Cellular confluence and cohesion regulates CXCL11/IP9 expression during keratinocyte re‐epithelialization

Abstract

A role for CXCL11/IP9/I‐TAC in coordinating cellular events to transition the regenerative phase to the remodeling phase of wound healing has been demonstrated. However, the physiologic signals regulating CXCL11 expression remain unknown. Of specific interest are the factors that stimulate and later downregulate expression of this transiently‐expressed chemokine. To investigate keratinocyte‐mediated CXCL11 expression, in vitro cell culture and skin organ culture model systems were used. CXCL11 expression was found to be upregulated soon after cellular confluence was reached. In addition, CXCL11 was not dependent upon calcium‐dependent differentiation as the increased expression was also noted in confluent cultures grown in low calcium conditions. These results suggest that achievement of cellular confluence results in the upregulation of chemokine CXCL11 likely as a paracrine to the underlying dermis that covering re‐epithelialization has occurred.