Linking Ketone Metabolism and Signaling in Heart Failure with Preserved Ejection Fraction

Project Information

KetoCardio

Grant agreement ID: 101078307

DOI

10.3030/101078307

EC signature date 6 December 2022

Start date 1 October 2023

End date 30 September 2028

Funded under

• European Research Council (ERC)

Total cost

€ 1 809 140,00

EU contribution

€ 1 809 140,00

Coordinated by

CHARITE - UNIVERSITAETSMEDIZIN BERLIN
Germany

Periodic Reporting for period 1 - KetoCardio (Linking Ketone Metabolism and Signaling in Heart Failure with Preserved Ejection Fraction)

Reporting period: 2023-10-01 to 2026-03-31

Summary of the context and overall objectives of the project

Heart failure with preserved ejection fraction (HFpEF) is now the predominant form of heart failure and remains without effective mechanism-based therapies. Its pathogenesis is driven by a complex cardiometabolic milieu in which traditional hemodynamic or inflammatory paradigms fail to explain the metabolic and epigenetic adaptations that characterize the syndrome. Ketone bodies have re-emerged as relevant modulators of cardiac metabolism. β-Hydroxybutyrate (β-OHB) functions not only as an energetic substrate but also as a signalling metabolite capable of modifying proteins through lysine β-hydroxybutyrylation. This places ketones at a critical intersection of metabolic adaptation, transcriptional regulation, and cardiomyocyte stress resilience. However, major mechanistic gaps persist: how ketone handling is rewired in HFpEF, how β-OHB influences chromatin and gene expression, and whether ketone-driven PTMs shape disease progression remain unknown. KetoCardio addresses these gaps by dissecting ketones as regulators of cardiomyocyte biology through an integrated approach combining metabolic flux analyses, PTM-resolved proteomics, epigenomic profiling, and in vivo HFpEF modelling. The project investigates whether ketone-dependent mechanisms contribute to HFpEF pathogenesis, compensate for metabolic dysfunction, or offer therapeutic entry points.Its objectives are: To define how ketone metabolism is remodeled in HFpEF and identify metabolic bottlenecks specific to the cardiometabolic state. To characterize β-OHB as a signalling molecule, with emphasis on β-hydroxybutyrylation and its regulatory influence on chromatin and stress-response networks. To establish the causal contribution of ketone-dependent metabolic and epigenetic pathways to HFpEF progression. KetoCardio is therefore positioned to provide a mechanistic framework that clarifies how metabolic stress is sensed and transduced in HFpEF. By elucidating ketone-driven pathways, the project is expected to reveal new therapeutic opportunities, define biomarkers of metabolic dysfunction, and support precision-medicine strategies in a syndrome that urgently requires mechanistic innovation.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

During the first 24 months, the project made substantial progress in defining how ketone metabolism and ketone-derived post-translational modifications shape cardiomyocyte adaptation in HFpEF. Work integrated in vivo metabolic phenotyping, ^13C-tracer studies, quantitative metabolomics, and the establishment of dedicated proteomic and epigenomic pipelines for β-hydroxybutyrylation (Kbhb), providing the biochemical and technical foundation for the project’s mechanistic aims. In the HFpEF diet–L-NAME model, high-resolution respirometry revealed impaired mitochondrial flexibility, with reduced fatty acid and glucose oxidation under cardiometabolic stress. Circulating and myocardial ketone concentrations were elevated, and ^13C-β-hydroxybutyrate tracing showed that ketone oxidation remained preserved but contributed disproportionately to ATP production, indicating a metabolic shift toward ketone reliance in HFpEF. A central achievement was the development of a robust platform for profiling lysine β-hydroxybutyrylation. The first high-confidence cardiac Kbhb proteome demonstrated widespread modification of mitochondrial and metabolic enzymes involved in β-oxidation, the TCA cycle, redox balance, and structural mitochondrial integrity, extending the role of Kbhb beyond chromatin-associated regulation.
Integrating metabolic flux data with PTM-resolved proteomics revealed that metabolic rewiring and Kbhb redistribution are tightly interconnected. Enzymes in fatty acid oxidation and the TCA cycle showed coordinated increases in β-hydroxybutyrylation during HFpEF stress, highlighting potential regulatory nodes through which ketone signalling may influence mitochondrial function.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The metabolic and post-translational modification results generated in the first two years of KetoCardio provide a solid mechanistic foundation with clear translational potential. By defining how ketone metabolism is altered in HFpEF and generating the first cardiac β-hydroxybutyrylation (Kbhb) atlas in this setting, the project begins to reshape the conceptual understanding of cardiometabolic heart failure. The work shows that ketone handling is a central determinant of energetic homeostasis in HFpEF, with direct implications for substrate competition, nutritional and metabolic interventions, and patient phenotyping. These findings offer a mechanistic rationale for targeting ketone pathways therapeutically and for interpreting shifts in fuel hierarchy as contributors to disease progression. Equally significant is the demonstration that Kbhb acts as a regulatory layer in the failing heart. The Kbhb proteomic landscape highlights extensive modification of mitochondrial and metabolic enzymes, expanding the role of β-hydroxybutyrate far beyond chromatin regulation. This establishes a framework for studying PTM-mediated control of mitochondrial function, identifying biomarkers of metabolic stress, and integrating PTMs into systems-level models of HFpEF progression. The accompanying chromatin data suggest that ketone-sensitive PTMs also influence transcriptional programs that shape cardiomyocyte stress adaptation. By linking ketone flux, PTM distribution, and enzymatic function, the project identifies specific molecular nodes that may be exploited therapeutically. These mechanistic insights support the development of modulators of PTM-regulated enzymes, strategies to manipulate ketone availability or oxidation, and refined models for stratifying HFpEF patients according to metabolic signatures. Together, these advances position KetoCardio to influence both cardiac metabolism research and the broader field of metabolic signalling. To enable full uptake of these insights, further work is needed to define causality through targeted perturbation of Kbhb-modified enzymes and chromatin marks, in vivo modulation of ketone levels, and deeper integration of liver–heart metabolic interactions. Progress will also depend on expanding proteomic depth, integrating additional PTMs, and refining metabolic modelling frameworks. Although commercialisation remains premature, the project has already begun to generate assets with potential diagnostic or therapeutic value, such as PTM signatures, enzyme targets, and novel assays for Kbhb detection.