Abstract
Purpose :
The pattern and localization of polarity proteins in the corneal epithelium is essential to understanding mechanisms of wound healing, which is inhibited in diabetics. We hypothesize that apical-basal and planar polarity must be established for proper wound edge closure and differentiation. Our goal is to examine the patterning and localization of the polarity proteins: Crumbs3 (Crb3), Zonula Occludens 1 (ZO1),PKCzeta, Occludens and Pannexin1 in corneas from wildtype and diet induced obese (DIO). Crb3 is associated and essential in establishing the apical membrane and members of the tight junction complex are associated with Crb3.
Methods :
Epithelial debridement wounds were performed on corneas from C57BL/6J wildtype and DiO mice. Immunohistochemical analyses were performed and imaged using confocal microscopy. Western blots were performed on epithelial lysates. Corneas were incubated in the presence or absence of pannexin inhibitors. Calcium mobilization was determined using a Zeiss 880 on FAST mode and AIRYScan.
Results :
A change in localization of polarity proteins occurs after injury and is further altered in tissue from mice fed a high fat diet for 15 weeks. Pannexin 1 was localized apically in wildtype and DiO unwounded corneal epithelium, however it was diffuse in the DiO. Two hours after injury, pannexin 1 localized to the wound margin and its fluorescence decreased away from the edge. In the DiO cornea, pannexin1 was diffuse and the lack of distinct pattern remained. When epithelium had healed in the wildtype by 20 hours there was intense staining between cells. Pannexin1 localization and cell-cell communication were reduced in presence of 10panx but not probenocid. The apical-basal proteins Crb3, PKCzeta, and ZO1 were detected apically in wildtype and DIO unwounded tissue. After corneas from wildtype were injured, Crb3, PKCζ, and ZO1 were detected in apical and basal cells. In comparison abraded corneas of DiO mice lost the distinct patterning, and planar cell polarity was not maintained.
Conclusions :
Planar and apical-basal polarity proteins display a change in localization adjacent to the wound. The distinct patterns are lost in the DiO corneal tissue compared to wildtype. Together these indicate that pre-Type II diabetic corneas display altered planar and apical-basal polarity necessary for wound repair.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.