Neurosphere

About: Neurosphere is a research topic. Over the lifetime, 5145 publications have been published within this topic receiving 321088 citations.

Store-operated CRAC channels regulate gene expression and proliferation in neural progenitor cells.

Abstract: Calcium signals regulate many critical processes during vertebrate brain development including neurogenesis, neurotransmitter specification, and axonal outgrowth. However, the identity of the ion channels mediating Ca2+ signaling in the developing nervous system is not well defined. Here, we report that embryonic and adult mouse neural stem/progenitor cells (NSCs/NPCs) exhibit store-operated Ca2+ entry (SOCE) mediated by Ca2+ release-activated Ca2+ (CRAC) channels. SOCE in NPCs was blocked by the CRAC channel inhibitors La3+, BTP2, and 2-APB and Western blots revealed the presence of the canonical CRAC channel proteins STIM1 and Orai1. Knock down of STIM1 or Orai1 significantly diminished SOCE in NPCs, and SOCE was lost in NPCs from transgenic mice lacking Orai1 or STIM1 and in knock-in mice expressing the loss-of-function Orai1 mutant, R93W. Therefore, STIM1 and Orai1 make essential contributions to SOCE in NPCs. SOCE in NPCs was activated by epidermal growth factor and acetylcholine, the latter occurring through muscarinic receptors. Activation of SOCE stimulated gene transcription through calcineurin/NFAT (nuclear factor of activated T cells) signaling through a mechanism consistent with local Ca2+ signaling by Ca2+ microdomains near CRAC channels. Importantly, suppression or deletion of STIM1 and Orai1 expression significantly attenuated proliferation of embryonic and adult NPCs cultured as neurospheres and, in vivo, in the subventricular zone of adult mice. These findings show that CRAC channels serve as a major route of Ca2+ entry in NPCs and regulate key effector functions including gene expression and proliferation, indicating that CRAC channels are important regulators of mammalian neurogenesis.

Analysis of host-mediated repair mechanisms after human CNS-stem cell transplantation for spinal cord injury: correlation of engraftment with recovery.

Abstract: BackgroundHuman central nervous system-stem cells grown as neurospheres (hCNS-SCns) self-renew, are multipotent, and have potential therapeutic applications following trauma to the spinal cord We have previously shown locomotor recovery in immunodeficient mice that received a moderate contusion spinal cord injury (SCI) and hCNS-SCns transplantation 9 days post-injury (dpi) Engrafted hCNS-SCns exhibited terminal differentiation to myelinating oligodendrocytes and synapse-forming neurons Further, selective ablation of human cells using Diphtheria toxin (DT) abolished locomotor recovery in this paradigm, suggesting integration of human cells within the mouse host as a possible mechanism for the locomotor improvement However, the hypothesis that hCNS-SCns could alter the host microenvironment as an additional or alternative mechanism of recovery remained unexplored; we tested that hypothesis in the present studyMethods and FindingsStereological quantification of human cells using a human-specific cytoplasmic marker demonstrated successful cell engraftment, survival, migration and limited proliferation in all hCNS-SCns transplanted animals DT administration at 16 weeks post-transplant ablated 805% of hCNS-SCns Stereological quantification for lesion volume, tissue sparing, descending serotonergic host fiber sprouting, chondroitin sulfate proteoglycan deposition, glial scarring, and angiogenesis demonstrated no evidence of host modification within the mouse spinal cord as a result of hCNS-SCns transplantation Biochemical analyses supplemented stereological data supporting the absence of neural stem-cell mediated host repair However, linear regression analysis of the number of engrafted hCNS-SCns vs the number of errors on a horizontal ladder beam task revealed a strong correlation between these variables (r = −078, p<005), suggesting that survival and engraftment were directly related to a quantitative measure of recoveryConclusionsAltogether, the data suggest that the locomotor improvements associated with hCNS-SCns transplantation were not due to modifications within the host microenvironment, supporting the hypothesis that human cell integration within the host circuitry mediates functional recovery following a 9 day delayed transplant

Characterisation and transplantation of enteric nervous system progenitor cells. Commentary

Abstract: Aims: Enteric nervous system (ENS) progenitor cells have been postulated to be an appropriate source of cells for the treatment of Hirschsprung's disease. In order for this to be successful, the techniques previously used for the isolation of rodent ENS progenitor cells need to be adapted for postnatal human tissue. In this paper, we describe a method suitable for the preparation of both mouse and human postnatal ENS progenitor cells and assess their transplantation potential. Method: Single cell suspensions were isolated from 11.5 days post-coitum embryonic mouse caecum and postnatal human myenteric plexus. These cells were cultured under non-adherent conditions to generate neurospheres which were implanted into aganglionic embryonic mouse hindgut explants. Cell proliferation, migration and differentiation were observed using immunofluorescence microscopy. Results: Neurospheres generated from both mouse and human tissues contained proliferating neural crest-derived cells that could be expanded in tissue culture to generate both glial cells and neurons. When implanted into aganglionic murine gut, cells migrated from the neurospheres using pathways appropriate for cells derived from the neural crest, and differentiated to become glia and neurons expressing neuronal phenotypic markers characteristic of the ENS including nitric oxide synthase and vasoactive intestinal polypeptide. Conclusion: We have developed a technique for the isolation and expansion of ENS progenitor cells from human neonates. These cells have the ability to differentiate into neurons and glia when transplanted into aganglionic gut, this demonstration being a necessary first step for their autologous transplantation in the treatment of Hirschsprung's disease.