Figure 1.

TDP-43 Loss Promotes Amyloid Phagocytosis and Degradation and Enhances Lysosomal Biogenesis in BV2 Microglia Cells

(A) Residual Aβ38, Aβ40, and Aβ42 levels from HeLa swAPP-conditioned medium, after overnight incubation with BV2 cells depleted of TDP-43, normalized to scrambled control and to cell viability (means ± SEM from three independent experiments, ^∗∗∗∗p < 0.0001, multiple unpaired t test).

(B) Western blot confirming the knockdown efficiency of Tardbp pool and single siRNA oligos in BV2 cells compared to scrambled control.

(C–H) Representative confocal micrograph (C) and relative quantification of BV2 cells uptaking fluorescently labeled Aβ40 (D) (scrambled control, n = 171 and Tardbp siRNA n = 147 BV2 cells); (E and F) dextran (control n = 47, Tardbp siRNA n = 47 cells) and (G and H) transferrin (control n = 68, Tardbp siRNA n = 68 cells); ^∗∗p < 0.005, ^∗∗∗∗p < 0.0001 using two-tailed unpaired t test.

(I and J) Representative confocal images of scrambled control and Tardbp knockdown BV2 cells (I), with relative quantification soon after (T0, control n = 23; Tardbp siRNA n = 35 cells) and 3 hr (T3 hr, control n = 13; Tardbp n = 27 cells) after 60 min incubation with 1 μM Aβ40 (J). Values are shown as mean ± SEM, ^∗p < 0.05, ^∗∗p < 0.01 versus scrambled control; ####p < 0.0001 Tardbp siRNA-T3 hr versus Tardbp siRNA-T0, using two-way ANOVA, followed by Bonferroni multiple comparison test.

(K and L) Representative confocal images of LysoTracker staining (K) and relative mean intensity quantification in control (n = 33) and TDP-43-depleted BV2 cells using siRNA Tardbp pool oligos, n = 36 or siRNA best 2 oligos, n = 36 (L). Data are shown as mean ± SEM, ^∗∗p < 0.01, ^∗∗∗∗p < 0.0001, using one-way ANOVA followed by Dunnett’s post hoc test.

(M) Representative blots for late endosomal/lysosomal markers in control and Tardbp knockdown BV2 cells.