[Effect of spleen tyrosine kinase on the proliferation of pulmonary vascular smooth muscle cells in rats].

OBJECTIVE

To investigate the role of spleen tyrosine kinase (Syk) in rat pulmonary vascular smooth muscle cells (PVSMCs) proliferation induced by platelet-derived growth factor-BB (PDGF-BB).

METHODS

PVSMCs from male Sprague-Dawley rats were cultured in vitro and the cells of passages 3-5 were used in the experiment. PVSMCs were stimulated by PDGF-BB and were treated with three different doses of piceatannol, a Syk selective inhibitor. Cell proliferation was assessed by methyl thiazolyl tetrazolium (MTT) assay. DNA synthesis was measured by ³H-thymidine incorporation (³H-TdR). Cellular cycle was observed by flow cytometry. Syk mRNA and protein expression were detected using real-time quantitative PCR and Western blot, respectively.

RESULTS

The expression of Syk protein of PVSMCs was significantly up-regulated following PDGF-BB stimulation. PDGF-BB stimulation dramatically increased PVSMCs proliferation. After piceatannol treatment, both Syk mRNA and protein expression decreased and the proliferation of PVSMCs was inhibited in a dose-dependent manner.

CONCLUSIONS

Syk may promote PVSMCs proliferation induced by PDGF-BB.