Abstract
Purpose :
Corneal alkali burn is a model of healing where the stroma and, above all, the extracellular matrix (ECM) is implicated. After corneal injury, collagen III is considered a marker of the extracellular matrix remodelling. Decorin and lumican play a crucial role in the collagen fibrils assembly. For this reason, the evolution of ECM components during the stroma repair, at molecular and histological level, give us basic knowledge in corneal wound healing.
Methods :
Forty two rabbits were burned for 60 seconds with an 8-mm filter paper soaked in 0.5N NaOH solution. Similar number of controls were used. Twenty one corneas were removed, fixed and paraffin-embedded at 1, 3 and 6 months after burning. Corneal sections were stained with modified Gomori Methenamine-Silver stain to localize the Collagen III. Other twenty one corneas were excised, at the same time points, and immersed in RNA later. Collagens I and III, Lumican and Decorin mRNA expression levels were determined by qRT- PCR. Actin beta was used as housekeeper gene and control corneas as calibrator.
Results :
Collagen I expression was up-regulated in wound area during the first month, it was similar to the control after 3 months and down-regulated at the end of experiment. Collagen III expression was up-regulated until 3 months and normalized at 6 months. Both proteoglycans, lumucan and decorin, expression dynamic was similar to that observed in collagen I. Histologycal sections showed lacunae filled of silver stained fibers at 1 and 3 months.
Conclusions :
In our rabbit alkali burn model, the stromal regeneration, is solved at 6 month from the molecular point of view.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.