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.

Cardiac remodeling, including hypertrophy, is associated with alterations in cytosolic Ca2+ homeostasis of cardiac myocytes that spill over into the nucleoplasm. To test whether nuclear Ca2+ signaling acts causally on the development of cardiac hypertrophy, we expressed parvalbumin to buffer nuclear Ca2+ and we blocked nuclear Ca2+-calmodulin signaling by Adeno-associated virus (AAV)-mediated expression of the calmodulin (CaM) binding-peptide nlsCaMBP4, respectively, in the nuclei of ES cell-derived (Cor.At) and neonatal rat ventricular cardiac myocytes (NRVCM). Expression of nlsCaMBP4, but not parvalbumin, leads to a significant reduction of hypertrophic growth induced by phenylephrine (PE). Expression of nlsCaMBP4 did not alter the amplitude of electrically-evoked intracellular Ca2+ transients in NRVCMs in the absence or presence of PE, and did not affect the PE-evoked increase in store-operated Ca2+ entry. Transcriptome analysis on NRVCMs expressing nlsCaMBP4 revealed that induction of classical hypertrophy markers such as ANF and BNP or MEF2 target genes (such as Srpk3, Xirp1 and Xirp2) were not reduced by nlsCaMBP4 expression. Further analysis of the nuclear Ca2+-calmodulin-regulated gene pool revealed differential expression of genes involved in mRNA translation, including the translation initiation factor subunits Eif2s1, Eif3d and Eif5, whose upregulation was absent in nlsCaMBP4-treated myocytes. Puromycin assays showed that inhibition of Ca2+-calmodulin signaling prevented catecholamine-evoked protein translation, suggesting that Ca2+-calmodulin signaling in the nucleus of cardiac myocytes regulates translation via transcriptional control mechanisms. However, future studies are needed to identify the exact molecular components and machinery that integrate Ca2+-calmodulin-dependent regulation of transcription, protein translation, and development of cardiac myocyte hypertrophy.

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.

DNA shuffling is a powerful technique for generating synthetic DNA via recombination of homologous parental sequences. Resulting chimeras are often incorporated into complex libraries for functionality screenings that identify novel variants with improved characteristics. To survey shuffling efficiency, subsequences of chimeras can be computationally assigned to their corresponding parental counterpart, yielding insight into frequency of recombination events, diversity of shuffling libraries and actual composition of final variants. Whereas tools for parental assignment exist, they do not provide direct visualization of the results, making the analysis time-consuming and cumbersome. Here we present ShuffleAnalyzer, a comprehensive, user-friendly, Python-based analysis tool that directly generates graphical outputs of parental assignments and is freely available under a BSD-3 license (https://github.com/joerg-swg/ShuffleAnalyzer/releases). Besides DNA shuffling, peptide insertions can be simultaneously analyzed and visualized, which makes ShuffleAnalyzer a highly valuable tool for integrated approaches often used in synthetic biology, such as AAV capsid engineering in gene therapy applications.

Any strategy that can selectively and persistently lower the brain levels of the cellular prion protein (PrPC) is expected to extend survival in prion diseases. Recent advances in the virus-mediated delivery of gene therapies prompted us to explore if a recombinant adeno-associated virus (rAAV) vector delivering a CRISPR-Cas-based gene editor can be devised that induces a functional knockout of the prion gene. Whereas the eventual objective is to assess the therapeutic potency of an optimized vector in prion-infected mice, in this proof-of-concept study, we evaluated tools and methods that are suited to achieve this goal. The result of these efforts is a first-generation all-in-one rAAV vector that codes for a prion gene-specific guide RNA and a small Cas9 endonuclease, whose expression is controlled by a truncated neural cell adhesion molecule 1 (NCAM1) promoter that is active in PrPC expressing cells. We also constructed a second rAAV vector coding for a prion gene-specific 'traffic light reporter' (TLR). The TLR can be used to monitor prion gene-editing efficacy by coding for red and green fluorescent proteins separated by a segment of the prion gene that is targeted by the gene editor. For the purification of AAVs, we adopted a robust and scalable rAAV vector assembly pipeline and undertook proof-of-concept prion gene editing experiments in human cells and mice, which to date yielded prion gene editing rates of approximately 20% and 5%, respectively. Finally, we compared brain distributions of rAAV vectors following intrathalamic versus retro-orbital injection, and selected the 9P31 capsid for future studies based on a 7.5-fold higher heterologous gene expression level as compared to the PHP.eB capsid.

Cardiac fibroblasts (CF) are key players after myocardial infarction (MI), but their signaling is only incompletely understood. Here we report a first secretome atlas of CF in control (cCF) and post-MI mouse hearts (miCF), combining a rapid cell isolation technique with SILAC and click chemistry. In CF, numerous paracrine factors involved in immune homeostasis are identified. Comparing secretome, transcriptome (SLAMseq), and cellular proteome disclose protein turnover. In miCF at day 5 post-MI, significantly upregulated proteins include SLIT2, FN1, and CRLF1 in mouse and human samples. Comparing the miCF secretome at days 3 and 5 post-MI reveals the dynamic nature of protein secretion. Specific in-vivo labeling of miCF proteins via biotin ligase TurboID using the POSTN promotor mirrors the in-vitro data. In summary, we identify numerous paracrine factors specifically secreted from CF in mice and humans. This secretome atlas may lead to new biomarkers and/or therapeutic targets for the activated CF.

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.

AbstractCardiac fibroblasts (CF) are key players after myocardial infarction (MI), but their signaling is only incompletely understood. Here we report a first secretome atlas of CF in control (cCF) and post-MI hearts (miCF), combining a rapid cell isolation technique with SILAC and click chemistry. In CF, numerous paracrine factors involved in immune homeostasis were identified. Comparing secretome, transcriptome (SLAMseq), and cellular proteome disclosed protein turnover. In miCF at day 5 post-MI, significantly upregulated proteins included SLIT2, FN1, and CRLF1 in mouse and human samples. Comparing the miCF secretome at day 3 and 5 post-MI showed the dynamic nature of protein secretion. Specific in-vivo labeling of miCF proteins via biotin ligase TurboID using the POSTN promotor mirrored the in-vitro data. In summary, we have identified numerous paracrine factors specifically secreted from CF in mice and humans. This secretome atlas may lead to new biomarkers and/or therapeutic targets for the activated CF.

AIMS:Physiological cardiac hypertrophy occurs in response to exercise and can protect against pathological stress. In contrast, pathological hypertrophy occurs in disease and often precedes heart failure. The cardiac pathways activated in physiological and pathological hypertrophy are largely distinct. Our prior work demonstrated that miR-222 increases in exercised hearts and is required for exercise-induced cardiac hypertrophy and cardiomyogenesis. Here, we sought to define the role of miR-222 in pathological hypertrophy.METHODS AND RESULTS:We found that miR-222 also increased in pathological hypertrophy induced by pressure overload. To assess its functional significance in this setting, we generated a miR-222 gain-of-function model through cardiac-specific constitutive transgenic miR-222 expression (TgC-miR-222) and used locked nucleic acid anti-miR specific for miR-222 to inhibit its effects. Both gain- and loss-of-function models manifested normal cardiac structure and function at baseline. However, after transverse aortic constriction (TAC), miR-222 inhibition accelerated the development of pathological hypertrophy, cardiac dysfunction, and heart failure. Conversely, miR-222-overexpressing mice had less pathological hypertrophy after TAC, as well as better cardiac function and survival. We identified p53-up-regulated modulator of apoptosis, a pro-apoptotic Bcl-2 family member, and the transcription factors, Hmbox1 and nuclear factor of activated T-cells 3, as direct miR-222 targets contributing to its roles in this context.CONCLUSION:While miR-222 is necessary for physiological cardiac growth, it inhibits cardiac growth in response to pressure overload and reduces adverse remodelling and cardiac dysfunction. These findings support the model that physiological and pathological hypertrophy are fundamentally different. Further, they suggest that miR-222 may hold promise as a therapeutic target in pathological cardiac hypertrophy and heart failure.

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.

Cardiac signaling pathways functionally important in the heart’s response to exercise often protect the heart against pathologic stress, potentially providing novel therapeutic targets. However, it is important to determine which of these pathways can be feasibly targeted in vivo. Transgenic overexpression of exercise-induced CITED4 has been shown to protect against adverse remodeling after ischemia/reperfusion injury (IRI). Here we investigated whether somatic gene transfer of CITED4 in a clinically relevant time frame could promote recovery after IRI. Cardiac CITED4 gene delivery via intravenous AAV9 injections in wild type mice led to a ∼3-fold increase in cardiac CITED4 expression. After four weeks, CITED4-treated animals developed physiologic cardiac hypertrophy without adverse remodeling. In IRI, delivery of AAV9-CITED4 after reperfusion resulted in a 6-fold increase in CITED4 expression one week after surgery, as well as reduced apoptosis, fibrosis, and inflammatory markers, culminating in a smaller scar and improved cardiac function eight weeks after IRI, compared to control mice receiving AAV9-GFP. Somatic gene transfer of CITED4 induced a phenotype suggestive of physiologic cardiac growth and mitigated adverse remodeling after ischemic injury. These studies support the feasibility of CITED4 gene therapy delivered in a clinically relevant time frame to mitigate adverse ventricular remodeling after ischemic injury.

Heart failure (HF) prevalence is rising due to reduced early mortality and demographic change. Relaxin (RLN) mediates protective effects in the cardiovascular system through Relaxin-receptor 1 (RXFP1). Cardiac overexpression of RXFP1 with additional RLN supplementation attenuated HF in the pressure-overload transverse aortic constriction (TAC) model. Here, we hypothesized that robust transgenic RXFP1 overexpression in cardiomyocytes (CM) protects from TAC-induced HF even in the absence of RLN. Hence, transgenic mice with a CM-specific overexpression of human RXFP1 (hRXFP1tg) were generated. Receptor functionality was demonstrated by in vivo hemodynamics, where the administration of RLN induced positive inotropy strictly in hRXFP1tg. An increase in phospholamban-phosphorylation at serine 16 was identified as a molecular correlate. hRXFP1tg were protected from TAC without additional RLN administration, presenting not only less decline in systolic left ventricular (LV) function but also abrogated LV dilation and pulmonary congestion compared to WT mice. Molecularly, transgenic hearts exhibited not only a significantly attenuated fetal and fibrotic gene activation but also demonstrated less fibrotic tissue and CM hypertrophy in histological sections. These protective effects were evident in both sexes. Similar cardioprotective effects of hRXFP1tg were detectable in a RLN-knockout model, suggesting an alternative mechanism of receptor activation through intrinsic activity, alternative endogenous ligands or crosstalk with other receptors. In summary, CM-specific RXFP1 overexpression provides protection against TAC even in the absence of endogenous RLN. This suggests RXFP1 overexpression as a potential therapeutic approach for HF, offering baseline protection with optional RLN supplementation for specific activation.