Abstract
Purpose :
In the cornea, healing of the wounded avascular surface is an intricate process comprising the involvement of communication between epithelial, stromal and neuronal cells. Previously, we have reported differences in the expression of BMP7 mRNA during wound healing using a murine cell culture model system. The present study is designed to investigate the effect of BMP7 on human corneal epithelial cells and keratocytes during wound healing.
Methods :
Telomerase-immortalized human corneal epithelial cells (CEs) were used in the present study. Primary human corneal fibroblasts (CFs) were cultured from donor corneas using an explant culture method. Transcriptome-wide gene-level expression profiling of CEs in the presence of BMP7 was performed using Clariom S arrays. Scratch wound healing assay was performed to study the effect of BMP7 on CEs. Furthermore, CEs and CFs were stimulated with BMP7 [100 ng/ml] and western blotting was performed to study activated signalling pathways.
Results :
Gene ontology analysis shows BMP7 stimulation activated TGF-β signalling and cell cycle pathways. Biological processes related to microtubule and intermediate filament cytoskeleton organization were significantly impacted upon BMP7 stimulation in CEs. Scratch wound healing assay shows an increased motility and migration of BMP7 treated CEs. Similarly, differences in the expression of claudin, Zink finger E-box-binding homeobox 1 and phosphorylation levels of cofilin were observed. Stimulation of CFs with BMP7 leading to their activation indicated by an increased expression of α-smooth muscle actin (SMA).
Conclusions :
Based on our transcriptome analysis data and the activated signalling molecules, we conclude that BMP7 contributes to epithelial-to-mesenchymal transition-like responses in CEs and plays a role equivalent to TGF-β by increasing the expression of α-SMA in CFs during the course of corneal wound healing.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.