REG OF THE NADPH OXIDASE BY ANTI-INFLAMMATORY AGENTS

该项目的长期目标将是研究吞噬白细胞产生超氧化物的NADPH氧化酶的调控。由该酶系统产生的氧在宿主防御感染以及炎症和再灌注损伤时的组织损伤中发挥重要作用。我们的工作将集中在NADPH氧化酶的细胞色素b成分，特别是编码gp91-phox的基因，吞噬细胞细胞色素b异源二聚体的91千道顿糖蛋白。该基因及密切相关基因的表达受发育调控，且几乎是骨髓单核细胞的谱系特异性基因。糖皮质激素和非甾体抗炎药（NSAID）调节多种基因的表达和细胞功能。拟议的研究将验证糖皮质激素和非甾体抗炎药通过下调编码NADPH氧化酶系统成分的基因表达来抑制吞噬细胞NADPH氧化酶活性的中心假设。我们将：1；开发一个系统，通过影响吞噬细胞功能的细胞因子分化人类单核细胞系THP-1：我们将检测NADPH氧化酶活性、细胞色素b含量和编码gp91-phox和其他NADPH氧化酶成分的基因表达。2. 研究糖皮质激素和非甾体抗炎药对细胞因子分化THP-1细胞NADPH氧化酶系统的影响：我们将研究糖皮质激素和非甾体抗炎药对NADPH氧化酶活性、细胞色素b含量以及编码gp91-phox和其他NADPH氧化酶成分的基因表达的影响。3. 研究细胞因子、糖皮质激素或非甾体抗炎药对人外周血单核/巨噬细胞NADPH氧化酶系统的调节作用：我们将研究在细胞因子刺激下，糖皮质激素或非甾体抗炎药对人外周血单核/巨噬细胞NADPH氧化酶活性、细胞色素b含量以及编码gp91-phox和其他NADPH氧化酶成分的基因表达的影响。所提出的研究将推进我们对髓细胞谱系中转录控制机制的基本认识，并确定抗炎药物发挥其抗炎作用的新机制，在这种情况下，通过下调编码吞噬细胞NADPH氧化酶系统成分的基因表达。更好地了解NADPH氧化酶系统的药理调控将提供信息，帮助调节其在炎症和氧化介导的组织损伤中的表达。

The long-term goal of this project will be to investigate the regulation of the superoxide-generating NADPH oxidase of phagocytic leukocytes. Oxygen species generated by this enzyme system play a major role in host defense against infection and as well as in tissue damage during inflammation and reperfusion injury. Our work will focus on the cytochrome b component of the NADPH oxidase, in particular the gene encoding gp91-phox, the 91 kilodalton glycoprotein of the phagocyte cytochrome b heterodimer. Expression of this and closely related genes is developmentally regulated and virtually lineage-specific to myelomonocytic cells. Glucocorticoids and non-steroidal anti-inflammatory drugs (NSAID) modulate the expression of various genes and cell functions. The proposed studies will test the central hypothesis that glucocorticoids and NSAID inhibit phagocytic NADH oxydase activity by down-regulating expression of genes encoding components of the NADPH oxidase system. We will: 1. Develop a system for the differentiation of the human monocytic cell line THP-1 by cytokines that influence phagocyte function: We will examine the NADPH oxidase activity, cytochrome b content, and expression of the genes encoding gp91-phox and the other NADPH oxidase components. 2. Study the effects of glucocorticoids and NSAID on the NADPH oxidase system of cytokine-differentiated THP-1 cells: We will examine the effect of glucocorticoids and NSAID on the NADPH oxidase activity, cytochrome b content, and expression of the genes encoding gp91-phox and the other NADPH oxidase components. 3. Investigate the effects of cytokines, glucocorticoids or NSAID on the regulation of the NADPH oxidase system in human peripheral blood monocytes/macrophages: We will investigate the effects of glucocorticoids or NSAID on the NADPH oxidase activity, cytochrome b content, and expression of the genes encoding gp91-phox and the other NADPH oxidase components in human peripheral blood monocytes/macrophages under cytokine stimulation. The proposed studies should advance our fundamental knowledge of transcriptional control mechanisms in the myelomonocytic lineage and as well determine new mechanisms by which anti-inflammatory agents exert their anti-inflammatory effects, in this case by down-regulating the expression of genes encoding components of the phagocytic NADPH oxidase system. Better understanding of the pharmacological regulation of the NADPH oxidase system will provide information to help modulate its expression during inflammation and oxidant-mediated tissue damage.