PhD Scientific Days 2022

Translational Medicine II. (Poster discussion will take place in the Aula during the Coffee Break)

Sex-related proteomic differences of the athlete’s heart

Text of the abstract

Introduction: Regular physical activity results in characteristic structural and functional changes in the heart, which are collectively referred to as the athlete’s heart. However, the extent of exercise-induced left ventricular (LV) hypertrophy and functional changes show significant differences between men and women, the molecular background of which is not fully elucidated.
Objective: The aim of this study was to provide a proteomic characterization of long-term, intense exercise-induced LV myocardial hypertrophy in a rat model, with a focus on sex-related differences.
Methods: Our rats were divided into trained (FEx) and control female (FCo) as well as trained (MEx) and control male (MCo) groups. In the trained groups, athlete’s heart was induced by swimming for 12 weeks. Myocardial hypertrophy was confirmed by cardiac ultrasound and functional adaptation by pressure-volume analysis. Proteomic measurements based on liquid chromatograph-coupled mass spectrometry were performed on proteins isolated from our left ventricular samples.
Results: Echocardiography and post-mortem myocardial mass showed significant LV hypertrophy in both sexes, which was more pronounced in female animals (tibial length normalized LV muscle mass: + 17.4% MEx vs. MCo, + 31.0% FEx vs. FCo). LV contractility has increased to the same extent in both sexes. Relative expression of 3074 proteins were determined by proteomics. There was a significant change in expression of 229 proteins in males and 599 in females compared to the level of same-sex controls. Based on our gene ontological analysis, physiological LV remodeling in females is characterized by increased expression of proteins in cellular respiration and fatty acid oxidation, whereas in males, proteins that bind to the actin cytoskeleton is primarily increased.
Conclusions: Our data suggests that physiological LV hypertrophy resulting from regular, balanced exercise is associated with sex-specific changes in the myocardial proteome. Our results contribute to the understanding of the development of physiological myocardial hypertrophy.
Funding: BO/00837/21 to A.O., K135076 to B.M., SE250+ to B.A.B.