Fig. 5
From: An in vitro paradigm to assess potential anti-Aβ antibodies for Alzheimer’s disease
Treatment of iNs with AD brain-derived soluble Aβ induces neuritic dystrophy. Live-cell imaging was used to monitor the effect of Aβ-containing AD brain extracts on iNs. a iN day 21 cultures were treated with mock-immunodepleted AD1 extract (Mock ID) or AD1 extract immunodepleted with the pan anti-Aβ antiserum AW7 (AW7 ID) and cells imaged for 72 h. Phase contrast images (left panels) at 0, 24, 48, and 72 h were analyzed using the IncuCutye NeuroTrack algorithm to identify neurites (middle panels) and the NeuroTrack-identified neurites (pink) are shown superimposed on the phase contrast image (right panels). Scale bars are 100 μm. b Each well of iNs was imaged for 6 h prior to addition of sample and NeuroTrack-identified neurite length and branch points used to normalize neurite length and branch points measured at each interval after addition of sample. Mock-ID AD1 extract was tested at 3 dilutions, 1:4, 1:8, and 1:16. Immunodepleted AD1 was tested at 1:4 and cells treated with medium alone were used to monitor the integrity of untreated cells. The values shown in graphs are the average of triplicate wells for each treatment ± SEM. c Plots of normalized neurite length (left panel) and neurite branch points (right panel) are derived from the last 6 h of the traces shown in b and in Supplementary Figure 8B and are presented as mean values ± SEM. Application of AD1 brain extract caused a decrease in both neurite length and branch points relative to: (i) the same neurons prior to treatment, and (ii) sister wells of untreated neurons (neurite length, p < 0.0001; branch points, p < 0.0001, two-way ANOVA). Importantly, AD1 extract that had been immunodepleted of Aβ had no significant effect on either neurite length or branch points (neurite length, p = 0.7195; branch points, p = 1.0000, two-way ANOVA). The results shown are representative of at least three independent experiments
