EMBO/SourceData huggingface dataset:
Figure 1.SIRT1 activity is required for resveratrol-induced autophagy but not for spermidine-mediated autophagy induction in mammalian cultured cells. (A-C) Human colon carcinoma HCT 116 cells were left untransfected (Co, control) or transfected with an irrelevant siRNA (UNR, unrelated) or siRNAs specific for ATG5, ATG7, or SIRT1 and then retransfected with a GFP-LC3-encoding plasmid, cultured in complete medium for 24 h, and left untreated or treated for 4 h with 100-µM resveratrol (Resv) or spermidine (Spd). The same experiment was performed in the presence of bafilomycin A1 (BafA1), which inhibits the fusion between lysosomes and autophagosomes, to evaluate the autophagic flux. (A) Representative images. (B) Quantitative data.SIRT1 activity is required for resveratrol-induced autophagy but not for spermidine-mediated autophagy induction in mammalian cultured cells. (A-C) Human colon carcinoma HCT 116 cells were left untransfected (Co, control) or transfected with an irrelevant siRNA (UNR, unrelated) or siRNAs specific for ATG5, ATG7, or SIRT1 and then retransfected with a GFP-LC3-encoding plasmid, cultured in complete medium for 24 h, and left untreated or treated for 4 h with 100-µM resveratrol (Resv) or spermidine (Spd). The same experiment was performed in the presence of bafilomycin A1 (BafA1), which inhibits the fusion between lysosomes and autophagosomes, to evaluate the autophagic flux. (A) Representative images. (B) Quantitative data. (C) Representative immunoblots of HCT 116 cells transfected either with an unrelated siRNA or with a SIRT1-specific siRNA showing LC3 lipidation after treatment with 100-µM spermidine in the presence or absence of bafilomycin A1.(D-F) HCT 116 cells were left transfected with a GFP-LC3 plasmid, cultured in complete medium for 24 h, and treated with either vehicle (Co), 100-µM resveratrol, or 100-µM spermidine in the presence or absence of the SIRT1 inhibitor EX527 for 4 h. (D) Representative images. (E) Quantitative data. (B and E) Bars depict the percentages of cells showing accumulation of GFP-LC3 in puncta (GFP-LC3vac; means ± SEM; n = 3; *, P < 0.05). (F) Representative immunoblots showing LC3 lipidation in HCT 116 cells treated with 100-µM spermidine in the presence or absence of EX527. GAPDH, glyceraldehyde 3-phosphate dehydrogenase.
Figure 2.The lifespan-extending and autophagy-inducing effects of spermidine in yeast are not mediated by Sir2. (A-E) EGFP-Atg8p was ectopically expressed in wild-type (WT) or Δsir2 S. cerevisiae undergoing chronological aging on small synthetic 2% glucose media with or without (Co, control) supplementation of 4-mM spermidine (Spd). (A) Representative images. EGFP-Atg8p localization (bottom) was visualized by fluorescence microscopy. Yeast cells undergoing autophagy (in which EGFP-Atg8p exhibits a prominent vacuolar localization) are indicated by arrows. Yeast morphology was monitored by differential interference contrast (DIC; top).(B) Representative immunoblots against EGFP. Free EGFP indicates the vacuolar degradation of EGFP-Atg8p fusion, thereby representing the autophagic flux. Notice that both WT and Δsir2 yeast cells show similar free EGFP levels after spermidine-mediated autophagy induction.(C) Relative alkaline phosphatase (ALP) activity indicative of autophagy. n = 3.(D) Survival data. n = 4.(E) Quantification of reactive oxygen species. Bars indicate the percentages of cells exhibiting the reactive oxygen species-mediated conversion of dihydroethidine (DHE) into ethidium (Eth; n = 4). Data represent means ± SEM; *, P < 0.001 as compared with untreated cells of the same genotype. GAPDH, glyceraldehyde 3-phosphate dehydrogenase. RFU, relative fluorescence unit.
Figure 3.The life-extending and autophagy-inducing effects of spermidine in C. elegans are not mediated by Sir2. (A) Fluorescence microscopy of C. elegans transgenic embryos expressing a full-length plgg-1DsRed::LGG-1 fusion protein indicative of autophagic activity. Two representative pictures of wild-type (WT) and sir-2.1 embryos untreated (Co, control) or treated with 0.2-mM spermidine (Spd) supplementation of food are shown. (B) Quantification of autophagic activity through the measurement of DsRed::LGG-1 pixel intensity from images of WT animals shown in A. Data represent means ± SEM (n = 3) with ≥25 images processed for each trial.C) Survival of WT C. elegans during aging with and without (control) supplementation of food (UV-killed E. coli) with 0.2-mM spermidine (n = 110; P < 0.005). (D) Survival of sir-2.1 C. elegans (ok434 phenotype) during aging with and without (control) supplementation of food (UV-killed E. coli) with 0.2-mM spermidine (n = 110; P < 0.01). P-values were calculated using the log-rank test as described in Materials and methods.
Figure 4.Convergent alterations in the phosphoproteome status after resveratrol and/or spermidine treatment. (A-C) Human colon carcinoma HCT 116 cells were treated for 2 h with vehicle (Co, control), 100-µM resveratrol (Resv), and 100-µM spermidine (Spd), alone or in combination (Resv + Spd). (A) Representative phosphoprotein arrays are shown.(B) Clustering analysis for the effects on protein kinase phosphorylation.(C) Representative immunoblots of selected kinases whose phosphorylation status was unaffected (PRKAA1, RPS6KB1, and acetyl-CoA carboxylase a [ACACA]) or affected by resveratrol or/and spermidine treatment (PTKB, AKT1, MAPK8, and CDKN1B), validating phosphoprotein array data.(D) Human colorectal carcinoma HCT 116 cells were transfected with a GFP-LC3-encoding plasmid, cultured in complete medium for 24 h, and then treated with either vehicle or the indicated dose of resveratrol or spermidine, alone or in combination, for 2 h. Quantitative data. Bars depict the percentages (means ± SD; n = 3; *, P < 0.05) of cells showing the accumulation of GFP-LC3 in puncta (GFP-LC3vac). GAPDH, glyceraldehyde 3-phosphate dehydrogenase.
Figure 5.Convergent acetylproteome modification after resveratrol or spermidine treatment. (A-C) Colon carcinoma HCT 116 cells were cultured for 2 wk in three different SILAC media containing different arginine and lysine isotopes. Cells were treated with 100-µM resveratrol (Resv) or spermidine (Spd) for 2 h, fractioned into cytoplasmic, nuclear, and mitochondrial extracts, processed for acetyl lysine peptide enrichment, and analyzed by MS. (A) Hierarchical clustering of drug-specific organellar distributions of all acetylated sites quantified in at least one fraction. Fold changes are calculated relative to untreated cells. Only sites regulated >1.5-fold were included in statistical analyses. (B) Graphical representation of peptides whose acetylation status was affected in a convergent or divergent way. n = 560.
Figure 6.Significant motifs among sites undergoing acetylation. (A) Hierarchical clustering of the organellar distributions of sites whose acetylation was increased by >1.5-fold in response to resveratrol or spermidine, at least in one organellar fraction. (B) Consensus acetylation motifs identified upon resveratrol (left) or spermidine (right) treatment are depicted using the MotifX algorithm (Schwartz and Gygi, 2005). Among sites that were hyperacetylated in response to both agents, the K(F/Y) motif is significantly enriched when tested against the whole proteome (P < 0.00001). (C) When testing against the largest acetylation site dataset from Choudhary et al. (2009) (acetylation background dataset [ABD]), the SxK motif is significant (P < 0.0001) for sites whose acetylation increased upon spermidine treatment. No general consensus motifs were found for sites whose acetylation increased in response to both agents.
Figure 7.Significant motifs among sites undergoing deacetylation. (A) Hierarchical clustering of the organellar distributions of sites whose deacetylation was increased by >1.5-fold in response to resveratrol or spermidine, at least in one organellar fraction. (B) Among sites that were hypoacetylated in response to both agents, the KP motif is significantly enriched when tested against ABD (P < 0.001). (C and D) When tested against the ABD (C) or the whole proteome (D), the KP motif is significant for sites undergoing hypoacetylation upon spermidine treatment (P < 0.0001). No general consensus motifs were found for sites whose acetylation decreased in response to both agents.
Figure 8.Autophagy can be efficiently regulated by cytoplasmic (de)acetylation reactions. (A and B) HCT 116 cells were transfected with a GFP-LC3-encoding plasmid, cultured in complete medium for 24 h, and enucleated to obtain cytoplasts. The cytoplasts were treated with either vehicle (Co, control), 100-µM resveratrol (Resv), or 100-µM spermidine (Spd) for 4 h. 1-µM rapamycin (Rapa) was used as a positive control. (A) Representative images of cytoplasts indicative of autophagic activity. Arrows indicate GFP-LC3-transfected cytoplasts, whereas insets show nonenucleated transfected cells. (B) Quantitative data. Bars show the percentages of cells or cytoplasts showing the accumulation of GFP-LC3 in puncta (GFP-LC3vac).(C-E) HCT 116 cells were cotransfected with a plasmid for the expression of RFP-LC3 together with an empty vector (pcDNA3) or plasmids encoding wild-type (WT) SIRT1 or a SIRT1 variant with a mutation in the nuclear localization signal fused to GFP (WT GFP-SIRT1 and mtNLS GFP-SIRT1, respectively) for 12 or 24 h, fixed, and analyzed by fluorescence microscopy. (C) Representative images indicative of 24-h autophagic activity.(D) Quantitative data. Bars depict the percentages of cells exhibiting the accumulation of RFP-LC3 in puncta (RFP-LC3vac). (B and D) Means ± SEM; n = 3; *, P < 0.05.(E) Representative immunoblots for 24-h endogenous LC3 lipidation. The asterisk stands for a nonspecific band. GAPDH, glyceraldehyde 3-phosphate dehydrogenase.
Figure 9.Low doses of resveratrol and spermidine synergistically induce autophagy in vitro and in vivo. (A) Human colorectal carcinoma HCT 116 cells were transfected with a GFP-LC3-encoding plasmid, cultured in complete medium for 24 h, and then treated with either vehicle (Co, control) or the indicated dose of resveratrol (Resv) or spermidine (Spd), alone or in combination, for 2 h. (top) Quantitative data. Bars depict the percentages (means ± SD; n = 3; **, P < 0.05) of cells showing the accumulation of GFP-LC3 in puncta (GFP-LC3vac). (bottom) Representative immunoblots showing endogenous LC3 lipidation.B) Representative immunoblots showing endogenous LC3 lipidation in the presence of bafilomycin A1 (BafA1). (C-E) Transgenic C57BL/6 mice expressing a GFP-LC3 fusion protein were injected with resveratrol and spermidine at the indicated concentrations. 3 h later, mice were killed, and tissues were processed for immunofluorescence microscopy determinations of GFP-LC3vac.C) Representative images(D) Quantitative results. Bars represent the percentages (means ± SEM; n = 3; *, P < 0.05; and **, P < 0.01 as compared with the same tissue from untreated animals) of cells exhibiting GFP-LC3vac.(E) Representative immunoblots showing endogenous LC3 lipidation and p62 protein content in WT C57BL/6 mouse tissues. GAPDH, glyceraldehyde 3-phosphate dehydrogenase.
Figure 3A) Correlations of mean fold-changes of the proteins changing PD-dependently in the Columbia and LCC cohorts. Only proteins quantified in both cohorts are shown (n=330). Proteins overlapping between the two cohorts are labeled with their name.
Figure 4B) Mean fold-changes for each of the 33 proteins that were LRRK2-dependently regulated in both cohorts using a pairwise t-test comparing the four subgroups (HC, NMC, iPD and LRRK2 PD).
Figure 5A) Pearson correlation scores and associated p-values [-log10] of all protein intensities with the MoCA total score. Either all PD patients (left), iPD patients (middle) or LRRK2 PD patients (right) were included in the analysis. Significantly correlated proteins with an FDR of 5% after Benjamini-Hochberg correction are highlighted in red.B) Pearson correlation scores and associated p-values [-log10] of all protein intensities with the UPDRS-III score. Either all PD patients (left), iPD patients (middle) or LRRK2 PD patients (right) were included. Significantly correlated proteins with an FDR of 5% after Benjamini-Hochberg correction are highlighted in red.
figf1(a,b) BJAB lymphoma cells stably expressing mCherry-GFP-LC3 were serially cultured at log phase followed by fluorescence-activated cell sorting for cells with high and low autophagic flux using the ratio of mCherry/GFP (a). The high and low 20% were sorted (a),(a,b) BJAB lymphoma cells stably expressing mCherry-GFP-LC3 were serially cultured at log phase followed by fluorescence-activated cell sorting for cells with high and low autophagic flux using the ratio of mCherry/GFP (a). The high and low 20% were sorted (a), re-plated and treated with lysosomal protease inhibitors pepstatin and E-64d for 1 h; lysates were then immunoblotted for the indicated proteins (b). (c) Densitometry of LC3-II and p62 western blots (normalized to actin and hour 0, mean ± s.e.m., n = 3 blots from 2 independent experiments, *P = 0.051, **P = 0.0091).(d); autophagic LC3 puncta were assessed by quantitative microscopy(d); autophagic LC3 puncta were assessed by quantitative microscopy (e; punctate area per cell, mean ± s.e.m., n = 50 fields, *P = 0.010, **P = 0.053).f) Electron micrographs of HeLa mCherry-GFP-LC3 cells sorted for autophagic flux as in a. Yellow arrows denote autophagosomes; red arrows indicate autolysosomes. (g) Quantification of autophagosomes and autolysomes from electron micrographs (mean ± s.e.m., n = 50 fields). Uncropped images of blots are shown in Supplementary Fig. 6.
figf2a-c) BJAB lymphoma cells stably expressing mCherry-GFP-LC3 were serially cultured at log phase followed by fluorescence-activated cell sorting for cells with high and low autophagic flux using the ratio of mCherry/GFP. Cells were then re-plated in growth medium and autophagic flux was again measured by flow cytometry at the indicated time points (median ratio of mCherry/GFP fluorescence ± s.e.m., n = 3 wells). Lysates from cells collected at the indicated time points were immunoblotted with the indicated antibodies (b). Representative flow cytometry histograms for cells at 0 h and 24 h after sorting (c).(d) BJAB mCherry-GFP-LC3 cells were sorted for autophagic flux as in a (top and bottom 20%). Following treatment with Fas ligand (1.5 ng ml−1) or TRAIL (4 ng ml−1), cell viability was determined by MTS assay (a tetrazolium reduction-based metabolic measurement) at 24 h (percentage of untreated control, mean ± s.e.m., n = 3 wells, *P = 2.3×10−4, **P = 0.0036).(e) Long-term growth of BJAB mCherry-GFP-LC3 cells sorted for autophagic flux followed by treatment with Fas ligand (4 ng ml−1) or TRAIL (15 ng ml−1) for 24 h. Cells were then re-plated and allowed to recover for 5 (Fas ligand) or 6 (TRAIL) days then assayed for viability (percentage of no ligand control, mean ± s.e.m., n = 3 wells, *P = 0.012).(f) BJAB mCherry-GFP-LC3 cells were sorted for autophagic flux as above and apoptosis was measured at 1 h by flow cytometry using AnnexinV and DAPI (mean ± s.e.m., n = 3 wells, *P = 0.0046).(g) Cells sorted as in a, were re-plated and, starting at the indicated times following sorting, treated with Fas ligand (4 ng ml−1) for 24 h; cell viability was then determined by MTS (percentage of untreated control, mean ± s.e.m., n = 3 wells). Uncropped images of blots are shown in Supplementary Fig. 6.
figf3(a) BJAB and Jurkat cells were treated with vehicle or chloroquine (BJAB, 20 μM; Jurkat, 10 μM) for 16 h followed by Fas ligand (1.5 ng ml−1). Cell viability was determined by MTS 24 h later (percentage of control (no ligand), mean ± s.e.m., n = 3 wells, *P = 0.0058).(b) Immunoblots of cells in a,c probed for the indicated antibodies. CQ, chloroquine(c) BJAB and Jurkat cells were treated with chloroquine (BJAB, 20 μM; Jurkat, 10 μM) for 16 h followed by treatment with Fas ligand (4 ng ml−1) for 24 h (same technical replicate as a). Cells were then re-plated at low density in growth media and allowed to recover for 5 days, and then assayed for viability (percentage of no ligand control, mean ± s.e.m., n = 3 wells, *P = 0.0024).(d) BJAB and Jurkat cells were transduced with the indicated lentiviral shRNA constructs, followed by 3 days of puromycin selection. Selected cells were plated and treated with Fas ligand (1.5 ng ml−1) or TRAIL (4 ng ml−1) for 24 h and viability was assessed by MTS (percentage of control (no ligand), mean ± s.e.m., n = 3, *P = 1.7×10−4, **P = 0.024).(e) Immunoblots for Atg5, Atg7 and p62 confirm protein depletion and autophagy inhibition in d,f.(f) BJAB and Jurkat cells expressing control or Atg5 shRNA were treated with Fas ligand (15 ng ml−1) or TRAIL (12.5 ng ml−1) for 24 h (same technical replicate as d). Cells were then re-plated at low density and allowed to recover for 5-6 days, and then assayed for viability (percentage of no ligand control, mean ± s.e.m., n = 3 wells, *P = 0.0089). Atg7 knockdown data were not included for long-term viability owing to the growth suppressive effect of Atg7 knockdown in the absence of drug treatment. Uncropped images of blots are shown in Supplementary Fig. 6.
figf4(a,b) BJAB and Jurkat cells stably expressing mCherry-GFP-LC3 were flow sorted for high and low autophagic flux, treated with Fas ligand (1.5 ng ml−1) for 24 h and viability was assessed by MTS (a; percentage of no ligand control, mean ± s.e.m., n = 3 wells, *P = 0.0046). (b) Immunoblots following sorting of the samples in a.(c,d) The indicated cell lines were treated with chloroquine (BJAB, CEM 20 μM; SKW6.4, 25 μM; Jurkat, 10 μM) for 16 h, followed by Fas ligand (BJAB, 12.5 ng ml−1; SKW6.4, 50 ng ml−1; Jurkat, 0.4 ng ml−1; CEM, 40 ng ml−1). Lysates from cells collected after chloroquine treatment were immunoblotted with the indicated antibodies (c).(c,d) The indicated cell lines were treated with chloroquine (BJAB, CEM 20 μM; SKW6.4, 25 μM; Jurkat, 10 μM) for 16 h, followed by Fas ligand (BJAB, 12.5 ng ml−1; SKW6.4, 50 ng ml−1; Jurkat, 0.4 ng ml−1; CEM, 40 ng ml−1). Lysates from cells collected after chloroquine treatment were immunoblotted with the indicated antibodies (c). Cell viability was assessed by MTS 24 h following Fas ligand treatment (d; percentage of control (no ligand), mean ± s.e.m., n = 3 wells, *P = 2.7×10−4, **P = 1.6×10−4).(e,f) BJAB and Jurkat cells were transduced with control, Atg5, Atg7 or Vps34 shRNA lentiviruses, followed by three days of puromycin selection. Cells were then treated with Fas ligand (1.25 ng ml−1) or TRAIL (1.25 ng ml−1) for 24 h and viability was assessed by MTS (e; percentage of control (no ligand), mean ± s.e.m., n = 3 wells, *P = 1.4×10−6, **P = 2.3×10−5, ***P = 3.9×10−5, §P = 9.2×10−6, §§P = 3.4×10−6, §§§P = 1.7×10−5). Immunoblots demonstrate Atg5, Atg7 and Vps34 knockdown, autophagy inhibition and altered Fap-1 levels. The blots are separated because different exposures were required to detect the proteins in one cell line without overexposing the lanes for the other; the Fap-1 blot is not separated to demonstrate the lack of Fap-1 protein in Type II Jurkat cells (f). Fap-1 blots (b,c,f) were run on separate gels owing to the quantity of protein required for detection (see Methods). Uncropped images of blots are shown in Supplementary Fig. 6.
figf5(a,b) BJAB and Jurkat cells expressing the indicated Fap-1 wild-type (WT) and catalytically inactive (ΔCD) constructs were treated with chloroquine (BJAB, 20 μM; Jurkat, 10 μM) for 16 h followed by Fas ligand (BJAB, 1.5 ng ml−1; Jurkat 15 ng ml−1) for 24 h. Cell viability was determined by MTS (a; percentage of control (no ligand), mean ± s.e.m., n = 3 wells, *P = 2.7×10−4, **P = 2.4×10−5, ***P = 0.0024). Cell lysates were blotted and probed with the indicated antibodies (b).c-e) BJAB cells expressing control or Fap-1 shRNAs were treated with 20 μM chloroquine for 16 h followed by Fas ligand (12.5 ng ml−1) or TRAIL (25 ng ml−1) for 24 h; cell viability was then determined by MTS (c; percentage of control (no ligand), mean ± s.e.m., n = 3 wells, *P = 4.8×10−6, **P = 8.1×10−5, ***P = 8.0×10−4, §P = 0.013, NS P>0.05).(d) Immunoblots of lysates collected following chloroquine treatment. Long-term growth was assessed in cells from c by re-plating them at low density and allowing them to recover for 5 days, followed by viability assay (percentage of untreated control, mean ± s.e.m., n = 3 wells, *P = 0.043; e). Fap-1 blots (b,d) were run on separate gels owing to the quantity of protein required for detection (see Methods). Uncropped images of blots are shown in Supplementary Fig. 6.
figf6a,b) Cell viability was determined by MTS assay following Fas ligand (4 ng ml−1) treatment in BJAB cells expressing control or p62 lentiviral shRNAs (a; percentage of control (no ligand), mean ± s.e.m., n = 3 wells, *P = 3.2×10−5, **P = 1.8×10−6). Immunoblots confirm p62 depletion and Fap-1 levels (b).(c) Co-immunoprecipitation of endogenous p62 and Fap-1 in BJAB cells treated with 20 μM chloroquine for 16 h, followed by treatment with Fas ligand (50 ng ml−1) for 2 h at 4°C.
Figure 1HDAC6 KO MEF cells are defective in aggregate clearance but not in autophagosome induction or targeting. (A) Filter‐trap analysis of MG132‐induced, SDS‐insoluble ubiquitinated aggregates generated in wild‐type (WT), HDAC6 KO, and KO MEFs reconstituted with different HDAC6 constructs as indicated. The signal intensity from the ubiquitinimmunoblot (bottom panel) was quantified and presented as the average of the means from three independent experiments along with the standard deviation (top). Note the significant accumulation of ubiquitin‐positive aggregates in HDAC6 KO MEFs and KO MEFs stably expressing HDAC6‐CD and ΔBUZ mutants. WT, HDAC6 KO, and HDAC6 KO MEFs stably expressing human HDAC6 (hHDAC6 WT), HDAC6 CD (catalytically inactive mutant), or HDAC6 ΔBUZ (ubiquitin‐binding‐deficient mutant) were analysed for the level of HDAC6 using an anti‐human HDAC6 antibody. Mouse endogenous HDAC6 (mHDAC6) and actin levels were determined by each corresponding antibody.(B) WT and HDAC6 KO MEFs were treated with MG132 and subjected to Western blot analysis for LC3, actin, and HDAC6.(C) Cells were treated with MG132 as described under Materials and methods and immunostained with antibodies to ubiquitin (green) and LC3 (red). Arrows indicate ubiquitin‐positive aggregates that colocalize with LC3‐positive autophagosomes. Scale bar, 10 μm.(D) WT and ATG5 KO MEFs are treated with 2.5 μM MG132 for 1 day and incubated with normal growth media for 18 h. MEFs are immunostained with anti‐LC3 (red) and anti‐ubiquitin antibody (green).
Figure 2(A) Wild‐type and HDAC6 KO MEFs were transfected with pcDNA, pcDNA‐HDAC6WT, HDAC6CD, or HDAC6ΔBuz, along with mCherry‐GFP‐LC3 as indicated. Yellow signals indicate non‐acidic autophagosomes and red signals indicate acidic autophagolysosomes. Scale bar, 10 μm.(B) The total number of yellow vesicles was quantified from three independent experiments (>12 cells each) and presented as the percentage of total mCherry‐GFP‐LC3 dots (red plus yellow) along with the standard deviation.(C)In vitro fusion assays. Autophagosomes (APGs) and lysosomes (Lys) purified from wild type and HDAC6−/− MEFs were subjected to heterotypic and homotypic in vitro fusion assays (representative fields are shown in Supplementary Figure S3). Values are means+s.e. of the percentages of fusion from three independent experiments (more than 10 images per each experiment).(D) EM images of wild‐type and HDAC6 KO MEFs in normal growth conditions. Yellow arrows, autophagosomes; red arrows, autophagolysosomes; green arrowheads, multilamellar bodies.(E) Quantification of autophagosomes and autophagolysosomes. The error bar represents the standard error.