p53 regulation by MDM2 contributes to self-renewal and differentiation of basal stem cells in mouse and human airway epithelium.

Proper physiological function of mammalian airways requires the differentiation of basal stem cells into secretory or multiciliated cells, among others. In addition, the self-renewal ability of these basal stem cells is crucial for developing a quick response to toxic agents in order to re-establish the epithelial barrier function of the airways. Although these epithelial missions are vital, little is known about those mechanism controlling airway epithelial regeneration in health and disease. p53 has been recently proposed as the guardian of homeostasis, promoting differentiation programs, and antagonizing a de-differentiation program. Here, we exploit mouse and human tracheal epithelial cell culture models to study the role of MDM2-p53 signaling in self-renewal and differentiation in the airway epithelium. We show that p53 protein regulation by MDM2 is crucial for basal stem cell differentiation and to keep proper cell proliferation. Therefore, we suggest that MDM2/p53 interaction modulation is a potential target to control regeneration of the mammalian airway epithelia without massively affecting the epithelium integrity and differentiation potential.