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Inhibition of cell proliferation and fibronectin biosynthesis by Na ascorbate
Author(s) -
Péterszegi G.,
Dagonet F. B.,
LabatRobert J.,
Robert L.
Publication year - 2002
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1046/j.1365-2362.2002.00992.x
Subject(s) - fibronectin , sodium ascorbate , ascorbic acid , biochemistry , cell growth , viability assay , chemistry , cell , biosynthesis , microbiology and biotechnology , population , biology , enzyme , medicine , food science , environmental health
Background The importance of ascorbate on the production of extracellular matrix proteins (as elastin and collagens) is now well documented, but no studies have been published concerning its effects on fibronectin biosynthesis. Fibronectin is important for cell attachment and for proliferation. Materials and methods The effects of Na ascorbate were investigated on cell attachment, proliferation, viability and fibronectin biosynthesis by human skin fibroblasts in vitro . Proliferation was followed by the monitoring of [ 3 H]‐thymidine incorporation; viability by the MTT‐test, cell adherence by counting adherent and nonadherent cells and fibronectin biosynthesis by immunoprecipitation of biosynthetically labelled fibronectin. Results In the presence of ascorbate, the fibroblasts showed a biphasic growth pattern. At 500 µM ascorbate, [ 3 H]‐thymidine incorporation was stimulated by 15% as compared to the controls. Higher concentrations gradually decreased proliferation up to 36% of the control value at 5 mM. These effects of ascorbate on DNA synthesis were followed to > 1·25 mM by a strong inhibition, cytotoxic effect and cell death. The non‐adherent cell count increased to 10% of the total population at 2·5 mM and to 31% at 5·0 mM ascorbate. Increasing concentrations of ascorbate resulted in a dose‐dependent decrease of fibronectin biosynthesis, both in the culture supernates and cell extracts. This inhibition mainly concerned cell membrane‐associated fibronectin. Superoxide‐dismutase or catalase could inhibit Na ascorbate‐induced cytotoxicity and partially re‐establish fibronectin biosynthesis. Desferrioxamine, ergothionein and vitamin E were inefficient. Conclusions Our results indicate that ascorbate decreases fibronectin biosynthesis of cultured human skin fibroblasts, thereby producing cell detachment and decreased proliferation. This effect is mainly mediated by the reactive oxygen species and can be inhibited by superoxide‐dismutase and catalase.