Human hepatic stellate cells express CCR5 and RANTES to induce proliferation and migration.
Activated hepatic stellate cells (HSCs) are the main producers of extracellular matrix in the fibrotic liver and are involved in the regulation of hepatic inflammation. The aim of this study was to characterize the role of regulated on activation, normal T-cell expressed, and presumably secreted (RANTES) in activated HSCs. RANTES mRNA and protein secretion were strongly induced after stimulating HSCs with TNF-alpha, IL-1beta, or CD40L. RANTES production was NF-kappaB dependent, because inhibitor-kappaB (IkappaB) superrepressor and dominant-negative IkappaB kinase-2 almost completely blocked RANTES expression. NF-kappaB activation was sufficient to drive RANTES expression as demonstrated by the strong induction of RANTES in HSCs expressing NF-kappaB-inducing kinase. The JNK/activator protein-1 pathway also contributed to RANTES expression as demonstrated by the blocking effects of the JNK inhibitor SP600125. HSCs responded to stimulation with recombinant human (rh)RANTES with an increase in intracellular calcium concentration and a rapid increase in free radical formation. Furthermore, rhRANTES induced ERK phosphorylation, ERK-dependent [3H]thymidine incorporation, and HSC proliferation. Additionally, rhRANTES induced focal adhesion kinase phosphorylation and a substantial increase in HSC migration. HSCs functionally expressed chemokine receptor-5 (CCR5), as shown by flow-cytometric analysis and RT-PCR, and the inhibitory effects of a blocking CCR5 antibody on rhRANTES-induced ERK activation, proliferation, and migration. Diphenylene iodonium and N-acetylcysteine inhibited rhRANTES-induced ERK activation and HSC proliferation, indicating that NADPH oxidase-dependent production of reactive oxygen species was required. In conclusion, RANTES and CCR5 represent potential mediators of 1) HSC migration and proliferation and 2) a cross-talk between HSCs and leukocytes during fibrogenesis.
Schwabe
Robert F
RF
Columbia University College of Physicians and Surgeons, 630 West 168th St., PH8East, Rm. 105J, New York, NY 10032-3784, USA.
Bataller
Ramon
R
Brenner
David A
DA
D002118:Calcium / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D018946:Chemokine CCL5 / Q000378:metabolism* / Q000494:pharmacology; D004789:Enzyme Activation; D005609:Free Radicals / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D051550:I-kappa B Kinase; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D019713:Receptors, CCR5 / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology
D018946:Chemokine CCL5; D005609:Free Radicals; D016328:NF-kappa B; D019713:Receptors, CCR5; D011994:Recombinant Proteins; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D002118:Calcium