Abstract
Purpose :
Activated mast cells has been shown to promote ocular surface angiogenesis. Here we investigated whether mast cells delay the regression of corneal neovascularization.
Methods :
Neovascularization was induced by placing a single figure-8 intrastromal suture in the cornea using 11-0 nylon. On day 14, the suture was removed upon establishment of mature blood vessels. Real-time vessel regression was followed by capturing slit-lamp pictures. To investigate the direct effect of mast cells on vessel regression, suture was placed in mast cell deficient cKitw-sh and their wildtype (WT) C57BL/6 controls. To evaluate the effect of pharmacological blockade of mast cells on the reversion of mature blood vessels, corneas were treated one day prior to suture removal with mast cell inhibitor, cromolyn (2% in PBS). Slit lamp images were analyzed using ImageJ software. Corneas were harvested on day of suture removal and 2 days post-suture removal and expression of VEGF-A.
Results :
By 48 hours following suture removal, a significant 51.3% regression of blood vessels were observed in mast cell-deficient cKitw-sh mice, compared to 11.5% regression in WT controls (p=0.002). Near complete regression of corneal neovessels was observed in mast cell-deficient mice by day 7 post-suture removal compared to WT controls (p=0.004). Similarly, cromolyn-mediated suppression of mast cells however, persistent pathological vessels were observed in WT controls. cromolyncccafdsfaccelerated accelerated the regression of inflammatory blood vessels, as demonstrated by complete regression of vessels by 24 hours post-suture removal, compared to PBS treatment. Furthermore, mRNA analysis showed a two-fold reduction in VEGF-A in the cromolyn-treated corneas, relative to PBS-treated groups (p=0.03).
Conclusions :
Our data demonstrate that ocular surface mast cells delay the regression of pathological corneal blood vessels
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.