Hoeg J M, Sviridov D D, Tennyson G E, Demosky S J, Meng M S, Bojanovski D, Safonova I G, Repin V S, Kuberger M B, Smirnov V N
Molecular Disease Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.
J Lipid Res. 1990 Oct;31(10):1761-9.
Apolipoprotein B (apoB), an apolipoprotein associated with very low density lipoproteins and the atherogenic low density lipoproteins (LDL), directs the metabolism of lipoprotein particles in plasma by interacting with the LDL receptor. Utilizing human intestinal biopsy organ cultures, we have studied the synthesis of intestinal apoB in man. Intestinal organ cultures from normal adults (n = 6) were incubated in the presence of protease inhibitors in media supplemented with [35S]methionine. Media from these cultures were evaluated by sequential NaDodSO4 polyacrylamide gel electrophoresis, radioautography, and Western blot analyses, and intestinal biopsies were studied using immunohistochemistry. The relative abundance of apoB-100 and apoB-48 mRNA was assessed using reverse transcriptase-polymerase chain reaction followed by primer extension. Although apoB-48 was the principal isoprotein that was newly synthesized by intestinal organ cultures, apoB-100 was also synthesized and secreted by human intestinal organ cultures with 16 +/- 3% of the intestinal apoB mRNA coding for apoB-100. These results establish that apoB-100 is produced by the human intestine. The synthesis of the atherogenic apoB-100 by the intestine has pathophysiologic implications for the development of diet-induced atherosclerosis.
载脂蛋白B（apoB）是一种与极低密度脂蛋白和致动脉粥样硬化的低密度脂蛋白（LDL）相关的载脂蛋白，它通过与LDL受体相互作用来指导血浆中脂蛋白颗粒的代谢。利用人体肠道活检器官培养物，我们研究了人体肠道apoB的合成。来自正常成年人（n = 6）的肠道器官培养物在补充有[35S]甲硫氨酸的培养基中，于蛋白酶抑制剂存在的情况下进行孵育。通过连续的十二烷基硫酸钠聚丙烯酰胺凝胶电泳、放射自显影和蛋白质印迹分析对这些培养物的培养基进行评估，并使用免疫组织化学研究肠道活检组织。使用逆转录聚合酶链反应随后进行引物延伸来评估apoB - 100和apoB - 48 mRNA的相对丰度。尽管apoB - 48是肠道器官培养物新合成的主要同工蛋白，但apoB - 100也由人体肠道器官培养物合成并分泌，编码apoB - 100的肠道apoB mRNA占16±3%。这些结果证实人体肠道能产生apoB - 100。肠道合成致动脉粥样硬化的apoB - 100对饮食诱导的动脉粥样硬化的发展具有病理生理学意义。
