Abstract
Purpose :
CUB domain-containing protein 1 (CDCP1) was originally discovered to be overexpressed on certain solid tumor cells, regulating tumor-cell anoikis resistance. We recently identified CDCP1 as a ligand of CD6, a T cell marker, suggesting that CDCP1 could regulate immune responses. We also found that CDCP1 is selectively expressed at a high level on normal corneal epithelial cells of the eye. Here, we investigated whether CDCP1 plays a role in corneal epithelial wound healing.
Methods :
Human telomerase reverse transcriptase (hTERT) immortalized corneal epithelial (hTCEpi) cells were transduced with lentivirus expressing CDCP1-specific shRNA or empty lentivirus, followed by flow sorting and expansion of clones with normal or knocked-down (KD) expression of CDCP1. In vitro wound healing assays were performed using these cells, and IL-6 level in the culture supernatants was measured by ELISA. For in vivo experiments, age and sex-matched C57BL/6 wild-type (WT) and CDCP1 knockout (KO) mice were anesthetized, and their central corneal epithelium was scraped using a blunt mini-blade following an established protocol. Corneal wounds were fluorescein stained then imaged, and their areas were quantitated at 0, 6, and 24 hr time points by Image J. At 24 hr, mice were euthanized and corneal infiltrating neutrophils were quantitated by flow cytometry after single cell suspension preparation.
Results :
Cultured CDCP1 KD human corneal epithelial cells showed significantly delayed gap closure after scraching, in association with reduced production of IL-6. In addition, CDCP1 KO mice also showed markedly impaired wound healing in vivo in connection with significantly reduced neutrophil infiltration in the cornea.
Conclusions :
CDCP1 has a previously unknown but pivotal role in facilitating corneal wound healing in which IL-6 and neutrophils might be integrally involved in the mechanism. These results suggest that CDCP1 could be a new target for developing therapeutics to improve corneal wound healing in patients.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.