Figure 5.

Stroke induces long-lasting alterations in glycolysis and itaconate production. (a) Glycolysis pathway with examples of associated genes. (b) Glycolysis is altered by stroke, and some of these modifications last for at least 12 weeks. Heatmap key provided in Figure 2 legend. (c–f) Graphs depicting the levels of representative compounds: (c) Glucose. (d) Dihydroxyacetone phosphate (DHAP). (e) Pyruvate. (f) Itaconate. *p < 0.05 by Brown-Forsythe and Welch’s ANOVA test followed by Dunnett’s T3 multiple comparisons test, all groups compared to aged naïve group, n = 5-7. (g) Itaconate, a competitive inhibitor of phosphoenolpyruvate (PEP), is produced by microglia and macrophages in response to an inflammatory signal that induces the expression of the Acod1 gene. By alkylating Kelch-like ECH-associated protein 1 (KEAP1) and releasing nuclear factor erythroid 2-related factor 2 (Nrf2) to mediate its numerous anti-inflammatory and antioxidant effects, itaconate is also thought to defend against inflammation and oxidative stress. (h) Imaging of a whole brain section reveals that Iba1 immunoreactivity is highest in the ipsilateral thalamus, n = 4. Scale bar = 1000 µm. Higher magnification imaging reveals that the Iba1 positive cells also colocalize with Acod1 RNA. There is little colocalization of GFAP with Acod1 RNA, n = 4. Scale bars = 50 µm.