Abstract:

Objective   To explore the possible mechanism underlying peroxynitrite (ONOO-)-induced discoidin domain receptor-2(DDR2) expression in human brain vascular smooth muscle cells (HBVSMCs). Methods   HBVSMCs were cultured in vitro in different concentrations of ONOO-, and PD98059, a specific inhibitor of ERK1/2. Morphology and viability of HBVSMCs pretreated with PD98059 were detected by an inverted phase contrast microscope, acridine orange staining and MTT assay.  Western blot and Real-time PCR were employed to determine expressions of DDR2/ MMP-9. Results   10μmol/L of ONOO- significantly induced expression of DDR2 at both protein and mRNA levels (P<0.05). With increase in concentrations of ONOO-, expression of DDR2 was markedly decreased(P<0.05). After pretreatment on HBVSMCs with PD98059, cellular morphology and viability had no significant change by an inverted phase contrast microscope, acridine orange staining and MTT assay(P>0.05). Pretreatment on HBVSMCs with PD98059 significantly inhibited expressions of DDR2/ MMP-9 in HBVSMCs induced by 10 μmol/L of ONOO- (P<0.05). Conclusion   PD98059 inhibits ONOO--induced DDR2 expression. The ERK1/2 signal transduction pathway might involve in ONOO-induced DDR2 expression in HBVSMCs.

Key words: Peroxynitrous acid; Muscle, smooth, vascular;  Discoidin domain receptor 2; PD98059; Gelatinase B