Bulera S J, Sattler C A, Pitot H C
McArdle Laboratory for Cancer Research, University of Wisconsin, Madison, USA.
Hepatology. 1996 Jun;23(6):1591-601. doi: 10.1002/hep.510230641.
A transgenic rat line carrying the alb-SV40A transgene has been described by this laboratory. Several cell lines have been established from the livers of two of these rats. One of these cell lines, L37, exhibits a large nuclear/cytoplasmic ratio and a well-differentiated cytoplasm containing numerous organelles. When L37 cells are placed into culture medium lacking necessary growth factors, cellular proliferation continues for 48 hours after medium change. Subsequent to the initial 48 hours, cells begin to shrink and lose contact with adjacent cells, eventually sloughing off the culture plate surface, with most cell deaths occurring between 48 and 96 hours after medium change. Microscopic examination of sloughing cells indicates they possess highly convoluted and blebbed plasma membranes, a morphological characteristic of apoptosis. Ultrastructural studies demonstrate the ubiquitous presence of apoptotic bodies. When DNA isolated from growth factor-depleted cells is resolved on agarose gels, DNA fragmentation ladders are observed at times of maximum apoptotic change. Quantitative analysis of L37 cells between 48 and 96 hours after the removal of the culture medium shows that 59% +/- 2% of the cells undergo apoptosis. When cycloheximide, puromycin, or actinomycin D is added to the L37 cultures, only cycloheximide is able to repress apoptosis, indicating that the mechanism of apoptosis in the L37 liver-derived cell line requires a cycloheximide-sensitive translational event. The extremely high rate of apoptosis, together with the maintenance of hepatocellular characteristics, indicates the usefulness of this cell line as a model in which to study the mechanisms of hepatocellular apoptosis.
本实验室已描述了一种携带alb - SV40A转基因的转基因大鼠品系。已从其中两只大鼠的肝脏建立了几种细胞系。其中一种细胞系L37，其核质比大，细胞质分化良好，含有众多细胞器。当将L37细胞置于缺乏必要生长因子的培养基中时，换液后细胞增殖可持续48小时。在最初的48小时之后，细胞开始收缩并与相邻细胞失去接触，最终从培养板表面脱落，大多数细胞死亡发生在换液后48至96小时之间。对脱落细胞的显微镜检查表明它们具有高度卷曲和起泡的质膜，这是细胞凋亡的形态学特征。超微结构研究证明凋亡小体普遍存在。当从缺乏生长因子的细胞中分离的DNA在琼脂糖凝胶上分离时，在最大凋亡变化时观察到DNA片段化梯带。对去除培养基后48至96小时之间的L37细胞进行定量分析表明，59%±2%的细胞发生凋亡。当向L37培养物中添加环己酰亚胺、嘌呤霉素或放线菌素D时，只有环己酰亚胺能够抑制细胞凋亡，这表明L37肝源性细胞系中的细胞凋亡机制需要一个对环己酰亚胺敏感的翻译事件。极高的细胞凋亡率，连同肝细胞特征的维持，表明该细胞系作为研究肝细胞凋亡机制的模型是有用的。
