Chip-chip from mechanical stretched interfollicular epidermal stem cells (IFESCs) with YAP. Homo sapiens

The renewing human epidermis constantly senses and adapts to a wide range of mechanical cues that are ubiquitous throughout life. The mechanisms of how mechanical forces are responded by interfollicular epidermal stem cells (IFESCs) and are transmitted directly into nucleus to modify gene expression was discovered to be mediated by transcriptional coactivators YAP. Interestingly, YAP, a critical modulator in controlling organ size by regulating both cell proliferation and apoptosis, was also found to induce self-renewal or amplification of epidermal progenitor/stem cells, and balance epidermal growth and differentiation. Because growth regulation imposed by different stimuli is achieved through distinct YAP target genes even in a single cell type. This study used chromatin immunoprecipitation (ChIP) coupled with human promoter tiling microarray analysis (ChIP-on-chip) to profile YAP at promoters genome-wide. The goal of the study was to identify the target genes occupied by YAP in IFESCs under the mechanical stretch condition. Overall design: ChIP-on-chip performed with antibodies to YAP on mechanical stretched or unstretched human interfollicular epidermal stem cells and with technical replicates in vitro.