Fig. 5: Knockdown of TREM2 aggravated α-Syn-induced lysosomal dysfunction in BV-2 cells via the ERK1/2/TFEB pathway.

A Representative images of western blotting analysis of TREM2, ERK1/2, and p-ERK1/2 expressions in TREM2^KD BV-2 cells and NC^KD BV-2 cells. B Representative images of western blotting analysis of Total-TFEB, Nuclear-TFEB, and Cytoplasm-TFEB expressions in TREM2^KD BV-2 cells and NC^KD BV-2 cells. C Quantification of TREM2, ERK1/2, p-ERK1/2, Total-TFEB, Nuclear-TFEB, and Cytoplasm-TFEB expressions proteins relative expression (n = 3, one-way ANOVA and Šídák’s multiple comparisons test). D Representative images of TFEB (red) immunofluorescence staining in TREM2^KD BV-2 cells and NC^KD BV-2 cells. Scale bar, 10 μm. E Quantification of Nuclear- Cytoplasm TFEB Fluorescence ratio in TREM2^KD BV-2 cells and NC^KD BV-2 cells (n = 3, one-way ANOVA and Šídák’s multiple comparisons test). F Representative images of DQ-BSA (red), Lysotracker (red), and CathB (red) in TREM2^KD BV-2 cells and NC^KD BV-2 cells. Scale bar, 10μm. G Representative images of α-Syn (red) and Lamp1 (green) immunofluorescence staining in TREM2^KD BV-2 cells and NC^KD BV-2 cells. Scale bar, 5 μm. H Quantification of integrated density of DQ-BSA, Lysotracker, and CathB in TREM2^KD BV-2 cells and NC^KD BV-2 cells (n = 3, one-way ANOVA and Šídák’s multiple comparisons test). I Quantification of MCC of α-Syn and Lamp1 in TREM2^KD BV-2 cells and NC^KD BV-2 cells (n = 3, unpaired Student’s t test) and mean Fluorescence intensity of α-Syn in TREM2^KD BV-2 cells and NC^KD BV-2 cells (n = 3, unpaired Student’s t test). The error bars represent ± SDs. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. PFFs, recombinant human A53T α-Syn pre-formed fibrils; MCC, Manders’ Colocalization Coefficients; TREM2^KD BV-2, BV-2 transfected with TREM2-shRNA, NC^KD BV-2, BV-2 transfected with LV-NC.