ISSN:
1437-7799
Keywords:
ticlopidine
;
platelet-derived growth factor
;
mitogen-activated protein kinase
;
c-Raf-1
;
DNA synthesis
;
rat mesangial cells
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Background We previously found that ticlopidine inhibits the proliferation of cultured rat mesangial cells that is induced by fetal bovine serum. This study was designed to examine the effects of ticlopidine on platelet-derived growth factor (PDGF)-induced DNA synthesis and mitogen-activated protein (MAP) kinase activation in such mesangial cells to clarify the mechanism of the antiproliferative action. Methods Glomerular mesangial cells were isolated from rat kidneys, and cells were incubated with various combinations of ticlopidine, PDGF, epidermal growth factor, phorbol 12-acetate 13-myristate (PMA), cilostazol (a phosphodiesterase inhibitor), and H-89 (a cAMP-dependent protein kinase A [PKA] inhibitor). A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and cell count involving the trypan blue exclusion test were performed for determination of cell viability. DNA synthesis and MAP kinase activity were assessed by means of a tritiated thymidine ([3H]thymidine) incorporation assay and the BiotrakTM MAP kinase assay system, respectively. Results Ticlopidine (1 μmol/L) significantly inhibited both PDGF-induced DNA synthesis and MAP kinase activation. Also, 1 μmol/L ticlopidine substantially blocked PMA-induced MAP kinase activation. Pretreatment with H-89 did not abolish the ability of ticlopidine to inhibit PDGF-induced MAP kinase activation, while H-89 pretreatment significantly reserved the inhibitory action of cilostazol on PDGF-induced MAP kinase activation. Conclusion These results suggest that ticlopidine might inhibit PDGF-induced DNA synthesis after MAP kinase activation by intercepting the signal transduction from c-Raf-1 to MAP kinase, independent of the cAMP-PKA pathway.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02479932
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