Growth Of Lens Epithelial Cells Research Articles

Differentiation of Rat Lens Epithelial Cells in Tissue Culture: (I) Effects of Cell Density, Medium and Embryonic Age of Initial Culture

The growth and differentiation of rat lens epithelial cells in tissue culture were studied. Cells could be maintained for a number of generations in an undifferentiated state in suspension culture. When cultured as monolayers, they grew and differentiated in a series of six defined stages described here. These stages include morphological changes (elongation, followed by cell "spreading" or formation of cell aggregates), and biochemical changes (appearance of nu-crystallin protein as detected by immunofluorescence). The process of differentiation appeared to be accelerated in the vicinity of elongated cells, occurred more rapidly at high cell density, and required frequent changes of medium. This suggests that cell-cell communication, and not medium factors, may be essential for promoting differentiation. The final morphology of the differentiated cells differed, depending on the embryonic age of the rats used as a source of lens epithelial cells. This implies that the programme for differentiation changes as a function of the embryonic age of the lens.

Growth and cytodifferentiation of embryonic chick lens epithelial cells in vitro

Cytodifferentiation, mitotic activity, tritiated thymidine binding and cell migration were studied in 297 6-day embryonic chick lens epithelia explanted into defined medium alone (UM) or into defined medium supplemented with serum (SM). Lens epithelial cells explanted into UM alone did not undergo significant cytodifferentiation nor cellular proliferation. Cells explanted directly into SM rapidly differentiated into short prospective lens fibers and failed to show significant proliferative activity. If the lens epithelial cells were precultured for 12 to 24 h in UM before transfer to SM, the cells rapidly lost their capacity to differentiate under these experimental conditions. As the ability to form short fibers was lost, the explanted cells showed greatly enhanced mitotic and migratory activity when stimulated by the addition of serum containing medium. The possibility is discussed that the rapidly lost capacity of lens epithelial cells to form fibers is due to the loss or inactivation of a cell component or components involved in the synthesis of tissue-specific proteins, and, being unable to differentiate under these experimental conditions, the cells are stimulated to proliferate and to migrate by the addition of serum.