BACKGROUND/AIMS: Connective tissue growth factor (CCN2) is expressed during activation of hepatic stellate cells (HSC) and promotes HSC proliferation, adhesion, and collagen production. The aim of the study was to investigate CCN2 signaling pathways in HSC. METHODS: Primary HSC were obtained by enzymatic perfusion of rat liver. DNA synthesis was evaluated by [(3)H]thymidine incorporation. Phosphorylation of Elk-1, extracellular signal-regulated kinase (ERK1/2) and focal adhesion kinase (FAK) was evaluated by Western blot. Transcriptional factor binding activity was determined by gel mobility shift assay while c-fos promoter and CCN2 promoter activity was evaluated using luciferase reporters. c-fos mRNA expression was evaluated by Northern blot. RESULTS: CCN2 stimulated DNA synthesis and phosphorylation of FAK, Elk-1 and ERK1/2, the latter of which was blocked by heparin. The serum response element binding activity and luciferase reporter activity of the c-fos promoter, together with expression of c-fos, were enhanced by CCN2. CCN2-induced c-fos gene activation, expression and cell proliferation were blocked by inhibiting ERK1/2 with PD98059. CCN2 promoter activity was enhanced by TGF-beta1 or PDGF via a Smad7-dependent pathway. CONCLUSIONS: CCN2-stimulated HSC DNA synthesis is associated with transient induction of c-fos gene activation and expression as well as activation of the ERK1/2 signal pathway.
BACKGROUND/AIMS: Connective tissue growth factor (CCN2) is expressed during activation of hepatic stellate cells (HSC) and promotes HSC proliferation, adhesion, and collagen production. The aim of the study was to investigate CCN2 signaling pathways in HSC. METHODS: Primary HSC were obtained by enzymatic perfusion of rat liver. DNA synthesis was evaluated by [(3)H]thymidine incorporation. Phosphorylation of Elk-1, extracellular signal-regulated kinase (ERK1/2) and focal adhesion kinase (FAK) was evaluated by Western blot. Transcriptional factor binding activity was determined by gel mobility shift assay while c-fos promoter and CCN2 promoter activity was evaluated using luciferase reporters. c-fos mRNA expression was evaluated by Northern blot. RESULTS: CCN2 stimulated DNA synthesis and phosphorylation of FAK, Elk-1 and ERK1/2, the latter of which was blocked by heparin. The serum response element binding activity and luciferase reporter activity of the c-fos promoter, together with expression of c-fos, were enhanced by CCN2. CCN2-induced c-fos gene activation, expression and cell proliferation were blocked by inhibiting ERK1/2 with PD98059. CCN2 promoter activity was enhanced by TGF-beta1 or PDGF via a Smad7-dependent pathway. CONCLUSIONS: CCN2-stimulated HSC DNA synthesis is associated with transient induction of c-fos gene activation and expression as well as activation of the ERK1/2 signal pathway.
Authors: Mark R Gray; Jennifer A Malmquist; Matthew Sullivan; Michael Blea; John J Castellot Journal: J Cell Commun Signal Date: 2007-11-13 Impact factor: 5.782
Authors: Erawan Borkham-Kamphorst; Claudia R van Roeyen; Eddy Van de Leur; Jürgen Floege; Ralf Weiskirchen Journal: J Cell Commun Signal Date: 2011-07-05 Impact factor: 5.782
Authors: Yunliang Chen; David J Abraham; Xu Shi-Wen; Jeremy D Pearson; Carol M Black; Karen M Lyons; Andrew Leask Journal: Mol Biol Cell Date: 2004-09-15 Impact factor: 4.138
Authors: Alain Dessein; Christophe Chevillard; Violaine Arnaud; Xunya Hou; Anas Ahmed Hamdoun; Helia Dessein; Hongbin He; Suzan A Abdelmaboud; Xinsong Luo; Jun Li; Arthur Varoquaux; Adil Mergani; Mohammed Abdelwahed; Jie Zhou; Ahmed Monis; Maira G R Pitta; Nagla Gasmelseed; Sandrine Cabantous; Yaqing Zhao; Aluizio Prata; Carlos Brandt; Nasr Eldin Elwali; Laurent Argiro; Yuesheng Li Journal: J Exp Med Date: 2009-10-12 Impact factor: 14.307