Comparison of epithelial cells from various epithelia and hair follicle stem cells [microarray]

The potency of an adult stem cell is restricted to certain lineages during embryonic life, in response to a specific microenvironment (the niche) and it is maintained for life. Lineage restriction is considered immutable. We have investigated if adult stem cells isolated from different epithelia could change fate by exposing them to a hairy skin niche. We have demonstrated that clonogenic stem cells restricted to a single epithelial lineage and cultured from various Tp63-expressing tissues e.g, the bladder the oral mucous, the oesophagus or the thymus can acquire new functionality. When exposed to a hair skin microenvironment, these stem cells acquire the capacity to generate hair follicles and sebaceous glands, thus behaving like bona fide hairy skin multipotent stem cells. Genome wide-screen analysis has demonstrated that the stem cells express transcription factors typical of hair follicle differentiation, even though they continue to express some of the genes linked to their origin. This increase in potency demonstrates that lineage restriction is not immutable. Expression profile difference between hair follicle and cells from various epithelia before and after transplantation into skin