in HSC-T6 cells. Furthermore, anti-RAGE treatment significantly ameliorated CCl4-induced liver fibrosis. In conclusion, the nuclear HMGB1 peptides released from parenchymal hepatocytes during liver injuries may directly activate HSCs through stimulating HSC proliferation and transformation, eventually leading to the fibrotic changes of livers. Blockade of HMGB1/RAGE signaling cascade may constitute a therapeutic strategy for treatment of liver fibrosis. (C) 2014 Elsevier B.V. All rights reserved.

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