The enteric nervous system (ENS) is an extensive network of neurons and glia within
the wall of the gastrointestinal (GI) tract that regulates many essential GI functions.
Consequently, disorders of the ENS due to developmental defects, inflammation, infection,
or age-associated neurodegeneration lead to serious neurointestinal diseases. Despite
the prevalence and severity of these diseases, effective treatments are lacking as
they fail to directly address the underlying pathology. Neuronal stem cell therapy
represents a promising approach to treating diseases of the ENS by replacing the absent
or injured neurons, and an autologous source of stem cells would be optimal by obviating
the need for immunosuppression. We utilized the swine model to address key questions
concerning cell isolation, delivery, engraftment, and fate in a large animal relevant
to human therapy. We successfully isolated neural stem cells from a segment of small
intestine resected from 1-month-old swine. Enteric neuronal stem cells (ENSCs) were
expanded as neurospheres that grew optimally in low-oxygen (5%) culture conditions.
Enteric neuronal stem cells were labeled by lentiviral green fluorescent protein (GFP)
transduction, then transplanted into the same swine from which they had been harvested.
Endoscopic ultrasound was then utilized to deliver the ENSCs (10,000-30,000 neurospheres
per animal) into the rectal wall. At 10 and 28 days following injection, autologously
derived ENSCs were found to have engrafted within rectal wall, with neuroglial differentiation
and no evidence of ectopic spreading. These findings strongly support the feasibility
of autologous cell isolation and delivery using a clinically useful and minimally
invasive technique, bringing us closer to first-in-human ENSC therapy for neurointestinal
diseases.
