Project description:The corneal epithelium is a stratified squamous epithelium that protects the eye from mechanical and toxic stress. In this system, cells are continually being sloughed off from the surface of the eye, and replenished by proliferation from corneal stem cells in the limbus, which migrate in and differentiate. During tissue development and homeostasis, distal regulatory regions called enhancers, which contain binding sites for numerous transcription factors, help to control and coordinate gene expression in a temporal and spatial specific manner. To identify enhancers in cornea epithelia, we performed ChIP-Seq with antibodies to the histone marks H3K4me3, H3K4me1, and H3K27ac in primary human corneal epithelial cells. Active enhancers were defined as having high levels of H3K4me1 and H3K27ac, and low levels of H3K4me3: 12,900 such regions were identified in the corneal epithelial cells. In combination with primary cell histone modification ChIP-Seq data from BROAD, 2946 active enhancer regions were identified that are unique to the corneal epithelial cells: 1551 of theses 2946 also overlie regions of high evolutionary constraint. Motif enrichment analysis of these regions has revealed binding sites for a number of transcription factors, highlighting their roles as key regulators of corneal epithelial development.
Project description:The cornea, composed of epithelium, stroma and endothelium, protects the anterior compartment of the eye from damage and allows transmission of light into the eye. While well described morphologically, no studies have investigated the global gene expression changes in the cornea throughout the mouseM-bM-^@M-^Ys life. We characterized the global gene expression profile of mouse cornea from early development through aging, and compared to gene expression in other epithelial tissue, to identify cornea enriched genes, pathways, and transcriptional regulators. We identified Ehf, an ets family transcription factor, as being highly selectively expressed in the corneal epithelium compared to the stroma, and highly expressed in cornea compared to other epithelial tissues. siRNA experiments and Ehf ChIP-Seq on mouse corneal epithelium confirm the role of this factor in promoting epithelial identity and cell differentiation, and suggest it carries out these functions through interactions with other cornea epithelial differentiation factors including Klf4. Whole eye globes were dissected from wild type CB6 mice. Corneal epithelium was isolated by digestion in 50% EMEM/dispase II with 50 mM sorbitol for two hours at 37M-BM-0C. ChIP was performed with an Ehf antibody, and was sequenced with an input control.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.