A Critical Role for p130Cas in the Progression of Pulmonary Hypertension in Humans and Rodents

L Tu, FS De Man, B Girerd, A Huertas… - American journal of …, 2012 - atsjournals.org
L Tu, FS De Man, B Girerd, A Huertas, MC Chaumais, F Lecerf, C François, F Perros…
American journal of respiratory and critical care medicine, 2012atsjournals.org
Rationale: Pulmonary arterial hypertension (PAH) is a progressive and fatal disease
characterized by pulmonary arterial muscularization due to excessive pulmonary vascular
cell proliferation and migration, a phenotype dependent upon growth factors and activation
of receptor tyrosine kinases (RTKs). p130Cas is an adaptor protein involved in several
cellular signaling pathways that control cell migration, proliferation, and survival. Objectives:
We hypothesized that in experimental and human PAH p130Cas signaling is overactivated …
Rationale: Pulmonary arterial hypertension (PAH) is a progressive and fatal disease characterized by pulmonary arterial muscularization due to excessive pulmonary vascular cell proliferation and migration, a phenotype dependent upon growth factors and activation of receptor tyrosine kinases (RTKs). p130Cas is an adaptor protein involved in several cellular signaling pathways that control cell migration, proliferation, and survival.
Objectives: We hypothesized that in experimental and human PAH p130Cas signaling is overactivated, thereby facilitating the intracellular transmission of signal induced by fibroblast growth factor (FGF)2, epidermal growth factor (EGF), and platelet-derived growth factor (PDGF).
Measurements and Main Results: In patients with PAH, levels of p130Cas protein and/or activity are higher in the serum, in the walls of distal pulmonary arteries, in cultured smooth muscle cells (PA-SMCs), and in pulmonary endothelial cells (P-ECs) than in control subjects. These abnormalities in the p130Cas signaling were also found in the chronically hypoxic mice and monocrotaline-injected rats as models of human PAH. We obtained evidence for the convergence and amplification of the growth-stimulating effect of the EGF-, FGF2-, and PDGF-signaling pathways via the p130Cas signaling pathway. We found that daily treatment with the EGF-R inhibitor gefitinib, the FGF-R inhibitor dovitinib, and the PDGF-R inhibitor imatinib started 2 weeks after a subcutaneous monocrotaline injection substantially attenuated the abnormal increase in p130Cas and ERK1/2 activation and regressed established pulmonary hypertension.
Conclusions: Our findings demonstrate that p130Cas signaling plays a critical role in experimental and idiopathic PAH by modulating pulmonary vascular cell migration and proliferation and by acting as an amplifier of RTK downstream signals.
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