Severe burns, major trauma, and sepsis cause systemic inflammation and metabolic stress, often leading to acute cardiac dysfunction. How myocardial sequelae evolve over time remains unclear. This meta-analysis evaluated whether consistent echocardiographic patterns of long-term dysfunction exist across these conditions and whether current data permit longitudinal comparison. A systematic search of PubMed, EMBASE, Web of Science, Cochrane, and Google Scholar (inception-July 2025) followed PRISMA guidelines. Eligible studies reported echocardiographic outcomes ≥72 h after injury or sepsis onset. Data on demographics, illness severity, and echocardiographic parameters were extracted. Subgroup and meta-analyses compared conditions and follow-up periods. In this meta-analysis of 47 studies (n = 3117; trauma: 282, sepsis: 959, burns: 1876) left ventricular ejection fraction (LVEF), heart rate (HR), and E/A ratio were the most common echocardiographic parameters. LVEF was reported in n = 35 (73%) studies: n = 9 (19%) trauma, n = 17 (35%) sepsis, and n = 9 (19%) burn studies, limited by substantial heterogeneity in patient severity and follow-up timing. The same applies to HR, reported in n = 11 (23%) studies (n = 3 (6.3%) trauma, n = 5 (10%) sepsis, and n = 3 (6.3%) burn studies), and E/A ratio reported in n = 14 (29%) studies (n = 4 (8.3%) trauma, n = 6 (13%) sepsis, and n = 4 (8.3%) burn studies). Marked heterogeneity in study design, patient selection, and echocardiographic assessment limited direct comparability across conditions. Despite signals of long-term alteration, analysis was restricted by short follow-up durations (median 9 days for sepsis, 10 for trauma, 447 for burns) and scarce longitudinal data, particularly in trauma and sepsis cohorts. This meta-analysis identifies long-term myocardial dysfunction after burns, sepsis, and trauma, most pronounced in burn survivors. Marked heterogeneity and limited longitudinal data hinder trajectory assessment. Prospective studies with standardized echocardiography are needed to define post-critical illness cardiac phenotypes.

Exercise promotes physiological cardiomyocyte growth and protects against ischaemia-reperfusion (IR) injury in the heart. The molecular mechanism by which exercise benefits cardiac metabolism and function remains largely unknown. Here, using a genetically encoded fluorescent sensor, we show that exercise increases cytosolic, but not mitochondrial, NADPH levels in cardiomyocytes. This effect is mediated by activation of the pentose phosphate pathway (PPP). Inhibition of PPP activity or depletion of cytosolic NADPH attenuates exercise-induced heart hypertrophy in mice. We observe that NADPH promotes cardiomyocyte growth by inhibiting HDAC3/C/EBPβ pathways. Moreover, exercise-activated PPP/NADPH pathway suppresses acute IR injury and preserves heart function 4 weeks after IR. Among 310 tested Tibetan compounds, the spermidine derivative lyciumspermidine-0527 directly activates the rate-limiting PPP enzyme glucose-6-phosphate dehydrogenase, elevates intracellular NADPH levels and alleviates IR injury. Altogether, these results show that PPP-derived NADPH is a critical metabolic checkpoint that regulates exercise-induced physiological cardiomyocyte growth and protects against IR-induced heart injury.

BACKGROUND:Guided by long-term safety data for AAV5 (adeno-associated virus 5) in humans, our translational study investigated whether AAV5 effectively delivers genes to healthy and achieves therapeutic efficacy in dysfunctional human-sized hearts, using a clinically applicable mode of administration and vector dosages. METHODS:AAV-mediated cardiac gene transfer in pigs was performed by percutaneous catheter-based retrograde intravenous vector delivery, and vector genome and transgene expression levels determined by reverse transcription-polymerase chain reaction and immunoblotting. Postmyocardial infarction (MI) cardiac dysfunction porcine and murine models were generated by coronary catheter-based occlusion and ligation, respectively. The study end points left ventricular ejection fraction and left ventricular MI size, were measured by cardiac magnetic resonance imaging and echocardiography. Bulk myocardial RNA-sequencing and weighted gene correlation network analysis were used to link study end points to molecular pathway mechanisms. Safety was assessed by clinical chemistry, blood count and ECG. RESULTS:In a first biodistribution study, AAV5 (1×1013 vector genomes; vgs) with the reporter gene luciferase (luc) achieved broad and homogenous transduction of healthy pig hearts 30 days after catheter-based retrograde intravenous vector delivery without toxicity. Both its myocardial and extra-cardiac distribution patterns were advantageous compared with AAV9-luc and AAV6-luc. Using AAV5 with the cardioprotective human gene S100A1 (hS100A1; 1×1013 vgcs) by catheter-based retrograde intravenous vector delivery in a subsequent therapy study in post-MI pigs prevented left ventricular MI extension and improved left ventricular ejection fraction after 3 months without clinical toxicity. Weighted gene correlation network analysis linked novel antiinflammatory actions and cardioprotective signaling mechanisms by hS100A1 to study end point improvements, which was confirmed in a post-MI mouse model. CONCLUSIONS:Providing the clinically relevant proof of concept for AAV5 to effectively transduce healthy and dysfunctional human-sized hearts, its clinical long-term safety, scalable producibility, and low preexisting immunity in humans may predestine AAV5 as an effective and safe gene carrier for a prevalent disease such as chronic heart failure, using therapeutic genetic effectors such as hS100A1 or others.

Background The EF-hand Ca 2+ sensor protein S100A1 has been identified as a molecular regulator and enhancer of cardiac performance. S100A1’s ability to recognize and modulate the activity of targets such as SERCA2a and RyR2 in cardiomyocytes has mostly been ascribed to its hydrophobic C-terminal α -helix (residues 75-94). Objective: We therefore hypothesized that a synthetic peptide consisting of residues 75-94 of S100A1 and an N-terminal solubilization tag (S100A1ct) could mimic the performance enhancing effects of S100A1 and may be suitable as a peptide therapeutic to improve the function of diseased hearts. Methods and Results: Applying an integrative translational research pipeline, ranging from computational molecular modeling to large animal cardiac disease models, we characterize S100A1ct as a cell-penetrating peptide with positive inotropic and antiarrhythmic properties in normal and failing myocardium in vitro and in vivo . This activity translates into improved contractile performance and survival in pre-clinical heart failure models with reduced ejection fraction after S100A1ct systemic administration. Mechanistically, S100A1ct exerts a fast and sustained dose-dependent enhancement of cardiomyocyte Ca 2+ cycling and prevents ß-adrenergic receptor triggered Ca 2+ imbalances by targeting SERCA2a and RyR2 activity. Modeling suggests that S100A1ct may stimulate SERCA2a by interacting with the sarcoplasmic transmembrane segments of the multi-span integral membrane Ca 2+ pump. Incorporation of a cardiomyocyte targeting peptide tag into S100A1ct (cor-S100A1ct) further enhanced its biological and therapeutic potency in vitro and in vivo . Conclusion: S100A1ct peptide is a promising lead for the development of a novel peptide-based therapeutic against heart failure with reduced ejection fraction.

Severe burns induce a hypermetabolic and inflammatory state, impairing wound healing and contributing to long-term morbidity. Fibroblast growth factor 21 (FGF-21), a metabolic hormone regulating lipid oxidation, glucose uptake, and mitochondrial homeostasis, has emerged as a potential biomarker and therapeutic modulator in critical illness. This systematic review followed PRISMA 2020 guidelines and assessed seven studies (2015-2024) published until April 2025. Clinical, in vivo, and in vitro investigations were included. Methodological quality was evaluated using the Level of Evidence, Newcastle-Ottawa Scale, and the SYRCLE Risk of Bias tool. In our study, FGF-21 was commonly upregulated following burn injury and was associated with hypermetabolism, adipose tissue browning, mitochondrial stress, and systemic inflammation. Nutritional interventions, including hydrolyzed collagen and omega-3 fatty acids, reduced FGF-21 levels, improved wound healing, and attenuated inflammatory responses. Preclinical models demonstrated that administration of exogenous FGF-21 enhanced re-epithelialization, angiogenesis, mitochondrial function, and anti-inflammatory signaling pathways. Conversely, chronically elevated endogenous FGF-21 levels were consistently linked to metabolic exhaustion, liver dysfunction, and impaired recovery. Overall, FGF-21 may be a promising diagnostic and therapeutic target in burn care. Its clinical relevance and long-term effects require further investigation for successful integration into clinical practice.

The EF-hand calcium (Ca 2+ ) sensor protein S100A1 combines inotropic with antiarrhythmic potency in cardiomyocytes (CM). Oxidative posttranslational modification (ox-PTM) of S100A1’s conserved, single cysteine residue (C85) via reactive nitrogen species (i.e. S-nitrosylation or glutathionylation) was proposed to modulate conformational flexibility of intrinsically disordered sequence fragments and to increase the molecule’s affinity towards Ca 2+ . In light of the unknown biological functional consequence, we aimed to determine the impact of the C85 moiety of S100A1 as a potential redox-switch. We first uncovered that S100A1 is endogenously glutathionylated in the adult heart in vivo. To prevent glutathionylation of S100A1, we generated S100A1 variants that were unresponsive to ox-PTMs. Overexpression of wildtype (WT) and C85-deficient S100A1 protein variants in isolated CM demonstrated equal inotropic potency, as shown by equally augmented Ca 2+ transient amplitudes under basal conditions and β-adrenergic receptor (βAR) stimulation. However, in contrast ox-PTM defective S100A1 variants failed to protect against arrhythmogenic diastolic sarcoplasmic reticulum (SR) Ca 2+ leak and ryanodine receptor (RyR2) hypernitrosylation during β-AR stimulation. Despite diastolic performance failure, C85-deficient S100A1 protein variants exerted similar Ca 2+ -dependent interaction with the RyR2 than WT-S100A1. Dissecting S100A1’s molecular structure-function relationship, our data indicate for the first time that the conserved C85 residue potentially acts as a redox-switch that is indispensable for S100A1’s antiarrhythmic but not its inotropic potency in CM. We therefore propose a model where C85’s ox-PTM determines S100A1’s ability to beneficially control diastolic but not systolic RyR2 activity.

The TCA cycle serves as a central hub to balance catabolic and anabolic needs of the cell, where carbon moieties can either contribute to oxidative metabolism or support biosynthetic reactions. This differential TCA cycle engagement for glucose-derived carbon has been extensively studied in cultured cells, but the fate of fatty acid (FA)-derived carbons is poorly understood. To fill the knowledge gap, we have developed a strategy to culture cells with long-chain FAs without altering cell viability. By tracing 13C-FA, we show that FA oxidation (FAO) is robust in both proliferating and oxidative cells while the metabolic pathway after citrate formation is distinct. In proliferating cells, a significant portion of carbon derived from FAO exits canonical TCA cycle as citrate and converts to unlabeled malate in cytosol. Increasing FA supply or β-oxidation does not change the partition of FA-derived carbon between cytosol and mitochondria. Oxidation of glucose competes with FA-derived carbon for the canonical TCA pathway thus promoting FA carbon flowing into the alternative TCA pathway. Moreover, the coupling between FAO and the canonical TCA pathway changes with the state of oxidative energy metabolism.NEW & NOTEWORTHY By using 13C stable isotope-resolved metabolomics and FA-driven oxygen consumption rate analysis, our study provides novel insights into the fate of FA carbon through β-oxidation and downstream TCA cycle in proliferative and oxidative cells. Although both proliferative and oxidative cells demonstrate robust β-oxidation, they demonstrate distinct metabolic carbon fate downstream of citrate during TCA cycle oxidation. This differential TCA cycle engagement is likely to be important to balance catabolic and anabolic demands of the cell.

Given the transformational impact that artificial intelligence (AI) is having on science, medicine and beyond, we here consider the potential of AI for the discovery of new medicines against heart disease. We define AI broadly as the use of machine learning, including statistics and deep learning, to identify patterns in datasets that can be used to make predictions. Recent breakthroughs in the ability to consider very large amounts of data have spurred a boom in AI-driven drug discovery in both academia and industry. Many new companies already have drug pipelines extending into clinical trials, but these do not yet include drugs against heart disease. We here describe the use of AI for the discovery of low-molecular weight drugs and biologics, including therapeutic peptides, as well as for predicting effects such as cardiotoxicity. The concerted use of AI together with physics-based simulations and experimental feedback loops will be necessary to fully realize the potential of AI for drug discovery and the development of precision medicines for cardiac conditions.

S100A1 is a small EF-type Ca 2+ sensor protein that belongs to the multigenic S100 protein family. It is abundantly expressed in cardiomyocytes (CMs) and has been described as a key regulator of CM performance due to its unique ability to interact with structural contractile proteins, regulators of cardiac Ca 2+ cycling, and mitochondrial proteins. However, our understanding of the molecular mechanisms regulating S100A1 protein levels is limited. We used the bioinformatics tool GPS-SUMO2.0 to identify a putative SUMO interacting motif (SIM) on S100A1. Consistently, a S100A1:SUMO interaction assay showed a Ca 2+ -dependent interaction of S100A1 with SUMO proteins. In neonatal rat ventricular myocytes (NRVM) and COS1 cells, S100A1 protein abundance increased in the presence of overexpressed SUMO1 without affecting the S100A1 mRNA transcript. We then generated S100A1 truncation mutants, where the SIM motif was removed by truncation or in which the core residues of the SIM motif (residues 77-79) were deleted or replaced by alanine. In COS1 cells and NRVM, overexpression of these S100A1 mutants led to elevated S100A1 mutant mRNA levels but failed to produce respective protein levels. Protein expression of these mutants could be rescued from degradation by addition of the proteasome inhibitor MG-132. By using an information-driven approach to dock the three-dimensional structures of S100A1 and SUMO, we predict a novel interaction mode between the SIM in S100A1 and SUMO. This study shows an important role of SUMO:SIM-mediated protein:protein interaction in the regulation of post-translational protein stability, and provides mechanistic insights into the indispensability of the core SIM for S100A1 post-translational stability.

Zusammenfassung Angesichts der umwälzenden Auswirkungen, die künstliche Intelligenz (KI) auf Wissenschaft, Medizin und darüber hinaus hat, betrachten wir hier das Potenzial von KI für die Entdeckung neuer Medikamente gegen Herzkrankheiten. Wir definieren KI im weitesten Sinne als den Einsatz von maschinellem Lernen, einschließlich Statistik und Deep Learning, um Muster in Datensätzen zu erkennen, die für Vorhersagen genutzt werden können. Jüngste Durchbrüche in der Fähigkeit, sehr große Datenmengen zu berücksichtigen, haben einen Boom in der KI-gestützten Arzneimittelentdeckung sowohl in der Wissenschaft als auch in der Industrie ausgelöst. Viele neue Unternehmen verfügen bereits über Arzneimittel-Pipelines, die bis in die klinische Erprobung reichen, aber noch keine Medikamente gegen Herzkrankheiten enthalten. Wir beschreiben hier den Einsatz von KI für die Entdeckung von niedermolekularen Medikamenten und Biologika, einschließlich therapeutischer Peptide, sowie für die Vorhersage von Wirkungen wie Kardiotoxizität. Der konzertierte Einsatz von KI zusammen mit physikbasierten Simulationen und experimentellen Rückkopplungsschleifen wird notwendig sein, um das Potenzial der KI für die Arzneimittelentdeckung und die Entwicklung von Präzisionsarzneimitteln für Herzkrankheiten voll auszuschöpfen.

Abstract Introduction Our clinical research unveiled chronic heart failure with preserved ejection fraction (HFpEF) as a long-term sequel in survivors of severe pediatric burn injury due to a yet unknown molecular pathomechanism. Applying a standardized rat model, we systematically determined the pathophysiological impact of burn injury on long-term cardiac performance to uncover systemic and molecular pathomechanisms that may cause post-burn HFpEF development. Methods Male adolescent SD-rats were subjected to a 60 % total body surface area (TBSA) full-thickness burn- or sham-trauma and subsequently characterized after burn-injury by serial transthoracic echocardiography, bulk myocardial next-generation sequencing and proteomics as well as RT-PCR, immuno-blotting (IB), histology and plasma proteomics for cardiac performance and molecular alterations, respectively, at 3, 7, 30 and 90days. Results In comparison to the sham-group (SG), animals from the burn-group (BG) recapitulated typical post-burn clinical traits, such as significant loss in body weight (BG 27 % less than SG at 30d, p< 0.05) or skeletal muscle wasting (27 % less at 30d, p< 0.05) in accord with elevated molecular atrophy markers. We show post-burn cardiac muscle wasting (BG 22 % less at 30d, p< 0.05) and persistent markers of cardiac dysfunction in accord with significant histological cardiomyocyte hypotrophy (BG -8 % at 30d, p< 0.05) and significantly diminished left ventricular (LV) global longitudinal strain and isovolumic relaxation time in BGs, while LV-EF remained unchanged. Weighted gene network correlation analysis from bulk myocardial NGS and clinical traits related activation of immunological and pro-fibrotic pathways in post-burn injury hearts to cardiac dysfunction in BGs. Subsequent RT-PCR and histology confirmed significant myocardial accumulation of cardio-depressive damage associated molecular patterns (i.e., S100A8 and A9) and infiltration by granulocytes and monocytes as well as significant LV fibrosis. Serial plasma proteomic analysis indicated elevated plasma levels of S100A8 and A9 and other heart failure markers that mirrored similar changes in human post-burn plasma samples. Conclusions Here we report the development of HFpEF as a novel systemic consequence of severe burn injury in a rodent model, which warrants further mechanistic and translational studies. Cardiac inflammation and fibrosis are known to negatively impact cardiac performance and may be mechanistic key findings that will guide further therapeutic studies and subsequent validation of post-burn heart failure biomarkers Applicability of Research to Practice This model is part of a translational and interdisciplinary experimental and clinical effort to inform pathophysiology and mechanistics of long-term heart failure in burn patients. Echocardiographic data and parameters from this model are currently being used to evaluate adult survivors of severe burn injury for signs of HFpEF.

BACKGROUND:Strategies to increase cellular NAD+ (oxidized nicotinamide adenine dinucleotide) level have prevented cardiac dysfunction in multiple models of heart failure, but molecular mechanisms remain unclear. Little is known about the benefits of NAD+-based therapies in failing hearts after the symptoms of heart failure have appeared. Most pretreatment regimens suggested mechanisms involving activation of sirtuin, especially Sirt3 (sirtuin 3), and mitochondrial protein acetylation.METHODS:We induced cardiac dysfunction by pressure overload in SIRT3-deficient (knockout) mice and compared their response with nicotinamide riboside chloride treatment with wild-type mice. To model a therapeutic approach, we initiated the treatment in mice with established cardiac dysfunction.RESULTS:We found nicotinamide riboside chloride improved mitochondrial function and blunted heart failure progression. Similar benefits were observed in wild-type and knockout mice. Boosting NAD+ level improved the function of NAD(H) redox-sensitive SDR (short-chain dehydrogenase/reductase) family proteins. Upregulation of Mrpp2 (mitochondrial ribonuclease P protein 2), a multifunctional SDR protein and a subunit of mitochondrial ribonuclease P, improves mitochondrial DNA transcripts processing and electron transport chain function. Activation of SDRs in the retinol metabolism pathway stimulates RXRα (retinoid X receptor α)/PPARα (proliferator-activated receptor α) signaling and restores mitochondrial oxidative metabolism. Downregulation of Mrpp2 and impaired mitochondrial ribonuclease P were found in human failing hearts, suggesting a shared mechanism of defective mitochondrial biogenesis in mouse and human heart failure.CONCLUSIONS:These findings identify SDR proteins as important regulators of mitochondrial function and molecular targets of NAD+-based therapy. Furthermore, the benefit is observed regardless of Sirt3-mediated mitochondrial protein deacetylation, a widely held mechanism for NAD+-based therapy for heart failure. The data also show that NAD+-based therapy can be useful in pre-existing heart failure.

Cardiac metabolism is vital for heart function. Given that cardiac contraction requires a continuous supply of ATP in large quantities, the role of fuel metabolism in the heart has been mostly considered from the perspective of energy production. However, the consequence of metabolic remodelling in the failing heart is not limited to a compromised energy supply. The rewired metabolic network generates metabolites that can directly regulate signalling cascades, protein function, gene transcription and epigenetic modifications, thereby affecting the overall stress response of the heart. In addition, metabolic changes in both cardiomyocytes and non-cardiomyocytes contribute to the development of cardiac pathologies. In this Review, we first summarize how energy metabolism is altered in cardiac hypertrophy and heart failure of different aetiologies, followed by a discussion of emerging concepts in cardiac metabolic remodelling, that is, the non-energy-generating function of metabolism. We highlight challenges and open questions in these areas and finish with a brief perspective on how mechanistic research can be translated into therapies for heart failure.

Branched-chain amino acid (BCAA) metabolism is linked to glucose homeostasis, but the underlying signaling mechanisms are unclear. We find that gluconeogenesis is reduced in mice deficient of Ppm1k, a positive regulator of BCAA catabolism, which protects against obesity-induced glucose intolerance. Accumulation of branched-chain keto acids (BCKAs) inhibits glucose production in hepatocytes. BCKAs suppress liver mitochondrial pyruvate carrier (MPC) activity and pyruvate-supported respiration. Pyruvate-supported gluconeogenesis is selectively suppressed in Ppm1k-deficient mice and can be restored with pharmacological activation of BCKA catabolism by BT2. Finally, hepatocytes lack branched-chain aminotransferase that alleviates BCKA accumulation via reversible conversion between BCAAs and BCKAs. This renders liver MPC most susceptible to circulating BCKA levels hence a sensor of BCAA catabolism.

Summary Toxicity by recombinant adeno-associated viruses (rAAV) in clinical gene therapy trials (e.g., by rAAV9-mediated fatal liver failure) significantly impairs translation of preclinical rAAV-based cardiac gene therapies employing these vectors. For rAAV5 - a capsid that has shown long-term safety in clinical trials - our translational study demonstrates effective transduction of the left ventricle (LV) of healthy pigs via catheter-based retrograde intravenous delivery (CRID) by means of luciferase reporter gene biodistribution analyses. Combination of rAAV5 with the cardioprotective human gene S100A1 ( hS100A1 ) prevents LV myocardial infarct (MI) enlargement and improves LV systolic contractile performance in a porcine model of post-MI chronic cardiac dysfunction. Use of a cardiac-biased promoter ensured the cardiac-directed expression of the therapeutic human transgene without signs of clinical toxicity. The beneficial effects of rAAV5- hS100A1 were linked to an attenuated activity of post-MI inflammatory gene networks and this was further validated in a murine model. These novel data together with proven scalable producibility and low pre-existing immunity against rAAV5 in humans may collectively advance clinical translation of rAAV5- hS100A1 as a gene therapy medicinal product (GTMP) for a common cardiovascular disease, such as chronic heart failure (CHF). Highlights Recent fatal adverse events in recombinant adeno-associated virus (AAV)-based clinical gene therapy trials advise the use of rAAV serotypes with proven long-term clinical safety, such as rAAV5, for the pre-clinical development and clinical translation of rAAV-based cardiac gene therapy medicinal products. In a biodistribution and therapeutic proof-of-concept study in farm pigs, rAAV5 was identified as an effective viral vector for cardiac gene transfer and gene therapy for post-ischemic cardiac dysfunction when applied by a standardized cardiac-targeted catheter-based route of administration with the luciferase reporter and cardioprotective human gene S100A1 ( hS100A1 ), respectively. A systems biology analysis linked the novel finding of mitigated inflammatory and activated cardioprotective gene network activities in rAAV5- hS100A1 treated postischemic myocardium with improved study left ventricular ejection fraction and prevention of myocardial infarct extension, respectively, which warrants further mechanistic molecular studies. Since rAAV5 has been recently approved for clinical use in a non-cardiac indication and cardiac-targeted S100A1 gene therapy has been effective in numerous pre-clinical animal models of acute and chronic cardiac dysfunction, our translational data support an expedited developmental path for rAAV5- hS100A1 throughout investigational new drug-enabling studies towards a first-in-human clinical trial for post-myocardial infarction heart failure.