Figure 5. Negative correlation between the acetylation of cytoplasmic proteins and autophagy induction. GFP-LC3-expressing human osteosarcoma U2OS cells were left untreated or treated with 30 µM of the phenolic compounds used in this study, including resveratrol, for 6 h. Thereafter, cells were processed for the immunofluorescence microscopy-assisted quantification of GFP-LC3⁺ dots and nuclear (A) or cytoplasmic (B–D) protein acetylation levels. In (A and B), population-based results (each dot representing the mean of n = 500 cells) are reported, together with linear regression curves and the corresponding statistical indicators (p values and determination coefficients, R²). In (C and D), results from one representative experiment are reported (each dot representing a single cell). In this latter scenario, p values and determination coefficients were invariably were > 0.2 and < 0.1, respectively.