Galectin-3 and CD147 Colocalization in Sterile Corneal Ulcers

Abstract

Purpose: Galectin-3 is a carbohydrate binding protein known to promote secretion of matrix metalloproteinases, a hallmark of ulceration, through interaction with the metalloproteinase inducer CD147. The aim of this study was to investigate the localization of galectin-3 and CD147 in patients with sterile corneal melting.

Methods: Human tissue was collected from six patients with active corneal ulceration due to Boston keratoprosthesis implants, rheumatoid arthritis, and mucous membrane pemphigoid. Galectin-3 and CD147 were localized on human tissue cryosections by immunofluorescence microscopy. Biologic assessment of gelatinolytic activity was evaluated by in situ zymography.

Results: Galectin-3 staining in the population study was predominant on apical cells of the stratified corneal epithelium, whereas discrete binding was observed on basal epithelial cells and keratocytes. Sporadic colocalization of CD147 and galectin-3 was observed at the epithelial-stromal junction and in corneal keratocytes, but not on the apical portion of the epithelium. Moreover, increased gelatinolytic activity was present within areas of galectin-3 and CD147 colocalization in the epithelial-stromal junction and keratocytes.

Conclusions: Galectin-3 and CD147 colocalize in basal corneal epithelial cells and in corneal keratocytes within areas associated with increased gelatinolytic activity. Sustained up-regulation of these molecules may potentially lead to stromal matrix degradation and be clinically relevant to corneal ulceration.