Fig. 1: Increased mitochondrial α-KG in CHCHD2-deficient cells.

A Schematic illustration of purification of mitochondria and metabolomic analysis. D2 KO: CHCHD2 knockout. Mito IP: mitochondria immunopurification. Created in BioRender. Gao, G. (2025) https://BioRender.com/a45x634. B Heatmap representing metabolites abundance of CHCHD2-deficient (KO) and control (ctrl) HEK293T cells. Red and blue reflect high and low abundance, respectively. N = 4 and 3 for control and CHCHD2 knockout cells, respectively. C Volcano plot showing the changes of mitochondrial metabolites in CHCHD2-deficient HEK293T cells compared to controls. N = 3 and 4 biological replicates for knockout and control cells, respectively. Significant metabolites were defined as those with a fold change >2 or <0.5, and a P < 0.05 (two-sided t test). Metabolites that are significantly increased and decreased in CHCHD2-deficient cells are highlighted in red and blue, respectively. D Schematic of TCA cycle and glutaminolysis metabolites. The levels of mitochondrial α-KG (E), citrate/iso citrate (F), glutamate (G) and succinate (H) of control and CHCHD2-deficient HEK293T cells. I The ratio of mitochondrial α-KG to succinate of control and CHCHD2-deficient cells. J The level of mitochondrial NAD⁺ of control and CHCHD2-deficient cells. K The ratio of mitochondrial GSH to GSSG of control and CHCHD2-deficient cells. For (E–K), all values were relative to the average levels of control conditions, and each data point represents a biological replicate (N = 4 and 3 for control and CHCHD2 knockout cells, respectively). All data shown are mean ± SEM. ns, not significant. Two-sided t test. Source data are provided as a Source Data file.