Heme oxygenase-1 does not mediate the effects of extracellular acidosis on vascular smooth muscle cell proliferation, migration, and susceptibility to apoptosis.

Background: Unbalanced vascular smooth muscle cell (VSMC) proliferation, migration, and apoptosis contribute to vascular disorders such as atherosclerosis, restenosis, and pulmonary hypertension. The effect of extracellular acidosis (EA) on VSMC homeostasis is incompletely understood but we previously reported that EA increases heme oxygenase-1 (HO-1) expression in VSMCs. Since HO-1 regulates VSMC proliferation and apoptosis we sought to define the role of HO-1 in VSMC responses to EA.