gms | German Medical Science

Introduction: A number of gastrointestinal disorders such as gut motility or inflammatory diseases are caused by abnormalities of the enteric nervous system (ENS). Neural stem cells of the ENS have been proposed as an appropriate cell pool to provide an alternative therapeutic option for the unsatisfactory current treatments of these diseases. Here, we investigated the in vitro and in vivo therapeutic potential of neural progenitors isolated from human postnatal gut.

Methods: Neural stem cells from human postnatal gut biopsies were propagated as neurosphere-like bodies (NLBs). For in vitro implantation studies, NLBs were grafted into fetal slice cultures and aganglionic hindgut explants. For in vivo testing, immunodeficient CD-1 nude mice served as recipient animals following chemical ablation of the myenteric plexus in a small colonic segment. NLBs were directly applied on the surface of the treated gut segments using a fibrin matrix. Neural cell integration and differentiation was demonstrated by in situ hybridization for the human Alu-sequence and immunohistochemistry for neural subtypes such as PGP9.5, NOS and S100b. Functional recovery of in vivo treated guts was proved by electrical field stimulation in organ bath.

Results: We were able to generate proliferating NLBs from human postnatal gut tissues in vitro. NLB-derived cells could be differentiated into functional neuronal and glial cells as demonstrated by the expression of a variety of neural markers and clearly distinguishable sodium currents. Both, the in vitro as well as in vivo transplantation approach showed neural stem cell integration within the smooth muscle layers of the gut wall and differentiation into glia and neurons. In vivo, NLB-derived cells were detected in the gut wall of all transplanted animals, although with high variability in the total amount of integrated cells and the ability to form neoganglia. However, in the organ bath analysis, only the transplanted group revealed a notable functional improvement of isometric contraction in the affected area suggesting real functional cell integration.

Discussion: This study provides a significant and necessary step for the further development of enteric neural transplantation in the treatment of a specific group of gastrointestinal disorders but, importantly, has wider applicability for the establishment of neural components within the many facets of regenerative medicine.