Role of bcl-2 and bax expression in apoptosis of pulmonary artery smooth muscle cells of rats induced by NHE-1 inhibition in vitro

AIM:To investigate the role of bcl-2 and bax expression in apoptosis of pulmonary artery smooth muscle cells(PASMC) of rats induced by Na +/H + exchanger isoform-1(NHE-1) inhibition in vitro. METHODS:Intracellular Ca 2+ concentration ([Ca 2+ ]i) was measured using Fura-2/AM. The expression of bcl-2 and bax mRNA in cells were detected by sqRT-PCR, and the expression of Bcl-2 and Bax protein were examined immunohistochemically. RESULTS:The expression of bax mRNA and Bax protein and [Ca 2+ ]i in cells transfected with NHE-1 ribozyme gene increased significantly compared with those of cells transfected with pLXSN and nontransfected control. Meanwhile, the expression of bcl-2 mRNA and Bcl-2 protein in cells transfected with NHE-1 ribozyme gene decreased significantly. CONCLUSION:Apoptosis of pulmonary artery smooth muscle cells induced by inhibiting NHE-1 may have relevance to the increase in [Ca 2+ ]i and bax expression and the decrease in bcl-2 expression.