Babaev V R, Kosykh V A, Tsibulsky V P, Ivanov V O, Repin V S, Smirnov V N
Institute of Experimental Cardiology, U.S.S.R. Cardiology Research Center, Academy of Medical Sciences, Moscow.
Hepatology. 1989 Jul;10(1):56-60. doi: 10.1002/hep.1840100112.
The binding and uptake of native low-density lipoproteins and malondialdehyde-treated low density lipoproteins by human hepatocytes in primary culture has been analyzed. Experiments with 125I-labeled malondialdehyde-treated low-density lipoproteins showed that cultured liver cells took up and degraded malondialdehyde-treated low-density lipoproteins, but the cell type(s) responsible for this action remain unclear. Immunofluorescent visualization of receptor-bound low-density lipoproteins revealed that low-density lipoprotein binding sites were distributed on the surface of nearly all cells of the culture. Binding sites for malondialdehyde-treated low-density lipoproteins were found in only 5% of the cultured cells, and these cells differed from hepatocytes in shape and size. Cultured hepatocytes internalized and native low-density lipoproteins, but not malondialdehyde-treated low-density lipoproteins, labeled with the fluorescent dye 3',3'-dioctadecylindocarbocyanine. About 15% of the cells that take up 3',3'-dioctadecylindocarbocyanine-labeled malondialdehyde-treated low-density lipoproteins could be identified as liver endothelial cells and macrophages, since they internalized formaldehyde-treated human albumin and fluorescent carboxylated microspheres. Our results indicate that human hepatocytes in primary culture express surface receptors for native low-density lipoproteins but not for modified low-density lipoproteins.
已对原代培养的人肝细胞对天然低密度脂蛋白和丙二醛处理的低密度脂蛋白的结合与摄取进行了分析。用125I标记的丙二醛处理的低密度脂蛋白进行的实验表明，培养的肝细胞摄取并降解了丙二醛处理的低密度脂蛋白，但负责此作用的细胞类型仍不清楚。受体结合的低密度脂蛋白的免疫荧光可视化显示，低密度脂蛋白结合位点分布在培养物中几乎所有细胞的表面。仅在5%的培养细胞中发现了丙二醛处理的低密度脂蛋白的结合位点，并且这些细胞在形状和大小上与肝细胞不同。培养的肝细胞内化了用荧光染料3',3'-二辛基吲哚碳菁标记的天然低密度脂蛋白，但没有内化丙二醛处理的低密度脂蛋白。摄取3',3'-二辛基吲哚碳菁标记的丙二醛处理的低密度脂蛋白的细胞中约15%可被鉴定为肝内皮细胞和巨噬细胞，因为它们内化了甲醛处理的人白蛋白和荧光羧化微球。我们的结果表明，原代培养的人肝细胞表达天然低密度脂蛋白的表面受体，但不表达修饰的低密度脂蛋白的表面受体。
