Neural stem cells express RET, produce nitric oxide, and survive transplantation in the gastrointestinal tract

Background & Aims: Transplantation of neural stem cells (NSC) has been show n to be successful in a variety of experimental models of nongastrointestin al diseases. The aim of this study was to assess the potential of NSC trans plantation as a therapeutic strategy for neuronal replacement in disorders of the enteric nervous system. Methods: Central nervous system-derived NSC (CNS-NSC) were obtained from the subventricular zone of rat brain (E17). Ex pression of RET, GFR(xi, and neuronal nitric oxide synthase (nNOS) was asse ssed by Western blot and immunocytochemistry. Nitric oxide (NO) production was assessed using the NO-sensitive fluorescent indicator DAF-2. CNS-NSC (l abeled with CM-Dil) were transplanted into the pylorus of mice and fluoresc ent double-labeling immunostaining for beta III-tubulin or PGP 9.5 and nNOS was performed at 2, 4, and 8 weeks after transplantation. Results: Our res ults show that CNS-NSC express both the receptors (RET and GFR(U) for the e nteric neurotrophin, GDNF; GDNF, in turn, induces expansion of the RET-expr essing CNS-NSC population. Furthermore, CNS-NSC express nNOS and produce NO in vitro. When transplanted into the gut, CNS-NSC differentiate into neuro ns, continue to express nNOS and survive at least 8 weeks. Conclusions: We conclude that transplantation of CNS-NSC bears promise as a potential cellu lar replacement strategy for enteric neurons.