Properties of secondary and tertiary human enteric nervous system neurospheres

Advances in enteric nervous system (ENS) stem cell biology have raised the possibility of treating Hirschsprung's disease with ENS stem/progenitor cell (ENSPC) transplantation. This study aimed to expand ENSPC numbers by the growth and redissociation of neurospheres and assess their differential potential.MethodsHuman ENS neurospheres were cultured as previously described and redissociated to generate secondary and tertiary neurospheres. Neurospheres were assessed for the presence of neuronal (PGP9.5), glial (S100), and stem cell (p75, nestin markers). The degree of immunofluorescence was quantified using the ImageJ program. Secondary/tertiary neurospheres were transplanted into mouse distal colon grown in tissue culture.ResultsSecondary/tertiary neurospheres could be generated with exponentially increasing numbers. Tertiary neurospheres showed a significant increase in the proportion of p75 staining but a significant decrease in the proportion of S100 staining. After transplantation, secondary/tertiary neurosphere–derived cells positive for PGP9.5 and S100 could be identified.ConclusionsIt is possible to exponentially expand neurosphere and therefore ENSPC numbers by repeated dissociation and culture. There is a loss of S100-positive cells in secondary/tertiary neurospheres, but the ENSPCs remain capable of differentiating into neurons and glia when transplanted into an embryonic gut environment.