Spleen tyrosine kinase modulates the proliferation and phenotypes of vascular smooth muscle cells induced by platelet-derived growth factor.

Platelet-derived growth factor BB (PDGF-BB) regulates vascular smooth muscle cells (VSMCs) by activating signaling cascades that promote vasoconstriction and growth, but the underlying mechanisms remain incompletely characterized. In this study, we aimed at investigating the role of spleen tyrosine kinase (Syk) in the proliferation and phenotypes in rat pulmonary arterial VSMCs. Our results demonstrate that PDGF-BB or Syk-adenovirus led to a substantial increase of proliferation of VSMCs and cytoskeleton rearrangement in rat VSMCs. Consistently, these cells underwent phenotype changes. Notably, Syk inhibitor piceatannol significantly inhibited those biological effects induced by PDGF-BB. Thus, we conclude that Syk plays an important role in vascular remodeling through the modulation of proliferation and phenotypes of VSMCs.