Extracellular matrix changes in corneal opacification vary depending on etiology

Area of Science:

• Ophthalmology
• Cell Biology
• Biochemistry

Background:

• Corneal opacification due to diseases like bullous keratopathy (BK), Fuchs' endothelial corneal dystrophy (FECD), and herpetic keratitis often necessitates corneal transplantation.
• Understanding the molecular changes in these conditions is crucial for developing targeted therapies.

Purpose of the Study:

• To investigate the expression patterns of tenascin-C and matrilin-2 in corneas affected by BK, FECD, and herpetic keratitis.
• To compare these expression levels with healthy donor corneas.

Main Methods:

• Analysis of corneal buttons from patients undergoing keratoplasty (BK, FECD, herpetic keratitis) and healthy controls.
• Chromogenic immunohistochemistry and light microscopy were employed to evaluate tenascin-C and matrilin-2 expression.
• Semiquantitative scoring was performed across different corneal layers, including detailed stromal sub-regions.

Main Results:

• Elevated tenascin-C expression was observed in all pathological conditions, particularly in the pre-Descemet's membrane.
• Matrilin-2 showed increased epithelial and stromal labeling and decreased endothelial labeling in BK.
• Low stromal localization of matrilin-2 was noted in other conditions, with minimal detection in controls.

Conclusions:

• Tenascin-C and matrilin-2 exhibit distinct expression profiles in various corneal pathologies.
• These proteins are implicated in the corneal matrix's regeneration and wound healing processes in these diseases.