Figure 4.

Pro-inflammatory Nur77-Deficient Macrophages Show Enhanced TCA Cycle Activity

(A and B) Principal-component analysis (PCA) (A) and random forest variable importance measures (B) of intracellular metabolite levels from untreated (n = 4 per group) or 24 hr LPS-treated (n = 6 per group) WT and Nur77-KO BMDMs, as determined by LC-MS (metabolomics).

(C) TCA cycle schematic summarizing metabolomics. Circles indicate metabolites, arrowheads indicate enzymes. Node colors indicate relative metabolite abundance, as shown in the lower left corner. Insets connected by dotted lines show relative metabolite abundance for untreated (−) and 24 hr LPS-treated groups. 2-HG, 2-hydroxyglutarate; IDH, isocitrate dehydrogenase; SDH, succinate dehydrogenase.

(D) Ratio of (iso)citrate to α-ketoglutarate abundance in WT and Nur77-KO BMDMs from metabolomics.

(E) Succinate secretion by WT and Nur77-KO BMDMs cultured in glutamine-containing (2 mM) or glutamine-free (0 mM) medium and either left untreated (−) or stimulated with LPS for 48 hr (+).

(F and G) Ratio of reduced (NADH) to oxidized (NAD⁺) nicotinamide adenine dinucleotide (F) and total 2-hydroxyglutarate (l- and d- forms) abundance (G) in WT and Nur77-KO BMDMs from metabolomics.

For (C)–(G), data are shown as means ± SEMs (n = 3 for [E]; n = 4–6 for [C], [D], [F], and [G]). p values were calculated using two-tailed Student’s t test (B, C, F, and H–J) or two-way ANOVA with Tukey’s post hoc test (E). n.s., non-significant. ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001.

See also Figure S4.