Abstract
Purpose :
We previously reported the direct reprograming of human corneal epithelial cells (CECs) from skin fibroblasts with the following 6 transcription factors (TFs): PAX6, OVOL2, KLF4, SOX9, P63, and MYC. (ARVO 2015). However, the molecular mechanism of that reprogramming has yet to be fully elucidated. The purpose of this present study was to clarify the underlying molecular mechanism of the reprogramming of CECs.
Methods :
We analyzed the expression level of keratin K3 and K12 genes by quantitative reverse transcription polymerase chain reaction (RT-PCR) at 10 days after the transduction of 5 TFs, were each removed from the pool of 6 TFs, to human skin fibroblasts. We then examined whether or not neural progenitor cells derived from neuroectoderm, which is closely related to the corneal epithelial lineage, a derivative of surface ectoderm, could be reprogrammed to CECs and analyzed the gene expression level in the same method as skin fibroblasts.
Results :
The expression levels of K3 and K12 decreased when TFs PAX6, OVOL2, and KLF4 were each removed from the pool of 6 TFs. Moreover, the overexpression of OVOL2 in the neural progenitor cells highly expressing PAX6 and KLF4 dramatically changed the morphology of neural progenitor cells which took on the appearance of epithelial-like cells at 2 weeks. RT-PCR analysis revealed that those induced-cells highly expressed K12 and ALDH3A1 (corneal epithelial specific genes) and low expression of Zeb1, Zeb2 and Snail2 (neural and mesenchymal-related genes).
Conclusions :
Our findings revealed that the transcriptional network consisting of TFs PAX6, OVOL2, and KLF4 is important for the reprograming of CECs.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.