Insulin-Like Growth Factor (IGF)-Binding Protein-1 Is Highly Induced during Acute Carbon Tetrachloride Liver Injury and Potentiates the IGF-I-Stimulated Activation of Rat Hepatic Stellate Cells
Author(s) -
JensGerd Scharf,
Frank Dombrowski,
Ruslan Novosyadlyy,
Christoph Eisenbach,
Ilaria Demori,
Bernd Kübler,
Thomas Braulke
Publication year - 2004
Publication title -
endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.674
H-Index - 257
eISSN - 1945-7170
pISSN - 0013-7227
DOI - 10.1210/en.2003-1541
Subject(s) - hepatic stellate cell , medicine , endocrinology , in situ hybridization , carbon tetrachloride , hepatocyte , insulin like growth factor binding protein , immunostaining , growth factor , northern blot , western blot , biology , liver injury , insulin like growth factor , messenger rna , chemistry , microbiology and biotechnology , in vitro , immunohistochemistry , gene , receptor , biochemistry , organic chemistry
Hepatic stellate cells (HSC) play a pivotal role in hepatic tissue repair and fibrogenesis. IGF-I has been considered a mitogenic signal for activation and proliferation of HSC in vitro. In the present study IGF-I and IGF-binding protein (IGFBP) gene expression was studied in a model of acute liver injury induced by a single intragastric dose of carbon tetrachloride (CCl(4)) in adult rats. Northern blot analysis revealed a marked increase in IGFBP-1 mRNA levels, with a maximum between 3 and 9 h after CCl(4) application, whereas steady state mRNA levels of IGF-I were only moderately altered. In situ hybridization experiments demonstrated that this increase in IGFBP-1 mRNA was due to a strong expression of IGFBP-1 in the perivenous region 6-12 h after CCl(4) application, extending to the midzonal region of the acinus within 24-48 h. Consequently, a prominent immunostaining for IGFBP-1 was observed in perivenous areas, with a maximum 24-48 h after intoxication. Preincubation of early cultured HSC with a nonphosphorylated IGFBP-1 from human amniotic fluid resulted in a 3.4-fold increase in IGF-I-induced DNA synthesis. The mitogenic effect of IGF-I was also potentiated when HSC were cocultivated with IGFBP-1-overexpressing BHK-21 cells compared with nontransfected cells. These data suggest that IGFBP-1 released during the early steps of liver tissue damage and repair may interact with HSC and potentiate the sensitivity of IGF-I to mitogenic signals.
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