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Mouse Anti-Rat radial glial cell marker Antibody, Unconjugated

RRID:AB_531887

Antibody ID

AB_531887

Target Antigen

Mouse Rat radial glial cell marker mouse, mouse, does not react with rat

Vendor

DSHB Go To Vendor

Cat Num

RC2

Proper Citation

(DSHB Cat# RC2, RRID:AB_531887)

Clonality

unknown

Host Organism

mouse

Spatiotemporal distribution of glia in and around the developing mouse optic tract.

  • Lee MA
  • J. Comp. Neurol.
  • 2018 May 9

Literature context: use monoclonal MIgM, Clone RC2, RRID:AB_531887 1:5


Abstract:

In the developing mouse optic tract, retinal ganglion cell (RGC) axon position is organized by topography and laterality (i.e., eye-specific or ipsi- and contralateral segregation). Our lab previously showed that ipsilaterally-projecting RGCs are segregated to the lateral aspect of the developing optic tract and found that ipsilateral axons self-fasciculate to a greater extent than contralaterally-projecting RGC axons in vitro. However, the full complement of axon-intrinsic and -extrinsic factors mediating eye-specific segregation in the tract remain poorly understood. Glia, which are known to express several guidance cues in the visual system and regulate the navigation of ipsilateral and contralateral RGC axons at the optic chiasm, are natural candidates for contributing to eye-specific pre-target axon organization. Here, we investigate the spatiotemporal expression patterns of both putative astrocytes (Aldh1l1+ cells) and microglia (Iba1+ cells) in the embryonic and neonatal optic tract. We quantified the localization of ipsilateral RGC axons to the lateral two-thirds of the optic tract, and analyzed glia position and distribution relative to eye-specific axon organization. While our results indicate that glial segregation patterns do not strictly align with eye-specific RGC axon segregation in the tract, we identify distinct spatiotemporal organization of both Aldh1l1+ cells and microglia in and around the developing optic tract. These findings inform future research into molecular mechanisms of glial involvement in RGC axon growth and organization in the developing retinogeniculate pathway. This article is protected by copyright. All rights reserved.

Funding information:
  • NHLBI NIH HHS - R01 HL115238(United States)

Cadherin-13 Deficiency Increases Dorsal Raphe 5-HT Neuron Density and Prefrontal Cortex Innervation in the Mouse Brain.

  • Forero A
  • Front Cell Neurosci
  • 2017 Oct 12

Literature context: Hybridoma Bank, Iowa, USA, cat# RRID:AB_531887), mouse anti-Nestin monoclonal


Abstract:

Background: During early prenatal stages of brain development, serotonin (5-HT)-specific neurons migrate through somal translocation to form the raphe nuclei and subsequently begin to project to their target regions. The rostral cluster of cells, comprising the median and dorsal raphe (DR), innervates anterior regions of the brain, including the prefrontal cortex. Differential analysis of the mouse 5-HT system transcriptome identified enrichment of cell adhesion molecules in 5-HT neurons of the DR. One of these molecules, cadherin-13 (Cdh13) has been shown to play a role in cell migration, axon pathfinding, and synaptogenesis. This study aimed to investigate the contribution of Cdh13 to the development of the murine brain 5-HT system. Methods: For detection of Cdh13 and components of the 5-HT system at different embryonic developmental stages of the mouse brain, we employed immunofluorescence protocols and imaging techniques, including epifluorescence, confocal and structured illumination microscopy. The consequence of CDH13 loss-of-function mutations on brain 5-HT system development was explored in a mouse model of Cdh13 deficiency. Results: Our data show that in murine embryonic brain Cdh13 is strongly expressed on 5-HT specific neurons of the DR and in radial glial cells (RGCs), which are critically involved in regulation of neuronal migration. We observed that 5-HT neurons are intertwined with these RGCs, suggesting that these neurons undergo RGC-guided migration. Cdh13 is present at points of intersection between these two cell types. Compared to wildtype controls, Cdh13-deficient mice display increased cell densities in the DR at embryonic stages E13.5, E17.5, and adulthood, and higher serotonergic innervation of the prefrontal cortex at E17.5. Conclusion: Our findings provide evidence for a role of CDH13 in the development of the serotonergic system in early embryonic stages. Specifically, we indicate that Cdh13 deficiency affects the cell density of the developing DR and the posterior innervation of the prefrontal cortex (PFC), and therefore might be involved in the migration, axonal outgrowth and terminal target finding of DR 5-HT neurons. Dysregulation of CDH13 expression may thus contribute to alterations in this system of neurotransmission, impacting cognitive function, which is frequently impaired in neurodevelopmental disorders including attention-deficit/hyperactivity and autism spectrum disorders.

Funding information:
  • Intramural NIH HHS - Z01ES102745(United States)

Llgl1 Connects Cell Polarity with Cell-Cell Adhesion in Embryonic Neural Stem Cells.

  • Jossin Y
  • Dev. Cell
  • 2017 Jun 5

Literature context: DSHB RC2; RRID:AB_531887 Mouse mono


Abstract:

Malformations of the cerebral cortex (MCCs) are devastating developmental disorders. We report here that mice with embryonic neural stem-cell-specific deletion of Llgl1 (Nestin-Cre/Llgl1fl/fl), a mammalian ortholog of the Drosophila cell polarity gene lgl, exhibit MCCs resembling severe periventricular heterotopia (PH). Immunohistochemical analyses and live cortical imaging of PH formation revealed that disruption of apical junctional complexes (AJCs) was responsible for PH in Nestin-Cre/Llgl1fl/fl brains. While it is well known that cell polarity proteins govern the formation of AJCs, the exact mechanisms remain unclear. We show that LLGL1 directly binds to and promotes internalization of N-cadherin, and N-cadherin/LLGL1 interaction is inhibited by atypical protein kinase C-mediated phosphorylation of LLGL1, restricting the accumulation of AJCs to the basolateral-apical boundary. Disruption of the N-cadherin-LLGL1 interaction during cortical development in vivo is sufficient for PH. These findings reveal a mechanism responsible for the physical and functional connection between cell polarity and cell-cell adhesion machineries in mammalian cells.

Funding information:
  • NCI NIH HHS - R01 CA131047()
  • NCI NIH HHS - R01 CA179914()
  • NICHD NIH HHS - T32 HD007183()
  • NINDS NIH HHS - R01 NS080194()

Surface topography during neural stem cell differentiation regulates cell migration and cell morphology.

  • Czeisler C
  • J. Comp. Neurol.
  • 2016 Dec 1

Literature context: ID: AB_305808; RRID: AB_477010; RRID: AB_531887; RRID: AB_561007; RRID: AB_6284


Abstract:

We sought to determine the contribution of scaffold topography to the migration and morphology of neural stem cells by mimicking anatomical features of scaffolds found in vivo. We mimicked two types of central nervous system scaffolds encountered by neural stem cells during development in vitro by constructing different diameter electrospun polycaprolactone (PCL) fiber mats, a substrate that we have shown to be topographically similar to brain scaffolds. We compared the effects of large fibers (made to mimic blood vessel topography) with those of small-diameter fibers (made to mimic radial glial process topography) on the migration and differentiation of neural stem cells. Neural stem cells showed differential migratory and morphological reactions with laminin in different topographical contexts. We demonstrate, for the first time, that neural stem cell biological responses to laminin are dependent on topographical context. Large-fiber topography without laminin prevented cell migration, which was partially reversed by treatment with rock inhibitor. Cell morphology complexity assayed by fractal dimension was inhibited in nocodazole- and cytochalasin-D-treated neural precursor cells in large-fiber topography, but was not changed in small-fiber topography with these inhibitors. These data indicate that cell morphology has different requirements on cytoskeletal proteins dependent on the topographical environment encountered by the cell. We propose that the physical structure of distinct scaffolds induces unique signaling cascades that regulate migration and morphology in embryonic neural precursor cells. J. Comp. Neurol. 524:3485-3502, 2016. © 2016 Wiley Periodicals, Inc.

Funding information:
  • NCI NIH HHS - CA92880(United States)

Isoform-specific localization of Nogo protein in the optic pathway of mouse embryos.

  • Wang L
  • J. Comp. Neurol.
  • 2016 Aug 1

Literature context: No. RC2, RRID:AB_531887) recognize


Abstract:

Expression of Nogo protein was investigated in the optic pathway of embryonic mice by using isoform-specific antibodies Bianca and 11C7, which recognize Nogo-A/B and Nogo-A, respectively. Our previous reports from using antibody N18 have shown that Nogo is localized on the radial glia in the retina and at the midline of the ventral diencephalon in mouse embryos during the ingrowth of retinal ganglion cells (RGCs) axons. This glial-specific localization is markedly different from findings in other studies. This study showed Nogo-A/B primarily on radial glia in the retina at E13 and then later on retinal ganglion cells and axons at E14 and E15, whereas Nogo-A was expressed preferentially by RGCs and their axons. In the ventral diencephalon, Nogo-A/B was expressed strongly on radial glia, particularly in those located in the midline region of the chiasm but also on RGC axons. In Nogo-A knockout embryos, the isoform Nogo-B (revealed by Bianca) was observed on radial glia in the ventral diencephalon and on RGCs and their axons. We concluded that Nogo-A is localized on the ganglion cells and retinal axons, whereas Nogo-B is expressed by the radial glia in the optic pathway. Nogo-B may play an important role in guiding axon growth in decisive regions of the visual pathway, which include the optic disc and the optic chiasm. J. Comp. Neurol. 524:2322-2334, 2016. © 2016 Wiley Periodicals, Inc.

Funding information:
  • NHLBI NIH HHS - R01 HL122494(United States)

Shp2-dependent ERK signaling is essential for induction of Bergmann glia and foliation of the cerebellum.

  • Li K
  • J. Neurosci.
  • 2014 Jan 15

Literature context:


Abstract:

Folding of the cortex and the persistence of radial glia (RG)-like cells called Bergmann glia (BG) are hallmarks of the mammalian cerebellum. Similar to basal RG in the embryonic neocortex, BG maintain only basal processes and continuously express neural stem cell markers. Past studies had focused on the function of BG in granule cell migration and how granule cell progenitors (GCP) regulate cerebellar foliation. The molecular control of BG generation and its role in cerebellar foliation are less understood. Here, we have analyzed the function of the protein tyrosine phosphatase Shp2 in mice by deleting its gene Ptpn11 in the entire cerebellum or selectively in the GCP lineage. Deleting Ptpn11 in the entire cerebellum by En1-cre blocks transformation of RG into BG but preserves other major cerebellar cell types. In the absence of BG, inward invagination of GCP persists but is uncoupled from the folding of the Purkinje cell layer and the basement membrane, leading to disorganized lamination and an absence of cerebellar folia. In contrast, removing Ptpn11 in the GCP lineage by Atoh1-cre has no effect on cerebellar development, indicating that Shp2 is not cell autonomously required in GCP. Furthermore, we demonstrate that Ptpn11 interacts with Fgf8 and is essential for ERK activation in RG and nascent BG. Finally, expressing constitutively active MEK1 rescues BG formation and cerebellar foliation in Shp2-deficient cerebella. Our results demonstrate an essential role of Shp2 in BG specification via fibroblast growth factor/extracellular signal-regulated protein kinase signaling, and reveal a crucial function of BG in organizing cerebellar foliation.

Funding information:
  • Wellcome Trust - 075491/Z/04/Z(United Kingdom)

Intrinsic and extrinsic connections of Tet3 dioxygenase with CXXC zinc finger modules.

  • Liu N
  • PLoS ONE
  • 2013 Dec 30

Literature context:


Abstract:

Tet proteins are emerging as major epigenetic modulators of cell fate and plasticity. However, little is known about how Tet proteins are targeted to selected genomic loci in distinct biological contexts. Previously, a CXXC-type zinc finger domain in Tet1 was shown to bind CpG-rich DNA sequences. Interestingly, in human and mouse the Tet2 and Tet3 genes are adjacent to Cxxc4 and Cxxc10-1, respectively. The CXXC domains encoded by these loci, together with those in Tet1 and Cxxc5, identify a distinct homology group within the CXXC domain family. Here we provide evidence for alternative mouse Tet3 transcripts including the Cxxc10-1 sequence (Tet3(CXXC)) and for an interaction between Tet3 and Cxxc4. In vitro Cxxc4 and the isolated CXXC domains of Tet1 and Tet3(CXXC) bind DNA substrates with similar preference towards the modification state of cytosine at a single CpG site. In vivo Tet1 and Tet3 isoforms with and without CXXC domain hydroxylate genomic 5-methylcytosine with similar activity. Relative transcript levels suggest that distinct ratios of Tet3(CXXC) isoforms and Tet3-Cxxc4 complex may be present in adult tissues. Our data suggest that variable association with CXXC modules may contribute to context specific functions of Tet proteins.

Funding information:
  • PHS HHS - HHSN272200900018C(United States)

Filamin A regulates neuronal migration through brefeldin A-inhibited guanine exchange factor 2-dependent Arf1 activation.

  • Zhang J
  • J. Neurosci.
  • 2013 Oct 2

Literature context:


Abstract:

Periventricular heterotopias is a malformation of cortical development, characterized by ectopic neuronal nodules around ventricle lining and caused by an initial migration defect during early brain development. Human mutations in the Filamin A (FLNA) and ADP-ribosylation factor guanine exchange factor 2 [ARFGEF2; encoding brefeldin-A-inhibited guanine exchange factor-2 (BIG2)] genes give rise to this disorder. Previously, we have reported that Big2 inhibition impairs neuronal migration and binds to FlnA, and its loss promotes FlnA phosphorylation. FlnA phosphorylation dictates FlnA-actin binding affinity and consequently alters focal adhesion size and number to effect neuronal migration. Here we show that FlnA loss similarly impairs migration, reciprocally enhances Big2 expression, but also alters Big2 subcellular localization in both null and conditional FlnA mice. FlnA phosphorylation promotes relocalization of Big2 from the Golgi toward the lipid ruffles, thereby activating Big2-dependent Arf1 at the cell membrane. Loss of FlnA phosphorylation or Big2 function impairs Arf1-dependent vesicle trafficking at the periphery, and Arf1 is required for maintenance of cell-cell junction connectivity and focal adhesion assembly. Loss of Arf1 activity disrupts neuronal migration and cell adhesion. Collectively, these studies demonstrate a potential mechanism whereby coordinated interactions between actin (through FlnA) and vesicle trafficking (through Big2-Arf) direct the assembly and disassembly of membrane protein complexes required for neuronal migration and neuroependymal integrity.

Funding information:
  • NIH HHS - R24 OD011194(United States)

Transplantation of CD15-enriched murine neural stem cells increases total engraftment and shifts differentiation toward the oligodendrocyte lineage.

  • Chaubey S
  • Stem Cells Transl Med
  • 2013 Jun 6

Literature context:


Abstract:

Neural stem cell (NSC) transplantation is a promising therapeutic approach for neurological diseases. However, only a limited number of cells can be transplanted into the brain, resulting in relatively low levels of engraftment. This study investigated the potential of using a cell surface marker to enrich a primary NSC population to increase stable engraftment in the recipient brain. NSCs were enriched from the neonatal mouse forebrain using anti-CD15 (Lewis X antigen, or SSEA-1) in a "gentle" fluorescence-activated cell sorting protocol, which yielded >98% CD15-positive cells. The CD15-positive cells differentiated into neurons, astrocytes, and oligodendrocytes in vitro, after withdrawal of growth factors, demonstrating multipotentiality. CD15-positive cells were expanded in vitro and injected bilaterally into the ventricles of neonatal mice. Cells from enriched and unenriched donor populations were found throughout the neuraxis, in both neurogenic and non-neurogenic regions. Total engraftment was similar at 7 days postinjection, but by 28 days postinjection, after brain organogenesis was complete, the survival of donor cells was significantly increased in CD15-enriched grafts over the unenriched cell grafts. The engrafted cells were heterogeneous in morphology and differentiated into all three neural lineages. Furthermore, in the CD15-enriched grafts, there was a significant shift toward differentiation into oligodendrocytes. This strategy may allow better delivery of therapeutic cells to the developing central nervous system and may be particularly useful for treating diseases involving white matter lesions.

Funding information:
  • NIEHS NIH HHS - R21 ES021983(United States)

Xenogeneic transfer of adult quail (Coturnix coturnix) spermatogonial stem cells to embryonic chicken (Gallus gallus) hosts: a model for avian conservation.

  • Roe M
  • Biol. Reprod.
  • 2013 May 24

Literature context:


Abstract:

As advanced reproductive technologies have become routine for domesticated species, they have begun to be applied in the field of endangered species conservation. For avian conservation, the most promising technology is the transfer of germ stem cells of exotic species to domestic hosts for the production of gametes. In this study, adult quail (model for exotic species) spermatogonial stem cells were xenogeneically transferred to stages 14-17 chicken host embryos. Fluorescent cellular dyes, quail-specific antibodies, and quail-specific quantitative PCR confirmed donor cell migration to and colonization of the host gonadal ridge. Donor-derived cells were observed by fluorescent microscopy in the caudal area as early as 2 h after injection, in the gonadal ridge at 4 h after injection, as well as in the gonads of stages 35-38 host embryos. Four of eight donor-derived cell flow cytometry-positive host gonads were confirmed by quantitative PCR using quail-specific primers. There was no statistically significant effect of host stage of injection, host gonad isolation stage, or host sex on the number of hosts positive for donor cells or the percent of donor-derived cells per positive gonad. Donor-derived cells isolated from stages 35-38 host gonads costained with the germ stem cell marker SSEA-1, indicating that the donor-derived cells have maintained stem cell-ness. This is the first study to suggest that it is feasible to rescue adult germ stem cells of deceased birds to prolong the reproductive lifespan of critically endangered species or genetically valuable individuals by transferring them to an embryonic chicken host.

Funding information:
  • NIGMS NIH HHS - R01 GM077402(United States)

MiR-30e and miR-181d control radial glia cell proliferation via HtrA1 modulation.

  • Nigro A
  • Cell Death Dis
  • 2012 Aug 2

Literature context:


Abstract:

The precise mechanisms by which microRNAs (miRNAs) contribute to the dynamic regulation of gene expression during the forebrain development are still partly elusive. Here we show that the depletion of miRNAs in the cerebral cortex and hippocampus, via genetic inactivation of Dicer after the onset of forebrain neurogenesis, profoundly impairs the morphological and proliferative characteristics of neural stem and progenitor cells. The cytoarchitecture and self-renewal potential of radial glial (RG) cells located within the cerebral cortex and the hippocampus were profoundly altered, thus causing a significant derangement of both the post natal dorsal sub-ventricular zone and the dentate gyrus. This effect was attributed to the High-temperature requirement A serine peptidase 1 (HtrA1) gene product whose overexpression in the developing forebrain recapitulated some of the aspects of the Dicer(-/-) phenotype. MiR-30e and miR-181d were identified as posttranscriptional negative regulators of HtrA1 by binding to its 3' untranslated region. In vivo overexpression of miR-30e and miR-181d in Dicer(-/-) forebrain rescued RG proliferation defects.

Funding information:
  • Intramural NIH HHS - Z01 AI000899-08(United States)
  • NIGMS NIH HHS - GM61372(United States)

Self-renewal and differentiation of reactive astrocyte-derived neural stem/progenitor cells isolated from the cortical peri-infarct area after stroke.

  • Shimada IS
  • J. Neurosci.
  • 2012 Jun 6

Literature context:


Abstract:

In response to stroke, subpopulations of cortical reactive astrocytes proliferate and express proteins commonly associated with neural stem/progenitor cells such as glial fibrillary acidic protein (GFAP) and Nestin. To examine the stem cell-related properties of cortical reactive astrocytes after injury, we generated GFAP-CreER(TM);tdRFP mice to permanently label reactive astrocytes. We isolated cells from the cortical peri-infarct area 3 d after stroke, and cultured them in neural stem cell medium containing epidermal growth factor and basic fibroblast growth factor. We observed tdRFP-positive neural spheres in culture, suggestive of tdRFP-positive reactive astrocyte-derived neural stem/progenitor cells (Rad-NSCs). Cultured Rad-NSCs self-renewed and differentiated into neurons, astrocytes, and oligodendrocytes. Pharmacological inhibition and conditional knock-out mouse studies showed that Presenilin 1 and Notch 1 controlled neural sphere formation by Rad-NSCs after stroke. To examine the self-renewal and differentiation potential of Rad-NSCs in vivo, Rad-NSCs were transplanted into embryonic, neonatal, and adult mouse brains. Transplanted Rad-NSCs were observed to persist in the subventricular zone and secondary Rad-NSCs were isolated from the host brain 28 d after transplantation. In contrast with neurogenic postnatal day 4 NSCs and adult NSCs from the subventricular zone, transplanted Rad-NSCs differentiated into astrocytes and oligodendrocytes, but not neurons, demonstrating that Rad-NSCs had restricted differentiation in vivo. Our results indicate that Rad-NSCs are unlikely to be suitable for neuronal replacement in the absence of genetic or epigenetic modification.

Funding information:
  • NINDS NIH HHS - R01 NS092786(United States)

F3/Contactin acts as a modulator of neurogenesis during cerebral cortex development.

  • Bizzoca A
  • Dev. Biol.
  • 2012 May 1

Literature context:


Abstract:

The expression of the cell recognition molecule F3/Contactin (CNTN1) is generally associated with the functions of post-mitotic neurons. In the embryonic cortex, however, we find it expressed by proliferating ventricular zone (VZ) precursors. In contrast to previous findings in the developing cerebellum, F3/Contactin transgenic overexpression in the early cortical VZ promotes proliferation and expands the precursor pool at the expense of neurogenesis. At later stages, when F3/Contactin levels subside, however, neurogenesis resumes, suggesting that F3/Contactin expression in the VZ is inversely related to neurogenesis and plays a role in a feedback control mechanism, regulating the orderly progression of cortical development. The modified F3/Contactin profile therefore results in delayed corticogenesis, as judged by downregulation in upper and lower layer marker expression and by BrdU birth dating, indicating that, in this transgenic model, increased F3/Contactin levels counteract neuronal precursor commitment. These effects also occur in primary cultures and are reproduced by addition of an F3/Fc fusion protein to wild type cultures. Together, these data indicate a completely novel function for F3/Contactin. Parallel changes in the generation of the Notch Intracellular Domain and in the expression of the Hes-1 transcription factor indicate that activation of the Notch pathway plays a role in this phenotype, consistent with previous in vitro reports that F3/Contactin is a Notch1 ligand.

Funding information:
  • NIAID NIH HHS - R01 AI074847(United States)

Multiple phenotypes in Huntington disease mouse neural stem cells.

  • Ritch JJ
  • Mol. Cell. Neurosci.
  • 2012 May 26

Literature context:


Abstract:

Neural stem (NS) cells are a limitless resource, and thus superior to primary neurons for drug discovery provided they exhibit appropriate disease phenotypes. Here we established NS cells for cellular studies of Huntington's disease (HD). HD is a heritable neurodegenerative disease caused by a mutation resulting in an increased number of glutamines (Q) within a polyglutamine tract in Huntingtin (Htt). NS cells were isolated from embryonic wild-type (Htt(7Q/7Q)) and "knock-in" HD (Htt(140Q/140Q)) mice expressing full-length endogenous normal or mutant Htt. NS cells were also developed from mouse embryonic stem cells that were devoid of Htt (Htt(-/-)), or knock-in cells containing human exon1 with an N-terminal FLAG epitope tag and with 7Q or 140Q inserted into one of the mouse alleles (Htt(F7Q/7Q) and Htt(F140Q/7Q)). Compared to Htt(7Q/7Q) NS cells, HD Htt(140Q/140Q) NS cells showed significantly reduced levels of cholesterol, increased levels of reactive oxygen species (ROS), and impaired motility. The heterozygous Htt(F140Q/7Q) NS cells had increased ROS and decreased motility compared to Htt(F7Q/7Q). These phenotypes of HD NS cells replicate those seen in HD patients or in primary cell or in vivo models of HD. Huntingtin "knock-out" NS cells (Htt(-/-)) also had impaired motility, but in contrast to HD cells had increased cholesterol. In addition, Htt(140Q/140Q) NS cells had higher phospho-AKT/AKT ratios than Htt(7Q/7Q) NS cells in resting conditions and after BDNF stimulation, suggesting mutant htt affects AKT dependent growth factor signaling. Upon differentiation, the Htt(7Q/7Q) and Htt(140Q/140Q) generated numerous Beta(III)-Tubulin- and GABA-positive neurons; however, after 15 days the cellular architecture of the differentiated Htt(140Q/140Q) cultures changed compared to Htt(7Q/7Q) cultures and included a marked increase of GFAP-positive cells. Our findings suggest that NS cells expressing endogenous mutant Htt will be useful for study of mechanisms of HD and drug discovery.

Funding information:
  • NIBIB NIH HHS - EB006356(United States)

Reciprocal induction of simple organogenesis by mouse kidney progenitor cells in three-dimensional co-culture.

  • Velagapudi C
  • Am. J. Pathol.
  • 2012 Feb 23

Literature context:


Abstract:

Kidney development is regulated by a coordinated reciprocal induction of metanephric mesenchymal (MM) and ureteric bud (UB) cells. Here, established MM and UB progenitor cell lines were recombined in three-dimensional Matrigel implants in SCID mice. Differentiation potential was examined for changes in phenotype, organization, and the presence of specialized proteins using immunofluorescence and bright-field and electron microscopy. Both cell types, when grown alone, did not develop into specialized structures. When combined, the cells organized into simple organoid structures of polarized epithelia with lumens surrounded by capillary-like structures. Tracker experiments indicated the UB cells formed the tubuloid structures, and the MM cells were the source of the capillary-like cells. The epithelial cells stained positive for pancytokeratin, the junctional complex protein ZO-1, collagen type IV, as well as UB and collecting duct markers, rearranged during transfection (RET), Dolichos biflorus lectin, EndoA cytokeratin, and aquaporin 2. The surrounding cells expressed α-smooth muscle actin, vimentin, platelet endothelial cell adhesion molecule 1 (PECAM), and aquaporin 1, a marker of vasculogenesis. The epithelium exhibited apical vacuoles, microvilli, junctional complexes, and linear basement membranes. Capillary-like structures showed endothelial features with occasional pericytes. UB cell epithelialization was augmented in the presence of MM cell-derived conditioned medium, glial-derived neurotrophic factor (GDNF), hepatocyte growth factor (HGF), or fibronectin. MM cells grown in the presence of UB-derived conditioned medium failed to undergo differentiation. However, UB cell-derived conditioned medium induced MM cell migration. These studies indicate that tubulogenesis and vasculogenesis can be partially recapitulated by recombining individual MM and UB cell lineages, providing a new model system to study organogenesis ex vivo.

Funding information:
  • NCI NIH HHS - R01 CA194547(United States)

Dpy19l1, a multi-transmembrane protein, regulates the radial migration of glutamatergic neurons in the developing cerebral cortex.

  • Watanabe K
  • Development
  • 2011 Nov 26

Literature context:


Abstract:

During corticogenesis, the regulation of neuronal migration is crucial for the functional organization of the neocortex. Glutamatergic neurons are major excitatory components of the mammalian neocortex. In order to elucidate the specific molecular mechanisms underlying their development, we used single-cell microarray analysis to screen for mouse genes that are highly expressed in developing glutamatergic neurons. We identified dpy-19-like 1 (Dpy19l1), a homolog of C. elegans dpy-19, which encodes a putative multi-transmembrane protein shown to regulate directed migration of Q neuroblasts in C. elegans. At embryonic stages Dpy19l1 is highly expressed in glutamatergic neurons in the mouse cerebral cortex, whereas in the subpallium, where GABAergic neurons are generated, expression was below detectable levels. Downregulation of Dpy19l1 mediated by shRNA resulted in defective radial migration of glutamatergic neurons in vivo, which was restored by the expression of shRNA-insensitive Dpy19l1. Many Dpy19l1-knockdown cells were aberrantly arrested in the intermediate zone and the deep layer and, additionally, some extended single long processes towards the pial surface. Furthermore, we observed defective radial migration of bipolar cells in Dpy19l1-knockdown brains. Despite these migration defects, these cells correctly expressed Cux1, which is a marker for upper layer neurons, suggesting that Dpy19l1 knockdown results in migration defects but does not affect cell type specification. These results indicate that Dpy19l1 is required for the proper radial migration of glutamatergic neurons, and suggest an evolutionarily conserved role for the Dpy19 family in neuronal migration.

Funding information:
  • NIAMS NIH HHS - AR061933(United States)

Disease-associated missense mutations in bestrophin-1 affect cellular trafficking and anion conductance.

  • Milenkovic VM
  • J. Cell. Sci.
  • 2011 Sep 1

Literature context:


Abstract:

Bestrophin-1, an integral membrane protein encoded by the BEST1 gene, is localized predominantly to the basolateral membrane of the retinal pigment epithelium. Mutations in the BEST1 gene have been associated with Best vitelliforme macular dystrophy (BMD), a central retinopathy with autosomal dominant inheritance and variable penetrance. Over 120 disease-causing mutations are known, the majority of which result in amino acid substitutions within four mutational hot-spot regions in the highly conserved N-terminal half of the protein. Although initially thought to impair Cl⁻ channel function, the molecular pathology of BEST1 mutations is still controversial. We have analyzed the subcellular localization of 13 disease-associated BEST1 mutant proteins in polarized MDCK II cells, an established model of apical to basolateral protein sorting. Immunostaining demonstrated that nine of the 13 mutant proteins failed to integrate into the cell membrane. The defective proteins were predominantly retained in the cytoplasm, whereas wild-type bestrophin-1 revealed cell membrane localization. Functional analysis of I⁻ fluxes in HEK-293 cells showed that all mutants exhibited a significant reduction in anion conductance. Our data indicate that defective intracellular trafficking could be a common cause of BMD accompanied by impaired anion conductance, representing a loss of anion channel function that is probably due to mistargeting of mutant protein.

Funding information:
  • NCI NIH HHS - CA122623(United States)
  • NIDDK NIH HHS - R01DK069351(United States)

Knockdown of BACE1-AS Nonprotein-Coding Transcript Modulates Beta-Amyloid-Related Hippocampal Neurogenesis.

  • Modarresi F
  • Int J Alzheimers Dis
  • 2011 Jul 25

Literature context:


Abstract:

Background. Alzheimer's disease (AD) is a devastating neurological disorder and the main cause of dementia in the elderly population worldwide. Adult neurogenesis appears to be upregulated very early in AD pathogenesis in response to some specific aggregates of beta-amyloid (Aβ) peptides, exhausting the neuronal stem cell pools in the brain. Previously, we characterized a conserved nonprotein-coding antisense transcript for β-secretase-1 (BACE1), a critical enzyme in AD pathophysiology. We showed that the BACE1-antisense transcript (BACE1-AS) is markedly upregulated in brain samples from AD patients and promotes the stability of the (sense) BACE1 transcript. In the current paper, we examine the relationship between BACE1, BACE1-AS, adult neurogenesis markers, and amyloid plaque formation in amyloid precursor protein (APP) transgenic mice (Tg-19959) of various ages. Results. Consistent with previous publications in other APP overexpressing mouse models, we found adult neurogenesis markers to be noticeably upregulated in Tg-19959 mice very early in the development of the disease. Knockdown of either one of BACE1 or BACE1-AS transcripts by continuous infusion of locked nucleic acid- (LNA-) modified siRNAs into the third ventricle over the period of two weeks caused concordant downregulation of both transcripts in Tg-19959 mice. Downregulation of BACE1 mRNA was followed by reduction of BACE1 protein and insoluble Aβ. Modulation of BACE1 and BACE1-AS transcripts also altered oligomeric Aβ aggregation pattern, which was in turn associated with an increase in neurogenesis markers at the RNA and protein level. Conclusion. We found alterations in the RNA and protein concentrations of several adult neurogenesis markers, as well as non-protein-coding BACE1-AS transcripts, in parallel with the course of β-amyloid synthesis and aggregation in the brain of Tg15999 mice. In addition, by knocking down BACE1 or BACE1-AS (thereby reducing Aβ production and plaque deposition), we were able to modulate expression of these neurogenesis markers. Our findings suggest a distortion of adult neurogenesis that is associated with Aβ production very early in amyloid pathogenesis. We believe that these alterations, at the molecular level, could prove useful as novel therapeutic targets and/or as early biomarkers of AD.

Funding information:
  • Canadian Institutes of Health Research - (Canada)
  • NIGMS NIH HHS - R01 GM073082-0181(United States)

Multiple telencephalic and extratelencephalic embryonic domains contribute neurons to the medial extended amygdala.

  • Bupesh M
  • J. Comp. Neurol.
  • 2011 Jun 1

Literature context:


Abstract:

Dysfunctions in emotional control and social behavior are behind human neuropsychiatric disorders, some of which are associated with an alteration of amygdalar development. The medial extended amygdala is a key telencephalic center for control of social behavior, but very little is known about its development. We used in vitro migration assays for analyzing the origin of the neurons of the medial extended amygdala in mouse embryos (E13.5-E16.5). We compared the migration assays with immunofluorescence/immunohistochemistry for calbindin and radial glial fibers and with mRNA expression of several genetic markers of distinct forebrain subdivisions. We provide experimental evidence for multiple embryonic origins of the principal neurons of the medial extended amygdala. In particular, we provide novel evidence indicating that a major part of the neurons derives from a caudoventral pallidal subdivision (previously called or included as part of the anterior peduncular area), forming a cell corridor with similar molecular features (expression of Lhx6 and calbindin), connectivity, and function, which relates to reproductive behavior. We also provide novel experimental evidence indicating that the ventral pallium produces some neurons for the medial amygdala, which correlates with data from Lhx9 expression. Our results also confirm that some neurons of the medial extended amygdala originate in the preoptic area (our results indicate that these cells specifically originate in its commissural subdivision) and the supraoptoparaventricular domain of the hypothalamus. Our study helps to set up the foundations for a better understanding of medial amygdalar control of behavior in normal and abnormal conditions.

Funding information:
  • Canadian Institutes of Health Research - (Canada)

Conditional knockout of protein O-mannosyltransferase 2 reveals tissue-specific roles of O-mannosyl glycosylation in brain development.

  • Hu H
  • J. Comp. Neurol.
  • 2011 May 1

Literature context:


Abstract:

The meninges produce essential signaling molecules and major protein components of the pial basement membrane during normal brain development. Disruptions in the pial basement membrane underlie neural ectopia seen in those congenital muscular dystrophies (CMDs) caused by mutations in genes involved in O-mannosyl glycosylation. In mammals, biosynthesis of O-mannosyl glycans is initiated by a complex of mutually indispensable protein O-mannosyltransferases 1 and 2 (POMT1 and 2). To study the roles of O-mannosylation in brain development we generated a conditional allele of POMT2. POMT2 nulllizygosity resulted in embryonic lethality because of a defective Reichert's membrane. Brain-specific deletion of POMT2 resulted in hypoglycosylation of α-dystroglycan (DG) and abolished laminin binding activity. The effect of POMT2 deletion on brain development was dependent on timing, as earlier deletion resulted in more severe phenotypes. Multiple brain malformations including overmigration of neocortical neurons and migration failure of granule cells in the cerebellum were observed. Immunofluorescence staining and transmission electron microscopy revealed that these migration defects were closely associated with disruptions in the pial basement membrane. Interestingly, POMT2 deletion in the meninges (and blood vessels) did not disrupt the development of the neocortex. Thus, normal brain development requires protein O-mannosylation activity in neural tissue but not the meninges. These results suggest that gene therapy should be directed to the neural tissue instead of the meninges.

Funding information:
  • NIDDK NIH HHS - R03 DK054823(United States)

Development of the mouse amygdala as revealed by enhanced green fluorescent protein gene transfer by means of in utero electroporation.

  • Soma M
  • J. Comp. Neurol.
  • 2009 Mar 1

Literature context:


Abstract:

The amygdala is located in the caudal part of the ventral telencephalon. It is composed of many subdivisions and is involved in the control of emotion. It is important to know the mechanisms of amygdalar development in order to analyze the pathogenesis of emotional disorders, but they are still not adequately understood. In the present study the migration, differentiation, and distribution of amygdalar neurons in the mouse embryo were investigated by means of in utero electroporation. Ventricular zone cells in restricted regions, that is, the caudal ganglionic eminence (CGE), the ventral pallium, the lateral pallium, and the diencephalon, were labeled with an expression vector of the enhanced green fluorescent protein (EGFP) gene. Labeling at embryonic day (E)10 revealed that the central nucleus originates from the neuroepithelium in the ganglionic eminence and the labeling at E11 and E12 revealed that the basolateral complex originates from the neuroepithelium of the ventral and lateral pallia. The introduction of the EGFP gene into the neuroepithelium of the third ventricle at E11 showed that the medial nucleus originates, at least in part, from the neuroepithelium of the diencephalon and migrates over the diencephalo-telencephalic boundary. The radial glial arrangement corresponded well with the initial migration of amygdalar neurons, and the radial processes later formed the boundary demarcating the basolateral complex. These findings indicate that the neurons originating from the temporally and spatially restricted neuroepithelium in both the telencephalon and diencephalon migrate and differentiate to form the mosaic of amygdalar subdivisions.

C3G regulates cortical neuron migration, preplate splitting and radial glial cell attachment.

  • Voss AK
  • Development
  • 2008 Jun 28

Literature context:


Abstract:

Neuronal migration is integral to the development of the cerebral cortex and higher brain function. Cortical neuron migration defects lead to mental disorders such as lissencephaly and epilepsy. Interaction of neurons with their extracellular environment regulates cortical neuron migration through cell surface receptors. However, it is unclear how the signals from extracellular matrix proteins are transduced intracellularly. We report here that mouse embryos lacking the Ras family guanine nucleotide exchange factor, C3G (Rapgef1, Grf2), exhibit a cortical neuron migration defect resulting in a failure to split the preplate into marginal zone and subplate and a failure to form a cortical plate. C3G-deficient cortical neurons fail to migrate. Instead, they arrest in a multipolar state and accumulate below the preplate. The basement membrane is disrupted and radial glial processes are disorganised and lack attachment in C3G-deficient brains. C3G is activated in response to reelin in cortical neurons, which, in turn, leads to activation of the small GTPase Rap1. In C3G-deficient cells, Rap1 GTP loading in response to reelin stimulation is reduced. In conclusion, the Ras family regulator C3G is essential for two aspects of cortex development, namely radial glial attachment and neuronal migration.

Funding information:
  • NIAMS NIH HHS - R03 AR049855(United States)

Breaches of the pial basement membrane and disappearance of the glia limitans during development underlie the cortical lamination defect in the mouse model of muscle-eye-brain disease.

  • Hu H
  • J. Comp. Neurol.
  • 2007 Mar 1

Literature context:


Abstract:

Neuronal overmigration is the underlying cellular mechanism of cerebral cortical malformations in syndromes of congenital muscular dystrophies caused by defects in O-mannosyl glycosylation. Overmigration involves multiple developmental abnormalities in the brain surface basement membrane, Cajal-Retzius cells, and radial glia. We tested the hypothesis that breaches in basement membrane and the underlying glia limitans are the key initial events of the cellular pathomechanisms by carrying out a detailed developmental study with a mouse model of muscle-eye-brain disease, mice deficient in O-mannose beta31,2-N-acetylglucosaminyltransferase 1 (POMGnT1). The pial basement membrane was normal in the knockout mouse at E11.5. It was breached during rapid cerebral cortical expansion at E13.5. Radial glial endfeet, which comprise glia limitans, grew out of the neural boundary. Neurons moved out of the neural boundary through these breaches. The overgrown radial glia and emigrated neurons disrupted the overlying pia mater. The overmigrated neurons did not participate in cortical plate (CP) development; rather they formed a diffuse cell zone (DCZ) outside the original cortical boundary. Together, the DCZ and the CP formed the knockout cerebral cortex, with disappearance of the basement membrane and the glia limitans. These results suggest that disappearance of the basement membrane and the glia limitans at the cerebral cortical surface during development underlies cortical lamination defects in congenital muscular dystrophies and a cellular mechanism of cortical malformation distinct from that of the reeler mouse, double cortex syndrome, and periventricular heterotopia.

Funding information:
  • NIBIB NIH HHS - 1R21EB017539-01A1(United States)

The endocannabinoid system promotes astroglial differentiation by acting on neural progenitor cells.

  • Aguado T
  • J. Neurosci.
  • 2006 Feb 1

Literature context:


Abstract:

Endocannabinoids exert an important neuromodulatory role via presynaptic cannabinoid CB1 receptors and may also participate in the control of neural cell death and survival. The function of the endocannabinoid system has been extensively studied in differentiated neurons, but its potential role in neural progenitor cells remains to be elucidated. Here we show that the CB1 receptor and the endocannabinoid-inactivating enzyme fatty acid amide hydrolase are expressed, both in vitro and in vivo, in postnatal radial glia (RC2+ cells) and in adult nestin type I (nestin(+)GFAP+) neural progenitor cells. Cell culture experiments show that CB1 receptor activation increases progenitor proliferation and differentiation into astroglial cells in vitro. In vivo analysis evidences that, in postnatal CB1(-/-) mouse brain, progenitor proliferation and astrogliogenesis are impaired. Likewise, in adult CB1-deficient mice, neural progenitor proliferation is decreased but is increased in fatty acid amide hydrolase-deficient mice. In addition, endocannabinoid signaling controls neural progenitor differentiation in the adult brain by promoting astroglial differentiation of newly born cells. These results show a novel physiological role of endocannabinoids, which constitute a new family of signaling cues involved in the regulation of neural progenitor cell function.

Funding information:
  • NHGRI NIH HHS - P41 HG002273(United States)

A unique subpopulation of Tbr1-expressing deep layer neurons in the developing cerebral cortex.

  • Kolk SM
  • Mol. Cell. Neurosci.
  • 2005 Dec 7

Literature context:


Abstract:

Cells of the subplate (SP) and deep cortical plate (CP) are among the pioneer neurons of the developing cerebral cortex, an important group of early-born cells that impact cortical organization and function. Similarities between pioneer neurons in different cortical positions and heterogeneities in pioneer cells in the same cortical location, however, have made it difficult to appreciate the characteristics and functions of particular sets of these cells. Here, we provide a tool to illuminate a unique subset of SP and deep CP neurons: expression of a Tbrain-1 (Tbr1)-driven transgene. Transgene-expressing cells were consistently positive for neuronal but not glial markers, were born early in corticogenesis, representing just a subset of SP and deep CP neurons, were morphologically complex during the formation of the cortex, and were maintained into maturity. This analysis reveals a novel group of pioneer neurons and demonstrates unrecognized diversity within this cortical population. In the future, this information will help to uncover the roles of discrete pioneer populations in cortical development.

Funding information:
  • NHGRI NIH HHS - U01 HG002712(United States)

Integrin-linked kinase deletion from mouse cortex results in cortical lamination defects resembling cobblestone lissencephaly.

  • Niewmierzycka A
  • J. Neurosci.
  • 2005 Jul 27

Literature context:


Abstract:

Integrin-linked kinase (Ilk) is a scaffold and kinase that links integrin receptors to the actin cytoskeleton and to signaling pathways involved in cell adhesion, migration, and extracellular matrix deposition. Targeted deletion of Ilk from embryonic mouse dorsal forebrain neuroepithelium results in severe cortical lamination defects resembling cobblestone (type II) lissencephaly. Defects in adult mutants include neuronal invasion of the marginal zone, downward displacement of marginal zone components, fusion of the cerebral hemispheres, and scalloping of the dentate gyrus. These lesions are associated with abundant astrogliosis and widespread fragmentation of the basal lamina at the cortical surface. During cortical development, neuronal ectopias are associated with severe disorganization of radial glial processes and displacement of Cajal-Retzius cells. Lesions are not seen when Ilk is specifically deleted from embryonic neurons. Interestingly, targeted Ilk deletion has no effect on proliferation or survival of cortical cells or on phosphorylation of two Ilk substrates, Pkb/Akt and Gsk-3beta, suggesting that Ilk does not regulate cortical lamination via these enzymes. Instead, Ilk acts in vivo as a major intracellular mediator of integrin-dependent basal lamina formation. This study demonstrates a critical role for Ilk in cortical lamination and suggests that Ilk-associated pathways are involved in the pathogenesis of cobblestone lissencephalies.

Funding information:
  • NIDCD NIH HHS - DC02310(United States)

Generation of regionally specified neurons in expanded glial cultures derived from the mouse and human lateral ganglionic eminence.

  • Skogh C
  • Mol. Cell. Neurosci.
  • 2001 May 18

Literature context:


Abstract:

The specific identity of neuronal precursors within the embryonic brain is, at present, not clear. Here we show that cultures with glial characteristics derived from the embryonic mouse or human lateral ganglionic eminence (LGE) can be expanded over many passages and maintain their glial identity. Interestingly, removal of serum and EGF from the culture medium results in the generation of large numbers of neurons. The neurons derived from these cultures display many characteristic features of striatal neurons, which normally derive from the LGE, even after extensive expansion in vitro. Furthermore, a portion of the neurons generated in these cultures were shown to arise from glial fibrillary acidic protein (GFAP)-expressing cells. These results demonstrate that at least a subpopulation of neurogenic LGE precursors exhibit glial characteristics.

Regulation of neuroblast mitosis is determined by PACAP receptor isoform expression.

  • Nicot A
  • Proc. Natl. Acad. Sci. U.S.A.
  • 2001 Apr 10

Literature context:


Abstract:

Although neurogenesis in the embryo proceeds in a region- or lineage-specific fashion coincident with neuropeptide expression, a regulatory role for G protein-coupled receptors (GPCR) remains undefined. Pituitary adenylate cyclase activating polypeptide (PACAP) stimulates sympathetic neuroblast proliferation, whereas the peptide inhibits embryonic cortical precursor mitosis. Here, by using ectopic expression strategies, we show that the opposing mitogenic effects of PACAP are determined by expression of PACAP receptor splice isoforms and differential coupling to the phospholipase C (PLC) pathway, as opposed to differences in cellular context. In embryonic day 14 (E14) cortical precursors transfected with the hop receptor variant, but not cells transfected with the short variant, PACAP activates the PLC pathway, increasing intracellular calcium and eliciting translocation of protein kinase C. Ectopic expression of the hop variant in cortical neuroblasts transforms the antimitotic effect of PACAP into a promitogenic signal. Furthermore, PACAP promitogenic effects required PLC pathway function indicated by antagonist U-73122 studies in hop-transfected cortical cells and native sympathetic neuroblasts. These observations highlight the critical role of lineage-specific expression of GPCR variants in determining mitogenic signaling in neural precursors.

Funding information:
  • NLM NIH HHS - 5-T15-LM007079-15(United States)

Proneural enhancement by Notch overcomes Suppressor-of-Hairless repressor function in the developing Drosophila eye.

  • Li Y
  • Curr. Biol.
  • 2001 Mar 6

Literature context:


Abstract:

BACKGROUND: The receptor protein Notch plays a conserved role in restricting neural-fate specification during lateral inhibition. Lateral inhibition requires the Notch intracellular domain to coactivate Su(H)-mediated transcription of the Enhancer-of-split Complex. During Drosophila eye development, Notch plays an additional role in promoting neural fate independently of Su(H) and E(spl)-C, and this finding suggests an alternative mechanism of Notch signal transduction. RESULTS: We used genetic mosaics to analyze the proneural enhancement pathway. As in lateral inhibition, the metalloprotease Kuzbanian, the EGF repeat 12 region of the Notch extracellular domain, Presenilin, and the Notch intracellular domain were required. By contrast, proneural enhancement became constitutive in the absence of Su(H), and this led to premature differentiation and upregulation of the Atonal and Senseless proteins. Ectopic Notch signaling by Delta expression ahead of the morphogenetic furrow also caused premature differentiation. CONCLUSIONS: Proneural enhancement and lateral inhibition use similar ligand binding and receptor processing but differ in the nuclear role of Su(H). Prior to Notch signaling, Su(H) represses neural development directly, not indirectly through E(spl)-C. During proneural enhancement, the Notch intracellular domain overcomes the repression of neural differentiation. Later, lateral inhibition restores the repression of neural development by a different mechanism, requiring E(spl)-C transcription. Thus, Notch restricts neurogenesis temporally to a narrow time interval between two modes of repression.

A subset of fibroblast growth factors (Fgfs) promote survival, but Fgf-8b specifically promotes astroglial differentiation of rat cortical precursor cells.

  • Hajihosseini MK
  • Mol. Cell. Neurosci.
  • 1999 Dec 17

Literature context:


Abstract:

Fibroblast growth factor-2 (Fgf-2 or basic Fgf) is known to promote the survival, proliferation, and differentiation of neural precursor cells. We have examined and compared the effects of Fgf-2 with those of Fgf-1, -4, -6, -7, -9, and -10, as well as three isoforms of Fgf-8 (-8a, -8b, and -8c), on the fate of cultured embryonic day 15 (E15) rat cortical cells. Clonal analysis, using retroviral tagging, shows that only Fgf-2, -4, and -8b can efficiently promote the survival of cortical precursor cells, the majority of which give rise to neurons. Surprisingly, and in contrast to other Fgfs, Fgf-8b also promotes astroglial differentiation of a subpopulation of these cells, which would otherwise appear to yield neurons. We also show that E15 cortical cells initially express the IIIc isoforms of Fgf-receptors (R-1,-2, and -3 but within 16 h of culturing they down regulate FgfR2-IIIc. These studies demonstrate that cortical precursor cells respond to Fgf stimulation in different ways depending on the ligand and by inference the Fgf receptors activated.

Funding information:
  • Intramural NIH HHS - (United States)

The homeodomain protein vax1 is required for axon guidance and major tract formation in the developing forebrain.

  • Bertuzzi S
  • Genes Dev.
  • 1999 Dec 1

Literature context:


Abstract:

The homeodomain protein Vax1 is expressed in a highly circumscribed set of cells at the ventral anterior midline of the embryonic CNS. These cells populate the choroid fissure of the optic disk, the body of the optic stalk and nerve, the optic chiasm and ventral diencephalon, and the anterior midline zones that abut developing commissural tracts. We have generated mutant mice that lack Vax1. In these mice (1) the optic disks fail to close, leading to coloboma and loss of the eye-nerve boundary; (2) optic nerve glia fail to associate with and appear to repulse ingrowing retinal axons, resulting in a fascicle of axons that are completely segregated from optic nerve astrocytes; (3) retinal axons fail to penetrate the brain in significant numbers and fail to form an optic chiasm; and (4) axons in multiple commissural tracts of the anterior CNS, including the corpus callosum and the hippocampal and anterior commissures, fail to cross the midline. These axon guidance defects do not result from the death of normally Vax1(+) midline cells but, instead, correlate with markedly diminished expression of attractive guidance cues in these cells. Vax1 therefore regulates the guidance properties of a set of anterior midline cells that orchestrate axon trajectories in the developing mammalian forebrain.

Funding information:
  • NEI NIH HHS - EY11160(United States)
  • NIGMS NIH HHS - U54 GM074929(United States)

Mitogen and substrate differentially affect the lineage restriction of adult rat subventricular zone neural precursor cell populations.

  • Whittemore SR
  • Exp. Cell Res.
  • 1999 Oct 10

Literature context:


Abstract:

The effects of specific mitogens and substrates on the proliferative capacity and the differentiated phenotypic plasticity of neural precursor cell populations isolated from the adult rat subventricular zone (SVZ) were examined. SVZ cells were grown on uncoated tissue culture plastic, extracellular matrix, or poly-D-ornithine with either laminin or fibronectin. SVZ neural precursor cells could not be generated with platelet-derived growth factor (PDGF), granulocyte macrophage colony stimulating factor, stem cell factor, heparin-binding epidermal growth factor (HB-EGF), granulocyte colony stimulating factor, or ciliary neurotrophic factor (CNTF), but could be with EGF, fibroblast growth factor 2 (FGF2), and FGF2 plus heparin. Varying combinations of substrate and mitogen resulted in very different expansion rates and/or lineage potential. Neurons, oligodendrocytes, and astrocytes differentiated from all cultures, but EGF-generated neural precursor cells were more restricted to an astrocytic lineage and FGF2-generated neural precursor cells had a greater capacity for neuronal differentiation. In both EGF- and FGF2-generated cell populations, CNTF increased the number of differentiated astrocytes, triiodothyronine oligodendrocytes, PDGF neurons, and brain-derived neurotrophic factor neurons only from EGF cells. Electrophysiological analysis of differentiated cells showed three distinct phenotypes, glial, neuronal, and presumed precursor cells, although the neuronal properties were immature. Collectively, these data indicate that CNS neural precursor cell populations isolated with different mitogens and substrates are intrinsically different and their characteristics cannot be directly compared.

Retinoids are produced by glia in the lateral ganglionic eminence and regulate striatal neuron differentiation.

  • Toresson H
  • Development
  • 1999 Mar 27

Literature context:


Abstract:

In order to identify molecular mechanisms involved in striatal development, we employed a subtraction cloning strategy to enrich for genes expressed in the lateral versus the medial ganglionic eminence. Using this approach, the homeobox gene Meis2 was found highly expressed in the lateral ganglionic eminence and developing striatum. Since Meis2 has recently been shown to be upregulated by retinoic acid in P19 EC cells (Oulad-Abdelghani, M., Chazaud, C., Bouillet, P., Sapin, V., Chambon, P. and Dollé, P. (1997) Dev. Dyn. 210, 173-183), we examined a potential role for retinoids in striatal development. Our results demonstrate that the lateral ganglionic eminence, unlike its medial counterpart or the adjacent cerebral cortex, is a localized source of retinoids. Interestingly, glia (likely radial glia) in the lateral ganglionic eminence appear to be a major source of retinoids. Thus, as lateral ganglionic eminence cells migrate along radial glial fibers into the developing striatum, retinoids from these glial cells could exert an effect on striatal neuron differentiation. Indeed, the treatment of lateral ganglionic eminence cells with retinoic acid or agonists for the retinoic acid receptors or retinoid X receptors, specifically enhances their striatal neuron characteristics. These findings, therefore, strongly support the notion that local retinoid signalling within the lateral ganglionic eminence regulates striatal neuron differentiation.

Funding information:
  • NIMH NIH HHS - MH57748(United States)
  • PHS HHS - HHSN272200900040C(United States)

The first retinal axon growth in the mouse optic chiasm: axon patterning and the cellular environment.

  • Marcus RC
  • J. Neurosci.
  • 1995 Oct 4

Literature context:


Abstract:

The retinofugal pathway is a useful model for axon guidance because fibers from each eye project to targets on both sides of the brain. Studies using static and real time analyses in mice at E15-17 demonstrated that uncrossed axons from ventrotemporal retina diverge from crossed axons in the optic chiasm, where specialized resident cells may direct divergence. Other studies, however, suggest that pioneering uncrossed retinal axons derive from a different retinal region, take a different course, and enter the ipsilateral optic tract independent of fiber-fiber interactions. We examine these differences by dye-labeling the earliest optic axons and immunocytochemically identifying cells in their path. The first optic axons arising from dorsocentral retina, enter the diencephalon at E12.5. All axons initially grow caudally, lateral to a radial glial palisade. In contrast to later growing axons, early uncrossed axons enter the ipsilateral optic tract directly. Crossed axons enter the glial palisade and course medially, then anteriorly, in a pathway corresponding to the border of an early neuronal population that expresses SSEA-1, CD44, and beta-tubulin. Axon patterning occurs independent of fiber-fiber interactions from both eyes, as the first uncrossed axons enter the optic tract before crossed ones from opposite eye. These analysis, in conjunction with our previous studies during the principal period of retinal axon growth in the diencephalon, suggest that the adult visual projection arises from age-dependent variations in the types and relative contribution of cues along the path through the emerging optic chiasm.

Funding information:
  • Wellcome Trust - 13031(United Kingdom)

Identification of radial glial cells within the developing murine central nervous system: studies based upon a new immunohistochemical marker.

  • Misson JP
  • Brain Res. Dev. Brain Res.
  • 1988 Nov 1

Literature context:


Abstract:

The monoclonal antibody RC2 was generated in mouse by conventional hybridoma methodology. The antigen recognized by RC2 is robust, allowing aldehyde fixation appropriate to high resolution light and electron microscopic analyses. From the neural tube stage of fetal development the antibody delineates throughout the central nervous system a subpopulation of neuroepithelial cells which have a radial bipolar morphology. A descending process extends to the ventricular margin, and an ascending process contacts the glial limiting membrane by one or more endfeet varicosities. The persistence of these cells through the neurogenetic period allows their identification as radial glial. From as early as E9-10 the fibers appear to be organized in simple straight fascicles. Later in fetal development these fascicles show marked region-specific transformations in density and trajectory, particularly in association with cerebral corticogenesis and with cerebellar and basal ganglia development. The bipolar forms continue to stain with RC2 until they disappear in the postnatal period. Concurrently with a progressive perinatal loss of stained bipolar radial glia, RC2 identifies multipolar cell forms at various levels of the brain wall, as consistent with the transformation of radial glia into astrocytes. RC2 also recognizes monopolar cell forms in the spinal cord and the cerebellum as early as E15, and in the dentate gyrus of the hippocampal formation from the day of birth. Monopolar forms in the cerebellum are inferred to be progenitors of Bergmann glia. Although Bergmann glia are known to persist in adult life, these cells do not stain with RC2 beyond the 2nd postnatal week. The robustness of the antigen recognized by RC2 makes this probe a valuable tool to study the morphological transformations of the bipolar radial glia during their mitotic turnover. It also provides a sensitive stain for the study of the organization and the histogenetic role of the overall radial fiber system.

Funding information:
  • NHGRI NIH HHS - HG004069-04S1(United States)

Comparison of fluid transport systems in lymphatics and veins.

  • Pippard C
  • Lymphology
  • 1987 Dec 6

Literature context:


Abstract:

In the anesthetized sheep, pressure pulses generated in the feet are transmitted downstream in the veins but not in the lymphatics at normal intralymphatic pressure. When the sheep is tilted on a tilt table, gravitational changes occur in venous pressure but not in the pressure in adjacent lymphatics. These results suggest that in limb lymphatics, unlike limb veins, the column of fluid is incomplete. This makes extrinsic pumping less effective for propelling fluid in lymphatics than in veins. At normal intralymphatic pressures, intrinsic pumping seems to be mainly responsible for lymph propulsion. The incompleteness of the fluid column in lymphatics might also protect these vessels against the hydrostatic problems experienced by veins during gravitational stress.

Funding information:
  • NHGRI NIH HHS - R01 HG003474-04(United States)
  • NICHD NIH HHS - HD-17228(United States)