Abstract: Objective This study was designed to investigate the change of PDCD4 gene expression in cerebral vascular smooth muscle cells (HCVSMCs) in response to peroxynitrite (ONOO-). Methods HCVSMCs were cultured in vitro and subjected to different concentrations of ONOO-. Cell viability was measured by MTT assay. The morphological changes were assessed by acridine orange staining as well as Ho33342/PI double staining to determine whether cell experienced apoptosis. The apoptotic rate was determined by flow cytometry. In particular, the expression of PDCD4 gene was examined by the means of RT-PCR and Western blot simultaneously. Results Direct exposure of HCVSMCs to ONOO- was able to block the cell proliferation, which was further revealed via the apoptotic pathway. Under the stress by ONOO-, the expression of PDCD4 gene was apparently increased at both mRNA and protein levels. Conclusions PDCD4 gene may play a pivotal role underlying the ONOO--induced apoptosis in HCVSMCs.

Key words: Peroxynitrite, PDCD4 gene, cerebral vascular smooth cells, Apoptosis