Stimulation of heparan sulfate proteoglycan synthesis and secretion during G1 phase induced by growth factors and PMA
✍ Scribed by Marimélia A. Porcionatto; Claudia R. Moreira; Claudimara F.P. Lotfi; Hugo A. Armelin; Carl P. Dietrich; Helena B. Nader
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 121 KB
- Volume
- 70
- Category
- Article
- ISSN
- 0730-2312
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✦ Synopsis
Fetal calf serum (FCS) and PMA (phorbol 12-myristate-13-acetate) specifically stimulate the synthesis of heparan sulfate proteoglycan in endothelial cells. Staurosporine and n-butanol, kinase inhibitors, abolish the PMA effect. Forskolin and 8-bromo adenosine 3':5'-cyclic monophosphate, activators of, respectively, adenylate cyclase and protein kinase A cannot reproduce the PMA effect. The kinetics of cell entry into S phase of the endothelial cells was determined by DNA synthesis ([ 3 H]-thymidine and Br-dU incorporation), and flow cytometry. The mitogenic effect of fetal calf serum is abolished by PMA. Also, PMA pre-treatment inhibits the enhanced synthesis of heparan sulfate proteoglycan after a second PMA exposure. Remarkably, the stimulation of heparan sulfate proteoglycan synthesis by fetal calf serum and PMA seems to be mainly restricted to G 1 phase. Therefore fetal calf serum and PMA cause an enhanced synthesis of heparan sulfate proteoglycan, and PMA causes a cell cycle block at G 1 phase.