Abstract
Purpose :
N-Methyl-D-aspartate receptors (NMDARs) are glutamate receptors that have been implicated in corneal wound healing. However, their role has yet to be elucidated. This study demonstrates NMDARs regulate corneal wound healing, using in vitro and in vivo models.
Methods :
Human primary corneal epithelial cells were analyzed for cell migration using a Boyden chamber migration assay. NMDA and (+)-MK 801 maleate, an NMDAR agonist and antagonist, were tested at 50 μM each. Negative and positive controls were performed in parallel. A Student T-test was used to determine statistical difference.
Six- to eight-week-old NR1F/F control and K14 cre NR1-/- mice underwent corneal epithelial wounding using a 0.5mm burr. Digital pictures of the cornea were taken at 0 hours and 18 hours after wounding. Images were analyzed using Image J. Single-factor analysis of variance (ANOVA) was used to compare wound healing rates. In parallel, globes were harvested at 0 and 18 hours after wounding and subjected to immunohistochemical staining.
Results :
The average migration % calculated from the Boyden chamber migration assay were 18.3% control, 19.6% NMDA , and 17.4% (+)-MK 801 maleate with P-values of 2.058 x 10^-2 and 1.979 x 10^-3 respectively. The average in vivo wound healing rates were 81.21% and 63.33% for the NR1F/F control and K14 cre NR1-/- mice, respectively. Single-factor ANOVA revealed a P-value 2.908 x 10^-2. Globes from NR1F/F and K14 cre NR1-/- control mice confirmed expression and absence of NR1, and thus NMDAR, in the corneal epithelium respectively.
Conclusions :
NMDAR is a key multi-subunit ion-channel glutamate receptor that has been implicated in corneal wound healing. Our results further expand on the current literature, establishing the presence of NMDARs in the mouse corneal epithelium and demonstrating that decreased NMDAR levels diminish corneal epithelial wound healing. The results of the Boyden chamber migration assay further support NMDAR’s importance in corneal wound healing where cells treated with NMDA, an NMDAR agonist, exhibited greater migration compared to control and cells treated with (+)-MK 801 maleate, an NMDAR antagonist. These results suggest NMDAR regulates corneal wound healing and that decreased NMDAR leads to reduced corneal wound healing. This study provides preliminary evidence to serve as a reference for the development of potential future therapies.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.