Influence of hepatocyte growth factor on iNOS, NO and IL-1β in the cerebrum during cerebral ischemia/reperfusion in rats

Abstract

To explore the effect of hepatocyte growth factor (HGF) on inducible nitric oxide synthase (iNOS), NO and interleukin-1β (IL-1β) in the cerebrum of rats subjected to cerebral ischemia/reperfusion (I/R). Sprague-Dawley rats were randomly divided into 5 groups: a sham group, an I/R group,an HGF1 group, an HGF2 group, and an HGF3 group. The latter 3 groups were respectively injected 15, 30 and 60 μg/kg HGF. The focal cerebral I/R model was established by sutureoccluded method. After 1.5 h ischemia followed by 24 h reperfusion, the iNOS activity and NO content in the ischemic cerebral tissue were assessed. The expression of iNOS mRNA and IL-1β mRNA was detected. The level of iNOS protein and IL-1β content were determined. In addition, cultured cerebral cortical neurons in vitro were exposed to I/R. Then the expression of iNOS and IL-1β protein in the neurons was detected, and NO content was assessed. The iNOS activity and NO content in the ischemic cerebral tissue were increased. The expression of iNOS mRNA and IL-1β mRNA was upregulated. The level of iNOS protein and IL- 1β content were increased. Administration of HGF decreased the iNOS activity and NO content, and downregulated the expression of iNOS mRNA, IL-1β mRNA, iNOS protein and IL-1β content in the ischemic cerebral tissue. HGF decreased the expression of IL-1β, iNOS protein and NO content in the cortical neurons exposed to I/R in vitro. HGF can inhibit the expression of IL-1β and decrease the expression of iNOS and content of NO, which is probably one of the mechanisms mediating the protection of HGF against cerebral ischemia injury.