Peroxynitrite-induced apoptosis in human brain vascular smooth muscle cells is associated with induction of PDCD4 gene expression.

The present study investigated whether peroxynitrite (ONOO-)-elicited cytotoxicity on human brain vessel smooth muscle cells (HBVSMCs) was related to alteration in programmed cell death 4 (PDCD4) gene expression. Cell viability, morphological changes and apoptosis were determined by_methylthiazoletetrazolium (MTT) assay, acridine orange staining and flow cytometry, respectively. Expressions of PDCD4 at both mRNA and protein levels were examined by RT-PCR and Western blot respectively. Protein expressions of caspase-3, Bcl-2 and Bax were detected by Western an increased apoptotic rate of HBVSMCs after treatment with ONOO-. ONOO- was able to upregulate mRNA and protein expressions of the PDCD4 gene. Moreover, protein expressions of caspase-3 and Bax were significantly increased, whereas the expression of Bcl-2 was markedly decreased in response to exposure of ONOO-. This study demonstrates, for the first time, that the PDCD4 gene is involved in ONOO- induced apoptosis in HBVSMCs.