In vivo and in vitro study on the regulatory mechanism of XiaoChaiHu decoction on PANoptosis in sepsis-induced cardiomyopathy.

ETHNOPHARMACOLOGICAL RELEVANCE: In accordance with the tenets of traditional Chinese medicine, sepsis is categorized into three distinct syndromes: heat syndrome, blood stasis syndrome, and deficiency syndrome. Xiaochaihu decoction (XCHD) has many functions, including the capacity to protect the liver, cholagogue, antipyretic, anti-inflammatory, and anti-pathogenic microorganisms. XCHD exerts the effect of clearing heat and reconciling Shaoyang. The XCHD contains many efficacious active ingredients, yet the mechanism of sepsis-induced cardiomyopathy (SIC) remains elusive. AIM OF THE STUDY: To investigate the molecular mechanisms underlying the protective effects of XCHD against SIC using an integrated approach combining network pharmacology and molecular biology techniques. MATERIALS AND METHODS: Network pharmacology methods identified the active ingredients, target proteins, and pathways affected by XCHD in the context of SIC. We conducted in vivo experiments using mice with lipopolysaccharide-induced SIC, evaluating cardiac function through echocardiography and histology. XCHD-containing serum was analyzed to determine its principal active components using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The effects of XCHD-containing serum on SIC were further tested in vitro in LPS-treated H9c2 cardiac cells. Protein expression levels were quantified via Western blotting and enzyme-linked immunosorbent assay (ELISA). Additionally, molecular docking was performed between the active components and ZBP1, a potential target protein. Overexpression of ZBP1 in H9c2 cells allowed for a deeper exploration of its role in modulating SIC-associated gene expression. RESULTS: UPLC-MS/MS identified 31 shared XCHD and XCHD-containing serum components. These included organic acids, terpenoids, and flavonoids, which have been identified as the active components of XCHD. Our findings revealed that XCHD alleviated LPS-induced myocardial injury, improved cardiac function, and preserved cardiomyocyte morphology in mice. In vitro studies, we demonstrated that XCHD-containing serum significantly suppressed the expression of inflammatory cytokines (IL-6, IL-1ß, and TNF-α) in LPS-induced H9c2 cells. Mechanistic investigations showed that XCHD downregulated genes associated with PANoptosis, a novel cell death pathway, suggesting its protective role in sepsis-damaged hearts. Conversely, overexpression of ZBP1 abolished the protective effects of XCHD and amplified PANoptosis-related gene expression. CONCLUSIONS: Our study provides the first evidence supporting the protective effects of XCHD against SIC, both in vitro and in vivo. The underlying mechanism involves the inhibition of ZBP1-initiated PANoptosis, offering new insights into treating SIC using XCHD.

Prognostic value of red blood cell distribution width in sepsis induced cardiomyopathy patients.

The potential association between red blood cell distribution width (RDW) at admission and prognosis in patients with sepsis-induced cardiomyopathy(SIC) remains uncertain. The purpose of this study was to explore the prognostic value of RDW on mortality in patients with SIC. Data for this retrospective study were obtained from the MIMIC IV2.2 database. We used propensity score matching (PSM) and Cox proportional hazards regression analysis to evaluate the main risk factors associated with mortality in SIC patients. This analysis was utilized to develop a predictive nomogram. To assess the predictive accuracy and clinical usefulness of the model, we employed the concordance index (C-index) and decision curve analysis. To define the high- and low-RDW groups among patients with SIC, we determined the optimal cut-off value by maximizing the Youden index. According to the screening criteria, we identified a cohort of 1051 patients diagnosed with SIC. When comparing the high-RDW group to the low-RDW group, it was found that the high-RDW group exhibited longer Los_ICU(4.5 days vs.3.8 days, respectively, P = 0.009) and higher mortality rates at 28 days (33.8% vs. 7.8%, respectively, P < 0.001). A nomogram model was created using matched patients which included various factors such as Age, RDW, LDH, CKMB, creatinine and the administration of ß-blocker. The C-index predicting 28-day survival probability was 0.846. Decision curves analysis demonstrated that the inclusion of RDW in the model provided a greater net benefit compared to excluding RDW. The prognosis of patients with SIC can be predicted by the RDW value. The nomogram model provides a useful tool in identifying and managing SIC patients.

Po-Ge-Jiu-Xin decoction alleviate sepsis-induced cardiomyopathy via regulating phosphatase and tensin homolog-induced putative kinase 1 /parkin-mediated mitophagy.

ETHNOPHARMACOLOGICAL RELEVANCE: Sepsis is a life-threatening systemic syndrome usually accompanied by myocardial dysfunction. Po-Ge-Jiu-Xin decoction (PGJXD), a traditional Chinese prescription medicine, has been used clinically to treat cardiovascular disease including heart failure, sepsis-induced cardiomyopathy (SIC) and even septic shock. Previous clinical studies suggested PGJXD has shown promising results in improving cardiac function and treating heart failure in sepsis. However, more research is needed to elucidate the mechanisms underlying PGJXD's therapeutic effects in sepsis-induced cardiomyopathy. MATERIALS AND METHODS: Initially, we identified the major compounds of PGJXD through ultra-performance liquid chromatography-mass spectrometry technology analysis. We established in a SIC rat model using cecal ligation and puncture(CLP) and treated by PGJXD and levosimendan. We evaluated pathological damage by hematoxylin and eosin staining and measured serum myocardial injury biomarkers. Myocardial apoptosis was detected by Tunel staining and quantifying specific biomarker protein levels. Subsequently, we evaluated myocardium mitochondrial quality using Transmission electron microscope (TEM), antioxidant stress indexes and tissue adenosine triphosphate(ATP) content. We detected the expression of phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1), parkin, LC3, and p62 using Western blotting and Quantitative real time polymerase chain reaction(qRT-PCR). (Lipopolysaccharides, LPS)-induced H9c2 cell model was established to further explore the mechanism of PGJXD on SIC. In addition to measuring cell viability, we measured mitochondrial membrane potential using JC-1 staining. Additionally, Parkin-siRNA transfected into H9c2 cells to validate whether PGJXD conducted protective effects against SIC through PINK1/Parkin-mediated mitophagy. RESULTS: It has been demonstrated that PGJXD reduced mortality in septic rat, contributed to ameliorating myocardium injury, suppressed inflammatory response and ameliorated the myocardial apoptosis. PGJXD could also alleviate mitochondrial structural abnormality, mitigated oxidative stress injury and promoted energy synthesis in CLP models. Western blotting and qRT-PCR have further confirmed that PGJXD can activate PINK1/parkin pathway-mediated mitophagy, resulting in preserving mitochondrial quality in the myocardium. Furthermore, Parkin siRNA partially reversed the beneficial effect of PGJXD on mitochondrial fission/fusion and mitophagy in vitro. Therefore, the cardioprotective effect of PGJXD is achieved by inducing PINK1/Parkin-mediated mitophagy in maintaining mitochondrial homeostasis. CONCLUSIONS: These results suggest that the potential therapeutic effect of PGJXD on cardiac dysfunction during sepsis and support its mechanism of targeted induction of PINK1-Parkin-mediated mitophagy.

Heart-type fatty acid binding protein (H-FABP) as an early biomarker in sepsis-induced cardiomyopathy: a prospective observational study.

BACKGROUND: Sepsis-induced cardiomyopathy (SICM) is a common and life-threatening complication of sepsis, significantly contributing to elevated mortality. This study aimed to identify crucial indicators for the prompt and early assessment of SICM. METHODS: Patients diagnosed with sepsis or SICM within 24 h of intensive care unit (ICU) admission were enrolled in this prospective observational study. Patients were assigned to the training set, validation set and external test set. The primary endpoint was 7-day ICU mortality, and the secondary endpoint was 28-day ICU mortality. Three machine learning algorithms were utilized to identify relevant indicators for diagnosing SICM, incorporating 64 indicators including serum biomarkers associated with cardiac, renal, and liver function, lipid metabolism, coagulation, and inflammation. Internal and external validations were performed on the screening results. Patients were then stratified based on the cut-off value of the most diagnostically effective biomarker identified, and their prognostic outcomes were observed and analyzed. RESULTS: A total of 270 patients were included in the training and validation set, and 52 patients were included in the external test set. Age, sex, and comorbidities did not significantly differ between the sepsis and SICM groups (P > 0.05). The support vector machine (SVM) algorithm identified six indicators with an accuracy of 84.5%, the random forest (RF) algorithm identified six indicators with an accuracy of 81.9%, and the logistic regression (LR) algorithm screened out seven indicators. Following rigorous selection, a diagnostic model for sepsis-induced cardiomyopathy was established based on heart-type fatty acid binding protein (H-FABP) (OR 1.308, 95% CI 1.170-1.462, P < 0.001) and retinol-binding protein (RBP) (OR 1.020, 95% CI 1.006-1.034, P < 0.05). H-FABP alone exhibited the highest diagnostic performance in both the internal (AUROC 0.689, P < 0.05) and external sets (AUROC 0.845, P < 0.05). Patients with SICM were further stratified based on an H-FABP diagnostic cut-off value of 8.335 ng/mL. Kaplan-Meier curve analysis demonstrated that elevated H-FABP levels at admission were associated with higher 7-day ICU mortality in patients with SICM (P < 0.05). CONCLUSIONS: This study revealed that H-FABP concentrations measured within 24 h of patient admission could serve as a crucial biomarker for the early and rapid diagnosis and short-term prognostic evaluation of SICM.

Inhibition of miR-194-5p avoids DUSP9 downregulation thus limiting sepsis-induced cardiomyopathy.

Sepsis-induced cardiomyopathy (SIC) is described as a reversible myocardial depression that occurs in patients with septic shock. Increasing evidence shows that microRNA-194-5p (miR-194-5p) participates in the regulation of oxidative stress, mitochondrial dysfunction, and apoptosis and its expression is associated with the occurrence and progression of cardiovascular disease; however, the effects of miR-194-5p in SIC are still unclear. This study explores whether miR-194-5p could modulate SIC by affecting oxidative stress, mitochondrial function, and apoptosis. Experimental septic mice were induced by intraperitoneal injection of lipopolysaccharide (LPS) in C57BL/6J mice. The biological role of miR-194-5p in SIC in vivo was investigated using cardiac echocardiography, ELISA, western blot, qRT-PCR, transmission electron microscopy, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, bioinformatics analysis, and dual-luciferase reporter gene assay. Our major finding is that miR-194-5p antagomir mitigates sepsis-induced cardiac dysfunction, inflammation, oxidative stress, apoptosis and mitochondrial dysfunction in the hearts of septic mice, while miR-194-5p agomir triggers the opposite effects. Furthermore, dual-specificity phosphatase 9 (DUSP9) is a direct target of miR-194-5p and the cardioprotective effects of miR-194-5p antagomir on cardiac dysfunction, inflammation, apoptosis, mitochondrial dysfunction and oxidative stress are abolished through inhibiting DUSP9. Therefore, miR-194-5p inhibition could mitigate SIC via DUSP9 in vivo and the novel miR-194-5p/DUSP9 axis might be the potential treatment targets for SIC patients.

ACE2 alleviates sepsis-induced cardiomyopathy through inhibiting M1 macrophage via NF-κB/STAT1 signals.

Angiotensin-converting enzyme 2 (ACE2), a crucial element of the renin-angiotensin system (RAS), metabolizes angiotensin II into Ang (1-7), which then combines with the Mas receptor (MasR) to fulfill its protective role in various diseases. Nevertheless, the involvement of ACE2 in sepsis-induced cardiomyopathy (SIC) is still unexplored. In this study, our results revealed that CLP surgery dramatically impaired cardiac function accompanied with disruption of the balance between ACE2-Ang (1-7) and ACE-Ang II axis in septic heart tissues. Moreover, ACE2 knockin markedly alleviated sepsis induced RAS disorder, cardiac dysfunction and improved survival rate in mice, while ACE2 knockout significantly exacerbates these outcomes. Adoptive transfer of bone marrow cells and in vitro experiments showed the positive role of myeloid ACE2 by mitigating oxidative stress, inflammatory response, macrophage polarization and cardiomyocyte apoptosis by blocking NF-κB and STAT1 signals. However, the beneficial impacts were nullified by MasR antagonist A779. Collectively, these findings showed that ACE2 alleviated SIC by inhibiting M1 macrophage via activating the Ang (1-7)-MasR axis, highlight that ACE2 might be a promising target for the management of sepsis and SIC patients.

Shark Fin Sign in a Patient with Sepsis-induced Cardiomyopathy Associated with Retained Placenta: A Case Report and Review of the Literature.

Retained placenta can lead to septic shock; however, sepsis-induced cardiomyopathy (SICM) due to retained placenta has not been reported previously. This report presents a rare case of SICM following septic shock due to retained placenta after miscarriage in a 40-year-old woman, accompanied by the "shark fin sign" on an electrocardiogram, a pattern typically linked to myocardial ischemia. She experienced ventricular tachycardia and required venoarterial extracorporeal membrane oxygenation; however, she was successfully treated. We also reviewed previous cases of shark fin sign in patients without myocardial infarction. A review showed that half of the cases experienced lethal arrhythmias, even without myocardial infarction.

Mechanisms of the septic heart: From inflammatory response to myocardial edema.

Sepsis-induced myocardial dysfunction (SIMD), also known as sepsis-induced cardiomyopathy (SICM), is linked to significantly increased mortality. Despite its clinical importance, effective therapies for SIMD remain elusive, largely due to an incomplete understanding of its pathogenesis. Over the past five decades, research involving both animal models and human studies has highlighted several pathogenic mechanisms of SICM, yet many aspects remain unexplored. Initially thought to be primarily driven by inflammatory cytokines, current research indicates that these alone are insufficient for the development of cardiac dysfunction. Recent studies have brought attention to additional mechanisms, including excessive nitric oxide production, mitochondrial dysfunction, and disturbances in calcium homeostasis, as contributing factors in SICM. Emerging clinical evidence has highlighted the significant role of myocardial edema in the pathogenesis of SICM, particularly its association with cardiac remodeling in septic shock patients. This review synthesizes our current understanding of SIMD/SICM, focusing on myocardial edema's contribution to cardiac dysfunction and the critical role of the bradykinin receptor B1 (B1R) in altering myocardial microvascular permeability, a potential key player in myocardial edema development during sepsis. Additionally, this review briefly summarizes existing therapeutic strategies and their challenges and explores future research directions. It emphasizes the need for a deeper understanding of SICM to develop more effective treatments.

Utilizing omics technologies in the investigation of sepsis-induced cardiomyopathy.

Sepsis-induced cardiomyopathy (SIC) is a common and high-mortality complication among critically ill patients. Uncertainties persist regarding the pathogenesis, pathophysiology, and diagnosis of SIC, underscoring the necessity to investigate potential biological mechanisms. With the rise of omics technologies, leveraging their high throughput and big data advantages, a systems biology perspective is employed to study the biological processes of SIC. This approach aids in gaining a better understanding of the disease's onset, progression, and outcomes, ultimately providing improved guidance for clinical practices. This review summarizes the currently applied omics technologies, omics studies related to SIC, and relevant omics databases.

Successful treatment of sepsis-induced cardiomyopathy with 36 hours refractory ventricular fibrillation: A case report.

Sepsis-induced cardiomyopathy (SIC) is generally characterized by decreased cardiac ejection fraction (EF) reversibility, less cardiac response to fluid resuscitation and catecholamine, and rarely complicated with refractory ventricular fibrillation (RVF). Once RVF is induced, the mortality rate of sepsis patients will be greatly increased. In this case, we reported a 26-year-old female patient who was diagnosed sepsis-induced cardiomyopathy (SIC), presented with RVF for 36 hours. The patient was maintained by the mechanical circulatory support (MCS) devices and experienced twice defibrillation. Finally, the patient was discharged without intracardial thrombosis and severe craniocerebral complications. This case suggested that early application of MCS and appropriate frequency of defibrillation may help the prognosis of SIC with RVF.

GDF15 attenuates sepsis-induced myocardial dysfunction by inhibiting cardiomyocytes ferroptosis via the SOCS1/GPX4 signaling pathway.

Sepsis is a systemic inflammatory response syndrome triggered by infection, presenting with symptoms such as fever, increased heart rate, and low blood pressure. In severe cases, it can lead to multiple organ dysfunction, posing a life-threatening risk. Sepsis-induced cardiomyopathy (SIC) is a critical factor in the poor prognosis of septic patients, leading to myocardial dysfunction characterized by cell death, inflammation, and diminished cardiac function. Ferroptosis, an iron-dependent form of programmed cell death, is a key mechanism causing cardiomyocyte damage in SIC. Growth differentiation factor 15 (GDF15), a member of the TGF-ß superfamily, is associated with various cardiovascular diseases and can inhibit oxidative stress, reduce reactive oxygen species (ROS), and suppress ferroptosis. Elevated serum GDF15 levels in sepsis are correlated with organ injuries, suggesting its potential as a therapeutic target. However, its role and mechanisms in SIC remain unclear. Glutathione peroxidase 4 (GPX4), the only enzyme capable of reducing lipid peroxides within cells, protects cells by reducing lipid peroxidation levels and inhibiting ferroptosis. Investigating the regulatory factors of GPX4 may provide a theoretical basis for SIC treatment. In this study, a mouse SIC model revealed that elevated GDF15 exerts a protective effect. Antagonizing GDF15 exacerbates myocardial damage. Through transcriptomic analysis and other methods, we confirmed that GDF15 inhibits the expression of SOCS1 by activating the ALK5-SMAD2/3 pathway, thereby activates the JAK2/STAT3 pathway, promotes the transcription of GPX4, inhibits ferroptosis in cardiomyocytes, and plays a myocardial protective role in SIC.

Quercetin Alleviates LPS-Stimulated Myocardial Injury through Regulating ALOX5/PI3K/AKT Pathway in Sepsis.

Quercetin (QUE) has been found to inhibit the progression of sepsis-related diseases, including sepsis-induced cardiomyopathy (SIC). More information about the role and mechanism of QUE in SIC progression deserves further exploration. Human cardiomyocytes (AC16) were induced with LPS to mimic SIC cell models. Cell proliferation and apoptosis were determined using CCK8 assay, EdU assay, and flow cytometry. Cell inflammation and ferroptosis were evaluated by detecting IL-1ß, TNF-α, Fe2+, ROS, GSH, and GPX4 levels. 5-lipoxygenase (ALOX5) expression was examined by quantitative real-time PCR and western blot. LPS treatment reduced AC16 cell proliferation, while enhanced apoptosis, inflammation, and ferroptosis. QUE repressed LPS-induced AC16 cell apoptosis, inflammation, and ferroptosis. ALOX5 was upregulated in SIC patients, and its expression was reduced by QUE. ALOX5 knockdown restrained LPS-induced apoptosis, inflammation, and ferroptosis in AC16 cells. The inhibitory effect of QUE on LPS-induced myocardial injury could be reversed by ALOX5 overexpression. QUE promoted the activity of PI3K/AKT pathway by reducing ALOX5 expression. QUE could alleviate LPS-induced myocardial injury by regulating ALOX5/PI3K/AKT pathway, suggesting that QUE might be used for treating SIC.

Exploring Ferroptosis-Associated Gene Signatures as Diagnostic and Therapeutic Targets for Sepsis-Induced Cardiomyopathy.

BACKGROUND: Sepsis-induced cardiomyopathy (SICM) is a severe complication of sepsis associated with high mortality rates. Despite its significance, the molecular mechanisms underlying SICM remain poorly understood, particularly the role of ferroptosis - a form of iron-dependent programmed cell death. METHODOLOGY: This study analyzed the GSE79962 dataset from the Gene Expression Omnibus, containing cardiac gene expression profiles from SICM patients and controls. A list of ferroptosis-related genes (FRGs) was retrieved from the FerrDb. We used the limma package in R for differential expression analysis, setting an adjusted P-value cutoff of <0.05 and a log2-fold change threshold of ±1 to identify differentially expressed ferroptosis-related genes (DE-FRGs). We applied machine learning algorithms for biomarker identification, including least absolute shrinkage and selection operator (LASSO) logistic regression and support vector machine with recursive feature elimination (SVM-RFE), implemented via the glmnet and e1071 packages in R, respectively. Gene set enrichment analysis (GSEA) was conducted using the GSEA package to investigate the biological pathways related to key DE-FRGs. RESULTS: After differential expression analysis, we identified 145 DE-FRGs. Functional enrichment analyses underscored the involvement of these genes in critical biological processes and pathways, such as lipid metabolism and insulin resistance. Machine learning approaches pinpointed five key DE-FRGs (NCOA4, GABARAPL1, GJA1, CISD1, CP), with strong predictive potential for SICM. Further analyses, including the construction of a ceRNA network, revealed intricate post-transcriptional regulatory mechanisms that may influence the expression of these key genes. CONCLUSIONS: Our findings highlight the central role of ferroptosis in SICM and identify potential biomarkers and therapeutic targets that could help refine diagnostic and treatment strategies. This study advances our understanding of the molecular underpinnings of SICM and sets the stage for future research aimed at mitigating this severe sepsis complication.

Atractylenolide I ameliorates sepsis-induced cardiomyocyte injury by inhibiting macrophage polarization through the modulation of the PARP1/NLRP3 signaling pathway.

Sepsis-induced cardiomyopathy (SIC) leads to high mortality and has no effective treatment strategy. Atractylenolide Ⅰ (AT-I) is a sesquiterpene lactone compound and possesses various biological activities such as anti-inflammatory and organ protection. This study was designed to explore the role and the mechanism of AT-I in SIC. CCK-8 assay was used to assess the viability of AT-I-treated RAW 264.7 cells and immunofluorescence assay was used to detect M1 marker CD86. The expressions of M1 markers Cox2, iNOS and CD11b and PARP1/NLRP3 signaling pathway-related proteins were detected using western blot. The transfection efficiency of oe-PARP1 was examined with RT-qPCR and western blot. The ROS activity in H9c2 cells was detected using DCFH-DA assay and western blot was used to detect the expressions of inflammation- and oxidative stress-related proteins. The apoptosis of H9c2 cells was detected using flow cytometry and western blot. The present study found that AT-I inhibited LPS-induced M1 polarization in RAW 264.7 cells through the downregulation of PARP1/NLRP3 signaling pathway, thereby inhibiting the oxidative stress and apoptosis of H9c2 cells. In conclusion, AT-I might be a promising therapeutic agent for SIC by suppressing macrophage polarization through the modulation of PARP1/NLRP3 signaling pathway.

Protective effects of Dioscin against sepsis-induced cardiomyopathy via regulation of toll-like receptor 4/MyD88/p65 signal pathway.

BACKGROUND: Dioscin has many pharmacological effects; however, its role in sepsis-induced cardiomyopathy (SIC) is unknown. Accordingly, we concentrate on elucidating the mechanism of Dioscin in SIC rat model. METHODS: The SIC rat and H9c2 cell models were established by lipopolysaccharide (LPS) induction. The heart rate (HR), left ventricle ejection fraction (LVEF), mean arterial blood pressure (MAP), and heart weight index (HWI) of rats were evaluated. The myocardial tissue was observed by hematoxylin and eosin staining. 4-Hydroxy-2-nonenal (4-HNE) level in myocardial tissue was detected by immunohistochemistry. Superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) activities in serum samples of rats and H9c2 cells were determined by colorimetric assay. Bax, B-cell lymphoma-2 (Bcl-2), toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), phosphorylated-p65 (p-p65), and p65 levels in myocardial tissues of rats and treated H9c2 cells were measured by quantitative real-time PCR and Western blot. Viability and reactive oxygen species (ROS) accumulation of treated H9c2 cells were assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and dihydroethidium staining assays. RESULTS: Dioscin decreased HR and HWI, increased LVEF and MAP, alleviated the myocardial tissue damage, and reduced 4-HNE level in SIC rats. Dioscin reversed LPS-induced reduction on SOD, CAT, GSH, and Bcl-2 levels, and increment on Bax and TLR4 levels in rats and H9c2 cells. Overexpressed TLR4 attenuated the effects of Dioscin on promoting viability, as well as dwindling TLR4, ROS and MyD88 levels, and p-p65/p65 value in LPS-induced H9c2 cells. CONCLUSION: Protective effects of Dioscin against LPS-induced SIC are achieved via regulation of TLR4/MyD88/p65 signal pathway.

Energy metabolism: from physiological changes to targets in sepsis-induced cardiomyopathy.

Sepsis is a systemic inflammatory response syndrome caused by a variety of dysregulated responses to host infection with life-threatening multi-organ dysfunction. Among the injuries or dysfunctions involved in the course of sepsis, cardiac injury and dysfunction often occur and are associated with the pathogenesis of hemodynamic disturbances, also defined as sepsis-induced cardiomyopathy (SIC). The process of myocardial metabolism is tightly regulated and adapts to various cardiac output demands. The heart is a metabolically flexible organ capable of utilizing all classes of energy substrates, including carbohydrates, lipids, amino acids, and ketone bodies, to produce ATP. The demand of cardiac cells for energy metabolism changes substantially in septic cardiomyopathy, with distinct etiological causes and different times. This review describes changes in cardiomyocyte energy metabolism under normal physiological conditions and some features of myocardial energy metabolism in septic cardiomyopathy and briefly outlines the role of the mitochondria as a center of energy metabolism in the septic myocardium, revealing that changes in energy metabolism can serve as a potential future therapy for infectious cardiomyopathy.

A Case Report of Sepsis-Induced Dilated Cardiomyopathy Secondary to Human Metapneumovirus Infection.

Sepsis is a medical emergency that describes the body's systemic immunological response to an infectious process that can lead to end-stage organ dysfunction and death. Sepsis-induced cardiomyopathy (SICM) is an increasingly recognized form of transient cardiac dysfunction characterized by left ventricular dilation, depressed ejection fraction, and recovery in 10 days without cardiac-related medical intervention. Injury to the myocardium by inflammatory cytokines has been proposed as one of the main causative mechanisms. Human metapneumovirus (hMPV) is a paramyxovirus and a common cause of respiratory tract infection that has been reported to modulate chemical mediators that produce inflammatory cytokines. Extra-pulmonary cardiac complications of hMPV have been reported; but literature on SICM associated with hMPV are very rare. We describe a case of a 43-year-old male with no known cardiac history diagnosed with SICM associated with hMPV. His sepsis was managed in the intensive care unit, and his heart ejection fraction improved within 10 days without the initiation of guideline-directed medical therapy.

ITGAM: A Pivotal Regulator in Macrophage Dynamics and Cardiac Function During Sepsis-Induced Cardiomyopathy.

BACKGROUND: Sepsis-induced cardiomyopathy (SIC) is a critical complication arising from sepsis characterized by reversible myocardial dysfunction. Despite the increasing attention to SIC in research, the underlying molecular mechanisms remain poorly comprehended. METHODS: In this study, we utilized bioinformatics to analyze RNA-sequencing (RNA-seq) and single-cell RNA-sequencing (scRNA-seq) data from the Gene Expression Omnibus (GEO) database to identify key immune cell populations and molecular markers associated with SIC. Our experimental approach combined in vitro and in vivo studies to investigate the roles of integrin alpha M (ITGAM) and intracellular adhesion molecule-1 (ICAM-1) in macrophage recruitment and phenotypic polarization, as well as their impact on cardiac function during SIC. RESULTS: The bioinformatics analysis disclosed significant alterations in gene expression and immune cell composition within the cardiac tissue during SIC, where macrophages emerged as the predominant immune cell type. Notably, ITGAM was identified as a key regulatory molecule that modulates macrophage function, driving the pathogenesis of SIC through its influence on the recruitment and functional reprogramming of these cells. In vitro experiments revealed that lipopolysaccharide (LPS) stimulation triggered an upregulation of ITGAM in macrophages and ICAM-1 in endothelial cells, underscoring their critical roles in immune cell mobilization and intercellular communication. The strategic administration of ITGAM-neutralizing antibodies to SIC mice resulted in a marked decrease in macrophage infiltration within the cardiac tissue, which was initially associated with an improvement in cardiac function. However, this intervention paradoxically resulted in an increased mortality rate during the later phases of SIC, underscoring the complex and dualistic function of ITGAM. CONCLUSION: This study provides new insights into the complex dynamics of immune cells within the cardiac environment during SIC, with a particular emphasis on the modulatory role of ITGAM in shaping macrophage behavior. The findings shed light on the reversible nature of myocardial dysfunction in SIC and emphasize the importance of targeted therapeutic strategies for the effective management of SIC.

Melatonin: A potential protective multifaceted force for sepsis-induced cardiomyopathy.

Sepsis is a life-threatening condition manifested by organ dysfunction caused by a dysregulated host response to infection. Lung, brain, liver, kidney, and heart are among the affected organs. Sepsis-induced cardiomyopathy is a common cause of death among septic patients. Sepsis-induced cardiomyopathy is characterized by an acute and reversible significant decline in biventricular both systolic and diastolic function. This is accompanied by left ventricular dilatation. The pathogenesis underlying sepsis-induced cardiomyopathy is multifactorial. Hence, targeting an individual pathway may not be effective in halting the extensive dysregulated immune response. Despite major advances in sepsis management strategies, no effective pharmacological strategies have been shown to treat or even reverse sepsis-induced cardiomyopathy. Melatonin, namely, N-acetyl-5-methoxytryptamine, is synthesized in the pineal gland of mammals and can also be produced in many cells and tissues. Melatonin has cardioprotective, neuroprotective, and anti-tumor activity. Several literature reviews have explored the role of melatonin in preventing sepsis-induced organ failure. Melatonin was found to act on different pathways that are involved in the pathogenesis of sepsis-induced cardiomyopathy. Through its antimicrobial, anti-inflammatory, and antioxidant activity, it offers a potential role in sepsis-induced cardiomyopathy. Its antioxidant activity is through free radical scavenging against reactive oxygen and nitrogen species and modulating the expression and activity of antioxidant enzymes. Melatonin anti-inflammatory activities control the overactive immune system and mitigate cytokine storm. Also, it mitigates mitochondrial dysfunction, a major mechanism involved in sepsis-induced cardiomyopathy, and thus controls apoptosis. Therefore, this review discusses melatonin as a promising drug for the management of sepsis-induced cardiomyopathy.

PLD2 deletion ameliorates sepsis-induced cardiomyopathy by suppressing cardiomyocyte pyroptosis via the NLRP3/caspase 1/GSDMD pathway.

OBJECTIVE: Sepsis-induced cardiomyopathy (SICM) is a life-threatening complication. Phospholipase D2 (PLD2) is crucial in mediating inflammatory reactions and is associated with the prognosis of patients with sepsis. Whether PLD2 is involved in the pathophysiology of SICM remains unknown. This study aimed to investigate the effect of PLD2 knockout on SICM and to explore potential mechanisms. METHODS: The SICM model was established using cecal ligation and puncture in wild-type and PLD2-knockout mice and lipopolysaccharide (LPS)-induced H9C2 cardiomyocytes. Transfection with PLD2-shRNA lentivirus and a PLD2 overexpression plasmid were used to interfere with PLD2 expression in H9C2 cells. Cardiac pathological alterations, cardiac function, markers of myocardial injury, and inflammatory factors were used to evaluate the SICM model. The expression of pyroptosis-related proteins (NLRP3, cleaved caspase 1, and GSDMD-N) was assessed using western blotting, immunofluorescence, and immunohistochemistry. RESULTS: SICM mice had myocardial tissue damage, increased inflammatory response, and impaired heart function, accompanied by elevated PLD2 expression. PLD2 deletion improved cardiac histological changes, mitigated cTNI production, and enhanced the survival of the SICM mice. Compared with controls, PLD2-knockdown H9C2 exhibits a decrease in inflammatory markers and lactate dehydrogenase production, and scanning electron microscopy results suggest that pyroptosis may be involved. The overexpression of PLD2 increased the expression of NLRP3 in cardiomyocytes. In addition, PLD2 deletion decreased the expression of pyroptosis-related proteins in SICM mice and LPS-induced H9C2 cells. CONCLUSION: PLD2 deletion is involved in SICM pathogenesis and is associated with the inhibition of the myocardial inflammatory response and pyroptosis through the NLRP3/caspase 1/GSDMD pathway.