Prokineticin-1 modulates proliferation and differentiation of enteric neural crest cells.

Prokineticins (Prok-1 and Prok-2) belong to a newly identified AVIT protein family. They are involved in variety of activities in various tissues, including smooth muscle contraction of the gastrointestinal tract and promoting proliferation of endothelial cells derived from adrenal gland. Importantly, they also act as the survival factors to modulate growth and survival of neurons and hematopoietic stem cells. In this study we demonstrated that Prok-1 (but not Prok-2) protein is expressed in the mucosa and mesenchyme of the mouse embryonic gut during enteric nervous system development. Its receptor, PK-R1 is expressed in the enteric neural crest cells (NCCs). To elucidate the physiological role(s) of Prok-1 in NCCs, we isolated the NCCs from the mouse embryonic gut (E11.5) and cultured them in the form of neurospheres. In an in vitro NCC culture, Prok-1 was able to activate both Akt and MAPK pathways and induce the proliferation and differentiation (but not migration) of NCCs via PK-R1. Knock-down of PK-R1 using siRNA resulted in a complete abolishment of Prok-1 induced proliferation. Taken together, it is the first report demonstrating that Prok-1 acts as a gut mucosa/mesenchyme-derived factor and maintains proliferation and differentiation of enteric NCCs.