Figure 3. Effect of ACA on heart structure, function, signaling, and proteomic composition.

(A–C) Echocardiography was conducted on mice at 22 months of age (n = 8 per sex for old controls; n = 12 per sex for ACA treated), and included a set of young (6-month) controls (n = 8 per sex). (D and E) Analysis of cardiac signaling pathways and ubiquitinated protein was conducted on tissue samples from 25-month-old mice by Western blot. (F) The relative presence of collagen was assessed by Picrosirius red staining. (G) Proteomics analysis was conducted on samples from 25-month-old mice and 6-month-old young controls (n = 8 per sex for each treatment group). Volcano plots for each sex are shown, highlighting the lack of proteins that have a consistent change with age in protein abundance. (H) The log₂ fold change in protein abundance from old control animals is shown for old mice treated with ACA for each protein that differs between control and ACA-treated mice after correction for FDR. Each error bar is a value for a different protein, with the figure showing relative change in abundance of proteins differing significantly between young and old mice on a control diet. Proteins were split according to their association with peroxisome, as defined by Gene Ontology (GO) cellular component annotation terms.*P < 0.05, **P < 0.01. In A–C and F, the P values were computed by running an ANOVA then Dunnett’s multiple comparison test, comparing young males and old ACA-treated males with old control males in separate comparisons. In D, P values were calculated with a Student’s t test.