Injury and stress responses of adult neural crest-derived cells.

Multipotent neural crest cells can self-renew and give rise to a plethora of neural and non-neural cell types in the vertebrate embryo. Intriguingly, cells reminiscent of such neural crest stem cells (NCSCs) have also been isolated from various postnatal and adult neural crest (NC)-derived structures. However, it has been debated whether NCSC-like cells in the adult correspond to 'in vitro artefacts' emerging upon isolation or fulfil a physiological role in vivo. Here, we discuss recent findings indicating that in different adult NC derivatives, injury or stress responses induce a NCSC-like state, presumably by reprogramming differentiated cells such as Schwann cells. Thereby, injury or stress appear to endow NC-derived cells with the capacity to generate new cell types during the repair process; in addition, injury can activate a repair program in adult NC-derived cells, which promotes tissue repair or regeneration by paracrine signalling. Thus, there is increasing evidence that NCSC-like cells in NC derivatives represent an in vivo state implicated in distinct physiological functions in the adult organism.