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Neural Progenitors (neural + progenitor)
Terms modified by Neural Progenitors Selected AbstractsColloquium C13: Neural progenitors of the subventricular zone and their role in pathology and repairJOURNAL OF NEUROCHEMISTRY, Issue 2005V. Gallo No abstract is available for this article. [source] Long chain-polyunsaturated fatty acids modulate membrane phospholipid composition and protein localization in lipid rafts of neural stem cell culturesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2010Bénédicte Langelier Abstract Rat neural stem cells/neural progenitors (NSC/NP) are generally grown in serum-free medium. In this study, NSC/NP were supplemented with the main long-chain polyunsaturated fatty acids (PUFAs) present in the brain, arachidonic acid (AA), or docosahexaenoic acid (DHA), and were monitored for their growth. Lipid and fatty acid contents of the cells were also determined. Under standard conditions, the cells were characterized by phospholipids displaying a highly saturated profile, and very low levels of PUFAs. When cultured in the presence of PUFAs, the cells easily incorporated them into the phospholipid fraction. We also compared the presence of three membrane proteins in the lipid raft fractions: GFR and connexin 43 contents in the rafts were increased by DHA supplementation, whereas G, subunit content was not significantly modified. The restoration of DHA levels in the phospholipids could profoundly affect protein localization and, consequently, their functionalities. J. Cell. Biochem. 110: 1356,1364, 2010. © 2010 Wiley-Liss, Inc. [source] Neural differentiation of human embryonic stem cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2008Sujoy K. Dhara Abstract Availability of human embryonic stem cells (hESC) has enhanced human neural differentiation research. The derivation of neural progenitor (NP) cells from hESC facilitates the interrogation of human embryonic development through the generation of neuronal subtypes and supporting glial cells. These cells will likely lead to novel drug screening and cell therapy uses. This review will discuss the current status of derivation, maintenance and further differentiation of NP cells with special emphasis on the cellular signaling involved in these processes. The derivation process affects the yield and homogeneity of the NP cells. Then when exposed to the correct environmental signaling cues, NP cells can follow a unique and robust temporal cell differentiation process forming numerous phenotypes. J. Cell. Biochem. 105: 633,640, 2008. © 2008 Wiley-Liss, Inc. [source] Comparative evaluation of human embryonic stem cell lines derived from zygotes with normal and abnormal pronucleiDEVELOPMENTAL DYNAMICS, Issue 2 2010Qing Huan Abstract Human embryonic stem (hES) cell lines have been derived from normally or abnormally fertilized zygotes. However, the similar and different properties of these two types of hES cell lines are not well-known. To address this question, we generated nine hES cell lines from zygotes containing normal (2PN) and abnormal (0PN, 1PN, 3PN) pronuclei. A side-by-side comparison showed that all cell lines exhibited distinct identity and karyotypical stability. They expressed similar "stemness" markers and alkaline phosphatase activity and differentiated into three embryonic germ lineages in embryoid bodies and teratomas. Under neural differentiation-promoting conditions, they were directed into neural progenitors and neurons. However, a variation in cell cycle and the relative abundance of gene expression of undifferentiated and differentiated markers were observed. These variations were also seen among individually derived normal hES cell lines. Thus, normal hES cell lines can be developed from fertilized zygotes with abnormal pronuclei usually excluded from clinical use. Developmental Dynamics 239:425,438, 2010. © 2009 Wiley-Liss, Inc. [source] Neural protein Olig2 acts upstream of the transcriptional regulator sim1 to specify diencephalic dopaminergic neuronsDEVELOPMENTAL DYNAMICS, Issue 4 2009Nataliya Borodovsky Abstract Neural factors are expressed in neural progenitors and regulate neurogenesis and gliogenesis. Recent studies suggested that these factors are also involved in determining specific neuronal fates by regulating the expression of their target genes, thereby creating transcriptional codes for neuronal subtype specification. In the present study, we show that in the zebrafish the neural gene Olig2 and the transcriptional regulator Sim1 are co-expressed in a subset of diencephalic progenitors destined towards the dopaminergic (DA) neuronal fate. While sim1 mRNA is also detected in mature DA neurons, the expression of olig2 is extinguished prior to terminal DA differentiation. Loss of function of either Olig2 or Sim1 leads to impaired DA development. Finally, Olig2 regulates the expression of Sim1 and gain of function of Sim1 rescues the deficits in DA differentiation caused by targeted knockdown of Olig2. Our findings demonstrate for the first time that commitment of basal diencephalic DA neurons is regulated by the combined action of the neural protein Olig2 and its downstream neuronal specific effector Sim1. Developmental Dynamics 238:826,834, 2009. © 2009 Wiley-Liss, Inc. [source] gfap and nestin reporter lines reveal characteristics of neural progenitors in the adult zebrafish brainDEVELOPMENTAL DYNAMICS, Issue 2 2009Chen Sok Lam Abstract Adult neurogenesis arises from niches that harbor neural stem cells (NSC). Although holding great promise for regenerative medicine, the identity of NSC remains elusive. In mammals, a key attribute of NSC is the expression of the filamentous proteins glial fibrillary acidic protein (GFAP) and NESTIN. To assess whether these two markers are relevant in the fish model, two transgenic zebrafish lines for gfap and nestin were generated. Analysis of adult brains showed that the fusion GFAP,green fluorescent protein closely mimics endogenous GFAP, while the nestin transgene recapitulates nestin at the ventricular zones. Cells expressing the two reporters display radial glial morphology, colocalize with the NSC marker Sox2, undergo proliferation, and are capable of self-renewal within the matrix of distinct thickness in the telencephalon. Together, these two transgenic lines reveal a conserved feature of putative NSC in the adult zebrafish brain and provide a means for the identification and manipulation of these cells in vivo. Developmental Dynamics 238:475,486, 2009. © 2009 Wiley-Liss, Inc. [source] Electroporation as a tool to study in vivo spinal cord regenerationDEVELOPMENTAL DYNAMICS, Issue 2 2003K. Echeverri Abstract Tailed amphibians such as axolotls and newts have the unique ability to fully regenerate a functional spinal cord throughout life. Where the cells come from and how they form the new structure is still poorly understood. Here, we describe the development of a technique that allows the visualization of cells in the living animal during spinal cord regeneration. A microelectrode needle is inserted into the lumen of the spinal cord and short rapid pulses are applied to transfer the plasmids encoding the green or red fluorescent proteins into ependymal cells close to the plane of amputation. The use of small, transparent axolotls permits imaging with epifluorescence and differential interference contrast microscopy to track the transfected cells as they contribute to the spinal cord. This technique promises to be useful in understanding how neural progenitors are recruited to the regenerating spinal cord and opens up the possibility of testing gene function during this process. Developmental Dynamics 226:418,425, 2003. © 2003 Wiley-Liss, Inc. [source] Evidence for neural stem cells in the medaka optic tectum proliferation zones,DEVELOPMENTAL NEUROBIOLOGY, Issue 10 2010Alessandro Alunni Abstract Few adult neural stem cells have been characterized in vertebrates. Although teleosts continually generate new neurons in many regions of the brain after embryogenesis, only two types of neural stem cells (NSCs) have been reported in zebrafish: glial cells in the forebrain resembling mammalian NSCs, and neuroepithelial cells in the cerebellum. Here, following our previous studies on dividing progenitors (Nguyen et al. [1999]: J Comp Neurol 413:385,404.), we further evidenced NSCs in the optic tectum (OT) of juvenile and adult in the medaka, Oryzias latipes. To detect very slowly cycling progenitors, we did not use the commonly used BrdU/PCNA protocol, in which PCNA may not be present during a transiently quiescent state. Instead, we report the optimizations of several protocols involving long subsequent incubations with two thymidine analogs (IdU and CldU) interspaced with long chase times between incubations. These protocols allowed us to discriminate and localize fast and slow cycling cells in OT of juvenile and adult in the medaka. Furthermore, we showed that adult OT progenitors are not glia, as they express neither brain lipid-binding protein (BLBP) nor glial fibrillary acidic protein (GFAP). We also showed that expression of pluripotency-associated markers (Sox2, Musashi1 and Bmi1) colocalized with OT progenitors. Finally, we described the spatio-temporally ordered population of NSCs and progenitors in the medaka OT. Hence, the medaka appears as an invaluable model for studying neural progenitors that will open the way to further exciting comparative studies of neural stem cells in vertebrates. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 693,713, 2010 [source] Functional differentiation of a clone resembling embryonic cortical interneuron progenitorsDEVELOPMENTAL NEUROBIOLOGY, Issue 14 2008Hedong Li Abstract We have generated clones (L2.3 and RG3.6) of neural progenitors with radial glial properties from rat E14.5 cortex that differentiate into astrocytes, neurons, and oligodendrocytes. Here, we describe a different clone (L2.2) that gives rise exclusively to neurons, but not to glia. Neuronal differentiation of L2.2 cells was inhibited by bone morphogenic protein 2 (BMP2) and enhanced by Sonic Hedgehog (SHH) similar to cortical interneuron progenitors. Compared with L2.3, differentiating L2.2 cells expressed significantly higher levels of mRNAs for glutamate decarboxylases (GADs), DLX transcription factors, calretinin, calbindin, neuropeptide Y (NPY), and somatostatin. Increased levels of DLX-2, GADs, and calretinin proteins were confirmed upon differentiation. L2.2 cells differentiated into neurons that fired action potentials in vitro, and their electrophysiological differentiation was accelerated and more complete when cocultured with developing astroglial cells but not with conditioned medium from these cells. The combined results suggest that clone L2.2 resembles GABAergic interneuron progenitors in the developing forebrain. © 2008 Wiley Periodicals, Inc. Develop Neurobiol 2008 [source] Intrinsic and spontaneous neurogenesis in the postnatal slice culture of rat hippocampusEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2004Maki Kamada Abstract Organotypic slice culture preserves the morphological and physiological features of the hippocampus of live animals for a certain time. The hippocampus is one of exceptional regions where neurons are generated intrinsically and spontaneously throughout postnatal life. We investigated the possibility that neurons are generated continuously at the dentate granule cell layer (GCL) in slice culture of the rat hippocampus. Using 5-bromodeoxyuridine (BrdU) labelling and retrovirus vector transduction methods, the phenotypes of the newly generated cells were identified immunohistochemically. At 4 weeks after BrdU exposure, BrdU-labelled cells were found in the GCL and were immunoreactive with a neuronal marker, anti-NeuN. There were fibrils immunoreactive with anti-glial fibrillary acidic protein (GFAP), an astrocyte marker, in the layer covering the GCL and occasionally encapsulated BrdU-labelled nuclei. When the newly divided cells were marked with the enhanced green fluorescent protein (EGFP) using a retrovirus vector, these cells had proliferative abilities throughout the following 4-week cultivation period. Four weeks after the inoculation, the EGFP-expressing cells consisted of various phenotypes of both early and late stages of differentiation; some were NeuN-positive cells with appearances of neurons in the GCL and some were immunoreactive with anti-Tuj1, a marker of immature neurons. Some EGFP-expressing cells were immunoreactive with anti-GFAP or anti-nestin, a marker of neural progenitors. The present study suggests that slice cultures intrinsically retain spontaneous neurogenic abilities for their cultivation period. The combination of slice culture and retrovirus transduction methods enable the newly divided cells to be followed up for a long period. [source] MSI-1, a neural RNA-binding protein, is involved in male mating behaviour in Caenorhabditis elegansGENES TO CELLS, Issue 11 2000Akinori Yoda Neural RNA-binding proteins are thought to play important roles in neural development and the functional regulation of postmitotic neurones by mediating post-transcriptional gene regulation. RNA-binding proteins belonging to the Musashi family are highly expressed in the nervous system; however, their roles are poorly understood. We identified a Caenorhabditis elegans Musashi homologue, MSI-1, whose RNA-recognition motifs show extensive similarity to those of Drosophila and vertebrate Musashi proteins. We isolated a msi-1 mutant and found males with this mutation to have a mating defect. C. elegans male mating behaviour includes a distinct series of steps: response to contact, backing, turning, vulva location, spicule insertion, and sperm transfer. msi-1 is required for the turning and vulva location steps. Like other Musashi family members, MSI-1 is expressed specifically in neural cells, including male-specific neurones required for turning and vulva location. However, msi-1 was not expressed in proliferating neural progenitors in C. elegans, unlike the Musashi family genes in other systems. Our results suggest that msi-1 is expressed specifically in postmitotic neurones in C. elegans. msi-1 is required for full development of male mating behaviour, possibly through regulation of msi-1 expressing neurones. [source] A role for Connexin43 during neurodevelopmentGLIA, Issue 7 2007Amy E. Wiencken-Barger Abstract Connexin43 (Cx43) is the predominant gap junction protein expressed in premitotic radial glial cells and mature astrocytes. It is thought to play a role in many aspects of brain development and physiology, including intercellular communication, the release of neuroactive substances, and neural and glial proliferation and migration. To investigate the role of Cx43 in brain physiology, we generated a conditional knockout (cKO) mouse expressing Cre recombinase driven by the human GFAP promoter and a floxed Cx43 gene. The removal of Cx43 from GFAP-expressing cells affects the behavior of the mice and the development of several brain structures; however, the severity of the phenotype varies depending on the mouse background. One mouse subline, hereafter termed Shuffler, exhibits cellular disorganization of the cortex, hippocampus, and cerebellum, accompanied by ataxia and motor deficits. The Shuffler cerebellum is most affected and displays altered distribution and lamination of glia and neurons suggestive of cell migration defects. In all Shuffler mice by postnatal day two (P2), the hippocampus, cortex, and cerebellum are smaller. Disorganization of the ventricular and subventricular zone of the cortex is also evident. Given that these are sites of early progenitor cell proliferation, we suspect production and migration of neural progenitors may be altered. In conclusion, neurodevelopment of Shuffler/Cx43 cKO mice is abnormal, and the observed cellular phenotype may explain behavioral disturbances seen in these animals as well as in humans carrying Cx43 mutations. © 2007 Wiley-Liss, Inc. [source] Group III metabotropic glutamate receptor activation suppresses self-replication of undifferentiated neocortical progenitor cellsJOURNAL OF NEUROCHEMISTRY, Issue 5 2008Noritaka Nakamichi§ Abstract We evaluated the possible functional expression of metabotropic glutamate receptors (mGluRs) by neural progenitors from embryonic mouse neocortex. Constitutive expression was seen with group I, II, and III mGluRs in undifferentiated cells and neurospheres formed by clustered cells during culture with epidermal growth factor. The group III mGluR agonist, l -2-amino-4-phosphonobutyrate, drastically reduced proliferation activity at 1,100 ,M without inducing cell death, with group I and group II mGluR agonists being ineffective, in these neurospheres. Both forskolin and a group III mGluR antagonist significantly increased the proliferation alone, but significantly prevented the suppression by l -2-amino-4-phosphonobutyrate. Activation of group III mGluR significantly decreased mRNA expression of the cell cycle regulator cyclinD1, in addition to inhibiting the transactivation mediated by cAMP of cyclinD1 gene in the pluripotent P19 progenitor cells. Prior activation of group III mGluR led to a significant decrease in the number of cells immunoreactive for a neuronal marker, with an increase in that for an astroglial marker irrespective of differentiation inducers. These results suggest that group III mGluR may be functionally expressed to suppress self-renewal capacity through a mechanism related to cAMP formation with promotion of subsequent differentiation into astroglial lineage in neural progenitors. [source] Promoting directional axon growth from neural progenitors grafted into the injured spinal cordJOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2010Joseph F. Bonner Abstract Spinal cord injury (SCI) is a devastating condition characterized by disruption of axonal connections, failure of axonal regeneration, and loss of motor and sensory function. The therapeutic promise of neural stem cells has been focused on cell replacement, but many obstacles remain in obtaining neuronal integration following transplantation into the injured CNS. This study investigated the neurotransmitter identity and axonal growth potential of neural progenitors following grafting into adult rats with a dorsal column lesion. We found that using a combination of neuronal and glial restricted progenitors (NRP and GRP) produced graft-derived glutamatergic and GABAergic neurons within the injury site, with minimal axonal extension. Administration of brain-derived neurotrophic factor (BDNF) with the graft promoted modest axonal growth from grafted cells. In contrast, injecting a lentiviral vector expressing BDNF rostral into the injured area generated a neurotrophin gradient and promoted directional growth of axons for up to 9 mm. Animals injected with BDNF lentivirus (at 2.5 and 5.0 mm) showed significantly more axons and significantly longer axons than control animals injected with GFP lentivirus. However, only the 5.0-mm-BDNF group showed a preference for extension in the rostral direction. We concluded that NRP/GRP grafts can be used to produce excitatory and inhibitory neurons, and neurotrophin gradients can guide axonal growth from graft-derived neurons toward putative targets. Together they can serve as a building block for neuronal cell replacement of local circuits and formation of neuronal relays. © 2009 Wiley-Liss, Inc. [source] Possible promotion of neuronal differentiation in fetal rat brain neural progenitor cells after sustained exposure to static magnetismJOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2009Noritaka Nakamichi Abstract We have previously shown significant potentiation of Ca2+ influx mediated by N-methyl- D -aspartate receptors, along with decreased microtubules-associated protein-2 (MAP2) expression, in hippocampal neurons cultured under static magnetism without cell death. In this study, we investigated the effects of static magnetism on the functionality of neural progenitor cells endowed to proliferate for self-replication and differentiate into neuronal, astroglial, and oligodendroglial lineages. Neural progenitor cells were isolated from embryonic rat neocortex and hippocampus, followed by culture under static magnetism at 100 mT and subsequent determination of the number of cells immunoreactive for a marker protein of particular progeny lineages. Static magnetism not only significantly decreased proliferation of neural progenitor cells without affecting cell viability, but also promoted differentiation into cells immunoreactive for MAP2 with a concomitant decrease in that for an astroglial marker, irrespective of the presence of differentiation inducers. In neural progenitors cultured under static magnetism, a significant increase was seen in mRNA expression of several activator-type proneural genes, such as Mash1, Math1, and Math3, together with decreased mRNA expression of the repressor type Hes5. These results suggest that sustained static magnetism could suppress proliferation for self-renewal and facilitate differentiation into neurons through promoted expression of activator-type proneural genes by progenitor cells in fetal rat brain. © 2009 Wiley-Liss, Inc. [source] AUF1 and Hu proteins in the developing rat brain: Implication in the proliferation and differentiation of neural progenitorsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2009Dolores Hambardzumyan Abstract Posttranscriptional events such as RNA stabilization are important for cell differentiation, but little is known about the impact of AU-rich binding proteins (AUBPs) on the fate of neural cells. Expression of destabilizing AUBPs such as AUF1 and neuronal-specific stabilizing proteins such as HuB, HuC and HuD was therefore analyzed in the developing central nervous system. Real-time RT-PCR indicated a specific developmental pattern in the postnatal cerebellum, with a progressive down-regulation of AUF1 from P1, whereas HuB was strongly up-regulated at about P7. These changes were accompanied by a progressive increase in AUF1p45 and the disappearance of one HuB isoform from P15, suggesting particular roles for these AUBPs in the developing cerebellum. AUF1 was detected in the three main cerebellar layers, whereas Hu proteins were found only in postmitotic neurons. A role for Hu proteins in the early stages of neuronal differentiation is further supported by arrest of cell proliferation following induction of HuB or HuD expression in a neural stem cell line. The decrease in nestin expression suggest that HuD, but not HuB, favors the transition of neural progenitors into early neuroblasts, but other factors are most probably required for their full differentiation into neurons, insofar as GAP-43 was not detected in HuD-transfected cells. These data suggest critical roles for HuB at the very earliest stages of neuronal differentiation, such as cell cycle exit, and HuD might also be involved in the transition of neural progenitors into early neuroblasts. Taken together, the present results strengthen the importance of AUBPs in brain ontogenesis. © 2008 Wiley-Liss, Inc. [source] Epigenetic modifications of SOX2 enhancers, SRR1 and SRR2, correlate with in vitro neural differentiation,JOURNAL OF NEUROSCIENCE RESEARCH, Issue 8 2008Marianna Sikorska Abstract SOX2 is a key neurodevelopmental gene involved in maintaining the pluripotency of stem cells and proliferation of neural progenitors and astroglia. Two evolutionally conserved enhancers, SRR1 and SRR2, are involved in controlling SOX2 expression during neurodevelopment; however, the molecular mechanisms regulating their activity are not known. We have examined DNA methylation and histone H3 acetylation at both enhancers in NT2-D1 progenitors, neurons and astrocytes, to establish the role of epigenetic mechanisms in cell-type-specific SOX2 expression. This study showed that 1) unmethylated DNA and acetylated histones at both enhancers correlated with a high level of SOX2 expression in proliferating neural progenitors and 2) reversible modifications of the SRR1 element were observed during gene reexpression in astrocytes, whereas permanent epigenetic marks on the SRR2 enhancer were seen in neurons where the gene was silenced. Taken together, these results are clear illustrations of cell-type-specific epigenomes and suggest mechanisms by which they may be created and maintained. © 2008 Wiley-Liss, Inc. [source] Ethanol exposure during embryogenesis decreases the radial glial progenitorpool and affects the generation of neurons and astrocytesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 3 2006Gemma Rubert Abstract Prenatal ethanol exposure induces functional abnormalities during brain development affecting neurogenesis and gliogenesis. We have previously reported that alcohol exposure during embryogenesis disrupts radial glia (RG) and gliogenesis. Taking into account the new role of RG as neural progenitors, we have investigated whether ethanol affects RG as a neural stem cell. We found that in utero ethanol exposure impairs cell proliferation and decreases neurons and astrocytes generated in cultured RG and in embryonic cerebral cortex. Telencephalic cultures obtained at E12 from ethanol-treated rats displayed a reduction in the proportion of actively dividing RG progenitors, as demonstrated by 5-bromo-2,-deoxyuridine incorporation, and in the percentage of brain lipid binding protein-positive RG. Consistently, neurosphere formation assay from E12 telencephalon showed a reduced number of multipotent progenitor cells in cultures isolated from ethanol-treated rats in comparison with pair-fed control group. Moreover, levels of activated Notch1 and fibroblast growth factor receptor 2, which regulate the maintenance of the progenitor state of RG, are decreased by prenatal ethanol exposure. These findings demonstrate that ethanol reduces the telencephalic RG progenitor pool and its transformation into neurons and astrocytes, which may contribute to an explanation of the defects in brain function often observed in fetal alcohol syndrome. © 2006 Wiley-Liss, Inc. [source] Molecular and cellular mechanisms of neuroprotection by vascular endothelial growth factorJOURNAL OF NEUROSCIENCE RESEARCH, Issue 1-2 2005Feng-Yan Sun Abstract The present view of the neuroprotective functions and mechanisms of action of vascular endothelial growth factor (VEGF) is based on studies of neuronal ischemic/hypoxic models in vivo and in vitro. Endogenous neuronal VEGF increases in the ischemic brain and plays a neuroprotective role in the pathophysiologic processes that follow stroke. Exogenous VEGF, directly administered or overexpressed by gene delivery into rat brains, reduces ischemic brain infarct and decreases hypoxic neuronal death. The main neuroprotective mechanisms of VEGF include: (1) modulation of the phosphatidylinositol 3,-kinase (PI3K)/Akt/nuclear factor-,B signaling pathway, inhibition of caspase-3 activity, and reduction of ischemic neuronal apoptosis; (2) inhibition of outward delayed rectifier potassium channel currents and increase of ischemia-induced tyrosine phosphorylation of Kv1.2 potassium channel proteins via activation of the PI3K pathway; and (3) enhancement of proliferation and migration of neural progenitors in the subventricular zone and improvement of striatal neurogenesis and maturation of newborn neurons in adult rat brains after stroke. © 2004 Wiley-Liss, Inc. [source] Expression of gangliosides in an immortalized neural progenitor/stem cell lineJOURNAL OF NEUROSCIENCE RESEARCH, Issue 5 2003Keiji Suetake Abstract Glycosphingolipids (GSLs) are known to play important roles in cellular growth and differentiation in the nervous system. The change in expression of gangliosides is correlated with crucial developmental events and is evolutionarily conserved among many vertebrate species. The emergence of neural progenitors represents a crucial step in neural development, but little is known about the exact composition and subcellular localization of gangliosides in neural progenitor cells. The C17.2 cell line was derived after v- myc transformation of neural progenitor cells isolated from neonatal mouse cerebellar cortex. The developmental potential of C17.2 cells is similar to that of endogenous neural progenitor/stem cells in that they are multipotential and capable of differentiating into all neural cell types. We characterized the GSL composition of C17.2 cells and found the presence of only a-series gangliosides. Subcellular localization studies revealed that GM1 and GD1a are localized mainly on the plasma membrane and partly in the cytoplasm, both as punctate clusters. Reverse transcription-polymerase chain reaction revealed the absence of ST-II transcripts in C17 cells, which most likely accounts for the lack of expression of b- and c-series complex gangliosides in this cell line. These data suggest that the divergence in ganglioside expression in C17.2 cells is regulated at the transcriptional level. © 2003 Wiley-Liss, Inc. [source] Characterization of a human fetal spinal cord stem cell line, NSI-566RSC, and its induction to functional motoneuronsJOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 3 2010Xiufang Guo Abstract Specific neuronal subtypes, especially motoneurons (MNs), derived from human stem cells provide a significant therapeutic potential for spinal cord diseases, such as amyotrophic lateral sclerosis (ALS) and spinal cord injury. So far, in vitro, MNs have only been successfully induced from embryonic stem cells (hESC) and human fetal cortical progenitors. Although neural progenitors from spinal cord would be a likely source for generating MNs, there has been no study reporting successful in vitro differentiation of MNs from spinal cord progenitors. This study first characterized a polyclonal spinal cord stem cell line isolated from an 8 week-old fetus. Then a paradigm was introduced to successfully induce MNs from this cell line, which was demonstrated by immunostaining using the MN markers HB9, Islet1 and choline acetyl transferase (ChAT). The combination of HB9 and ChAT immunostainings indicated that ,20% of the cells were MNs after this induction protocol. The presence of other cell types in the differentiated culture was also analysed. Finally, the electrophysiological properties of these differentiated MNs were characterized to confirm their functional integrity. The majority of these MNs fired repetitive action potentials (APs), which is an indicator of functional maturation. The recordings of spontaneous excitatory postsynaptic currents (EPSCs) confirmed the formation of synapses onto these MNs. This study reports the first successful differentiation of MNs from human spinal cord stem cells in vitro, providing a novel approach for obtaining functional MNs when designing the therapeutic strategy for spinal cord diseases or injuries. Copyright © 2009 John Wiley & Sons, Ltd. [source] Chemokine receptor expression by neural progenitor cells in neurogenic regions of mouse brainTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 6 2007Phuong B. Tran Abstract We previously demonstrated that chemokine receptors are expressed by neural progenitors grown as cultured neurospheres. To examine the significance of these findings for neural progenitor function in vivo, we investigated whether chemokine receptors were expressed by cells having the characteristics of neural progenitors in neurogenic regions of the postnatal brain. Using in situ hybridization we demonstrated the expression of CCR1, CCR2, CCR5, CXCR3, and CXCR4 chemokine receptors by cells in the dentate gyrus (DG), subventricular zone of the lateral ventricle, and olfactory bulb. The pattern of expression for all of these receptors was similar, including regions where neural progenitors normally reside. In addition, we attempted to colocalize chemokine receptors with markers for neural progenitors. In order to do this we used nestin-EGFP and TLX-LacZ transgenic mice, as well as labeling for Ki67, a marker for dividing cells. In all three areas of the brain we demonstrated colocalization of chemokine receptors with these three markers in populations of cells. Expression of chemokine receptors by neural progenitors was further confirmed using CXCR4-EGFP BAC transgenic mice. Expression of CXCR4 in the DG included cells that expressed nestin and GFAP as well as cells that appeared to be immature granule neurons expressing PSA-NCAM, calretinin, and Prox-1. CXCR4-expressing cells in the DG were found in close proximity to immature granule neurons that expressed the chemokine SDF-1/CXCL12. Cells expressing CXCR4 frequently coexpressed CCR2 receptors. These data support the hypothesis that chemokine receptors are important in regulating the migration of progenitor cells in postnatal brain. J. Comp. Neurol. 500:1007,1033, 2007. © 2006 Wiley-Liss, Inc. [source] Low-density lipoprotein receptor-related protein (LRP)-2/megalin is transiently expressed in a subpopulation of neural progenitors in the embryonic mouse spinal cordTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 2 2005Grzegorz Wicher Abstract The lipoprotein receptor LRP2/megalin is expressed by absorptive epithelia and involved in receptor-mediated endocytosis of a wide range of ligands. Megalin is expressed in the neuroepithelium during central nervous system (CNS) development. Mice with homozygous deletions of the megalin gene show severe forebrain abnormalities. The possible role of megalin in the developing spinal cord, however, is unknown. Here we examined the spatial and temporal expression pattern of megalin in the embryonic mouse spinal cord using an antibody that specifically recognizes the cytoplasmic part of the megalin molecule. In line with published data, we show expression of megalin in ependymal cells of the central canal from embryonic day (E)11 until birth. In addition, from E11 until E15 a population of cells was found in the dorsal part of the developing spinal cord strongly immunoreactive against megalin. Double labeling showed that most of these cells express vimentin, a marker for immature astrocytes and radial glia, but not brain lipid binding protein (BLBP), a marker for radial glial cells, or glial fibrillary acidic protein (GFAP), a marker for mature astrocytes. These findings indicate that the majority of the megalin-positive cells are astroglial precursors. Megalin immunoreactivity was mainly localized in the nuclei of these cells, suggesting that the cytoplasmic part of the megalin molecule can be cleaved following ligand binding and translocated to the nucleus to act as a transcription factor or regulate other transcription factors. These findings suggest that megalin has a crucial role in the development of astrocytes of the spinal cord. J. Comp. Neurol. 492:123,131, 2005. © 2005 Wiley-Liss, Inc. [source] Transitin, a nestin-related intermediate filament, is expressed by neural progenitors and can be induced in Müller glia in the chicken retinaTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2005Andy J. Fischer Abstract The purpose of this study was to test whether transitin, the avian homologue of nestin, is expressed by retinal progenitors in the developing and postnatal chicken. Because nestin has been widely used as a cell-distinguishing marker of neural progenitors in the mammalian nervous system, we expected to find transitin expressed specifically by the neural progenitors of the retina. In early stages of development, transitin is expressed by neural progenitors in the retina and by cells in the developing ciliary body. During later stages of development, transitin expression persists in differentiating Müller glia but is down-regulated by these cells as maturation proceeds. In the postnatal chick, transitin expression is restricted to neural progenitors at the peripheral edge of the retina. We found that the expression of transitin in mature Müller glia was induced by intraocular injections of insulin and fibroblast growth factor-2 (FGF2) but not by ciliary neurotrophic factor. In response to insulin and FGF2, the expression of transitin was induced in the nonpigmented epithelium (NPE) of the ciliary body. In the postnatal retina, acute retinal damage transiently induces transitin expression in Müller glia. We propose that the expression of transitin by retinal Müller glia and NPE cells in the postnatal animal represents a state of de-differentiation and a step toward becoming neurogenic progenitor cells. Taken together, our findings indicate that transitin is expressed by neural progenitors in the embryonic and postnatal chicken retina. However, transitin is not exclusively expressed by neural progenitors and is also expressed by non-neurogenic cells. J. Comp. Neurol. 484:1,14, 2005. © 2005 Wiley-Liss, Inc. [source] Recent Insights into PDGF-Induced GliomagenesisBRAIN PATHOLOGY, Issue 3 2010Filippo Calzolari Abstract Gliomas are aggressive and almost incurable glial brain tumors which frequently display abnormal platelet-derived growth factor (PDGF) signaling. Evidence gained from studies on several in vivo animal models has firmly established a causal connection between aberrant PDGF signaling and the formation of some gliomas. However, only recently has significant knowledge been gained regarding crucial issues such as the glioma cell of origin and the relationship between the transforming stimulus and the cellular characteristics of the resulting tumor. Based on recent evidence, we propose that PDGF can bias cell-fate decisions, driving the acquisition of cell type-specific features by the progeny of multipotent neural progenitors, thus determining the shape and direction of the transformation path. Furthermore, recent data about the cellular mechanisms of PDGF-driven glioma progression and maintenance indicate that PDGF may be required, unexpectedly, to override cell contact inhibition and promote glioma cell infiltration rather than to stimulate cell proliferation. [source] | |||||||||||||