Figure 1: LPS can induce the de novo formation of TDP-43 foci.

(a) Immunofluorescence microscopy assay (IFA) of stable GFP-TDP-43-expressing RAW 264.7 macrophages following exposure to LPS (80 ng ml⁻¹) for 2 or 6 h. Quantitative analysis of de novo TDP-43 foci formation. Values represent the average (n=100–120 cells) of three independent experiments. Arrowheads indicate TDP-43-enriched subnuclear foci. Scale bars, 5 μm. *P<0.01 (two-tailed Student’s t-test). (b) RAW macrophages were stimulated with LPS (80 ng ml⁻¹) for the indicated times. Cell lysates were immunoblotted with anti-TDP-43 or anti-β-actin antibody. (c) LPS stimulation (80 ng ml⁻¹) for 6 h leads to the enrichment of endogenous TDP-43 in subnuclear sites of RAW macrophages and primary BMDCs. Anti-TDP-43 primary antibody was used, along with Alexa 488-conjugated secondary antibody and 4′,6-diamidino-2-phenylindole (DAPI). Scale bars, 5 μm. Quantitative analysis of de novo TDP-43-enriched foci formation. Values represent the average (n=100 cells) of three independent experiments. *P<0.05 (Student’s t-test). (d) TDP-43 foci do not appear in NF-κB-deficient MEFs in the presence of LPS (80 ng ml⁻¹). Endogenous TDP-43 was observed by anti-TDP-43 antibody. Scale bars, 5 μm. (e) Macrophages containing TDP-43-enriched nuclear foci display disrupted CB formation. RAW macrophages were exposed to LPS (80 ng ml⁻¹) for 6 h, stained with anti-TDP-43 and anti-coilin antibody, and examined by IFA assay. Arrowheads indicate TDP-43-enriched foci. Scale bars, 5 μm. Data are representative of at least three independent experiments (mean±s.d. in a and c).