Fig. 2

Overexpressing tau upregulates mTORC1 signaling. HEK293T (a) or N2a (b) cells transiently transfected with eGFP-tau, and the increased levels of phosphorylated 4EBP1, p70S6K1 and ULK1 were detected by Western blotting in the tau-OE group (n = 9). c The increased level of p-4EBP1 in primary cultured hippocampal neurons were detected by Western blotting in the tau-OE group (n = 9). d The hyperphosphorylation levels of p70S6K1 and ULK1 in the hippocampus of 12 month-old hTau mice were detected by Western blotting (n = 9). e HEK293T cells were treated with different concentrations of rapamycin for 6 h, and a dose-dependent reduction in p-4EBP1 and p-ULK1 was detected by Western blotting (n = 9). f Rapamycin decreased tau induced hyperphosphorylation of p70S6K1 and 4EBP1 in HEK293T cells, which was detected by Western blotting (n = 9). g Immunofluorescence staining results showed that the number of LC3 puncta (at least 22 cells were analyzed for each group) in HEK293T cells was recovered in tau/rapamycin group, scale bar = 20 μm. The yellow arrow points to the LC3 puncta. 4EBP1 eukaryotic translation initiation factor 4E-binding protein 1, GFP green fluorescent protein, Hippo hippocampus, LC3 microtubule-associated protein light chain 3, ns non-significant, p70S6K1 70 kDa ribosomal protein S6 kinase 1, Rapa rapamycin, 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