Secretion of serum amyloid protein and assembly of serum amyloid protein-rich high density lipoprotein in primary mouse hepatocyte culture.
Secretion of serum amyloid protein and assembly of serum amyloid protein-rich high density lipoprotein in primary mouse hepatocyte culture.
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DOI：
10.1016/s0021-9258(18)34048-1
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发表时间：
1982-09
期刊：
影响因子：
--
通讯作者：
J. S. Hoffman;E. Benditt
中科院分区：
文献类型：
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作者：
J. S. Hoffman;E. Benditt
血清淀粉样蛋白 (apo-SAA) 是一种独特的高密度脂蛋白脱辅基蛋白，在宿主损伤后血浆浓度急剧增加。在给予有效的 apo-SAA 诱导剂、细菌内毒素（腹腔内给予 50 微克伤寒沙门氏菌脂多糖）后 3 小时收获的成年 BALB/c 小鼠肝细胞的原代无血清培养物中，研究了涉及 apo-SAA 的分泌和富含 apo-SAA 的脂蛋白颗粒组装的事件。与从对照小鼠分离的肝细胞相比，观察到apo-SAA分泌的初始速率增加了大约3.5倍，而apo-A-I分泌速率在施用内毒素后没有变化。十二烷基硫酸钠凝胶电泳和[35S]甲硫氨酸标记的细胞产物的放射自显影表明肝细胞合成了两种主要的小鼠apo-SAA同种型。基本上所有分泌的apo-SAA均在Sephadex G-150中进行色谱分析，洗脱体积对应于大约12,000的分子量。超速离心分级分离后，约 90% 的分泌 apo-SAA 在级分（d 大于 1.21 g/ml）中回收。在补充有人脂蛋白（100微克/ml）的培养基中，大约50%的分泌的apo-SAA在高密度脂蛋白部分中被回收。这些结果表明，小鼠 apo-SAA 以单体形式分泌，并与血管内的脂蛋白结合。
The serum amyloid protein (apo-SAA) is a unique high density lipoprotein apoprotein exhibiting dramatic increases in plasma concentration following host injury. The events involved in the secretion of apo-SAA and assembly of apo-SAA-rich lipoprotein particles were studied in primary, serum-free culture of adult BALB/c mouse hepatocytes harvested 3 h following administration of the potent apo-SAA inducer, bacterial endotoxin (50 micrograms of intraperitoneally administered Salmonella typhosa lipopolysaccharide). An approximately 3.5-fold increase in the initial rate of apo-SAA secretion was observed over that of hepatocytes isolated from control mice, whereas the rate of apo-A-I secretion was unchanged by endotoxin administration. Sodium dodecyl sulfate-gel electrophoresis and autoradiography of [35S]methionine-labeled cell products indicated the synthesis of both major mouse apo-SAA isotypes by hepatocytes. Essentially all of the secreted apo-SAA chromatographed in Sephadex G-150 with an elution volume corresponding to a molecular weight of approximately 12,000. Approximately 90% of the secreted apo-SAA was recovered in fractions (d greater than 1.21 g/ml) following ultracentrifugal fractionation. In media supplemented with human lipoproteins (100 micrograms/ml), approximately 50% of the secreted apo-SAA was recovered in the high density lipoprotein fraction. These results suggest that mouse apo-SAA is secreted in monomeric form and becomes associated with lipoproteins in the intravascular compartment.