Ultrastructure and morphology of healing corneal stroma in a keratocyte-specific hyaluronan synthases 2-deficient mouse

Abstract

Purpose : We examined OCT-based observation of morphological alteration over time of and ultrastructure of healing tissue of corneal stroma following an incision injury in wild-type (WT) and KeraCre-driven keratocyte-specific conditional hyaluronan synthesis 2 (HAS2)-deficient mice. We previously reported that gene deletion of HAS2 in corneal stromal cells delayed primary repair of an incision injury in corneal stroma in association of less appearance of myofibroblasts in mice (16th Korea-China-Japan Ophthalmology Joint Meeting, 2023).

Methods : A liner incision injury was produced in one eye of WT and KO mice by using a micro-surgical blade. The alteration of the time-course alteration of morphology of the stromal wound in each mouse was examined by using an OCT image. The tissue ultrastructure was also observed.

Results : The closure of the wound as delayed in the absence of HAS2. During healing interval OCT showed the healing tissue was less compact with many macro-cavities in KO mice as compared with WT mice. Ultrastructure observation showed that corneal fibroblasts in a healing tissue seemed more elongated with a thinner cytoplasm and KO cells were thicker without elongated cytoplasm. Spaces among corneal (myo)fibroblasts seemed more packed in a KO tissue, while more cell-free spaces were seen in a WT tissue.

Conclusions : Blocking hyaluronan synthesis in corneal stromal cells by the loss of HAS2 affects the macro- and micro-structure of healing tissue of corneal stroma in mice.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.