1. Empagliflozin Improves Diastolic Function in HFpEF by Restabilizing the Mitochondrial Respiratory Chain.
- Author
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Schauer A, Adams V, Kämmerer S, Langner E, Augstein A, Barthel P, Männel A, Fabig G, Alves PKN, Günscht M, El-Armouche A, Müller-Reichert T, Linke A, and Winzer EB
- Subjects
- Animals, Male, Ventricular Function, Left drug effects, Rats, Inbred SHR, Electron Transport drug effects, Rats, Glucosides pharmacology, Benzhydryl Compounds pharmacology, Sodium-Glucose Transporter 2 Inhibitors pharmacology, Heart Failure drug therapy, Heart Failure physiopathology, Heart Failure metabolism, Mitochondria, Heart drug effects, Mitochondria, Heart metabolism, Mitochondria, Heart ultrastructure, Disease Models, Animal, Diastole drug effects, Rats, Zucker, Stroke Volume drug effects
- Abstract
Background: Clinical studies demonstrated beneficial effects of sodium-glucose-transporter 2 inhibitors on the risk of cardiovascular death in patients with heart failure with preserved ejection fraction (HFpEF). However, underlying processes for cardioprotection remain unclear. The present study focused on the impact of empagliflozin (Empa) on myocardial function in a rat model with established HFpEF and analyzed underlying molecular mechanisms., Methods: Obese ZSF1 (Zucker fatty and spontaneously hypertensive) rats were randomized to standard care (HFpEF, n=18) or Empa (HFpEF/Empa, n=18). ZSF1 lean rats (con, n=18) served as healthy controls. Echocardiography was performed at baseline and after 4 and 8 weeks, respectively. After 8 weeks of treatment, hemodynamics were measured invasively, mitochondrial function was assessed and myocardial tissue was collected for either molecular and histological analyses or transmission electron microscopy., Results: In HFpEF Empa significantly improved diastolic function (E/é: con: 17.5±2.8; HFpEF: 24.4±4.6; P <0.001 versus con; HFpEF/Empa: 19.4±3.2; P <0.001 versus HFpEF). This was accompanied by improved hemodynamics and calcium handling and by reduced inflammation, hypertrophy, and fibrosis. Proteomic analysis demonstrated major changes in proteins involved in mitochondrial oxidative phosphorylation. Cardiac mitochondrial respiration was significantly impaired in HFpEF but restored by Empa (V
max complex IV: con: 0.18±0.07 mmol O2 /s/mg; HFpEF: 0.13±0.05 mmol O2 /s/mg; P <0.041 versus con; HFpEF/Empa: 0.21±0.05 mmol O2 /s/mg; P =0.012 versus HFpEF) without alterations of mitochondrial content. The expression of cardiolipin, an essential stability/functionality-mediating phospholipid of the respiratory chain, was significantly decreased in HFpEF but reverted by Empa (con: 15.9±1.7 nmol/mg protein; HFpEF: 12.5±1.8 nmol/mg protein; P =0.002 versus con; HFpEF/Empa: 14.5±1.8 nmol/mg protein; P =0.03 versus HFpEF). Transmission electron microscopy revealed a reduced size of mitochondria in HFpEF, which was restored by Empa., Conclusions: The study demonstrates beneficial effects of Empa on diastolic function, hemodynamics, inflammation, and cardiac remodeling in a rat model of HFpEF. These effects were mediated by improved mitochondrial respiratory capacity due to modulated cardiolipin and improved calcium handling., Competing Interests: Disclosures Dr Winzer reports personal fees from Amarin, Amgen, AstraZeneca, Daiichi Sankyo, Bayer, Boehringer Ingelheim, CVRx, and Novartis for lectures and advisory board activities outside the submitted work. Dr Linke reports grants from Novartis, personal fees from Medtronic, Abbott, Edwards Lifesciences, Boston Scientific, AstraZeneca, Novartis, Pfizer, Abiomed, Bayer, Boehringer, and other from Picardia, Transverse Medical, Claret Medical, outside the submitted work. The other authors report no conflicts.- Published
- 2024
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