Disruption of platelet-derived growth factor-dependent phosphatidylinositol 3-kinase and phospholipase Cgamma 1 activity abolishes vascular smooth muscle cell proliferation and migration and attenuates neointima formation in vivo.
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Caglayan E, Vantler M, Leppanen O, Gerhardt F, Mustafov L, Ten Freyhaus H, Kappert K, Odenthal M, Zimmermann WH, Tallquist MD, Rosenkranz S
Disruption of platelet-derived growth factor-dependent phosphatidylinositol 3-kinase and phospholipase Cgamma 1 activity abolishes vascular smooth muscle cell proliferation and migration and attenuates neointima formation in vivo.
J Am Coll Cardiol. 2011 Jun 21;57(25):2527-38. doi: 10.1016/j.jacc.2011.02.037.
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- 21679854 [ View in PubMed]
- Abstract
OBJECTIVES: We tested the hypothesis whether selective blunting of platelet-derived growth factor (PDGF)-dependent vascular smooth muscle cell (VSMC) proliferation and migration is sufficient to prevent neointima formation after vascular injury. BACKGROUND: To prevent neointima formation and stent thrombosis after coronary interventions, it is essential to inhibit VSMC proliferation and migration without harming endothelial cell function. The role of PDGF-a potent mitogen and chemoattractant for VSMC that does not affect endothelial cells-for neointima formation remains controversial. METHODS: To decipher the signaling pathways that control PDGF beta receptor (betaPDGFR)-driven VSMC proliferation and migration, we characterized 2 panels of chimeric CSF1R/betaPDGFR mutants in which the binding sites for betaPDGFR-associated signaling molecules (Src, phosphatidylinositol 3-kinase [PI3K], GTPase activating protein of ras, SHP-2, phospholipase Cgamma 1 [PLCgamma]) were individually mutated. Based on in vitro results, the importance of PDGF-initiated signals for neointima formation was investigated in genetically modified mice. RESULTS: Our results indicate that the chemotactic response to PDGF requires the activation of Src, PI3K, and PLCgamma, whereas PDGF-dependent cell cycle progression is exclusively mediated by PI3K and PLCgamma. These 2 signaling molecules contribute to signal relay of the betaPDGFR by differentially regulating cyclin D1 and p27(kip1). Blunting of betaPDGFR-induced PI3K and PLCgamma signaling by a combination mutant (F3) completely abolished the mitogenic and chemotactic response to PDGF. Disruption of PDGF-dependent PI3K and PLCgamma signaling in mice expressing the F3 receptor led to a profound reduction of neointima formation after balloon injury. CONCLUSIONS: Signaling by the activated betaPDGFR, particularly through PI3K and PLCgamma, is crucial for neointima formation after vascular injury. Disruption of these specific signaling pathways is sufficient to attenuate pathogenic processes such as vascular remodeling in vivo.