Fig. 5: Metabolomics reveal dysregulated glutamate and glutamine neuronal metabolism.

a Box plots of absolute ion abundance of disease-related metabolites. P-value is reported as one-way ANOVA for hydroxypropionic acid, and unpaired t-test for propionyl-carnitine, and lactate. b Schematic of labelled ¹³C-glutamine metabolism into the TCA cycle. Labelled carbons = filled black circles. c Stacked bar chart of contribution of labelled glutamine carbons to aspartate (left) and box plot of absolute ion abundance of aspartate pool (right). P-value calculated via unpaired t-test. d Box plot of ratio between M + 5 to M + 4 labelled citrate fractions (left) and box plot of ratio between M + 3 to M + 4 labelled malate or aspartate fractions (right). P-value is reported as unpaired t test. e Representative schematic for the entry of dimethyl-2-oxoglutarate (DM-2OG) into the TCA cycle and selected anaplerotic entry points. f Box plot of absolute ion abundance of propionyl-carnitine and lactate in DM-2OG treated neurons. P value is reported as unpaired t test. g Box plot of total fractional contribution of carbons to untreated and DM-2OG treated neuronal abundance of aspartate. P-value is reported as Mann–Whitney (left). h Stacked bar chart of contribution of labelled carbons to untreated and DM-2OG treated neuronal abundance of malate (left) and citrate (right). i Box plots of ratio between M + 3 to M + 4 labelled aspartate and malate fractions (left and right) in DM-2OG treated neurons and box plot of ratio between M + 5 to M + 4 labelled citrate fractions (middle) in DM-2OG treated neurons. In (a, c, d, f, g, h), error = min/max (box plot) or SD (fractional bar plot). Each datapoint represents 3 technical replicates from one independent sample. Genotype conditions are pooled into control (blue) and patient (no colour). In significance tests: ns ≥ 0.05, * ≤ 0.05, *** ≤ 0.001, **** ≤ 0.0001. In all panels, control is represented by Ct1.2 and Ct2. Patient is represented by Pt1.2 and Pt2.2.