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Neurosphere
About: Neurosphere is a research topic. Over the lifetime, 5145 publications have been published within this topic receiving 321088 citations.
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TL;DR: The modified radial glia appear to be neural progenitor cells belonging to the astroglial lineage (type B cells) assuring both stem cell self-renewal and production of a differentiated progeny in the adult subventricular zone, and also playing regulatory roles in stem cell niche maintenance.
117 citations
TL;DR: The A20 protein is a known inhibitor of apoptosis that here is shown to be a novel cancer stem cell-promoting factor associated with poor glioma patient survival.
Abstract: Glioblastomas are deadly cancers that display a functional cellular hierarchy maintained by self-renewing glioblastoma stem cells (GSCs). GSCs are regulated by molecular pathways distinct from the bulk tumor that may be useful therapeutic targets. We determined that A20 (TNFAIP3), a regulator of cell survival and the NF-κB pathway, is overexpressed in GSCs relative to non-stem glioblastoma cells at both the mRNA and protein levels. To determine the functional significance of A20 in GSCs, we targeted A20 expression with lentiviral-mediated delivery of short hairpin RNA (shRNA). Inhibiting A20 expression decreased GSC growth and survival through mechanisms associated with decreased cell-cycle progression and decreased phosphorylation of p65/RelA. Elevated levels of A20 in GSCs contributed to apoptotic resistance: GSCs were less susceptible to TNFα-induced cell death than matched non-stem glioma cells, but A20 knockdown sensitized GSCs to TNFα-mediated apoptosis. The decreased survival of GSCs upon A20 knockdown contributed to the reduced ability of these cells to self-renew in primary and secondary neurosphere formation assays. The tumorigenic potential of GSCs was decreased with A20 targeting, resulting in increased survival of mice bearing human glioma xenografts. In silico analysis of a glioma patient genomic database indicates that A20 overexpression and amplification is inversely correlated with survival. Together these data indicate that A20 contributes to glioma maintenance through effects on the glioma stem cell subpopulation. Although inactivating mutations in A20 in lymphoma suggest A20 can act as a tumor suppressor, similar point mutations have not been identified through glioma genomic sequencing: in fact, our data suggest A20 may function as a tumor enhancer in glioma through promotion of GSC survival. A20 anticancer therapies should therefore be viewed with caution as effects will likely differ depending on the tumor type.
117 citations
TL;DR: This work isolated somatic stem cells from the human periodontium that were collected during minimally invasive periodontal access flap surgery as part of guided tissue regeneration therapy to assess neural differentiation after treatment of the expanded cells with a novel induction medium.
Abstract: Neural stem cells (NSCs) are potential sources for cell therapy of neurodegenerative diseases and for drug screening. Despite their potential benefits, ethical and practical considerations limit the application of NSCs derived from human embryonic stem cells (ES) or adult brain tissue. Thus, alternative sources are required to satisfy the criteria of ready accessibility, rapid expansion in chemically defined media and reliable induction to a neuronal fate. We isolated somatic stem cells from the human periodontium that were collected during minimally invasive periodontal access flap surgery as part of guided tissue regeneration therapy. These cells could be propagated as neurospheres in serum-free medium, which underscores their cranial neural crest cell origin. Culture in the presence of epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2) under serum-free conditions resulted in large numbers of nestin-positive/Sox-2-positive NSCs. These periodontium-derived (pd) NSCs are highly proliferative and migrate in response to chemokines that have been described as inducing NSC migration. We used immunocytochemical techniques and RT-PCR analysis to assess neural differentiation after treatment of the expanded cells with a novel induction medium. Adherence to substrate, growth factor deprivation, and retinoic acid treatment led to the acquisition of neuronal morphology and stable expression of markers of neuronal differentiation by more than 90% of the cells. Thus, our novel method might provide nearly limitless numbers of neuronal precursors from a readily accessible autologous adult human source, which could be used as a platform for further experimental studies and has potential therapeutic implications.
117 citations
TL;DR: Observations suggest that Meteorin plays important roles in both glial cell differentiation and axonal network formation during neurogenesis.
Abstract: Glial cells are major components of the nervous system. The roles of these cells are not fully understood, however. We have now identified a secreted protein, designated Meteorin, that is expressed in undifferentiated neural progenitors and in the astrocyte lineage, including radial glia. Meteorin selectively promoted astrocyte formation from mouse cerebrocortical neurospheres in differentiation culture, whereas it induced cerebellar astrocytes to become radial glia. Meteorin also induced axonal extension in small and intermediate neurons of sensory ganglia by activating nearby satellite glia. These observations suggest that Meteorin plays important roles in both glial cell differentiation and axonal network formation during neurogenesis.
116 citations
TL;DR: Given the efficacy findings and lack of adverse events in the RCS rat in combination with the results from ongoing clinical investigations, HuCNS‐SC appear to be a well‐suited candidate for cell therapy in retinal degenerative conditions.
Abstract: Stem cells derived from the human brain and grown as neurospheres (HuCNS-SC) have been shown to be effective in treating central neurodegenerative conditions in a variety of animal models. Human safety data in neurodegenerative disorders are currently being accrued. In the present study, we explored the efficacy of HuCNS-SC in a rodent model of retinal degeneration, the Royal College of Surgeons (RCS) rat, and extended our previous cell transplantation studies to include an in-depth examination of donor cell behavior and phenotype post-transplantation. As a first step, we have shown that HuCNS-SC protect host photoreceptors and preserve visual function after transplantation into the subretinal space of postnatal day 21 RCS rats. Moreover, cone photoreceptor density remained relatively constant over several months, consistent with the sustained visual acuity and luminance sensitivity functional outcomes. The novel findings of this study include the characterization and quantification of donor cell radial migration from the injection site and within the subretinal space as well as the demonstration that donor cells maintain an immature phenotype throughout the 7 months of the experiment and undergo very limited proliferation with no evidence of uncontrolled growth or tumor-like formation. Given the efficacy findings and lack of adverse events in the RCS rat in combination with the results from ongoing clinical investigations, HuCNS-SC appear to be a well-suited candidate for cell therapy in retinal degenerative conditions.
116 citations