Abstract
Purpose :
A critical barrier in developing vision-saving strategies for ophthalmic injury repair is the limited knowledge of the cellular changes involved in the destruction of normal cellular architecture and replacement with scar tissue leading to fibrosis. Keratins are structural proteins that provide cells with the ability to cope with injury and stress. Here, we used embryonic and adult zebrafish and human embryonic stem cell (hESC) models to test the hypothesis that ocular Keratins 8 and 18 (KRT8 and KRT18) are involved in ocular neural crest cell (NCC) migration and differentiation and ocular wound healing.
Methods :
Krt8 and krt18a.1 expression during zebrafish embryonic neural crest development was examined using in situ hybridization. Krt8 and Krt18a.1 expression levels were genetically manipulated using morpholino antisense oligonucleotides (MOs) to examine gene function. Directed differentiation of hESCs into neural crest-derived keratocytes, followed by immunohistochemistry and western blot analysis was used to examine keratin expression during cellular differentiation. Mechanical corneal injury was performed on adult zebrafish and immunohistochemistry was used to examine keratin expression during wound healing.
Results :
Krt8 and krt18a.1 are expressed in the early neural plate border and in migrating NCCs during early development. MO knockdown of Krt8 and Krt18a.1 decreased the migration of sox10- and foxd3-positive neural crest cell populations into the craniofacial region and eye at 48 hours postfertilization (hpf), resulting in microphthalmia and jaw malformation. In addition, KRT8 and KRT18 were expressed during the differentiation of hESCs into NCCs and subsequent NCC derivatives. Further, Krt8 and Krt18a.1 expression was also detected at various timepoints during corneal wound healing.
Conclusions :
Taken together, these results suggest that Krt8/18 regulate NCC dynamics during embryonic development and play a role in ocular wound healing.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.