Abstract
Purpose :
Fuch’s endothelial corneal dystrophy (FECD) is more common in women than men. We hypothesized that sex steroids play a role in this discrepancy. To define the potential role of sex steroids in corneal endothelium, we investigated the expression of estrogen receptor beta (ERβ) in normal and FECD ex vivo human corneal endothelium.
Methods :
Following approval by the Research and Development Committee (VA, Buffalo, NY, USA) human corneas were obtained from the Anatomical Gift Program (Univ. at Buffalo) and FECD samples were obtained from surgical specimens. Total RNA was isolated from normal corneal endothelium and utilized for RT-PCR using primers crossing an intron for ERβ. Immunoblots were performed with a commercial ERβ antibody using total protein extracted from normal corneal endothelium and from the MCF-7 breast cancer cell line for positive control. Immunofluorescence localization for ERβ utilizing the same antibody was performed on frozen sections of FECD corneal specimens or en face on 37°C ex vivo cultured corneas subjected to mechanical scrape wounds to the central endothelium to stimulate a stress response.
Results :
ERβ mRNA and protein are expressed in human corneal endothelium, demonstrated by RT-PCR and immunoblot. The subcellular location of ERβ in ex vivo human corneal endothelium shows distinct expression patterns within the same cornea; from predominantly nuclear to predominantly cytoplasmic (n= 4 individual corneal samples). Following a mechanical scrape wound, cells nearest the wound edge had mixed nuclear and cytoplasmic expression (n= 4 individual corneal samples). ERβ expression in FECD corneal specimens showed all subcellular localization patterns (n=2 FECD specimens).
Conclusions :
ERβ is present in human corneal endothelium. Its diverse cellular expression patterns suggest distinct roles for ERβ in normal corneal endothelium, endothelial wound healing, and FECD. In future studies, we will investigate the role of estradiol in ERβ expression and response to stress.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.