Master transcription factors in corneal epithelial cells [OVOL2 transduced experimental samples]

In development, embryonic ectoderm differentiates into several lineages including neuroectoderm and surface ectoderm, through the mechanism largely unclear. Here we report that OVOL2 is required for the transcriptional program of corneal epithelium cell(CEC)s, a derivative of surface ectoderm, and it might regulates the differential transcriptional programs between the two lineages. By a functional screening, we identified transcription factors (TFs) maintaining human CECs. OVOL2 was necessary to maintain the transcriptional program in CECs, particularly through repressing expression of mesenchymal genes. OVOL2 combined with several TFs were able to activate the transcriptional program of CECs in fibroblasts, accompanied by induction of chromatin landscape. Moreover, our analysis revealed that neuroectoderm derivatives express some of mesenchymal genes. In fact, OVOL2 alone was able to induce the transcriptional program of CECs in neural progenitor cells (NPCs) through repression of mesenchymal genes as well as activation of epithelial genes. Our data suggest that the difference between the transcriptional programs of surface ectoderm-derivatives and neuroectoderm-derivatives is regulated in part by the reciprocally-repressive mechanism between epithelial and mesenchymal genes that is seen in epithelial-to-mesenchymal transition.

4