The Unique 473HD-Chondroitinsulfate Epitope Is Expressed by Radial Glia and Involved in Neural Precursor Cell Proliferation

Abstract

Neural stem cells have been documented in both the developing and the mature adult CNSs of mammals. This cell population holds a considerable promise for therapeutical applications in a wide array of CNS diseases. Therefore, universally applicable strategies for the purification of this population to further its cell biological characterization are sought. Here, we report that the unique chondroitin sulfate epitope recognized by the monoclonal antibody 473HD is surface expressed on actively cycling, multipotent progenitor cells of the developing telencephalon with radial glia-like properties. When used for immunopanning, the antibody enriched at least threefold for neural stem/progenitor cells characterized by the ability to self-renew as neurospheres that generated all major neural lineages in differentiation assays. In contrast, the 473HD-depleted cell fraction was mostly devoid of neurosphere-forming cells. The isolation of 473HD-positive adult multipotent progenitors from the subependymal zone of the lateral ventricle wall revealed a substantial overlap with the known adult neural stem cell marker LewisX. When the chondroitin sulfates were removed from immunoselected 473HD-positive neural stem/progenitor cell surfaces by chondroitinase ABC treatment or perturbed by the monoclonal antibody 473HD that recognizes the unique DSD-1 chondroitin sulfate epitope, the generation of neurospheres was significantly reduced. Thus, the 473HD epitope could not only be used for the isolation of multipotent neural progenitors during forebrain development as well as from the adult neurogenic niche but may also constitute a functionally important entity of the neural stem cell niche.

Neural Stem/Progenitor Cells Express 20 Tenascin C Isoforms That Are Differentially Regulated by Pax6

“…The observation of a largely overlapping pattern of Tnc isoform complexity between P6 cerebellum and E13 forebrain neurospheres was unexpected, because we initially assumed a neural stem cell-specific signature of Tnc isoform expression. However, our findings could relate to the fact that in neurospheres many radial glia-like neural precursor cells are found (28). Consequently, we rather may have revealed a radial glia-specific Tnc isoform expression pattern, which is also interesting because the number of radial glia cells is reduced in Tnc-deficient mice (14).…”

“…After permeabilization in PBS, 0.1% Triton X-100, 1% BSA the cells were immunostained using BLBP (1:1000, Chemicon), GLAST (1:1000, Chemicon), RC2 hybridoma supernatant (1:10, Developmental Hybridoma Bank), Pax6 (undiluted hybridoma supernatant), and GFAP (1:300, DAKO, Denmark). For detection of the 473HD epitope, the cells were live stained with 473HD antibody (1:200) for 20 min at room temperature before fixation in 4% paraformaldehyde (28). The primary antibodies were detected using the appropriate secondary antibodies from Dianova as outlined above.…”

The Adult Mouse Subependymal Zone Regenerates Efficiently in the Absence of Tenascin-C

“…One explanation could be the existence of a network of compensatory ECM molecules within the adult SEZ. Chondroitin-sulfate-containing proteoglycans are present in high concentrations in the same area (Thomas et al, 1996;von Holst et al, 2006) whereas other ECM molecules, like fibulins (Rauch et al, 2005) or other members of the tenascin family (Jones and Jones, 2000), have been suggested to be able to partly compensate for the loss of TnC. It would therefore be of interest to further investigate any compensatory upregulation of other ECM molecules in the TnC deficient SEZ.…”

CSF-1 Receptor Signaling in Myeloid Cells

“…Thus caution should be taken in extrapolating results to different developmental stages, or types of macrophages. The existence of a new CSF-1R ligand, IL-34, that also interacts with PTP-z, which is coexpressed with the CSF-1R in several cell types, including HSC (Sarrazin et al 2009;Himburg et al 2012) and neural progenitors (von Holst et al 2006;Nandi et al 2013), may provide additional mechanisms for fine-tuning CSF-1R signaling in development, immunity, and disease. The discovery that Epstein -Barr virus encodes BamHI-A rightward frame-1 (BARF1), a secreted hexameric protein that binds the CSF-1 dimer interface with picomolar affinity and conformationally renders the cytokine unable to interact with the CSF-1R (Strockbine et al 1998;Elegheert et al 2012;Shim et al 2012), explains how Epstein -Barr virus eludes the immune response and offers a starting point for therapeutic targeting of both CSF-1 and BARF1.…”