Aerobic exercise reduces lactate accumulation and improves cardiac function after myocardial infarction

Figures

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  Figure 1. Lactate induces NIH 3 T3 cells activation. (A) Expression of COL I and α-SMA in NIH 3 T3 cells stimulated with lactate at different concentrations (CTRL, 1 mM, 2 mM, 5 mM). (B) Expression of COL I and α-SMA in NIH 3 T3 cells stimulated with TGF-β1 at different concentrations (CTRL, 5 ng/mL, 10 ng/mL, 20 ng/mL). (C,D) Quantitative analysis of COL I and α-SMA protein levels in NIH 3 T3 cells stimulated with lactate by Western blot (n = 6). (E,F) Quantitative analysis of COL I and α-SMA protein levels in NIH 3 T3 cells stimulated with TGF-β1 by Western blot (n = 6). (G) Expression of COL I and α-SMA in NIH 3 T3 cells stimulated with 5 mM lactate and 20 ng/mL TGF-β1. (H,I) Quantitative analysis of COL I and α-SMA protein levels in NIH 3 T3 cells stimulated with 5 mM lactate and 20 ng/mL TGF-β1 by Western blot (n = 6). (J,K) mRNA expression levels of Col1a2 and Acta2 in NIH 3 T3 cells stimulated with 5 mM lactate and 20 ng/mL TGF-β1 determined by qRT-PCR (n = 6). All data are presented as Mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001.

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  Figure 2. Metabolomic profiling of serum from SED-MI and SED-MI + LAC mice. (A) KEGG pathway enrichment heatmap of differential metabolites. (B) Volcano plot of differential metabolites. (C) OPLS-DA score plot for SED-MI and SED-MI + LAC groups. (D) Box plot of top differential metabolite expression. (E) Bubble plot of KEGG pathway enrichment analysis. (F) Hierarchical clustering heatmap of differential metabolites.

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  Figure 3. IGF1 inhibits lactate-induced NIH 3 T3 activation. (A) Expression of COL I and α-SMA in NIH 3 T3 stimulated with 5 mM lactate and 100 ng/mL IGF1. (B,C) Quantitative analysis of COL I and α-SMA protein levels in NIH 3 T3 stimulated with 5 mM lactate and 100 ng/mL IGF1 by Western blot (n = 6). (D,E) mRNA expression levels of Col1a2 and Acta2 in NIH 3 T3 stimulated with 5 mM lactate and 100 ng/mL IGF1 determined by qRT-PCR (n = 6). Data are expressed as Mean ± SEM, *p < 0.05, **p < 0.01, ***p < 0.001.

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  Figure 4. AE reduces lactate accumulation and ameliorates post-MI cardiac function. (A) Schematic illustration of the experimental animal grouping design. (B) Cardiac tissue lactate levels in each group (n = 6). (C) Serum lactate levels in each group (n = 6). (D) Representative echocardiographic images from each experimental group. (E) Comparison of LVEF across groups (n = 6–7). (F) Comparison of LVFS across groups (n = 6–7). (G) Heart weight to body weight ratio of animals in each group (n = 10). (H) Heart weight to tibia length ratio of animals in each group (n = 10). (I) Exercise capacity ratio of animals in each group (n = 10). Data are expressed as Mean ± SEM, nsP > 0.05, *p < 0.05, **p < 0.01, ***p < 0.001.

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  Figure 5. Correlation between lactate levels and cardiac function in mice. (A) Correlation between cardiac lactate and LVEF. (B) Correlation between cardiac lactate and LVFS. (C) Correlation between serum lactate and LVEF. (D) Correlation between serum lactate and LVFS.