Fig. 5: CDO1 restoration impairs mitochondrial function.

A JC-1 staining was performed as described in Materials and Methods. The representative images of JC-1 staining in the control or the CDO1-restored MKN45 or NCI-N87 cells are presented here (left panel). The fluorescence intensity ratio of JC-1 aggregates (red) against JC-1 monomers (green) markedly decreased in MKN45 and NCI-N87 cells, indicating that mitochondrial depolarization occurred in GC cells with CDO1^WT re-expression. Scale bars, 100 μm. B ATP generation, which is the major function of mitochondria, was substantially reduced as the result of CDO1^WT restoration. C Test of OCR in MKN45 (left panel) and NCI-N87 (right panel) cells from the N.C. and CDO1^WT group, showing that respiration activity of mitochondria was markedly blocked by CDO1^WT. Bottom, quantification of basal respiration and maximal respiration as measured by OCR (mean ± SD; N = 3). Data shown is a representative experiment of two independent ones. D Metabolomics study targeting key metabolites implicated in cellular ATP generation process showed that succinate, AMP, cis-aconitate, GMP, NADH, and NADPH were all significantly decreased in CDO1^WT-overexpressing MKN45 cells compared to N.C. ones. *p < 0.05, **p < 0.01, ***p < 0.001.