Corneal Wound Healing: Is Sex a Biological Variable?

Abstract

Purpose : Wound healing varies significantly in a tissue-dependent manner in people. Dermal wounds heal faster in women whereas mucosal wounds heal faster in men. Whether corneal wound healing occurs more rapidly in men or women remains unknown. This study examined the role of sex in corneal wound healing using an established in vivo rabbit model.

Methods : Corneal wounds in New Zealand White rabbits were produced by a single topical alkali (0.5N NaOH) application. Serial slitlamp and stereo biomicroscopy evaluated ocular health and corneal opacity. Tonometry measured intraocular pressure (IOP) in live animals. Corneas were collected 14 days after injury and subjected to qRT-PCR, western blotting and immunofluorescence to quantify changes in the mRNA and protein levels of alpha-smooth muscle actin (αSMA), transforming growth factor beta (TGFβ), and extracellular modeling proteins involved in corneal healing. TUNEL assays evaluated levels of apoptotic cell death.

Results : Male and female rabbits showed no statistically significant differences in corneal opacity (Fantes score 2.7 ±0.5) or IOP levels (9.5 mm/Hg ±1.5). No major differences in the mRNA levels of αSMA (male 12.4 vs. female 11.9 fold), TGFβ (male 10.4 vs. female 10.9 fold), Collagen-1 (male 6.9 vs. female 7.1 fold), or Fibronectin (male 7.1 vs. female 7.5 fold) were detected in wounded rabbit corneas. The comparative immunofluorescence showed no statistically significant differences in expression of αSMA, Fibronectin, Collagen-I or TGFβ proteins in male versus female corneal sections. Additional sex-specific gene and protein expression analyses are underway.

Conclusions : Data analyzed thus far suggests that sex has a limited role in the modulation of corneal wound healing in rabbits in vivo. Further studies are warranted.

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