Fig. 7: Confocal imaging of postmortem brain tissues from AD, FTD, and PD patients upon treatment with I-43. | Nature Communications

Fig. 7: Confocal imaging of postmortem brain tissues from AD, FTD, and PD patients upon treatment with I-43.

From: Discovery of NIRF theranostic probes targeting amyloid-β and cholinesterases in Alzheimer’s disease models

Fig. 7: Confocal imaging of postmortem brain tissues from AD, FTD, and PD patients upon treatment with I-43.

a Paraffin-embedded AD brain sections showed Aβ-positive puncta stained with known standards (ThT, CRANAD-2, and Congo Red). Counterstaining with I-43 revealed high colocalization with these dyes, especially in mature plaques. CAA-associated deposits visualized by Congo Red were also effectively labeled by I-43. b–e Confocal images of AD patient brain tissues co-stained with I-43 (NIR channel) and anti-Aβ antibodies (D54D2, 6E10, OC, and A11; green channel). c1 and d1 Semiquantitative fluorescence intensity analysis of regions of interest (ROIs) determined using ImageJ. Data represent mean ± SD. In panel c1, n = 12; two-tailed unpaired t test (nsP = 0.466). In panel d1, n = 9; one-way ANOVA with Dunnett’s post hoc test (****P < 0.0001, and *P = 0.0402). f IHC confocal images of PD striatum showing α-Synuclein deposits (pSer129α-Syn antibody); I-43 counterstaining showed no colocalization. g Confocal images of AD and FTD brain sections revealed mature tau tangles (Tau46, AT8 antibodies) with no detectable NIR signal from I-43 in tau-positive puncta. h Confocal images showing CAA-associated staining in the green (OC antibody) and NIR (I-43) channels. Imaging was performed on an LSM 780 (Axio Imager 2) using FITC, TRITC, and 700 nm emission filters for ThT, CRANAD-2, and I-43, respectively. Scale bar: 20 µm. i Confocal images of larval imaginal discs from WT (Oregon R⁺; panels i1–i2) and AD (ey-GAL4-UAS-Aβ42/CyO; panels i3–i4) flies stained with I-43 (n ≥ 10). Panels i2 and i4 are 40× magnifications of panels i1 and i3, respectively (scale bars: 50 µm for i1/i3; 20 µm for i2/i4; λem = 700 nm; LSM 780). An orthogonal view from panel i4 reveals discrete amyloid plaques. j Fluorescence images of adult WT (j1-j2) and AD (j3-j4) fly eyes after feeding with I-43 (10 µM), acquired at 20× magnification using a NIS-Elements BR microscope (scale bar, 100 µm). White circles indicate ROIs used for fluorescence intensity quantification (red channel). k Semiquantitative fluorescence intensity plot of I-43 in the eyes of WT vs AD flies (n ≥ 10, mean ± SD, ****P < 0.0001 compared to WT, analyzed by two-tailed unpaired t-test). Source data are provided as a Source Data file.

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