Wride M A
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Alberta, Canada.
Apoptosis. 2000 Jun;5(3):203-9. doi: 10.1023/a:1009653326511.
The lens represents an ideal model system for studying many of the cellular and molecular events of differentiation. It is composed of two ectodermally-derived cell types: the lens epithelial cells and the lens fibre cells, which are derived from the lens epithelial cells by differentiation. Programmed removal of nuclei and other organelles from the lens fibre cells ensures that an optically clear structure is created, while the morphology of the degenerating nuclei is similar to that observed during apoptosis and is accompanied by DNA fragmentation. These observations suggest the existence of biochemical parallels between the process of lens fibre cell organelle loss and classical apoptosis. For example, proteins encoded by the bcl-2 and caspase gene families are expressed in developing lenses and nuclear degeneration in lens fibre cells can be inhibited in vivo by overexpression of bcl-2 and in vitro by incubation of differentiating lens epithelial cell cultures with caspase inhibitors. Thus, the developing lens may represent a particularly useful model system for researchers interested in apoptosis. In this review, the recent literature pertaining to lens fibre cell organelle loss and its relationship to apoptosis is reviewed and possible future research directions are suggested.
晶状体是研究许多细胞和分子分化事件的理想模型系统。它由两种外胚层来源的细胞类型组成：晶状体上皮细胞和晶状体纤维细胞，晶状体纤维细胞是由晶状体上皮细胞分化而来的。晶状体纤维细胞中细胞核和其他细胞器的程序性去除确保了形成一个光学透明的结构，而退化细胞核的形态与凋亡过程中观察到的相似，并伴有DNA片段化。这些观察结果表明，晶状体纤维细胞器丢失过程与经典凋亡之间存在生化相似性。例如，bcl-2和半胱天冬酶基因家族编码的蛋白质在发育中的晶状体中表达，并且在体内通过bcl-2的过表达以及在体外通过用半胱天冬酶抑制剂培养分化的晶状体上皮细胞培养物，可以抑制晶状体纤维细胞中的核退化。因此，对于对凋亡感兴趣的研究人员来说，发育中的晶状体可能是一个特别有用的模型系统。在这篇综述中，回顾了与晶状体纤维细胞器丢失及其与凋亡的关系相关的近期文献，并提出了未来可能的研究方向。
