[摘要]：Nuclear translocation of cytosolic CLIC4 is an essential feature of its proapoptotic and prodifferentiation functions. Here we demonstrate that CLIC4 is induced concurrently with inducible nitric oxide synthase (iNOS) and S-nitrosylated in proinflammatory peritoneal macrophages. Chemical inhibition or genetic ablation of iNOS inhibits S-nitrosylation and nuclear translocation of CLIC4. In macrophages, iNOS-induced nuclear CLIC4 coincides with the proto anti-inflammatory transition of the cells because IL-1 beta and CXCL1 mRNA remain elevated in CLIC4 and iNOS knockout macrophages at late time points, whereas TNF alpha mRNA is elevated only in the iNOS knockout macrophages. Active IL-1 beta remains elevated in CLIC4 knockout macrophages and in macrophages in which CLIC4 nuclear translocation is prevented by the NOS inhibitor L-NAME. Moreover, overexpression of nuclear-targeted CLIC4 down-regulates IL-1 beta in stimulated macrophages. In mice, genetically null for CLIC4, the number of phagocytosing macrophages stimulated by LPS is reduced. Thus, iNOS-induced nuclear CLIC4 is an essential part of the macrophage deactivation program.
