Cardioprotective Effects of Palmitoleic Acid (C16:1n7) in a Mouse Model of Catecholamine-Induced Cardiac Damage Are Mediated by PPAR Activation

Figures

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  Figure 1. Palmitoleic acid (C16:1n7)-derived gene expression regulation of primary adult cardiomyocytes (PCMs) and HL-1 cardiomyocytes. (A) RNA-Seq results of PCMs stimulated with 470 μM C16:1n7 or 10% FFA-free BSA control for 3 h. Heatmap of 50 significantly up- and downregulated genes; mean base expression, 50; fold change filter, 1.5×; FDR-adjusted p-value of 0.1; >100 base expressions per sample; n = 3. (B) Cumulative results of all C16:1n7-regulated genes, detected using RNA-Seq analysis; mean base expression, 50; fold change filter, 1.5×; FDR-adjusted p-value of 0.1; n = 3. (C, D) Confirmatory experiments performed on PCMs treated with C16:1n7 470 μM C16:1n7 or 10% FFA-free BSA control for 3 h in experiments perform parallel to RNA-Seq analysis. Relative expressions of Angptl4 and Pdk4 are shown, as indicated. (E–G) Confirmatory experiments performed on HL-1 cardiomyocytes treated with C16:1n7 470 μM C16:1n7 or 10% FFA-free BSA control for 3 h. Relative expressions of Angptl4, Pdk4 and Hilpda are shown, as indicated. Angptl4: Angiopoietin-like factor 4; Pdk4: Pyruvate Dehydrogenase Kinase 4, Hilpda: Hypoxia Inducible Lipid Droplet Associated. Data are presented as mean ± SEM. n = 3,…

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  Figure 2. (A) CPDB pathway analysis of RNA-Seq data presented in Figure 1. For details, please see Materials and Methods. (B,C) Western blot analysis of ERK1/2 phosphorylation in HL-1 cardiomyocytes, stimulated with 471 µM C16:1n7 for 5 and 15 min. Data are presented as mean ± SEM. n = 3, n = 3; *** p < 0.001, **** p < 0.0001, as analyzed using unpaired t-tests.

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  Figure 3. C16:1n7 application to mice protects against ISO-induced cardiac damage. (A) Experimental design. The 129 sv wt mice were daily orally supplemented with C16:1n7 or vehicle as the control. After 5 days (pretreatment), the mice received additional s. c. ISO/Veh application for 4 consecutive days. At baseline, the day after the last ISO application and during the final examination (day 22), the animals underwent echocardiographic analysis. (B–F) Results from the echocardiographic analysis of the mice: (B) left ventricular ejection fraction (EF); (C) global longitudinal peak strain (GLS); (D) GLS trend; (E) global radial peak strain (GRS); (F) global circumferential peak strain (GCS). (G–I) Analysis of cardiac fibrosis using Picrosirius red staining. (G) Representative images are shown. Scale bar = 1 mm. (H) Representative images of subendocardial fibrosis are shown. Scale bar = 100 μm, as indicated. (I) Relative content of subendocardial collagen; data presented as a ration between endocardial and epicardial fibrosis, as indicated. Data are presented as mean ± SEM. n = 8–10 per group, or as indicated. ns: p>0.05, * p < 0.05, *** p < 0.001, **** p < 0.0001 as analyzed by two-way…

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  Figure 4. C16:1n7 mediates its cardioprotective effects activating PPAR target gene expression. qRT-PCR-based cardiac array of PPAR target genes, n = 3 per group. A hierarchical clustering and heatmap of expression values with color-coded row z-scores is shown.