Perlecan-associated defective epithelial basement membrane regeneration in rabbit corneas after fibrosis-inducing epithelial-stromal injury

Abstract

Purpose : To study epithelial basement membrane (EBM) regeneration after photorefractive keratectomy (PRK) injuries that healed with and without stromal fibrosis.

Methods : One hundred sixteen rabbits had either no surgery, -4.5 diopter (D) PRK, or -9D PRK. Immunohistochemistry (IHC) was performed on cryofixed corneas at time points from unwounded to eight weeks, with four corneas at each time point in each group. Multiplex IHC was performed for laminin alpha 5, laminin beta 3, perlecan, and/or nidogen-1, keratocan, vimentin, and alpha-smooth muscle actin (SMA). Corneas at the one month peak for myofibroblast and fibrosis development were evaluated using Imaris 3D analysis.

Results : Laminin alpha-5, laminin beta 3, and nidogen-1 were incorporated into nascent EBMs. Defective perlecan incorporation in the nascent EBM was noted in corneas that developed large numbers of myofibroblasts and fibrosis in the anterior stroma.

Conclusions : Defective incorporation of transforming growth factor (TGF)-beta-modulating perlecan into the regenerating EBM by subepithelial myofibroblasts, and likely their precursor cells, underlies the development of stromal fibrosis after corneal injury.

This is a 2021 ARVO Annual Meeting abstract.

 

Figure 1. Laminin alpha5, perlecan, and nidogen-1 expression at three and four weeks after -4.5 D and -9.0 D PRK.

 

Figure 2. Imaris 3D constructions of confocal microscopy images of laminin alpha 5, perlecan and nidogen-1 in the epithelium, EBM and anterior stroma in unwounded (A) and four weeks -4.5D (B) and -9D (C) PRK corneas.