Smooth muscle cell cycle and proliferation. Relationship between calcium influx and sarco-endoplasmic reticulum Ca2+ATPase regulation
| Autor: | C, Magnier-Gaubil, J M, Herbert, R, Quarck, B, Papp, E, Corvazier, F, Wuytack, S, Lévy-Tolédano, J, Enouf |
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| Rok vydání: | 1996 |
| Předmět: |
Platelet-Derived Growth Factor
Indoles Nifedipine Swine Cell Cycle Imidazoles Calcium-Transporting ATPases DNA Calcium Channel Blockers Muscle Smooth Vascular S Phase Kinetics Sarcoplasmic Reticulum Transforming Growth Factor beta Animals Humans Calcium Sulfones Phosphorylation Aorta Cell Division Cells Cultured Thymidine |
| Zdroj: | The Journal of biological chemistry. 271(44) |
| ISSN: | 0021-9258 |
| Popis: | The role of Ca2+ influx in the regulation of the sarco-endoplasmic reticulum Ca2+ATPases (SERCA) associated with intracellular Ca2+ pools was investigated during smooth muscle cell (SMC) proliferation induced by platelet-derived growth factor (PDGF). We first defined that the previously described up-regulation of the SERCA2a isoform found in vascular SMC after a 24-h stimulation with PDGF (Magnier, C. , Papp, B., Corvazier, E., Bredoux, R., Wuytack, F., Eggermont, F., Maclouf, J., and Enouf, J. (1992) J. Biol. Chem. 267, 15808-15815) was precisely associated with SMC entry into S phase as it appeared linked with [3H]thymidine incorporation. This was further confirmed by testing the effect of transforming growth factor-beta1, which inhibited both aortic SMC proliferation associated with G1 cell cycle arrest and PDGF-induced SERCA2a up-stimulation. Then, we tested the role of Ca2+ influx by using SR 33805, a new Ca2+ channel blocker, which was characterized with regard to the voltage Ca2+ channel blocker nifedipine and the capacitative entry Ca2+ blocker SKF 96365. SR 33805 was found to be the most potent inhibitor of both PDGF-induced SMC proliferation and the associated rise in intracellular Ca2+ concentration with IC50 values of 0.2 +/- 0.1 and 0.31 +/- 0. 04 microM, respectively. Finally, by examining in parallel both SERCA2a and SERCA2b isoforms, in terms of activity and expression, we could determine that PDGF-induced stimulation of total SERCA activity (detected by formation of the phosphorylated intermediate, E approximately P) and of SERCA2a expression (Western blotting) were abolished when extracellular Ca2+ entry was prevented by SR 33805. This study demonstrates that SERCA2a up-regulation is: 1) related to the G1/S transition step of cell cycle and 2) dependent on Ca2+ entry during PDGF-induced SMC proliferation. |
| Databáze: | OpenAIRE |
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