Therapeutic effects on the development of heart failure with preserved ejection fraction by the sodium-glucose cotransporter 2 inhibitor dapagliflozin in type 2 diabetes

Figures

• 

  Fig. 1. The effects of dapagliflozin on the metabolic characteristics in ZDF rats. a Changes in body weight. b Random blood glucose. c, d Diastolic and systolic blood pressure. e, f Intraperitoneal glucose tolerance tests were performed, and the area under the curve was calculated. g–i The serum lipid profile of all rats. The data are presented as the mean ± SD. n = 8 per group. *P < 0.05, **P < 0.01 vs. Lean; #P < 0.05, ##P < 0.01 vs. ZDF

• 

  Fig. 2. Dapagliflozin improved left ventricular diastolic function and myocardial hypertrophy in ZDF rats. a–d Key parameters obtained from invasive left cardiac catheterization. e Representative LV pressure–volume (P–V) loops and the slope of EDPVR. f Representative images of M-mode echocardiography. g HE staining of heart sections is presented. Bar = 100 μm, Magnification = ×40. h The cardiomyocyte diameter/TL ratio was calculated. i Correlation analysis between cardiomyocyte diameter/TL and the slope of EDPVR. Data are the mean ± SD. n = 8 per group. *P < 0.05 vs. Lean; #P < 0.05 vs. ZDF

• 

  Fig. 3. The effects of dapagliflozin on myocardium fibrosis in diabetic rats. a Representative images of Masson's trichrome and PicroSirius staining. Bar = 200 and 100 μm, respectively. Magnification = ×20. b, c Fibrotic area quantification of stained sections. d Correlation analysis between PicroSirius positive area and the slope of EDPVR. e–g Quantitative real-time PCR was conducted to detect the mRNA expression of Fibronectin-1, Collagen-1, and TGF-β in the myocardium. Values are expressed as the mean ± SD. n = 8 per group. *P < 0.05, **P < 0.01 vs. Lean; #P < 0.05 vs. ZDF

• 

  Fig. 4. Dapagliflozin alleviated myocardial nitro-oxidative stress and inflammatory response. Real-time PCR measurements of a–c PLB and SERCA2a, d Thioredoxin-1, and e Catalase in the myocardium. f Serum 3-NT levels in the experimental groups. g–i The activity of classical antioxidants and j content of cardiac MDA. (k) Representative western blot bands of myocardial p-P65, P65, and IκBα levels. l, m Densitometric semi-quantitative determination of protein expression levels using ImageJ. n Gene expression of classic pro-inflammatory cytokines. Values are expressed as the mean ± SD. n = 8 per group. *P < 0.05, **P < 0.01 vs. Lean; #P < 0.05 vs. ZDF

• 

  Fig. 5. The effects of dapagliflozin on apoptosis and DNA fragmentation in cardiomyocytes. a Representative images of TUNEL staining. Bar = 200 μm, magnification = ×10. b Quantification of TUNEL-positive nuclei. c Representative western blot bands of cleaved PARP-1 and Bcl-2 levels in the myocardium. d, e Relative protein levels were densitometrically quantified with ImageJ. Data are expressed as the mean ± SD. *P < 0.05, **P < 0.01 vs. Lean; #P < 0.05, ##P < 0.01 vs. ZDF

• 

  Fig. 6. Modulatory effects of dapagliflozin on the myocardial AMPK/mTOR signaling pathway and autophagic flux in T2DM rats. a Representative western blot bands of p-AMPK and p-mTOR levels in the myocardium. b, c Densitometric semi-quantitative determination of protein expression. d Representative western blot bands of myocardial p62 and LC3-I/II expression. e, f Semi-quantitative analysis of relative protein levels. Data are expressed as the mean ± SD. *P < 0.05, **P < 0.01 vs. Lean; #P < 0.05, ##P < 0.01 vs. ZDF

• 

  Fig. 7. Proteomics deciphered the changes in the treated T2DM individuals with HFpEF. a Summary of differentially expressed proteins for each pairwise comparison. b Venn diagram showing the relationship between three pairwise comparisons. c Heatmap for protein detection from the proteomics data. Each column represents a protein marker, and each row represents a loading sample of the DM-HF and the DAPA group. d Volcano plots of the proteomics data for the pairwise comparison. Up-regulated and down-regulated proteins are marked with red and blue colors, respectively. e KEGG pathway enrichment and f GO term analyses. g The interaction relationship of differentially expressed proteins was obtained from the STRING database (https://string-db.org/), and the top 25 proteins were selected to draw the interaction network diagram. Red represents up-regulated genes, and the green represents down-regulated genes. The size of the circle represents the degree of connectivity

• 

  Fig. 8. Metabolomics revealed the effects of dapagliflozin on serum metabolite profiles. a Heatmap for differentially expressed metabolites. Each row represents a metabolite marker, and each column represents a loading sample. b Volcano plots of the metabolomics data for the pairwise comparison. Up-regulated and down-regulated proteins are marked with red and blue colors, respectively. c Top 20 significant functional pathways enriched by differentially expressed metabolites