Impaired healing of cutaneous wound in a Trpv1 deficient mouse.

Abstract

Transient Receptor Potential (TRP) ion channels mediate the influx of cations into cells responding to chemical or physical stimuli. TRP vanilloid 1 (TRPV1) regulates cutaneous functions. Its function in cutaneous wound healing, however, has not been clarified. The current study elucidated the role of TRPV1 in cutaneous wound healing of dorsal circular excisional injury using Trpv1-null (KO) and wild type (WT) male/female C57BL/6 mice. Macroscopic observation showed that the remaining cutaneous lesion was significantly larger in KO than that of WT at postoperative days (POD) 7 and 10. Histological analysis showed significantly delayed re-epithelialization in KO at POD7. The number of macrophages in KO and WT similarly returned to the reduced state from POD4 to POD7. Whereas, the number of neutrophils in KO did not significantly return to the reduced state, in contrast to WT. Of note, The H3Cit-labeled NETs (Neutrophil Extracellular Traps) formation of KO was prominently increased both in POD4 and 7. The current results suggest that the loss of TRPV1 induces prolonged neutrophilic inflammation and NETs formation, retarding murine cutaneous wound healing in vivo. This study provides a possible link with TRPV1 and neutrophilic regulation in cutaneous wound healing.