Extracellular matrix changes in corneal opacification vary depending on etiology

Mol Vis. 2021 Jan 15:27:26-36. eCollection 2021.

Abstract

Purpose: The purpose of this study is to examine the expression of tenascin-C and matrilin-2 in three different disorders, which frequently require corneal transplantation. These pathological conditions include bullous keratopathy (BK), Fuchs' endothelial corneal dystrophy (FECD), and corneal scarring in herpetic keratitis.

Methods: Histological sections of corneal buttons removed during keratoplasty were analyzed in BK (n = 20), FECD (n = 9), herpetic keratitis (n = 12), and cadaveric control (n = 10) groups with light microscopy following chromogenic immunohistochemistry. The sections were evaluated by three investigators, and semiquantitative scoring (0 to 3+) was applied according to standardized methods at 400X magnification. Each layer of the cornea was investigated; moreover, the stroma was subdivided into subepithelial, middle, and pre-Descemet's membrane areas for more detailed analysis.

Results: Excessive epithelial and stromal expression of tenascin-C was identified in all investigated conditions; the results were most pronounced in the pre-Descemet's membrane. Regarding matrilin-2, when examined in BK, there was increased labeling intensity in the epithelium (p<0.001) and stromal layers (p<0.05), and a decrease in the endothelium (p<0.001). In the other investigated conditions, only a low degree of stromal localization (p<0.05) of matrilin-2 was detected.

Conclusions: The expression of tenascin-C and matrilin-2 differs when examined in various corneal pathologies resulting in opacification. Both molecules seem to be involved in regeneration and wound healing of the corneal matrix in these diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Blister / complications
  • Blister / metabolism*
  • Blister / surgery
  • Corneal Opacity / etiology
  • Corneal Opacity / metabolism*
  • Corneal Opacity / surgery
  • Extracellular Matrix / metabolism*
  • Female
  • Fuchs' Endothelial Dystrophy / complications
  • Fuchs' Endothelial Dystrophy / metabolism*
  • Fuchs' Endothelial Dystrophy / surgery
  • Humans
  • Immunohistochemistry
  • Keratitis, Herpetic / complications
  • Keratitis, Herpetic / metabolism*
  • Keratitis, Herpetic / surgery
  • Keratoplasty, Penetrating
  • Male
  • Matrilin Proteins / metabolism
  • Middle Aged
  • Retrospective Studies
  • Tenascin / metabolism*
  • Visual Acuity

Substances

  • MATN2 protein, human
  • Matrilin Proteins
  • TNC protein, human
  • Tenascin