Fig. 9: Effects of [L2Zn3]6+, [L2Cu3]6+ and [L2Mn3]6+ complexes on autophagy and of [L2Zn3]6+ on cellular ATP levels, glycolysis and mitochondrial respiration.
a Representative fluorescent images showing CYTO-ID autophagic staining (green) and Hoechst (blue) with bright field overlay of HCT116 p53−/− cells treated with 3.125 µM [L2Zn3]6+, [L2Cu3]6+ or [L2Mn3]6+ for 40 h. White arrows indicate intracellular vacuoles. Similar results were obtained in n = 3 independent experiments. b, Cellular ATP levels in ARPE-19 non-cancer cells and HCT116 p53+/+ cancer cells with 20 h exposure to [L2Zn3]6+ at the indicated concentrations; ATP levels expressed relative to levels in vehicle control-treated cells. n = 3 biologically independent experiments. Mean ATP levels ± SD. c, d Metabolic phenograms showing cellular rate of oxygen consumption (OCR) as measure of mitochondrial respiratory rate and extracellular acidification rate (ECAR) as a measure of glycolytic rate in ARPE-19 and HCT116 cells (closed circles, basal metabolic rates). c Effect of 1 h 25 µM [L2Zn3]6+, d Effect of 20 h 25 µM [L2Zn3]6+. Open circles represent maximal ECAR and OCR (metabolic capacity/reserve) of control and [L2Zn3]6+ treated cells, determined by addition of a metabolic stress mixture (oligomycin and FCCP). Black line/circle indicates vehicle control-treated cells; red line/circle indicates [L2Zn3]6+ treated cells. n = 3 independent experiments; mean ± SD.
