Journal: Brain, behavior, and immunity
Article Title: A Novel Role for Osteopontin in Macrophage-Mediated Amyloid-β Clearance in Alzheimer’s Models
doi: 10.1016/j.bbi.2017.08.019
Figure Lengend Snippet: (A) Schematic illustration of in vitro studies: BM was isolated from WT mice (8- to 12-weeksold) and cultured for 6 or 7 days in MCSF-enriched media to differentiate into macrophages (MΦBM). On day 6, cells underwent overnight treatment with GA, siRNA or minocycline, except for untreated control cells (labeled ‘C’). On day 7, fibrillar Aβ (fAβ40 or fAβ42) was added in a subset of experiments, followed by phagocytosis assays. Brefeldin A (BFA) treatment was performed 3 hours prior to phagocytosis. (B) Constitutive secretion of OPN by MΦBM during a 24 hour period. Primary MΦBM media were collected after 15 min, and then after 1, 4, 6, and 24 hours. OPN protein levels were measured at each time point (ELISA; n=3 wells/time point, 1×106 cells/well, in triplicates). (C–E) Intracellular OPN expression in MΦBM. Scale bars = 10µm. Representative fluorescent micrographs of MΦBM immunostained for OPN, (C) early endosomal antigen (EEA1) marker, (D) late endosome-lysosomal marker Ras-related protein (Rab7), or (E) Golgi marker 58K protein, and nuclei (DAPI). The merged images demonstrate subcellular OPN expression within vesicles, predominantly confined to the trans-Golgi network (yellow punctate signal). (F–J) Upregulation of OPN in MΦBM by GA treatment. (F–G) Representative fluorescent micrographs demonstrate the effect of GA treatment on MΦBM expression of OPN in the absence of Aβ, either (F) without BFA treatment or (G) with BFA pre-treatment. MΦBM were immunostained for OPN (red), which was more highly expressed following GA treatment. (F: insert) Subcellular OPN within transport vesicles in MΦBM. (G) Round-shaped MΦBM after BFA inhibition of OPN secretion. Scale bars: 20 µm, insert scale 5 µm. (H) Quantitative ICC of OPN-immunoreactive area revealed a significant upregulation of OPN in MΦBM following GA treatment, with or without BFA inhibition. Means of individual cell fluorescent areas are indicated (n=5–9 images/well, average 100 cells/image, and n = 3–5 wells/treatment group). (I) Western blot image of cell lysates from above-mentioned experimental groups. (J) Corresponding densitometry results of OPN levels in Western blots (normalized to β-actin levels; n=3 wells/group, 1×106 cells/well; repeated experiments). Group means, SEMs and individual data points are shown. Fold increases in mean values compared with controls indicated in red. *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001, by one-way ANOVA and Dunnett's multiple comparisons post-tests.
Article Snippet: Sections were then hybridized with various primary antibodies (overnight at 4°C): goat polyclonal OPN (R&D systems), mouse anti-human Aβ [residues 17–24, mAb clone 4G8 (1:100; Covance), and residues 1–16, mAb clone 6E10 (1:100; Covance)], rabbit anti-GFAP pAb (1:100; Sigma-Aldrich), rabbit anti-Iba1 pAb (1:250; Wako Chemicals), rabbit anti-GFP pAb (1:500; MBL), rat anti-CD68 mAb (1:100; Abcam), rabbit anti-iNOS pAb (1:100; Cell signaling), rat anti-CD45 mAb clone 30-F11 (1:25; BD Pharmingen), mouse anti-human CD45 mAb (1:20; BD Pharmingen), mouse anti-Tuj1 mAb (1:200; Abcam), rabbit anti-NeuN mAb (1:200; Abcam) and goat anti-MMP9 pAb (1:100; R&D systems).
Techniques: In Vitro, Isolation, Cell Culture, Labeling, Enzyme-linked Immunosorbent Assay, Expressing, Marker, Inhibition, Western Blot