SGLT2 inhibitor dapagliflozin treats heart failure with preserved ejection fraction via the SIRT1/PGC-1α pathway

Figure 1 Dapagliflozin improves cardiac diastolic function and alleviates HFpEF symptoms in HFpEF rats (A) Representative pictures of echocardiography. (B‒D) Statistical analysis of EF (B), E/e’ (C) and LVPWd (D) (n = 6). (E) Statistical analysis of non-invasive tail artery blood pressure (n = 6). (F) Statistical analysis of running distance (n = 6). (G) Statistical analysis of wet lung-dry lung/ body weight (n = 6). EF: ejection fraction, LVPWd: left ventricular posterior wall diastolic. SBP: Systolic Blood Pressure. *P < 0.05, **P < 0.01, ***P < 0.001. ns, not significant.

Figure 2 Dapagliflozin attenuates myocardial injury in HFpEF rats (A) Representative pictures of HE and Masson staining to observe myocardial hypertrophy and fibrosis in rats of each group. The scale bar is 100 μm. (B,C) Statistical analysis of cross-sectional area (E) and fibrosis (F) (n = 6). (D) Statistical analysis of serum NT-proBNP (n = 6). (E) Statistical analysis of the mass ratio of HW/BW (heart weight to body weight) (n = 6). (F) mRNA levels of Nppa, Nppb, Myh-6, Col1a, and Col3a (n = 4). (G) Representative pictures of TUNEL staining. The scale bar is 100 μm. (H) Statistical analysis of Tunel+/DAPI (n = 6). NT-proBNP: NT-pro brain natriuretic peptide. *P < 0.05, **P < 0.01, ***P < 0.001.

Figure 3 Dapagliflozin activates mitochondrial regeneration and the SIRT1/PGC-1α signaling pathway in HFpEF rats (A) Volcano plot of DEGs. (B) Gene Set Enrichment Analysis of DEGs. (C) Representative micrographs of heart tissue sections examined by transmission electron micrographs. The scale bar is 1 μm. (D) Statistical analysis of mitochondrial area (n = 6). (E) Statistical analysis of mitochondria number (n = 6). (F) Statistical analysis of ATP content in mitochondria of myocardial tissue (n = 6). (G) mRNA levels of Sirt1, Pgc-1a, and Mfn-2 in the heart (n = 4). (H,I) Representative western blots and statistical analysis of SIRT1, PGC-1α and Mfn-2 in the heart (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001.

Figure 4 Dapagliflozin improves mitochondrial respiratory function through the SIRT1/PGC-1α pathway in the HFpEF cell model (A,B) Representative western blots and statistical analysis of SIRT1, PGC-1α and Mfn-2 in AMVMs (n = 3). (C) mRNA levels of Sirt1, Pgc-1a, and Mfn-2 (n = 3). (D) Statistical analysis of ATP content in mitochondria of AMVMs (n = 4). (E) Statistical analysis of NADP(H) content in mitochondria of AMVMs (n = 4). (F) Real-time mitochondrial respiration of AMVMs (n = 3 independent experiments). (G) Statistical analysis of basal OCR of AMVMs (n = 3 independent experiments). (H) Statistical analysis of maximal OCR of AMVMs (n = 3 independent experiments). (I) Real-time glycolytic capacity of AMVMs (n = 3 independent experiments). (J) Statistical analysis of basal ECAR of AMVMs (n = 3 independent experiments). (K) Statistical analysis of maximal ECAR of AMVMs (n = 3 independent experiments). *P < 0.05, **P < 0.01, ***P < 0.001.

Figure 5 Inhibiting SIRT1 weakens the therapeutic effects of dapagliflozin on HFpEF rats (A) Representative pictures of echocardiography. (B‒D) Statistical analysis of EF (B), E/e’ (C) and LVPWd (D) (n = 6). (E) Statistical analysis of non-invasive tail artery blood pressure (n = 6). (F) Statistical analysis of running distance (n = 6). (G) Statistical analysis of wet lung-dry lung/ body weight (n = 6). *P < 0.05, **P < 0.01, ***P < 0.001. ns, not significant.

Figure 6 Inhibiting SIRT1 reverses the enhancement of myocardial hypertrophy and fibrosis by dapagliflozin (A) Representative pictures of HE and Masson staining to observe myocardial hypertrophy and fibrosis in rats of each group. The scale bar is 100 μm. (B,C) Statistical analysis of cross-sectional area (E) and fibrosis (F) (n = 6). (D) Statistical analysis of serum NT-pro brain natriuretic peptide (NT-proBNP) (n = 6). (E) Statistical analysis of the mass ratio of heart weight to body weight (n = 6). (F) mRNA levels of Nppa, Nppb, Myh-6, Col1a, and Col3a (n = 4). (G) Representative pictures of TUNEL staining. The scale bar is 100 μm. (H) Statistical analysis of TUNEL+/DAPI (n = 6). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.

Figure 7 Dapagliflozin is associated with improvements in HFpEF phenotypes via the SIRT1/PGC-1α signaling pathway (A) Representative micrographs of heart tissue sections examined by transmission electron micrographs. The scale bar is 1 μm. (B) Statistical analysis of mitochondrial area (n = 6). (C) Statistical analysis of mitochondria number (n = 6). (D) Statistical analysis of ATP content in mitochondria of myocardial tissue (n = 6). (E) mRNA levels of Sirt1, Pgc-1a, and Mfn-2 in the heart (n = 6). (F,G) Representative western blots and statistical analysis of SIRT1, PGC-1α and Mfn-2 in the heart (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001.

Figure 8 Diagram of the treatment of HFpEF with dapagliflozin via the SIRT1/PGC-1α pathway