In vitro alterations of epidermal cell adhesion induced by temperature, substrate, and cations.

Epidermal cell-to-cell or basal cell-to-substrate adhesion in vitro, involves as yet, unknown mechanisms. The rate of attachment of newly dissociated neonatal mouse epidermal cells and the rate of keratinocyte detachment from preformed epidermal monolayers was investigated under a variety of experimental conditions. In the present investigation, we obtained the following results: (1) variables such as temperature, nature of substrate, and presence of cations in the growth medium were important in the initial cel-to-substrate attachment; (2) removal of Ca++ and Mg++ from the growth medium was associated with a very low attachment rate (less than 5% at 24 hr and 48 hr); (3) the initial cell-to-substrate attachment of epidermal cells decreased about 50% when maintained in medium deficient in either Mg++ or Ca++ indicating that both cations are important in the cell-to-substrate attachment; (4) keratinocyte-detachment from preformed monolayers increased in medium deficient in Ca++, Mg++ as well as in medium only deficient in Ca++. However, detachment in cultures maintained in Mg++ deficient medium was similar to controls. In conclusion, Ca++ is one factor that may regulate epidermal cell-to-cell and cell-to-substrate interactions in vitro. Mg++ appears to influence also in the initial attachment process of epidermal basal cells.