Med1 KO Model Shows Hair Regeneration Potential
Because both enamel and epidermal lineages are derived from the ectoderm, they likely share some signaling pathways involved with differentiation. Epidermal lineage may be the default fate for DE-SCs, such that Med1 deletion or other stimuli in dental cells may induce an epidermal fate. In fact, hair was accidentally regenerated during experiments undertaken to generate tooth germs (personal communication) in which ES-derived dental epithelia and dental mesenchyme were transplanted under the renal capsules [45]. Because hair is difficult to regenerate, our study demonstrates the potential that human hair could be regenerated by other epithelial cells.
In summary, we propose a model in which Med1 ablation affects the stem cell function at two locations. Med1 may be a master regulator not only for ESC but also for adult stem cells to determine cell fate. Med1 regulation through a Notch signaling partnership with calcium induces a cell fate switch. Our study shows the potential to develop a new hair regeneration therapy to treat diseases such as alopecia or ectoderm dysplasia.
