Hepatocyte growth factor stimulates the induction of cytokine-induced neutrophil chemoattractant through the activation of NF-kappaB in rat hepatocytes.
BACKGROUND
Recent evidence indicates that CXC chemokines such as human interleukine-8 (IL-8) and rat cytokine-induced neutrophil chemoattractant (CINC) have mitogenic and anti-apoptotic functions in addition to their chemotactic activity toward neutrophils. In the liver, hepatocyte growth factor (HGF) is implicated as a mitogen in the regeneration of liver. However, little is known the interaction between HGF and CXC chemokines during liver injury, repair and regeneration. We hypothesized that HGF may stimulate the expression of such chemokines, which contributes to mitogenic action in liver regeneration.


METHODS
Primary cultured rat hepatocytes were treated with recombinant human HGF (rhHGF), in the absence and presence of calpain inhibitor-1 (CI-1), genistein or anti-CINC-1 antibody. Levels of CINC-1 and its mRNA, tyrosine phosphorylation of HGF receptor (c-Met), the activation of transcription factor, nuclear factor-kappaB (NF-kappaB), and activities of DNA synthesis were measured.


RESULTS
rhHGF enhanced the production of CINC-1 time- and dose-dependently, which followed the increased levels of CINC-1 mRNA. Under the same conditions, rhHGF increased the tyrosine phosphorylation of c-Met. The electrophoretic mobility shift assay revealed that rhHGF activated the nuclear translocation of NF-kappaB and its DNA binding. Proteasome inhibitor (CI-1) blocked the NF-kappaB activation and the CINC-1 production. The tyrosine kinase inhibitor (genistein) inhibited the activities of CINC-1 production and the DNA synthesis stimulated by rhHGF. However, the treatment of anti-CINC-1 antibody had no effect on the DNA synthesis.


CONCLUSIONS
These results demonstrate that rhHGF can stimulate the induction of CINC-1 gene expression through the activation of NF-kappaB via its receptor c-Met in hepatocytes. Although CINC-1 seems to be not associated with the enhancement of DNA synthesis by rhHGF, it cannot negate the possibility that CINC-1 may contribute to liver repair and regeneration.
Kaibori
Masaki
M
Department of Surgery, Kansai Medical University, Moriguchi, Osaka, Japan.
Yanagida
Hidesuke
H
Nakanishi
Hideki
H
Ozaki
Takashi
T
Yoshida
Hideyuki
H
Matsui
Kosuke
K
Hijikawa
Takeshi
T
Kamiyama
Yasuo
Y
Okumura
Tadayoshi
T
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002478:Cells, Cultured; D054360:Chemokine CXCL1; D019743:Chemokines, CXC / Q000235:genetics* / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D019833:Genistein / Q000494:pharmacology; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000276:immunology; D008115:Liver Regeneration / Q000187:drug effects / Q000502:physiology; D008297:Male; D016328:NF-kappa B / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000494:pharmacology
D000906:Antibodies; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; C513297:Cxcl1 protein, rat; D004791:Enzyme Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; D016328:NF-kappa B; D012333:RNA, Messenger; D011994:Recombinant Proteins; D017228:Hepatocyte Growth Factor; D019833:Genistein; D011505:Protein-Tyrosine Kinases