Showing papers on "Radial glial cell published in 2009"
TL;DR: It is found that mammalian partition defective protein 3 (mPar3), a key cell polarity determinant, exhibits dynamic distribution in radial glial progenitors and becomes dispersed and shows asymmetric localization as cell cycle progresses.
325 citations
TL;DR: It is concluded that Sox1 enhances neuroectodermal commitment and maintenance but blocks further differentiation, in contrast, Pax6 is involved in the progression of neuroectoderm toward radial glia, a feature typical of radial glio‐derived early neurons.
Abstract: The transcription factors Sox1 and Pax6 are expressed sequentially during early mouse embryonic neurogenesis. Sox1 expression starts upon formation of neuroectoderm, whereas Pax6 is subsequently expressed in radial glial cells, the latter giving rise to most neurons of the cerebral cortex. Here we used mouse embryonic stem (ES) cells to study the role of Sox1 and Pax6 in regulating differentiation of neural progenitors. For this purpose, we investigated the effect of overexpression and knockdown of Sox1 and Pax6, using three differentiation protocols. We show that (a) expression of Sox1 or Pax6 in uncommitted ES cells favored neuroectodermal lineage choice; (b) continuous Sox1 expression maintained cells at the neuroepithelial stage and prevented expression of Pax6 and other radial glial cell markers; (c) Sox1 knockdown facilitated exit from the progenitor stage, whereas Pax6 knockdown decreased formation of radial glia; (d) forced Pax6 expression in neuroepithelial cells triggered their differentiation into radial glia and neurons; and (e) Pax6 expression induced cell migration, a feature typical of radial glia-derived early neurons. We conclude that Sox1 enhances neuroectodermal commitment and maintenance but blocks further differentiation. In contrast, Pax6 is involved in the progression of neuroectoderm toward radial glia.
115 citations
TL;DR: It is demonstrated in mice that the myristoylated alanine-rich C-kinase substrate protein (MARCKS), a prominent cellular substrate for PKC, modulates radial glial placement and expansion and that the membrane-associated targeting of MARCKS and the resultant polarized distribution of signaling complexes essential for apicobasal polarity may constitute a critical event.
Abstract: The radial glial cells serve as neural progenitors and as a migratory guide for newborn neurons in the developing cerebral cortex. These functions require appropriate organization and proliferation of the polarized radial glial scaffold. Here, we demonstrate in mice that the myristoylated alanine-rich C-kinase substrate protein (MARCKS), a prominent cellular substrate for PKC, modulates radial glial placement and expansion. Loss of MARCKS results in ectopic collection of mitotically active radial progenitors away from the ventricular zone (VZ) in the upper cerebral wall. Apical restriction of key polarity complexes [CDC42, beta-catenin (CTNNB1), N-cadherin (CDH2), myosin IIB (MYOIIB), aPKCzeta, LGL, PAR3, pericentrin, PROM1] is lost. Furthermore, the radial glial scaffold in Marcks null cortex is compromised, with discontinuous, non-radial processes apparent throughout the cerebral wall and deformed, bulbous, unbranched end-feet at the basal ends. Further, the density of radial processes within the cerebral cortex is reduced. These deficits in radial glial development culminate in aberrant positioning of neurons and disrupted cortical lamination. Genetic rescue experiments demonstrate, surprisingly, that phosphorylation of MARCKS by PKC is not essential for the role of MARCKS in radial glial cell development. By contrast, the myristoylation domain of MARCKS needed for membrane association is essential for MARCKS function in radial glia. The membrane-associated targeting of MARCKS and the resultant polarized distribution of signaling complexes essential for apicobasal polarity may constitute a critical event in the appropriate placement, proliferation and organization of polarized radial glial scaffold in the developing cerebral cortex.
65 citations
TL;DR: It is suggested that echinoderms and chordates might have inherited the RS-producing radial glial cell type from the central nervous system of their common ancestor, i.e., the last common ancestor of all the Deuterostomia.
Abstract: Echinoderms and chordates belong to the same monophyletic taxon, the Deuterostomia. In spite of significant differences in body plan organization, the two phyla may share more common traits than was thought previously. Of particular interest are the common features in the organization of the central nervous system. The present study employs two polyclonal antisera raised against bovine Reissner's substance (RS), a secretory product produced by glial cells of the subcomissural organ, to study RS-like immunoreactivity in the central nervous system of sea cucumbers. In the ectoneural division of the nervous system, both antisera recognize the content of secretory vacuoles in the apical cytoplasm of the radial glia-like cells of the neuroepithelium and in the flattened glial cells of the non-neural epineural roof epithelium. The secreted immunopositive material seems to form a thin layer covering the cell apices. There is no accumulation of the immunoreactive material on the apical surface of the hyponeural neuroepithelium or the hyponeural roof epithelium. Besides labelling the supporting cells and flattened glial cells of the epineural roof epithelium, both anti-RS antisera reveal a previously unknown putative glial cell type within the neural parenchyma of the holothurian nervous system. Our results show that: a) the glial cells of the holothurian tubular nervous system produce a material similar to Reissner's substance known to be synthesized by secretory glial cells in all chordates studied so far; b) the nervous system of sea cucumbers shows a previously unrealized complexity of glial organization. Our findings also provide significant clues for interpretation of the evolution of the nervous system in the Deuterostomia. It is suggested that echinoderms and chordates might have inherited the RS-producing radial glial cell type from the central nervous system of their common ancestor, i.e., the last common ancestor of all the Deuterostomia.
43 citations
TL;DR: The results indicate that GBC4 cells may be multipotent neural progenitor cells similar to tanycytes, and this line will be useful for studies on gene expression/regulation and neural development.
Abstract: A clonal cell line, GBC4, derived from grouper (Epinephelus coioides) brain is proposed to represent an immature astroglial cell line because it expresses glial fibrillary acidic protein (GFAP), cytokeratin and vimentin. In teleost brain, tanycytes are the most abundant GFAP-expressing cell type, suggesting that GBC4 cells are derived from tanycytes. To test this hypothesis, protein and mRNA expression profiles of GBC4 cells were evaluated. We detected protein and/or mRNA expression of aromatase B, brain lipid binding protein, connexin43 protein, glutamine synthetase, S100 protein and Sox2. These proteins/mRNAs are also expressed in fish tanycytes. GBC4 cells also contained oligodendroglia proteins, including A2B5, galactocerebroside, myelin basic protein, proteolipid protein and platelet-derived growth factor receptor α as well as certain neuronal protein markers such as connexin35 protein and tyrosine hydroxylase. Our results indicate that GBC4 cells may be multipotent neural progenitor cells similar to tanycytes. Because GBC4 expresses several neural-specific genes, this line will be useful for studies on gene expression/regulation and neural development.
18 citations
TL;DR: Although RG3.6 transplantation, reduced activity of macrophages as early as 1–2 weeks post-injury, the expression levels of inflammatory genes were not decreased and genes associated with tissue protection and neural cell development were found to be significantly up-regulated by RG 3.6 transplants.
Abstract: Cell-based therapy has been widely evaluated in spinal cord injury (SCI) animal models and shown to improve functional recovery. However, host response to cell transplants at gene expression level is rarely discussed. We reported previously that acute transplantation of radial glial cells RG3.6 following SCI promoted early locomotion improvement within 1 week post-injury. To identify rapid molecular changes induced by RG3.6 transplantation in the host tissue, distal spinal cord segments were subjected to microarray analysis. Although RG3.6 transplantation, reduced activity of macrophages as early as 1–2 weeks post-injury, the expression levels of inflammatory genes (e.g., IL-6, MIP-2, MCP-1) were not decreased by RG3.6 treatment as compared to medium or other cell controls at 6–12 h post-injury. However, genes associated with tissue protection (Hsp70 and Hsp32) and neural cell development (Foxg1, Top2a, Sox11, Nkx2.2, Vimentin) were found to be significantly up-regulated by RG3.6 transplants. Foxg1 was the most highly induced gene in the RG3.6-treated spinal cords, and its expression by immunocytochemistry was confirmed in the host tissue. Moreover, RG3.6 treatment boosted the number of Nkx2.2 cells in the spinal cord, and these cells frequently co-expressed NG2, which marks progenitor cells. Taken together, these results demonstrate that radial glial transplants induced rapid and specific gene expression in the injured host tissue, and suggest that these early responses are associated with mechanisms of tissue protection and activation of endogenous neural progenitor cells.
18 citations
01 Jan 2009
TL;DR: In this paper, the authors describe classical studies that suggest that neurogenesis in the cerebral cortex is dependent on asymmetric divisions, where one daughter remains in a progenitor state while the other exits to become a mature neuron.
Abstract: The six distinct laminae within the mammalian cerebral cortex contain neurons that exhibit a wide variety of specific physiological properties and synaptic connections. This diversity emerges from a restricted progenitor pool within the embryonic cortical ventricular zone. Individual cortical progenitors produce multiple subtypes over a prolonged period during corticogenesis. This article describes classical studies that suggest that neurogenesis in the cerebral cortex is dependent on asymmetric divisions, where one daughter remains in a progenitor state while the other exits to become a mature neuron. The present understanding of the molecular mechanisms regulating both asymmetric cell division and the sequential production of different neuronal subtypes during development is reviewed. However, as yet only a subset of the factors controlling each of these two events has been identified. This suggests that present genetic approaches will soon significantly extend our understanding of these developmental processes.