MACROPHAGE ACTIVATION AND LIPOPROTEIN METABOLISM

巨噬细胞激活和脂蛋白代谢

• 批准号: 2223233
• 负责人: MARIA F LOPES-VIRELLA
• 金额: $ 20.93万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-01 至 1997-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2223233
• 关键词: HMG coA reductases; RNase protection assay; antibody; antibody receptor; blood lipoprotein metabolism; cell membrane; cholesterol; chromatography; cytokine; enzyme activity; genetic transcription; human subject; immune complex; lipid metabolism; low density lipoprotein; macrophage; nuclear runoff assay; polymerase chain reaction; protein degradation; protein transport; receptor; receptor binding; receptor expression; western blottings

We have demonstrated that the uptake of LDL-containing immune complexes (LDL-IC) by human monocyte-derived macrophages induces the transformation of these cells into foam cells and promotes their activation leading to a paradoxical increase in LDL receptor cell surface expression and to the release of cytokines. In this proposal we plan to analyze the molecular mechanisms responsible for the increase in LDL receptor cell surface expression. We will determine whether the increase in LDL receptor expression, observed in human macrophages stimulated by LDL-containing immune complexes (LDL-IC), is due to increased transcription of the LDL receptor gene, increased mRNA stability, increased mRNA translation, decreased LDL receptor protein degradation or increased translocation of the LDL receptor protein to the cell membrane. We will also investigate whether this increase in LDL receptor expression is secondary to a decrease in the intracellular cholesterol regulatory pool and if so, whether the depletion in this regulatory pool is secondary to enhanced sterol mobilization to the ACAT substrate pool. Furthermore, we will determine whether factors released during macrophage activation mediate or facilitate the increase in LDL receptor cell surface expression. We will also investigate whether the stimulation of LDL receptor cell surface expression is a consequence of the uptake of the LDL-containing immune complexes by a specific Fc receptor subtype (Fc-gamma-RI, Fc-gamma-RII or Fc-gamma-RIII). Since HMGCoA reductase activity and LDL receptor activity usually have a coordinate regulation, we will determine whether HMGCoA reductase activity is also increased in LDL-IC-stimulated macrophages. This project will involve cell culture, cell isolation and cell fractionation procedures, studies of intracellular lipid metabolism, receptor binding studies, immunoblotting and molecular biology techniques. Our overall objective is to provide insight into the mechanisms by which anti-LDL antibodies and macrophage activation may contribute to the development(acceleration of the arteriosclerotic process.

我们已经证明了含有LDL的免疫复合物的摄取 （LDL-IC）通过人类单核细胞衍生的巨噬细胞引起转化 这些细胞进入泡沫细胞并促进其激活导致 LDL受体细胞表面表达的矛盾增加和 细胞因子的释放。 在此提案中，我们计划分析负责的分子机制 为了增加LDL受体细胞表面表达。我们将 确定是否在 含LDL免疫复合物（LDL-IC）刺激的人类巨噬细胞， 由于LDL受体基因的转录增加，mRNA增加 稳定性，增加mRNA翻译，降低LDL受体蛋白 LDL受体蛋白降解或增加易位 细胞膜。我们还将调查LDL的增加是否 受体表达是细胞内降低的继发 胆固醇调节池等，是否耗尽 调节池是固醇动员为ACAT增强的继发于ACAT 基板池。此外，我们将确定是否发布因素 在巨噬细胞激活期间，介导或促进LDL的增加 受体细胞表面表达。我们还将调查是否 LDL受体细胞表面表达的刺激是 特定FC的含LDL免疫复合物的摄取 受体亚型（FC-GAMMA-RI，FC-GAMMA-RII或FC-GAMMA-RIII）。自从 HMGCOA还原酶活性和LDL受体活性通常具有 协调调节，我们将确定HMGCOA还原酶是否活性 LDL-IC刺激的巨噬细胞也增加了。 该项目将涉及细胞培养，细胞分离和细胞 分级程序，细胞内脂质代谢的研究， 受体结合研究，免疫印迹和分子生物学技术。 我们的总体目标是洞悉该机制 抗LDL抗体和巨噬细胞激活可能有助于 开发（动脉硬化过程的加速。