Regulatory feedback loop between NF-κB and MCP-1-induced protein 1 RNase

A novel gene ZC3H12A, encoding MCP-1-induced protein 1 (MCPIP), was recently identified in human peripheral blood monocytes treated with monocyte chemotactic protein 1 (MCP-1) and in human monocyte-derived macrophages stimulated with interleukin (IL)-1 beta. These experiments revealed that the gene undergoes rapid and potent transcription induction upon stimulation with proinflammatory molecules, such as MCP-1, IL-1 beta, tumour necrosis factor a and lipopolysaccharide. Here we show that the induction of ZC3H12A by IL-1 beta is predominantly NF-kappa B-dependent because inhibition of this signalling pathway results in the impairment of ZC3H12A transcription activation. Our results indicate the presence of an IL-1 beta-responding region within the second intron of the ZC3H12A gene, which contains four functional NF-kappa B-binding sites. Therefore, we propose that this transcription enhancer transduces a ZC3H12A transcription-inducing signal after IL-1 beta stimulation. Recent reports suggest that MCPIP acts as a negative regulator of in. ammatory processes because it is engaged in the degradation of transcripts coding for certain proinflammatory cytokines. Our observations provide evidence for a novel negative feedback loop in the activation of NF-kappa B and point to potential significance of MCPIP in the treatment of various pathological states, such as diabetes or cancer that involve disturbances in the functioning of the NF-kappa B system.