Fig. 1

Overexpressing tau inhibits autophagy and disrupts autophagosome formation. a Overexpressing tau decreased LC3 II protein levels in HEK293T cells, as detected by Western blotting. The LC3 II level was normalized against LC3 I (n = 9). b Overexpressing tau decreased numbers of LC3 puncta in HEK293T cells, as measured by immunofluorescence staining (at least 30 cells were analyzed for each group, scale bar = 20 μm). The yellow arrow points to LC3 puncta. c Overexpressing tau decreased the autophagosome formation in primary hippocampal neurons, as measured by transmission electron microscopy, scale bar = 1 μm. The yellow arrow points to the autophagosome. d Overexpressing tau decreased autophagosome formation of HEK293T cells, as measured by coimmunoprecipitation of ULK1 and ATG13 (n = 6). ATG13 autophagy protein 13, GFP green fluorescent protein, IP immunoprecipitation, LC3 microtubule-associated protein light chain 3, ULK1 unc-51-like autophagy-activating kinase 1, Vec vector. All data are expressed as the mean ± SEM. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001