Brown M L, Ramprasad M P, Umeda P K, Tanaka A, Kobayashi Y, Watanabe T, Shimoyamada H, Kuo W L, Li R, Song R, Bradley W A, Gianturco S H
Department of Medicine, Division of Gerontology and Geriatrics, University of Alabama, Birmingham, AL 35294-0012, USA.
Proc Natl Acad Sci U S A. 2000 Jun 20;97(13):7488-93. doi: 10.1073/pnas.120184097.
We have cloned a human macrophage receptor that binds to apolipoprotein (apo)B48 of dietary triglyceride (TG)-rich lipoproteins. TG-rich lipoprotein uptake by the apoB48R rapidly converts macrophages and apoB48R-transfected Chinese hamster ovary cells in vitro into lipid-filled foam cells, as seen in atherosclerotic lesions. The apoB48R cDNA (3,744 bp) encodes a protein with no known homologs. Its approximately 3.8-kb mRNA is expressed primarily by reticuloendothelial cells: monocytes, macrophages, and endothelial cells. Immunohistochemistry shows the apoB48R is in human atherosclerotic lesion foam cells. Normally, the apoB48R may provide essential lipids to reticuloendothelial cells. If overwhelmed, foam cell formation, endothelial dysfunction, and atherothrombogenesis may ensue, a mechanism for cardiovascular disease risk of elevated TG.
我们克隆了一种人类巨噬细胞受体，它能与富含膳食甘油三酯（TG）的脂蛋白中的载脂蛋白（apo）B48结合。如在动脉粥样硬化病变中所见，富含TG的脂蛋白通过apoB48R被摄取后，可迅速将巨噬细胞和转染了apoB48R的中国仓鼠卵巢细胞在体外转化为充满脂质的泡沫细胞。apoB48R cDNA（3744 bp）编码一种无已知同源物的蛋白质。其约3.8 kb的mRNA主要由网状内皮细胞表达：单核细胞、巨噬细胞和内皮细胞。免疫组织化学显示apoB48R存在于人类动脉粥样硬化病变的泡沫细胞中。正常情况下，apoB48R可能为网状内皮细胞提供必需的脂质。如果负担过重，可能会导致泡沫细胞形成、内皮功能障碍和动脉粥样血栓形成，这是TG升高导致心血管疾病风险的一种机制。
