Kidd G L, Reddan J R, Russell P
Laboratory of Mechanisms of Ocular Disease, National Eye Institute, National Institutes of Health, Bethesda, MD 20892.
Differentiation. 1994 Apr;56(1-2):67-74. doi: 10.1046/j.1432-0436.1994.56120067.x.
Lens epithelial cells in culture can sometimes be induced to form spheroid aggregates termed lentoid bodies, composed of cells exhibiting various characteristics of the more highly differentiated lens fiber cells. However, lentoid bodies are often slow to form, and the ability to produce them declines with serial subculture. It was therefore of interest to establish and/or characterize lens epithelial cell lines capable of forming lentoid bodies. The differentiation state was assessed in lentoid bodies formed by each of two lens epithelial cell lines, the transformed alpha TN4 cell line from mouse and the nontransformed N/N1135A cell line from rabbit. Lentoid and monolayer cultures of each cell line were examined for transcripts of the lens-specific alpha A-crystallin ("alpha A"), gamma D-crystallin ("gamma D"; formerly gamma 1-crystallin) and MP26 genes. alpha TN4 lentoid bodies contained 2.5 times the alpha A RNA found in monolayer cells, but lacked detectable gamma D and MP26 RNA. None of the three markers were detected in either lentoid or monolayer N/N1135A cultures grown under the conditions described. Lentoid body formation alone, therefore, does not indicate the extent of differentiation occurring. At least some of the changes in cell adhesion occurring during lentoid body formation involve laminin-like and fibronectin-like interactions, and are reminiscent of those observed during embryonic lens formation. Finally, vascular endothelial growth factor mRNA was absent from the lens but present in alpha TN4 cells, suggesting a mechanism whereby the lens tumors of the founder mouse became vascularized.
培养中的晶状体上皮细胞有时可被诱导形成称为类晶状体小体的球状聚集体，其由表现出更高度分化的晶状体纤维细胞各种特征的细胞组成。然而，类晶状体小体的形成通常较慢，并且随着连续传代培养，产生它们的能力会下降。因此，建立和/或表征能够形成类晶状体小体的晶状体上皮细胞系很有意义。对由两种晶状体上皮细胞系（来自小鼠的转化αTN4细胞系和来自兔子的未转化N/N1135A细胞系）各自形成的类晶状体小体中的分化状态进行了评估。检查了每个细胞系的类晶状体和单层培养物中晶状体特异性αA-晶状体蛋白（“αA”）、γD-晶状体蛋白（“γD”；以前称为γ1-晶状体蛋白）和MP26基因的转录本。αTN4类晶状体小体中αA RNA的含量是单层细胞中的2.5倍，但缺乏可检测到的γD和MP26 RNA。在所描述条件下生长的N/N1135A类晶状体或单层培养物中均未检测到这三种标志物中的任何一种。因此，仅类晶状体小体的形成并不表明发生的分化程度。类晶状体小体形成过程中发生的细胞黏附的至少一些变化涉及层粘连蛋白样和纤连蛋白样相互作用，并且让人想起在胚胎晶状体形成过程中观察到的那些变化。最后，晶状体中不存在血管内皮生长因子mRNA，但在αTN4细胞中存在，这表明了一种使创始小鼠的晶状体肿瘤血管化的机制。
