RESUMO
Identification of the stem cell niche is crucial for understanding the factors that regulate these cells. Rodent enteric neural crest-derived stem cells have previously been isolated by flow cytometry and culture of cell suspensions from the outer smooth muscle layers or the entire gut wall from postnatal and adult animals. Such cell suspensions contain a mixture of cell types, including smooth muscle, fibroblasts and cells associated with the vasculature and extrinsic innervation. Thus these preparations may be contaminated by stem cells associated with extrinsic sensory and autonomic nerves and by other types of stem cell that reside in the gut. Here we describe a different approach, similar to that recently used for infant human gut, to obtain enteric ganglion-derived cells, with properties of neural progenitor cells, using isolated myenteric ganglia from postnatal rat ileum. Myenteric ganglia were separated from the gut wall, dispersed and resulting cell dissociates were plated in non-adherent culture conditions with EGF and FGF-2. Under these conditions neurosphere-like bodies (NLB) developed. Cells in NLB incorporated BrdU and expressed the stem cell marker nestin but not the pan-neuronal marker PGP 9.5. Upon growth factor withdrawal some BrdU-immunopositive cells assumed the morphology of neurons and expressed PGP 9.5; others were flattened and expressed the glial cell marker GFAP. This work therefore provides evidence that neural crest-derived progenitors in the postnatal rat gut are located in the myenteric plexus, and shows that these cells can be expanded and differentiated in NLB in vitro.
Assuntos
Diferenciação Celular/fisiologia , Gânglios Autônomos/citologia , Plexo Mientérico/citologia , Neurônios/fisiologia , Células-Tronco/fisiologia , Fatores Etários , Animais , Animais Recém-Nascidos , Bromodesoxiuridina/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Fator de Crescimento Epidérmico/farmacologia , Fator 2 de Crescimento de Fibroblastos/farmacologia , Citometria de Fluxo/métodos , Proteína Glial Fibrilar Ácida/metabolismo , Plexo Mientérico/crescimento & desenvolvimento , Ratos , Ratos Sprague-Dawley , Células-Tronco/efeitos dos fármacos , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismoRESUMO
Colostrinin (CLN), a complex mixture of proline-rich polypeptides derived from colostrums, can alleviate cognitive decline in early Alzheimer's disease patients. The molecular basis of the action of CLN has been studied in vitro using human neuroblastoma cell lines. The aim of the present study was to use quantitative immunocytochemistry and immunoblotting to investigate the ability of CLN to relieve amyloid-beta (Abeta)-induced cytotoxicity in rat primary hippocampal neuronal cells. Our data confirm that CLN alleviates the effect of Abeta-induced cytotoxicity and causes a significant reduction in the elevated levels of the antioxidant enzyme SOD1.