Matrix Metalloproteinases and the Pathogenesis of Recurrent Corneal Erosions and Epithelial Basement Membrane Dystrophy

Simple Summary Based on our previous studies on the levels of selected matrix metalloproteinases (MMPs) in patients with recurrent corneal erosions (RCE), we made a detailed assessment of their possible contribution to the development of corneal epithelial basement membrane dystrophy. The existing literature describing the structure, nomenclature, activation, and substrate specificity of metalloproteinases, as well as factors affecting their activity, are summarized. A separate section focuses on the effect of metalloproteinases on the corneal healing process, which is a preview of the final considerations on the effect of metalloproteinases on the development of recurrent corneal erosions and corneal epithelial basement membrane dystrophy. Our previous experimental studies revealed elevated metalloproteinase concentrations in the corneal epithelium of patients with recurrent corneal erosions concomitant with epithelial basement membrane dystrophy. These MMP concentrations are correlated with histopathology and confocal microscopy findings typical of this group of patients. Based on the consistency of the obtained results, the authors suggest a contribution of matrix metalloproteinases to the development of corneal epithelial basement membrane dystrophy.Abstract Matrix metalloproteinases (MMPs) are a group of proteolytic enzymes which are members of the zinc endopeptidase family. They have the ability to degrade extracellular matrix elements, allowing for the release of binding molecules and cell migration. Although metalloproteinases regulate numerous physiological processes within the cornea, overexpression of metalloproteinase genes and an imbalance between the levels of metalloproteinases and their inhibitors can contribute to the inhibition of repair processes, the development of inflammation and excessive cellular proliferation. The involvement of MMPs in the pathogenesis of dystrophic corneal diseases needs clarification. Our analyses focus on the involvement of individual metalloproteinases in the pathogenesis of recurrent corneal erosions and highlight their impact on the development of corneal epithelial basement membrane dystrophy (EBMD). We hypothesize that abnormalities observed in patients with EBMD may result from the accumulation and activation of metalloproteinases in the basal layers of the corneal epithelium, leading to basement membrane degradation. A barrier formed from degradation materials inhibits the normal migration of epithelial cells to the superficial layers, which contributes to the development of the aforementioned lesions. This hypothesis seems to be lent support by the elevated concentrations of metalloproteinases in the corneal epithelium of these patients found in our previous studies on the relationships between MMPs and recurrent corneal erosions.

Automated summary

Based on previous studies, this article provides a detailed assessment of the levels of matrix metalloproteinases (MMPs) in patients with recurrent corneal erosions (RCE) and their possible contribution to the development of corneal epithelial basement membrane dystrophy. The involvement of MMPs in the pathogenesis of corneal diseases is discussed, particularly their impact on the development of corneal epithelial basement membrane dystrophy. The authors hypothesize that the accumulation and activation of MMPs in the basal layers of the corneal epithelium may lead to basement membrane degradation and the development of lesions.