Keratocyte-derived canonical Wnt signaling modulates corneal wound healing

Abstract

Purpose : Corneal stromal-epithelial interaction plays pivotal role in the maintenance of corneal homeostasis. This study is to determine whether keratocyte-derived Wnt singling plays a role in corneal epithelial debridement wound healing.

Methods : A Doxycycline (Dox)-inducible quadruple transgenic mouse line (Kera^RT; TetO-Cre; Ctnnb1^fE3; Axin2^LacZ) was generated to conditionally expressing a b-catenin gain-of-function mutant (Ctnnb1^ΔE3) and to simultaneously monitoring Wnt signaling activity by the knock-in allele Axin2^LacZ. A 2 mm debridement wound was made in the corneal epithelium of the adult experimental mice. Wound healing was monitored between 0 h and 48 h post-debridement via fluorescein uptake. Collected eyeballs were subjected to examination by X-Gal, H&E, IHC staining and western blots.

Results : X-gal staining showed that endogenous canonical Wnt signaling activity is dramatically decreased during the whole process of corneal epithelial debridement wound healing. Expression of Ctnnb1^ΔE3 in stromal keratocytes retarded corneal wound healing via inhibition of epithelial cell proliferation. IHC staining suggested that TGFb signaling was inhibited by ectopic canonical Wnt signaling activation in the corneal stroma during wound healing. Phalloidin staining did not reveal any striking distinctions in cell shape between the mutant and wildtype mice.

Conclusions : These data implicate keratocyte-derived canonical Wnt signaling plays a role in corneal epithelial wound healing.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.