ROLE OF MACROPHAGE RECEPTORS FOR OXLDL IN ATHEROGENESIS

OXLDL 巨噬细胞受体在动脉粥样硬化形成中的作用

• 批准号: 6273232
• 负责人: DANIEL STEINBERG
• 金额: $ 18.08万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6273232
• 关键词: CD antigens; Xenopus oocyte; atherosclerotic plaque; binding proteins; blood lipoprotein; chimeric proteins; gene targeting; human subject; in situ hybridization; laboratory mouse; low density lipoprotein receptor; macrophage; molecular cloning; molecular pathology; phlebotomy; receptor binding; thrombospondins; transfection; vitronectin

The long term goal of the proposed studies is to improve our understanding of lipoprotein-macrophage interactions that may contribute to foam cell formation and atherogenesis. Emphasis will be placed on the acetyl LDL receptor (SRA), hCD36 and its mouse homologue (mDC36), and a 94-97 kDa oxidized LDL (OxLDL)- binding protein from mouse peritoneal macrophages which we have previously characterized and have now identified as macrosialin. Macrosialin and its human homologue, DC68, both previously clones, are found predominantly in the late endosomal fraction and their functions are not known. We propose to study their transport between subcellular compartment, to prepare stably transfected cells to characterize their ligand-binding properties, identify ligand binding sites by preparation of chimeric proteins and by site- directed mutagenesis, and prepare a mcarosialin knockout mouse to ascertain phenotypic consequences with regard to macrophage function, immune function and atherogenesis. CD36, an established OxLDL-binding receptor, functions in the binding and phagocytosis of apoptotic cells in cooperation with the vitronectin receptor and thrombospondin. We will test the hypothesis that binding of OxLDL may be modulated by interactions of this kind. Using cells from the SRA knockout mouse (gift of Dr. T. Kodama), we will assess the role of the receptor in OxLDL metabolism in vitro and in vivo. Finally, we will continue to use expression cloning in Xenopus oocytes to search for additional macrophage proteins that may participate in uptake of OxLDL or/and of damaged or apoptotic cells. Five clones have already been isolated. None of them represents either SRA, mCD36, or macrosialin. These will be sequenced and characterized.

拟议研究的长期目标是改善我们的 了解脂蛋白-巨噬细胞相互作用，可能 有助于泡沫细胞形成和动脉粥样硬化形成。 强调将 放置在乙酰LDL受体（SRA）、hCD36及其小鼠上 同源物 (mDC36) 和 94-97 kDa 氧化 LDL (OxLDL)- 我们拥有的来自小鼠腹腔巨噬细胞的结合蛋白 之前已进行表征，现已鉴定为大唾液酸蛋白。 Macrosialin 及其人类同源物 DC68，均先前 克隆，主要存在于晚期内体部分和 它们的功能尚不清楚。 我们建议研究他们的交通 亚细胞区室之间，制备稳定转染的细胞 表征其配体结合特性，识别配体 通过制备嵌合蛋白和通过位点结合位点 定向诱变，并制备 mcarosialin 敲除小鼠 确定巨噬细胞的表型后果 功能、免疫功能和动脉粥样硬化。 CD36，已建立的 OxLDL 结合受体，具有结合和吞噬作用 凋亡细胞与玻连蛋白受体的配合 血小板反应蛋白。 我们将检验以下假设： OxLDL 可以通过这种相互作用进行调节。 使用细胞 从 SRA 基因敲除小鼠（T. Kodama 博士的礼物）中，我们将 评估受体在体外和体内 OxLDL 代谢中的作用 体内。 最后，我们将继续使用表达克隆 非洲爪蟾卵母细胞寻找额外的巨噬细胞蛋白 可能参与 OxLDL 或/和受损或 凋亡细胞。五个克隆体已经被分离出来。 没有一个 它们代表 SRA、mCD36 或大唾液酸蛋白。 这些将 进行测序和表征。