Figure 7. Loss of UCP2 alters acetyl-CoA levels and histone marks in cardiomyocytes.

(A and B) Acetyl-CoA levels are significantly increased in NRVMs (A) and adult cardiomyocytes from WT mice (B) under moderate hypoxia and decreased after loss of UCP2 as measured by mass spectrometry–based quantification (n = 3 per group). (C and D) Immunoblot and qPCR validations showing increased levels of enzymes and genes involved in acetyl-CoA signaling and reduced after UCP2 silencing in NRVMs under moderate hypoxia (n = 3). (E) Immunoblot validation showing histone 3 is acetylated in hypoxia and deacetylated after UCP2 silencing in NRVMs. (F) Chart resulting from a qPCR array for 84 chromatin remodeling enzymes indicating the percentage of genes upregulated, downregulated, and unchanged after siRNA-mediated silencing of UCP2 in NRVM after 48 hours of moderate hypoxia (n = 3). (G) Heatmap of the 84 chromatin remodeling enzymes after siRNA-mediated silencing of UCP2 in NRVM under hypoxia. Upregulated, green; downregulated, red (n = 3). (H) Volcano plot highlighting upregulation of histone deacetylation enzymes and downregulation of a histone acetylation enzyme in the qPCR array after UCP2 silencing. Upregulated < fold change 1.5, downregulated > fold change 1.5 (n = 3). (I) Schematic illustration summarizing the findings of this study. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Data from A, C, and D were analyzed using Kruskal-Wallis test with Dunn’s correction for multiple comparisons; for B, Mann-Whitney U test was applied.