No abstract

The enteric nervous system (ENS) has to respond to continuously changing microenvironmental challenges within the gut and is therefore dependent on a neural stem cell niche to keep the ENS functional throughout life. In this study, we hypothesize that this stem cell niche is also affected during inflammation and therefore investigated lipopolysaccharides (LPS) effects on enteric neural stem/progenitor cells (NSPCs). NSPCs were derived from the ENS and cultured under the influence of different LPS concentrations. LPS effects upon proliferation and differentiation of enteric NSPC cultures were assessed using immunochemistry, flow cytometry, western blot, Multiplex ELISA and real-time PCR. LPS enhances the proliferation of enteric NSPCs in a dose-dependent manner. It delays and modifies the differentiation of these cells. The expression of the LPS receptor toll-like receptor 4 on NSPCs could be demonstrated. Moreover, LPS induces the secretion of several cytokines. Flow cytometry data gives evidence for individual subgroups within the NSPC population. ENS-derived NSPCs respond to LPS in maintaining at least partially their stem cell character. In the case of inflammatory disease or trauma where the liberation and exposure to LPS will be increased, the expansion of NSPCs could be a first step towards regeneration of the ENS. The reduced and altered differentiation, as well as the induction of cytokine signalling, demonstrates that the stem cell niche may take part in the LPS-transmitted inflammatory processes in a direct and defined way.

No abstract

The enteric nervous system (ENS) controls and modulates gut motility and responds to food intake and to internal and external stimuli such as toxins or inflammation. Its plasticity is maintained throughout life by neural progenitor cells within the enteric stem cell niche. Granulocyte-colony stimulating factor (G-CSF) is known to act not only on cells of the immune system but also on neurons and neural progenitors in the central nervous system (CNS). Here, we demonstrate, for the first time, that G-CSF receptor is present on enteric neurons and progenitors and that G-CSF plays a role in the expansion and differentiation of enteric neural progenitor cells. Cultured mouse ENS-neurospheres show increased expansion with increased G-CSF concentrations, in contrast to CNS-derived spheres. In cultures from differentiated ENS- and CNS-neurospheres, neurite outgrowth density is enhanced depending on the amount of G-CSF in the culture. G-CSF might be an important factor in the regeneration and differentiation of the ENS and might be a useful tool for the investigation and treatment of ENS disorders.

The interaction of cells with their microenvironment is an important factor, which influences phenotype, differentiation state and cell function. Interactions between cells and extracellular matrix (ECM) components are of crucial significance, especially for the development of electrical activity in neurons. For this study multi‐electrode arrays were used to examine the influence of different substrates (glass, poly‐D‐lysine (PDL), PDL/laminin and laminin) on myenteric neurons during stimulation with lipopolysaccharide (LPS). The effect of LPS upon neurons grown on PDL/laminin resulted in an increased neuronal activity and calcium influx through L‐type voltage gated calcium channels. Cultures on glass or PDL were not influenced. This demonstrates that the local microenvironment plays an essential role for the electrical potential of myenteric neurons.(© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)