The mechanism of hydralazine-induced collagen biosynthesis in cultured fibroblasts.
The finding that hydralazine (HYD) affects collagen metabolism led us to investigate the mechanism of its action on collagen biosynthesis, prolidase expression and activity, expression of α2β1 integrin, insulin-like growth factor-I receptor (IGF-IR), focal adhesion kinase (FAK), mitogen-activated protein (MAP) kinases (ERK1, ERK2), and transcription factors hypoxia-inducible factor-1α (HIF-1α) and nuclear factor-κB p65 (NF-κB p65) in human dermal fibroblasts. Confluent fibroblasts were treated with micromolar concentrations (50-500 μM) of HYD for 24 h. HYD had no influence on cell viability. It was found that HYD-dependent increase in collagen biosynthesis was accompanied by a parallel increase in prolidase activity and expression, HIF-1α expression, and decrease in DNA biosynthesis, compared to untreated cells. Since collagen biosynthesis and prolidase activity are regulated by a signal induced by activated α2β1 integrin receptor as well as IGF-IR, the expression of these receptors was measured by Western immunoblot analysis. The exposure of the cells to HYD contributed to the increase in IGF-IR expression without any effect on α2β1 integrin receptor and FAK expressions. It was accompanied by a decrease in expression of MAP kinases and NF-κB p65, the known inhibitor of collagen gene expression. The data suggest that the HYD-dependent increase of collagen biosynthesis in cultured human skin fibroblasts results from activation of IGF-IR expression and prolidase activity and downregulation of NF-κB p65.
Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2D, Bialystok, Poland.
Ewa
E
Karna
Lukasz
L
Szoka
Jerzy A
JA
Palka
D000959:Antihypertensive Agents / Q000494:pharmacology*; D002470:Cell Survival; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis*; D004247:DNA / Q000096:biosynthesis; D004150:Dipeptidases / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D006801:Humans; D006830:Hydralazine / Q000494:pharmacology*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D038982:Integrin alpha2beta1 / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D051996:Transcription Factor RelA / Q000378:metabolism
D000959:Antihypertensive Agents; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D038982:Integrin alpha2beta1; D051996:Transcription Factor RelA; D006830:Hydralazine; D003094:Collagen; D004247:DNA; D017526:Receptor, IGF Type 1; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D004150:Dipeptidases; C022449:proline dipeptidase