), Canadian Stroke Network (to A.J.V. 4N) or neurons (Fig. At least two mice per time point were analyzed. Because several classes of central glia express SPARC, we also examined SPARC expression in peripheral glia. 3; Table 2), with high levels of expression detected in the inferior colliculus (Fig. SPARC and tumor growth: where the seed meets the soil?
2019;68(2):695-710. doi: 10.3233/JAD-181032.
A comprehensive systematic review of CSF proteins and peptides that define Alzheimer's disease. The widespread expression of SPARC by radial glia in the postnatal brain suggests that its expression may be retained in adult radial glia. 3A–C,K,N), choroid plexus (CP, Fig. 1C,E,F), and overlaps with regions of BLBP‐positive radial glia (Fig. During later postnatal development (P14), SPARC is present in a small number of radial glia–like processes, most of which also express nestin (arrow in Fig. However, the expression of SPARC is in turn regulated by each of these factors; decreased by FGF2 and EGF, increased by IGF‐1, and reciprocally regulated by TGFβ (Wrana et al.,1991; Chandrasekhar et al.,1994; Delany and Canalis,1998; Shiba et al.,1998,2001). SPARC in Bergmann glia and Müller glia. A role for SPARC in synaptogenesis and synaptic plasticity is suggested by its restriction to key populations of astrocytes in brainstem nuclei (Fig. 4; Table 2). 3I) and P14 (Fig. 5) suggests that this deadhesive protein may play a role in maintaining microglial homeostasis in the normal brain, as it does in ovarian cancer cells (Said et al.,2007b).
Images were corrected for sharpness, contrast, and brightness. SPARC mRNA appears to be widely expressed in the adult mouse brain (Fig. SPARC is concentrated in the cell soma of Schwann cells (S100‐positive, Fig. SPARC is expressed by (C,E–H) nestin+ radial glia, in their cell bodies (bracket in F) and processes (inset in C, arrow in F), and overlaps with regions of (A,B,I–K) BLBP+ radial glia (arrows). SPARC also has the potential to regulate angiogenesis in the developing brain (Figs. SPARC produced by olfactory ensheathing cells (OECs) can promote axon sprouting in vitro and in vivo. SPARC in Bergmann glia and Müller glia. During postnatal development, SPARC may facilitate neuronal migration along the RMS, which contains SPARC during the peak of postnatal interneuron migration to the olfactory bulb (Fig. NIH Primary antibodies included goat anti‐SPARC (1:500; R&D Systems, Minneapolis, MA), monoclonal anti‐PCNA (1:5,000; Sigma), rabbit anti‐BLBP (brain lipid binding protein; 1:1,000; Chemicon, Temecula, CA), rabbit anti‐βIII tubulin (TUJ1 clone; 1:1,000; CoVance, Princeton, NJ), rabbit anti‐S100 (1:1,000; Neomarkers, Waltham, MA), rabbit anti‐Iba‐1 (1:1,000, Wako Chemicals USA, Richmond, VA), rabbit anti‐nestin (1:1,000; Covance), rabbit anti‐Dcx (doublecortin; 1:1,000; Cell Signaling Technology, Danvers, MA), and rabbit anti‐Adam21 (a disintegrin and metallopeptidase domain 21; 1:1,000; Chemicon). 2B,G). Perfused tissue was post‐fixed overnight in 4% PFA, cryopreserved in 30% sucrose in PBS, and frozen in Tissue‐Tex optimal cutting compound (Sakura, Tokyo, Japan) in isopentane over dry ice. Here, we show that in the developing nervous system of the mouse, SPARC is expressed by radial glia, blood vessels, and other pial‐derived structures during embryogenesis and postnatal development. 3A,B). 3I–K). The sections were washed with 0.3% Triton X‐100 in PBS and then incubated with secondary antibodies raised in donkey and conjugated to Alexa Fluor 488 or 594 for 1 hr at room temperature (1:200; Molecular Probes, Eugene, OR). Scale bars = (A–D,I,J) 100 μm; (E–H, K–O) 50 μm. This project was funded by the Spinal Research Trust (to A.J.V. Glial gene networks associated with alcohol dependence. Molecular cloning and characterization of the matricellular protein Sparc/osteonectin in flatfish, Scophthalmus maximus, and its developmental stage-dependent transcriptional regulation during metamorphosis. The distribution of SPARC along radial glial processes may facilitate the apical migration of neuroblasts from the ventricular layer towards the pia mater (Rakic,1972). 3G; Table 2). Radial glia express the marker nestin (Hockfield and McKay,1985), an intermediate filament protein, and subpopulations express the neurogenic radial glial markers, brain lipid binding protein (BLBP) (Feng et al.,1994; Anthony et al.,2004), and a disintegrin and metalloprotease 21 (ADAM21) (Yang et al.,2005). From its presence in other non‐neuronal cell types, SPARC has the potential to play a plethora of other roles in the developing or injured nervous system.
This is consistent with the finding that glioma cell lines are more migratory when secreting high levels of SPARC (Rempel et al.,2001). 1–4), microglia (Figs. SPARC in Schwann cells and olfactory ensheathing cells. SPARC is maintained at a low level in the adult subventricular zone (SVZ; Fig. 3D,E), fimbria (Fig. This project was funded by the Spinal Research Trust (to A.J.V. SPARC staining is present in the endfeet of Müller glia at all developmental stages (arrows in Fig. 2A), SPARC is expressed in the hippocampal neuroepithelium (Fig. Seven days after…, In SPARC nulls, microgliosis is increased and functional recovery is enhanced, following photothrombotic…, SPARC inhibits microglial proliferation in…, SPARC inhibits microglial proliferation in vivo and in vitro . Images were captured using an Axioplan2 Imaging epifluorescent microscope (Zeiss, Jena, Germany) and Northern Eclipse 6.0 software (Empix Imaging, Mississauga, ON, Canada), and processed using Photoshop 7.0 software (Adobe Systems, San Jose, CA).
Working off-campus? The cell bodies of radial glia line the brain ventricles, and their processes extend to the pial surface where they attach with endfeet (Rakic,1972). 1; At embryonic day 10.5 (E10.5), SPARC is expressed in parts of the ventricular zone in all brain vesicles, for example, in the septal neuroepithelium (SN) in the telencephalon (Fig. Directional arrows apply to A–G,I–L. In the retina, Müller glia, or their precursors, express SPARC and nestin from early in embryonic development (Fig.
2B,F–H) and brainstem (Fig. SPARC is highly enriched in radial glial (A,D–F,I–K) cell bodies (arrows, bracket in E), and (A,B) endfeet (barbed arrows), and is present in their processes (arrows in B,E). Prominent SPARC expression also persists in cortical radial glial at P5 (Fig.
), Canadian Stroke Network (to A.J.V. D,E: SPARC is expressed in the cortex by (D) microglia (Iba‐1+), but not by (E) astrocytes (S100+). SPARC is completely segregated from (E–G) axons (βIII tubulin+).
Notably, SPARC is highly enriched in brain flexures (Fig. 4A), except in blood vessels (arrowhead) and pia mater (asterisk), but is present at P5 as punctate staining in the layer containing Bergmann glia and Purkinje cell bodies (arrows in Fig. Synapse elimination activates a coordinated homeostatic presynaptic response in an autaptic circuit. SPARC is also present in the rostral migratory stream (RMS) surrounding proliferating (PCNA+) migratory cells (Fig. 3O). 3I–K). 4M), but not by neuroblasts (Fig.