The mechanism of hydralazine-induced collagen biosynthesis in cultured fibroblasts

• Published in: Naunyn-Schmiedeberg's archives of pharmacology 2013-04, Vol.386 (4), p.303-309
• Main Authors: Karna, Ewa, Szoka, Lukasz, Palka, Jerzy A.
• Format: Article
• Language: English
• Subjects: Antihypertensive Agents - pharmacology; Biomedical and Life Sciences; Biomedicine; Cell Survival; Cells, Cultured; Collagen - biosynthesis; Dipeptidases - metabolism; DNA - biosynthesis; Fibroblasts - drug effects; Fibroblasts - metabolism; Focal Adhesion Kinase 1 - metabolism; Humans; Hydralazine - pharmacology; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; Integrin alpha2beta1 - metabolism; Mitogen-Activated Protein Kinase 1 - metabolism; Mitogen-Activated Protein Kinase 3 - metabolism; Neurosciences; Original; Original Article; Pharmacology/Toxicology; Receptor, IGF Type 1 - metabolism; Transcription Factor RelA - metabolism
• ISSN: 0028-1298; 1432-1912
• DOI: 10.1007/s00210-013-0836-5

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 α 2 β 1 integrin, insulin-like growth factor-I receptor (IGF-IR), focal adhesion kinase (FAK), mitogen-activated protein (MAP) kinases (ERK 1 , ERK 2 ), 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 α 2 β 1 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 α 2 β 1 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.