Rainwater D L, Lanford R E
Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, TX 78284.
Biochim Biophys Acta. 1989 May 15;1003(1):30-5. doi: 10.1016/0005-2760(89)90094-5.
Primary baboon hepatocytes were cultured in a serum-free medium formulation that permitted the analysis of lipoprotein(a) (Lp(a] production by the cells. The hepatocytes were determined to synthesize Lp(a) on the basis of the following observations: (1) the culture medium reacted in an ELISA designed for detection of baboon Lp(a) in serum samples; (2) the Lp(a)-specific protein, apo(a), was detected in the culture medium by immunoblotting techniques; (3) the unique protein structure of Lp(a) was demonstrated (i.e., association of apo(a) with apoB via interchain disulfide bonds to form apoLp(a]; and (4) the Lp(a) proteins occurred in the medium at a density of about 1.05 g/ml when subjected to density gradient ultracentrifugation. De novo synthesis of Lp(a) by cultured hepatocytes was demonstrated by incorporation of [35S]cysteine. Lp(a) was produced by the hepatocytes throughout a 20 day culture period. Finally, apo(a) isoform patterns in the hepatocyte culture medium and the hepatocyte donors' serum were indistinguishable.
原代狒狒肝细胞在一种无血清培养基配方中培养，该配方允许分析细胞产生的脂蛋白(a) [Lp(a)]。基于以下观察结果确定肝细胞能够合成Lp(a)：(1) 培养基在用于检测血清样本中狒狒Lp(a)的ELISA中发生反应；(2) 通过免疫印迹技术在培养基中检测到Lp(a)特异性蛋白载脂蛋白(a) [apo(a)]；(3) 证明了Lp(a)独特的蛋白质结构（即apo(a)通过链间二硫键与载脂蛋白B [apoB] 结合形成载脂蛋白Lp(a) [apoLp(a)]）；(4) 当进行密度梯度超速离心时，培养基中Lp(a)蛋白的密度约为1.05 g/ml。通过掺入[35S]半胱氨酸证明培养的肝细胞从头合成Lp(a)。在整个20天的培养期内，肝细胞都能产生Lp(a)。最后，肝细胞培养基和肝细胞供体血清中的apo(a)同工型模式无法区分。
