CXCL11 Expression by Keratinocytes Occurs Transiently Between Reaching Confluence and Cellular Compaction

Area of Science:

• Dermatology
• Wound Healing Research
• Cell Biology

Background:

• CXCL11 (C-X-C motif chemokine ligand 11) plays a role in wound healing.
• The precise triggers for CXCL11 expression during re-epithelialization remain unclear.

Purpose of the Study:

• To determine if keratinocyte differentiation or cellular confluence drives CXCL11 expression patterns in re-epithelialization.
• To elucidate the role of cellular density in regulating chemokine expression during wound repair.

Main Methods:

• Utilized in vitro HaCaT keratinocyte models of re-epithelialization.
• Monitored differentiation markers (desmoplakin, cytokeratins) and CXCL11 expression.
• Evaluated expression patterns in sparse, confluent, and postconfluent cultures, including low calcium conditions.

Main Results:

• CXCL11 expression peaked near cellular confluence and decreased postconfluence, independent of desmoplakin accumulation.
• Low calcium conditions, which inhibit differentiation, also showed a biphasic CXCL11 pattern.
• Highest CXCL11 expression correlated with newly confluent areas expressing keratin 14 and keratin 6.

Conclusions:

• Cellular confluence, rather than differentiation, is the primary trigger for CXCL11 expression in migrating keratinocytes.
• CXCL11 signaling via CXCR3 may facilitate the transition from the proliferative to the remodeling phase of cutaneous wound healing.