Upregulated expression of STIM2, TRPC6, and Orai2 contributes to the transition of pulmonary arterial smooth muscle cells from a contractile to proliferative phenotype.

Pulmonary arterial hypertension (PAH) is a progressive disease that, if left untreated, eventually leads to right heart failure and death. Elevated pulmonary arterial pressure (PAP) in patients with PAH is mainly caused by an increase in pulmonary vascular resistance (PVR). Sustained vasoconstriction and excessive pulmonary vascular remodeling are two major causes for elevated PVR in patients with PAH.

Pathogenic role of store-operated and receptor-operated ca(2+) channels in pulmonary arterial hypertension.

Pulmonary circulation is an important circulatory system in which the body brings in oxygen. Pulmonary arterial hypertension (PAH) is a progressive and fatal disease that predominantly affects women. Sustained pulmonary vasoconstriction, excessive pulmonary vascular remodeling, in situ thrombosis, and increased pulmonary vascular stiffness are the major causes for the elevated pulmonary vascular resistance (PVR) in patients with PAH.

Enhanced Ca(2+)-sensing receptor function in idiopathic pulmonary arterial hypertension.

Rationale: A rise in cytosolic Ca(2+) concentration ([Ca(2+)](cyt)) in pulmonary arterial smooth muscle cells (PASMC) is an important stimulus for pulmonary vasoconstriction and vascular remodeling. Increased resting [Ca(2+)](cyt) and enhanced Ca(2+) influx have been implicated in PASMC from patients with idiopathic pulmonary arterial hypertension (IPAH).

Objective: We examined whether the extracellular Ca(2+)-sensing receptor (CaSR) is involved in the enhanced Ca(2+) influx and proliferation in IPAH-PASMC and whether blockade of CaSR inhibits experimental pulmonary hypertension.