Abstract
Purpose :
The aim of this study is to determine the roles of collagen XIV in the regulation of stromal hierarchical organization, keratocyte organization and corneal mechanics.
Methods :
The temporal and spatial expression of collagen XIV at postnatal days (P) 4, 10, 30, 90 and 150 was evaluated in wild type (WT) mice. The role of collagen XIV in hierarchical organization was analyzed by measuring fibril diameter and density within ultrastructural micrographs obtained from WT and Col14a1-/- deficient mice. Keratocyte morphology and networks were assessed using actin staining with phalloidin and in vivo confocal microscopy. The effects of collagen XII in corneal biomechanics was evaluated using atomic force microscopy. Expression of collagen XIV was investigated following incisional and abrading injury of the stroma.
Results :
In WT corneas, collagen XIV mRNA expression was dynamic, strong at P4 - P10 and started to decrease at P30. Immuno-blotting showed decreased collagen XIV protein expression after P30. Immunofluorescence microscopy showed homogenous localization of collagen XIV in the full thickness of the stroma at P4 and P10. Immunoreactivity decreased at P30 and continued to decrease at P90. Immunoreactivity was localized to the anterior stroma after P90. No immunoreactivity was noted at P150. There was abnormal collagen fibril assembly with a shift towards larger diameter fibrils, and increased interfibrillar spacing in the absence of collagen XIV, (p<0.001). Corneal stiffness was similar in the adult P60 cornea with or without collagen XIV, p=1.2. Collagen XIV expression was recapitulated during woung healing. Collagen XIV mRNA and protein expression were noted 3 weeks post injury.
Conclusions :
Collagen XIV plays a regulatory role in corneal development and influences stromal hierarchical organization. Collagen XIV expression is recapitulated during stromal injury.
This is a 2020 ARVO Annual Meeting abstract.