Cadherin-Mediated Cell–Cell Contact Regulates Keratinocyte Differentiation

Cell–extracellular matrix (ECM) and cell–cell interactions regulate keratinocyte cell fate and differentiation. In the present analysis, we examined the differentiation of primary human keratinocytes cultured on micropatterned substrates that varied the extent of cell–cell contact while maintaining constant cell–ECM areas. Bowtie-shaped micropatterned areas (75–1600 μm2) were engineered to either permit or prevent cell–cell contact for pairs of adherent keratinocytes. Cell pairs with direct cell–cell contact exhibited enhanced expression of the differentiation markers involucrin and keratin 10 compared to cells with no cell–cell contact. In contrast, available cell-spreading area, as regulated by pattern size, did not alter keratinocyte involucrin expression. Disruption of E-cadherin binding by either antibody blocking or expression of a dominant-negative receptor diminished the ability of micropattern-regulated cell–cell contact to modulate involucrin expression. These results demonstrate that cadherin-mediated cell–cell contact regulates early keratinocyte differentiation independently from changes in cell shape.