Figure 1.
TAM receptors expression and α-synuclein preformed fibril uptake by human microglia. All human primary microglia (hMGL) data are from in vitro hMGL, unless otherwise specified. (A and B) RNA-sequencing (RNAseq) assessment of TYRO3, AXL and MERTK expression in hMGL and induced pluripotent stem cell-derived microglia (iMGL). A one-way ANOVA with Sidak’s post hoc test was performed for pairwise comparisons between hMGL and iMGL in A. TPM = transcripts per million. Mean ± SEM of n = 4; ***P < 0.001. A two-way ANOVA with Dunnett’s post hoc test was performed to compare in vitro hMGL and iMGL to ex vivo hMGL in B. Mean ± SEM of n = 4; ***P < 0.001 versus ex vivo hMGL. (C) Western blot of MerTK, AXL and GAPDH. (D) Quantification of AXL and MerTK expression using GAPDH as a loading control. t-tests were performed. Mean ± SEM of n = 3; *P < 0.05. (E–I) hMGL and iMGL were challenged with pHrodoTM Green-labelled α-synuclein (α-syn) preformed fibrils (PFFs) for 2 h. (E) Merged phase contrast and green fluorescence images. Scale bar = 50 μm. (F) Quantification of mean green fluorescence intensity (MFI) in hMGL culture. A paired t-test was performed; n = 5; *P < 0.05; a.u. = arbitrary unit. (G) Representative fluorescence images of hMGL counterstained with Hoechst 33342 (blue). Scale bar = 500 μm. (H) Quantification of MFI in iMGL culture. A paired t-test was performed; n = 4; *P < 0.05; a.u. = arbitrary unit. (I) Representative fluorescence images of iMGL counterstained with Hoechst 33342 (blue). Scale bar = 300 μm.