Protein Expression by Human Pulmonary Artery Smooth Muscle Cells Containing a BMPR2 Mutation and the Action of ET-1 as Determined by Proteomic Mass Spectrometry.

Pulmonary arterial hypertension (PAH) is a disease characterized by increased pulmonary vascular resistance and remodeling. Increase in the population of vascular smooth muscle cells is among the key events contributing to the remodeling. Endothelin-1 (ET-1), a potent vasoconstrictor, is linked to the etiology and progression of PAH. Here we analyze changes in protein expressions in response to ET-1 in pulmonary arterial smooth muscle cells (PASMC) from a healthy Control (non-PAH) and a PAH subject presenting a bone morphogenetic protein type II receptor (BMPR2) mutation with exon 1-8 deletion. Protein expressions were analyzed by proteomic mass spectrometry using label-free quantitation and the correlations were subjected to Ingenuity™ Pathway Analysis. The results point to eIF2/mTOR/p70S6K, RhoA/actin cytoskeleton/integrin and protein unbiquitination as canonical pathways whose protein expressions increase with the development of PAH. These pathways have an intimal function in the PAH-related physiology of smooth muscle proliferation, apoptosis, contraction and cellular stress. Exposure of the cells to ET-1 further increases protein expression within these pathways. Thus our results show changes in signaling pathways as a consequence of PAH and the effect of ET-1 interference on Control and PAH-affected cells.