IL-1β induced down-regulation of cysteine dioxygenase gene

Abstract

Cysteine dioxygenase (CDO) catalyzes the first step reaction of L-cysteine metabolic pathway. This enzyme regulates taurine synthesis in mammals. A dose-dependent decrease in CDO mRNA level was observed by treatment of HepG2 cells with IL-1β. The CDO mRNA level decreased after 2h and reached a minimum at 6h -16h after the IL-1β treatment. H7 completely blocked the IL-1β-induced down-regulation of CDO gene. HA-1004 also blocked the down“regulation only minimally. These results suggest that the protein kinase C (PKC) mediated signaling pathway may act mainly in the IL-1β-induced down-regulation of CDO gene. In contrast. treatment of HepG2 cells with each of cycloheximide or anisomycin increased the CDO mRNA level. The IL-1β-induced down-regulation of CDO gene was also observed in the cells treated with each of cycloheximide or anisomycin. These results suggest that the two independent regulatory mechanisms may exist in the regulation of CDO gene.