Fig. 5: AMPK mediates SIRT4-regulated autophagy and regulates p53 phosphorylation in PDAC.

A Western blotting analysis was used to detect the expressions of AMPK and its downstream target proteins in PDAC cells when SIRT4 was overexpressed or depleted. B Western blotting analysis was used to detect whether the decrease of AMPK expression in PDAC cells could affect the phosphorylation of p53 protein and the expressions of ARGs in Capan-2 and Hs766T cells overexpressing SIRT4. C, D Representative images (left) and its quantification (right panel) of the autophagic flux detection with the mRFP-GFP-LC3 reporter in CCC-HPE-2 cells co-transfected with scramble or sh-SIRT4 vectors, respectively, in the absence or presence of platycodin D, an AMPK activator. The indicated cells were treated with or without 10 nM Baf-A1 inhibited autophagosome-lysosome fusion. E, F After AMPK was depleted in Capan-2 cell lines overexpressing SIRT4, the mRFP-GFP-LC3 dual fluorescence labeling method was applied to detect the occurrence of autophagy. The indicated cells were treated with or without 10 nM Baf-A1 inhibited autophagosome-lysosome fusion. G SEM was applied to detect autophagy in CCC-HPE-2 and HPDE6-C7 cells. H SEM was applied to detect autophagy in Capan-2 and Hs766T cells. GraphPad software was used for the independence sample t-test (*P < 0.05; **P < 0.01).