Effect of cyclic AMP, caffeine and theophylline on differentiation of lens epithelial cells

Abstract

PAPACONSTANTINOU has clearly shown that differentiation of lens epithelial cells into fibre cells involves a complex series of morphological and biochemical events¹; however, at the molecular level the factors involved in the initiation of this differentiation are almost entirely unknown. The purification and characterisation of the mRNA species specifying bovine lens proteins² have made desirable the development of a system in which details of lens differentiation could be studied. Such a system for the study of lens epithelial cell differentiation in tissue culture should have the following characteristics: (1) The differentiation should demonstrate characteristic morphological changes which can be correlated with those expected of the process in vivo; (2) specific proteins characteristic of the differentiated tissue should be absent in epithelial cells inoculated into the culture and should appear during the course of the morphological changes; (3) it should be possible to maintain the epithelial cells in culture in an undifferentiated state by the criteria of unaltered morphology and the absence of specific proteins), and to induce them to differentiate in response to a specific set of conditions; (4) clones of epithelial cells should show characteristics similar to freshly explanted epithelial cells. In addition to these criteria, a useful characteristic of the system would be an accelerated or inhibited differentiation in response to hormones of cyclic nucleotides.