Pathophysiology of sepsis-related cardiac dysfunction: driven by inflammation, energy mismanagement, or both?

Tomentosin mitigates the LPS induced cardiac injury by regulating Nrf-2/Nf-κβ pathway in mice

Endotoxemic shock is a severe complication characterized by multiple organ failure, hypotension, and impaired tissue perfusion, all contributing to high morbidity and mortality. Recent studies have highlighted the anti-inflammatory and antioxidant properties of tomentosin. This study investigates the protective effects of tomentosin against lipopolysaccharide (LPS)-induced cardiac injury and elucidates its underlying mechanisms. Mice were pre-treated with tomentosin before the LPS administration. Subsequently, cardiac injury markers, oxidative stress parameters, inflammatory mediators, and Nrf-2/NF-κB protein expression levels were analysed. The results demonstrated that tomentosin significantly reduced Troponin and CK-MB levels, alleviated oxidative stress, and suppressed inflammatory responses. Furthermore, tomentosin inhibited NF-κB activation while enhancing Nrf-2 expression. In conclusion, our findings suggest that tomentosin exerts cardioprotective effects by modulating the Nrf-2/NF-κB pathway, positioning it as a potential therapeutic candidate for preventing LPS-induced cardiac dysfunction.

Interaction between post-tumor inflammation and vascular smooth muscle cell dysfunction in sepsis-induced cardiomyopathy

Background

Sepsis-induced cardiomyopathy (SIC) presents a critical complication in cancer patients, contributing notably to heart failure and elevated mortality rates. While its clinical relevance is well-documented, the intricate molecular mechanisms that link sepsis, tumor-driven inflammation, and cardiac dysfunction remain inadequately explored. This study aims to elucidate the interaction between post-tumor inflammation, intratumor heterogeneity, and the dysfunction of VSMC in SIC, as well as to evaluate the therapeutic potential of exercise training and specific pharmacological interventions.

Methods

Transcriptomic data from NCBI and GEO databases were analyzed to identify differentially expressed genes (DEGs) associated with SIC. Weighted gene co-expression network analysis (WGCNA), gene ontology (GO), and KEGG pathway enrichment analyses were utilized to elucidate the biological significance of these genes. Molecular docking and dynamics simulations were used to investigate drug-target interactions, and immune infiltration and gene mutation analyses were carried out by means of platforms like TIMER 2.0 and DepMap to comprehend the influence of DVL1 on immune responsiveness.

Results

Through the utilization of the datasets, we discovered the core gene DVL1 that exhibited remarkable up-regulated expression both in SIC and in diverse kinds of cancers, which were associated with poor prognosis and inflammatory responses. Molecular docking revealed that Digoxin could bind to DVL1 and reduce oxidative stress in SIC. The DVL1 gene module related to SIC was identified by means of WGCNA, and the immune infiltration analysis demonstrated the distinctive immune cell patterns associated with DVL1 expression and the impact of DVL1 on immunotherapeutic resistance.

Conclusions

DVL1 is a core regulator of SIC and other cancers and, therefore, can serve as a therapeutic target. The present study suggests that targeted pharmacological therapies to enhance response to exercise regimens may be a novel therapeutic tool to reduce the inflammatory response during sepsis, particularly in cancer patients. The identified drugs, Digoxin, require further in vivo and clinical studies to confirm their effects on SIC and their potential efforts to improve outcomes in immunotherapy-resistant cancer patients.

Cardiopulmonary Physiology of Hypoxemic Respiratory Failure Among Preterm Infants with Septic Shock

OBJECTIVE

To examine cardiopulmonary physiological alterations associated with hypoxemic respiratory failure (HRF; fraction of inspired oxygen ≥0.60) among preterm neonates requiring vasopressors/inotropes during sepsis (septic shock).

STUDY DESIGN

We conducted a retrospective cohort study from 2015 through 2022 at a tertiary neonatal intensive care unit. Neonates <34 weeks gestational age who had septic shock and underwent a comprehensive targeted neonatal echocardiography (TNE) ≤72 hours of sepsis onset were included. TNE findings of patients with shock and HRF were compared with those with shock without HRF. Indices of pulmonary vascular resistance (PVR), right ventricular (RV) and left ventricular (LV) systolic and diastolic function, measured using conventional, tissue Doppler imaging and speckle-tracking echocardiography, were examined.

RESULTS

Of 52 included infants with septic shock, 19 (37%) also had HRF. Baseline characteristics were similar. On TNE, although the HRF group more frequently had bidirectional/right-to-left flow across the patent ductus arteriosus (67% vs 33%; P = .08), all indices of PVR and RV function were similar. However, the HRF group demonstrated reduced LV systolic function (ejection fraction, 51.8% ± 12.3% vs 62.6% ± 13.0%; global peak systolic longitudinal strain -15.2% ± 4.5% vs -18.6% ± 4.5%), diastolic function (early [2.3 ± 1.0/s vs 3.6 ± 1.2/s]) and late (2.4/s [IQR, 1.9-2.6/s] vs 2.8/s [2.3-3.5/s] diastolic strain rate), and higher frequency of LV output <150 mL/min/kg (44% vs 12%) (all P < .05).

CONCLUSIONS

Acute HRF occurring in preterm neonates with septic shock is associated with alterations in TNE measures of LV function, and not PVR or RV function. Future studies should evaluate the impact of supporting LV function in these patients.

MicroRNAs as regulators of cardiac dysfunction in sepsis: pathogenesis and diagnostic potential

Introduction

Sepsis, a life-threatening condition arising from an uncontrolled immune response to infection, can lead to organ dysfunction, with severe inflammation potentially causing multiple organ failures. Sepsis-induced cardiac dysfunction (SIMD) is a common and severe complication of sepsis, significantly increasing patient mortality. Understanding the pathogenesis of SIMD is crucial for improving treatment, and microRNAs (miRNAs) have emerged as important regulators in this process.

Methods

A comprehensive literature search was conducted in PubMed, Science Direct, and Embase databases up to September 2024. The search terms included ["miRNA" or "microRNA"] and ["Cardiac" or "Heart"] and ["Sepsis" or "Septic"], with the language limited to English. After initial filtering by the database search engine, Excel software was used to further screen references. Duplicate articles, those without abstracts or full texts, and review/meta-analyses or non-English articles were excluded. Finally, 106 relevant research articles were included for data extraction and analysis.

Results

The pathogenesis of SIMD is complex and involves mitochondrial dysfunction, oxidative stress, cardiomyocyte apoptosis and pyroptosis, dysregulation of myocardial calcium homeostasis, myocardial inhibitory factors, autonomic nervous regulation disorders, hemodynamic changes, and myocardial structural alterations. miRNAs play diverse roles in SIMD. They are involved in regulating the above-mentioned pathological processes.

Discussion

Although significant progress has been made in understanding the role of miRNAs in SIMD, there are still challenges. Some studies on the pathogenesis of SIMD have limitations such as small sample sizes and failure to account for confounding factors. Research on miRNAs also faces issues like inconsistent measurement techniques and unclear miRNA-target gene relationships. Moreover, the translation of miRNA-based research into clinical applications is hindered by problems related to miRNA stability, delivery mechanisms, off-target effects, and long-term safety. In conclusion, miRNAs play a significant role in the pathogenesis of SIMD and have potential as diagnostic biomarkers. Further research is needed to overcome existing challenges and fully exploit the potential of miRNAs in the diagnosis and treatment of SIMD.

Septic cardiomyopathy or myocardial infarction?: A case report of septic shock with ST-segment elevation on ECG

RATIONALE

Sepsis is one of the most prevalent and deadly diseases today. Sepsis involving the heart can progress to septic cardiomyopathy; however, there is a lack of uniform diagnostic criteria. A review of the literature reveals a paucity of literature on sepsis combined with acute myocardial infarction (AMI) and no reports on emergency surgical treatment.

PATIENTS CONCERNS

A 52-year-old patient with trauma-induced sepsis leading to acute heart failure with elevated ST-segment on electrocardiogram and postoperative coronary angiography suggestive of AMI.

DIAGNOSES

Small bowel rupture, infectious shock, AMI, hypertensive disease, old cerebral infarction.

INTERVENTIONS

The patient was admitted to the hospital and immediately underwent emergency surgery to remove the infected focus, with treatment with meropenem for anti-infection, ambroxol for sputum, parenteral nutritional support, sedation and analgesia, esmolol to control the ventricular rate, uradil to control blood pressure, and transfusion of red blood cells and plasma for correction of anemia and coagulation functions. Coronary angiography was performed 6 months later.

OUTCOMES

The patient was discharged after showing signs of improvement and was subsequently monitored in an outpatient clinic setting. At the time of writing, the patient is still alive and well.

LESSONS

In cases of acute heart failure resulting from trauma-induced sepsis, it is crucial to consider myocardial ischemia as a potential factor. Early surgical removal of infected foci may prove beneficial in improving the patient's prognosis. However, differentiating between septic cardiomyopathy and sepsis-combined myocardial infarction can be challenging, and the appropriateness of the diagnostic criteria for sepsis at this stage is debatable.

Fermented Houttuynia cordata Juice Exerts Cardioprotective Effects by Alleviating Cardiac Inflammation and Apoptosis in Rats with Lipopolysaccharide-Induced Sepsis

BACKGROUND/OBJECTIVES

Sepsis-induced cardiac dysfunction is a major problem that often leads to severe complications and a poor prognosis. Despite the growing awareness of its impact, effective treatment options for sepsis-induced cardiac dysfunction remain limited. To date, fermented products of Houttuynia cordata (HC), known for its rich bioactive properties, have shown potential in modulating inflammatory and oxidative stress pathways. However, treatment with fermented HC juice (FHJ) in lipopolysaccharide (LPS)-induced sepsis in rats has not been investigated.

METHODS

Rats were pretreated with FHJ at doses of 200 mg/kg and 400 mg/kg for 2 weeks. After that, the rats were injected with a single dose of LPS (10 mg/kg), and 12 h after injection, they developed sepsis-induced cardiac dysfunction. Then, cardiac function, oxidative stress, inflammation, apoptosis, and cardiac injury markers were determined.

RESULTS

Pretreatment with FHJ at doses of 200 mg/kg and 400 mg/kg prevented LPS-induced cardiac dysfunction in rats by attenuating cardiac inflammation (IL-1β, TLR-4, and NF-κB levels), oxidative stress (MDA levels), and apoptosis (cleaved-caspase 3 and Bax/Bcl-2 expression) and reducing markers of cardiac injury (LDH and CK-MB levels).

CONCLUSIONS

These results suggest that FHJ could be a potential therapeutic agent for sepsis-induced heart disease.

Dexmedetomidine therapy promotes cardiac dysfunction and increases mortality in sepsis: A translational study

Previous studies demonstrated that dexmedetomidine (Dex) posttreatment aggravated myocardial dysfunction and reduced survival in septic mice. Yet, whether Dex elicits similar effects in septic patients as defined by Sepsis-3 remains unknown. This study sought to assess the effects of Dex-based sedation on mortality and cardiac dysfunction in septic patients defined by Sepsis-3 and to further reveal the mechanisms in septic rats. In the retrospective cohort study, patients were categorised into sepsis with Dex, other sedatives (propofol or midazolam) or without sedatives, mortality at 28 days were compared, and patients with measurements of cardiovascular biomarkers and echocardiography were used to examine the effect of Dex on cardiac dysfunction. Septic rats and Langendorff-perfused isolated rat hearts were used, cardiac function, mortality and pro-inflammatory mediators were analyzed. The all-cause mortality of septic patients receiving Dex reached to 35.2 % on Day 28, significantly higher than that of patients with other sedatives (16.1 %), while no difference with group of no sedatives (27.3 %). Patients in Dex group showed lower left ventricular EF and lateral mitral annular early diastolic peak velocities, but higher interventricular septum diastolic dimension compared to those with other sedatives. The plasma levels of H-FABP, NT-proBNP and HMGB1 in Dex and other sedative groups showed no difference, while both were significantly lower than the group of no sedative. Notably, Dex posttreatment deteriorated cardiac dysfunction, increasing mortality in septic rats with enhanced systemic and myocardial proinflammatory mediators, including TNF-α, IL-1β, IL-6 and VCAM-1. Mechanistical study by Langendorff-perfusion revealed that Dex directly acted on the heart, aggravating LPS-induced myocardial inflammation and dysfunction. These results suggest that Dex increases mortality and deteriorates myocardial dysfunction compared with other sedatives in septic patients defined by Sepsis 3.0, maybe partly through promoting proinflammatory response via directly acting on the heart.

A murine model of acute and prolonged abdominal sepsis, supported by intensive care, reveals time-dependent metabolic alterations in the heart

BACKGROUND

Sepsis-induced cardiomyopathy (SICM) often occurs in the acute phase of sepsis and is associated with increased mortality due to cardiac dysfunction. The pathogenesis remains poorly understood, and no specific treatments are available. Although SICM is considered reversible, emerging evidence suggests potential long-term sequelae. We hypothesized that metabolic and inflammatory cardiac changes, previously observed in acute sepsis as potential drivers of SICM, partially persist in prolonged sepsis.

METHODS

In 24-week-old C57BL/6J mice, sepsis was induced by cecal ligation and puncture, followed by intravenous fluid resuscitation, subcutaneous analgesics and antibiotics, and, in the prolonged phase, by parenteral nutrition. Mice were killed after 5 days of sepsis (prolonged sepsis, n = 15). For comparison, we included acutely septic mice killed at 30 h (acute sepsis, n = 15) and healthy controls animals (HC, n = 15). Cardiac tissue was collected for assessment of inflammatory and metabolic markers through gene expression, metabolomic analysis and histological assessment.

RESULTS

In prolonged sepsis, cardiac expression of IL-1β and IL-6 and macrophage infiltration remained upregulated (p ≤ 0.05). In contrast, tissue levels of Krebs cycle intermediates and adenosine phosphates were normal, whereas NADPH levels were low in prolonged sepsis (p ≤ 0.05). Gene expression of fatty acid transporters and of the glucose transporter Slc2a1 was upregulated in prolonged sepsis (p ≤ 0.01). Lipid staining and glycogen content were elevated in prolonged sepsis together with increased gene expression of enzymes responsible for lipogenesis and glycogen synthesis (p ≤ 0.05). Intermediate glycolytic metabolites (hexose-phosphates, GADP, DHAP) were elevated (p ≤ 0.05), but gene expression of several enzymes for glycolysis and mitochondrial oxidation of pyruvate, fatty-acyl-CoA and ketone bodies to acetyl-CoA were suppressed in prolonged sepsis (p ≤ 0.05). Key metabolic transcription factors PPARα and PGC-1α were downregulated in acute, but upregulated in prolonged, sepsis (p ≤ 0.05 for both). Ketone body concentrations were normal but ketolytic enzymes remained suppressed (p ≤ 0.05). Amino acid metabolism showed mild, mixed changes.

CONCLUSIONS

Our results suggest myocardial lipid and glycogen accumulation and suppressed mitochondrial oxidation, with a functionally intact Krebs cycle, in the prolonged phase of sepsis, together with ongoing myocardial inflammation. Whether these alterations have functional consequences and predispose to long-term sequelae of SICM needs further research.

Potential cardioprotective effect of trimetazidine in mice model of endotoxemia: role of AMPK-Nrf2

OBJECTIVE

Aim: To clarify the potential cardioprotective effect of Trimetazidine against experimentally sepsis-caused endotoxic cardiac injury damage in mice.

PATIENTS AND METHODS

Materials and Methods: 24 Mice were divided into four groups (n=6): Sham group, CLP group DMSO group, trimetazidine-treated group 50 mg/kg IP, 1hr before CLP, then the animals were sacrificed 24 hr after CLP and tissue sample was taken for measurement of TNF-α, TNF-αr1, IL-1β, HO-1, MPO, caspase-11, F2-isoprostane and serum troponin by ELISA and gene expression of AMPK-Nrf2 by qpcr and histopathological study.

RESULTS

Results: trimetazidine treated group showed significant changes as compared with clp group regarding TNF-α, TNF-αr1, IL-1β, HO-1, MPO, CASPASE-11, F2-ISOPROSTANE as well as affect tissue mRNA expression of AMPK-Nrf2 genes p<0.05.

CONCLUSION

Conclusions: We evaluate that Trimetazidine has cardio protective effects due to its anti-inflammatory and anti-oxidative action. Also, trimetazidine showed a cardio-protective effect as they affect tissue mRNA expression of AMPK-Nrf2 genes.

Immunopharmacological Insights into Cordyceps spp.: Harnessing Therapeutic Potential for Sepsis

Cordyceps spp. (CS), a well-known medicinal mushroom that belongs to Tibetan medicine and is predominantly found in the high altitudes in the Himalayas. CS is a rich reservoir of various bioactive substances including nucleosides, sterols flavonoids, peptides, and phenolic compounds. The bioactive compounds and CS extract have antibacterial, antioxidant, immunomodulatory, and inflammatory properties in addition to organ protection properties across a range of disease states. The study aimed to review the potential of CS, a medicinal mushroom, as a treatment for sepsis. While current sepsis drugs have side effects, CS shows promise due to its anti-inflammatory, antioxidant, and antibacterial properties. We have performed an extensive literature search based on published original and review articles in Scopus and PubMed. The keywords used were Cordyceps, sepsis, and inflammation. Studies indicate that CS extract and bioactive compounds target free radicals including oxidative as well as nitrosative stress, lower inflammation, and modulate the immune system, all of which are critical components in sepsis. The brain, liver, kidneys, lungs, and heart are among the organs that CS extracts may be able to shield against harm during sepsis. Traditional remedies with anti-inflammatory and protective qualities, such as Cordyceps mushrooms, are promising in sepsis. However, more research including clinical trials is required to validate the usefulness of CS metabolites in terms of organ protection and fight infections in sepsis.

Cardiovascular effects of Roflumilast during sepsis: Risks or benefits?

BACKGROUND

Phosphodiesterase-4 (PDE4) is responsible for terminating cyclic adenosine monophosphate (cAMP) signalling. PDE4 inhibitors, such as roflumilast (RFM), have anti-inflammatory activity and have been studied in inflammation-induced tissue damage in sepsis. However, the role of RFM on cardiovascular derangements induced by sepsis is still unknown. Thus, we aimed to evaluate the potential effects of RFM on cardiovascular collapse and multiorgan damage caused by sepsis.

METHODS

Sepsis was induced by cecal ligation and puncture (CLP) in male rats. Six hours after the CLP or sham procedure, animals were randomly assigned to receive either RFM (0.3 mg/kg) or vehicle subcutaneously, and cardiovascular parameters were assessed 24 h after the surgery and organ/plasma samples were collected for further analyses.

RESULTS

Sepsis induced hypotension, tachycardia, reduced renal blood flow (RBF) and hyporeactivity to vasoconstrictors both in vivo and ex vivo. RFM treatment increased systemic cAMP levels and RBF. RFM also attenuated hypoperfusion and liver damage induced by CLP. Furthermore, RFM reduced systemic nitric oxide (NO) levels in septic rats, while there were no changes in hepatic NOS-2 expression. Nevertheless, RFM exacerbated sepsis-induced hypotension and tachycardia without ameliorating vascular hyporeactivity.

CONCLUSION

Our data show that PDE-4 inhibition protects septic rats from hepatic injury and improves renal perfusion. However, RFM worsened hemodynamic parameters and showed no protection against sepsis-induced cardiovascular dysfunction and mortality. Thus, despite the anti-inflammatory benefits of RFM, its application in sepsis should be approached cautiously.

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.

Complex Management of Respiratory Failure, Atrial Fibrillation, Ventricular Tachycardia, and Stenotrophomonas maltophilia in a Patient Following Osteomyelitis Amputation: A Case of Multisystem Complications Occurring Postoperatively

Stenotrophomonas maltophilia is an opportunistic, multidrug-resistant gram-negative bacterium often affecting patients with significant comorbidities. This case report examines the hospital course of a 75-year-old male with a history of atrial fibrillation and heart failure with preserved ejection fraction (HFpEF), who presented with compromised respiratory status and recurrent infections, highlighting the complexities of clinical management in the setting of multidrug-resistant HFpEF organisms and postoperative complications. The patient was admitted following an episode of ventricular tachycardia and acute respiratory failure, requiring rapid airway management and intensive clinical intervention. His recent hospitalization for sepsis, pneumonia, and osteomyelitis complicated his clinical profile, particularly given his recurrent urinary tract infections (UTIs), which prevented the use of sodium-glucose cotransporter-2 inhibitor therapy for heart failure management. Respiratory cultures confirmed the presence of S. maltophilia, prompting treatment with minocycline and piperacillin-tazobactam. This case highlights the significant risks associated with postoperative arrhythmias in patients with underlying cardiac disease, particularly when superimposed with sepsis. Furthermore, the management of recurrent UTIs posed a barrier to optimizing heart failure therapy, further complicating the patient's clinical stability. The need for vigilant monitoring and tailored therapeutic strategies is essential to improve outcomes in this vulnerable patient population. The interplay between multidrug-resistant infections, arrhythmias, and comorbidities emphasizes the importance of comprehensive clinical management and the need for further research to develop targeted therapies and clinical plans for at-risk populations.

Acute exposure to LPS induces cardiac dysfunction via the activation of the NLRP3 inflammasome

Systemic inflammation contributes to left ventricular (LV) dysfunction, however the role of the NLRP3 inflammasome in LV dysfunction in acute inflammatory conditions is unclear. This study investigated the role of the NLRP3 inflammasome in acute (24 h) cardiac structural and functional changes in vivo and in vitro in lipopolysaccharide (LPS)-induced inflammation. LPS-treated Sprague-Dawley (SD) rats showed increased LPS metabolite abundance in their LVs as measured by atmospheric pressure matrix-assisted laser desorption ionisation (AP-MALDI) mass spectrometry imaging (MSI). Echocardiography and histology showed that in LPS-exposed rats, LV internal diameter was decreased, with evidence of macrophage infiltration and oedema. However, there were no changes in LV wall thickness or collagen volume. Additionally, LPS-exposed rats exhibited impaired LV relaxation, potentially contributing to decreased stroke volume. While global systolic function was preserved, LPS exposure in SD rats resulted in impaired myocardial deformation assessed by speckle-tracking echocardiography. Exposure to LPS resulted in upregulation of the expression of components of the NLRP3 inflammasome in rodents. In vitro LPS exposure resulted in increased gene expression of NLRP3 and downstream cytokines IL-1β and IL-18, antioxidant SOD2, and elevated markers of pyroptosis (GSDMD) which were inhibited by treatment with a NLRP3 antagonist. However, LPS-induced increases in the gene expression of apoptosic markers (BAX/Bcl2) were not impacted by NLRP3 antagonism. These findings suggest that inflammation induced adverse cardiac structural and functional changes is, at least in part, mediated by the NLRP3 inflammasome in acute, high-grade inflammatory states. In addition, in vitro findings suggest that while the NLRP3 inflammasome mediates pyroptotic pathways, regulation of apoptosis that is independent of the inflammasome.

Minocycline alleviates lipopolysaccharide-induced cardiotoxicity by suppressing the NLRP3/Caspase-1 signaling pathway

Minocycline (Min), as an antibiotic, possesses various beneficial properties such as anti-inflammatory, antioxidant, and anti-apoptotic effects. Despite these known qualities, the precise cardioprotective effect and mechanism of Min in protecting against sepsis-induced cardiotoxicity (SIC) remain unspecified. To address this, our study sought to assess the protective effects of Min on the heart. Lipopolysaccharide (LPS) was utilized to establish a cardiotoxicity model both in vivo and in vitro. Min was pretreated in the models. In the in vivo setting, evaluation of heart tissue histopathological injury was performed using hematoxylin and eosin (H&E) staining and TUNEL. Immunohistochemistry (IHC) was employed to evaluate the expression levels of NLRP3 and Caspase-1 in the heart tissue of mice. During in vitro experiments, the viability of H9c2 cells was gauged utilizing the CCK8 assay kit. Intracellular ROS levels in H9c2 cells were quantified using a ROS assay kit. Both in vitro and in vivo settings were subjected to measurement of oxidative stress indexes, encompassing glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD) levels. Additionglly, myocardial injury markers like lactate dehydrogenase (LDH) and creatine kinase MB (CK-MB) activity were quantified using appropriate assay kits. Western blotting (WB) analysis was conducted to detect the expression levels of NOD-like receptor protein-3 (NLRP3), caspase-1, IL-18, and IL-1β, alongside apoptosis-related proteins such as Bcl-2 and Bax, and antioxidant proteins including superoxide dismutase-1 (SOD-1) and antioxidant proteins including superoxide dismutase-1 (SOD-2), both in H9c2 cells and mouse heart tissues. In vivo, Min was effective in reducing LPS-induced inflammation in cardiac tissue, preventing cell damage and apoptosis in cardiomyocytes. The levels of LDH and CK-MB were significantly reduced with Min treatment. In vitro studies showed that Min improved the viability of H9C2 cells, reduced apoptosis, and decreased ROS levels in these cells. Further analysis indicated that Min decreased the protein levels of NLRP3, Caspase-1, IL-18, and IL-1β, while increasing the levels of SOD-1 and SOD-2 both in vivo and in vitro. Min alleviates LPS-induced SIC by suppressing the NLRP3/Caspase-1 signalling pathway in vivo and in vitro.

Oxycodone attenuates lipopolysaccharide-induced myocardial injury by inhibiting inflammation, oxidation and pyroptosis via Nrf2/HO-1 signalling pathway

Myocardial injury and cardiovascular dysfunction are the most common complications of sepsis, and effective therapeutic candidate is still lacking. This study aims to investigate the protective effect of oxycodone in myocardial injury of lipopolysaccharide-induced sepsis and its related signalling pathways. Wild-type and nuclear factor erythroid 2-related factor 2 (Nrf2)-knockout mice, as well as H9c2 cardiomyocytes cultures treated with lipopolysaccharide (LPS) were used as models of septic myocardial injury. H9c2 cardiomyocytes culture showed that oxycodone protected cells from pyroptosis induced by LPS. Mice model confirmed that oxycodone pretreatment significantly attenuated myocardial pathological damage and improved cardiac function demonstrated by increased ejection fraction (EF) and fractional shortening (FS), as well as decreased cardiac troponin I (cTnI) and creatine kinase isoenzymes MB (CK-MB). Oxycodone also reduced the levels of inflammatory factors and oxidative stress damage induced by LPS, which involves pyroptosis-related proteins including: Nod-like receptor protein 3 (NLRP3), Caspase 1, Apoptosis-associated speck-like protein contain a CARD (ASC), and Gasdermin D (GSDMD). These changes were mediated by Nrf2 and heme oxygenase-1 (HO-1) because Nrf2-knockout mice or Nrf2 knockdown in H9c2 cells significantly reversed the beneficial effect of oxycodone on oxidative stress, inflammatory responses and NLRP3-mediated pyroptosis. Our findings yielded that oxycodone therapy reduces LPS-induced myocardial injury by suppressing NLRP3-mediated pyroptosis via the Nrf2/HO-1 signalling pathway in vivo and in vitro.

Apelin-13 administration allows for norepinephrine sparing in a rat model of cecal ligation and puncture-induced septic shock

BACKGROUND

Infusion of exogenous catecholamines (i.e., norepinephrine [NE] and dobutamine) is a recommended treatment for septic shock with myocardial dysfunction. However, sustained catecholamine infusion is linked to cardiac toxicity and impaired responsiveness. Several pre-clinical and clinical studies have investigated the use of alternative vasopressors in the treatment of septic shock, with limited benefits and generally no effect on mortality. Apelin-13 (APL-13) is an endogenous positive inotrope and vasoactive peptide and has been demonstrated cardioprotective with vasomodulator and sparing life effects in animal models of septic shock. A primary objective of this study was to evaluate the NE-sparing effect of APL-13 infusion in an experimental sepsis-induced hypotension.

METHODS

For this goal, sepsis was induced by cecal ligation and puncture (CLP) in male rats and the arterial blood pressure (BP) monitored continuously via a carotid catheter. Monitoring, fluid resuscitation and experimental treatments were performed on conscious animals. Based on pilot assays, normal saline fluid resuscitation (2.5 mL/Kg/h) was initiated 3 h post-CLP and maintained up to the endpoint. Thus, titrated doses of NE, with or without fixed-doses of APL-13 or the apelin receptor antagonist F13A co-infusion were started when 20% decrease of systolic BP (SBP) from baseline was achieved, to restore SBP values ≥ 115 ± 1.5 mmHg (baseline average ± SEM).

RESULTS

A reduction in mean NE dose was observed with APL-13 but not F13A co-infusion at pre-determined treatment time of 4.5 ± 0.5 h (17.37 ± 1.74 µg/Kg/h [APL-13] vs. 25.64 ± 2.61 µg/Kg/h [Control NE] vs. 28.60 ± 4.79 µg/Kg/min [F13A], P = 0.0491). A 60% decrease in NE infusion rate over time was observed with APL-13 co-infusion, (p = 0.008 vs NE alone), while F13A co-infusion increased the NE infusion rate over time by 218% (p = 0.003 vs NE + APL-13). Associated improvements in cardiac function are likely mediated by (i) enhanced left ventricular end-diastolic volume (0.18 ± 0.02 mL [Control NE] vs. 0.30 ± 0.03 mL [APL-13], P = 0.0051), stroke volume (0.11 ± 0.01 mL [Control NE] vs. 0.21 ± 0.01 mL [APL-13], P < 0.001) and cardiac output (67.57 ± 8.63 mL/min [Control NE] vs. 112.20 ± 8.53 mL/min [APL-13], P = 0.0036), and (ii) a reduced effective arterial elastance (920.6 ± 81.4 mmHg/mL/min [Control NE] vs. 497.633.44 mmHg/mL/min. [APL-13], P = 0.0002). APL-13 administration was also associated with a decrease in lactate levels compared to animals only receiving NE (7.08 ± 0.40 [Control NE] vs. 4.78 ± 0.60 [APL-13], P < 0.01).

CONCLUSION

APL-13 exhibits NE-sparing benefits in the treatment of sepsis-induced shock, potentially reducing deleterious effects of prolonged exogenous catecholamine administration.

Estradiol contributes to sex differences in resilience to sepsis-induced metabolic dysregulation and dysfunction in the heart via GPER-1-mediated PPARδ/NLRP3 signaling

BACKGROUND AND AIM

Clinically, septic males tend to have higher mortality rates, but it is unclear if this is due to sex differences in cardiac dysfunction, possibly influenced by hormonal variations. Cardiac dysfunction significantly contributes to sepsis-related mortality, primarily influenced by metabolic imbalances. Peroxisome proliferator-activated receptor delta (PPARδ) is a key player in cardiac metabolism and its activation has been demonstrated to favor sepsis outcomes. While estradiol (E2) is abundant and beneficial in females, its impact on PPARδ-mediated metabolism in the heart with regards to sex during sepsis remains unknown.

METHODS AND RESULTS

Here, we unveil that while sepsis diminishes PPARδ nuclear translocation and induces metabolic dysregulation, oxidative stress, apoptosis and dysfunction in the heart thereby enhancing mortality, these effects are notably more pronounced in males than females. Mechanistic experiments employing ovariectomized(OVX) mice, E2 administration, and G protein-coupled estrogen receptor 1(GPER-1) knockout (KO) mice revealed that under lipopolysaccharide (LPS)-induced sepsis, E2 acting via GPER-1 enhances cardiac electrical activity and function, promotes PPARδ nuclear translocation, and subsequently ameliorates cardiac metabolism while mitigating oxidative stress and apoptosis in females. Furthermore, PPARδ specific activation using GW501516 in female GPER-1-/- mice reduced oxidative stress, ultimately decreasing NLRP3 expression in the heart. Remarkably, targeted GPER-1 activation using G1 in males mirrors these benefits, improving cardiac electrical activity and function, and ultimately enhancing survival rates during LPS challenge. By employing NLRP3 KO mice, we demonstrated that the targeted GPER-1 activation mitigated injury, enhanced metabolism, and reduced apoptosis in the heart of male mice via the downregulation of NLRP3.

CONCLUSION

Our findings collectively illuminate the sex-specific cardiac mechanisms influencing sepsis mortality, offering insights into physiological and pathological dimensions. From a pharmacological standpoint, this study introduces specific GPER-1 activation as a promising therapeutic intervention for males under septic conditions. These discoveries advance our understanding of the sex differences in sepsis-induced cardiac dysfunction and also present a novel avenue for targeted interventions with potential translational impact.

GSDMD in regulated cell death: A novel therapeutic target for sepsis

Sepsis is a life-threatening multi-organ dysfunction syndrome caused by an abnormal host response to infection. Regulated cell death is essential for maintaining tissue homeostasis and eliminating damaged, infected, or aging cells in multicellular organisms. Gasdermin D, as a member of the gasdermin family, plays a crucial role in the formation of cytoplasmic membrane pores. Research has found that GSDMD plays important roles in various forms of regulated cell death such as pyroptosis, NETosis, and necroptosis. Therefore, through mediating regulated cell death, GSDMD regulates different stages of disease pathophysiology. This article mainly summarizes the concept of GSDMD, its role in regulated cell death, its involvement in organ damage associated with sepsis-related injuries mediated by regulated cell death via GSDMD activation and introduces potential drugs targeting GSDMD that may provide more effective treatment options for sepsis patients through drug modification.

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.

The concomitant use of ultra short beta-blockers with vasopressors and inotropes in critically ill patients with septic shock: A systematic review and meta-analysis of randomized controlled trials

Background

Septic shock is associated with systemic inflammatory response, hemodynamic instability, impaired sympathetic control, and the development of multiorgan dysfunction that requires vasopressor or inotropic support. The regulation of immune function in sepsis is complex and varies over time. However, activating Beta-2 receptors and blocking Beta-1 receptors reduces the proinflammatory response by influencing cytokine production. Evidence that supports the concomitant use of ultra short beta-blockers with inotropes and vasopressors in patients with septic shock is still limited. This study aimed to evaluate the use of ultra short beta-blockers and its impact on the ICU related outcomes such as mortality, length of stay, heart rate control, shock resolution, and vasopressors/inotropes requirements.

Methods

A systematic review and meta-analysis of randomized controlled trials including critically ill patients with septic shock who received inotropes and vasopressors. Patients who received either epinephrine or norepinephrine without beta-blockers "control group" were compared to patients who received ultra short beta-blockers concomitantly with either epinephrine or norepinephrine "Intervention group". MEDLINE and Embase databases were utilized to systematically search for studies investigating the use of ultra short beta-blockers in critically ill patients on either epinephrine or norepinephrine from inception to October 10, 2023. The primary outcome was the 28-day mortality. While, length of stay, heart rate control, and inotropes/ vasopressors requirements were considered secondary outcomes.

Results

Among 47 potentially relevant studies, nine were included in the analysis. The 28-day mortality risk was lower in patients with septic shock who used ultra short beta-blockers concomitantly with either epinephrine or norepinephrine compared with the control group (RR (95%CI): 0.69 (0.53, 0.89), I2=26%; P=0.24). In addition, heart rate was statistically significantly lower with a standardized mean difference (SMD) of -22.39 (95% CI: -24.71, -20.06) among the beta-blockers group than the control group. The SMD for hospital length of stay and the inotropes requirement were not statistically different between the two groups (SMD (95%CI): -0.57 (-2.77, 1.64), and SMD (95%CI): 0.08 (-0.02, 0.19), respectively).

Conclusion

The use of ultra short beta-blockers concomitantly with either epinephrine or norepinephrine in critically ill patients with septic shock was associated with better heart rate control and survival benefits without increment in the inotropes and vasopressors requirement.

Nicorandil Regulates Ferroptosis and Mitigates Septic Cardiomyopathy via TLR4/SLC7A11 Signaling Pathway

This study mainly explored the role of nicorandil in regulating ferroptosis and alleviating septic cardiomyopathy through toll-like receptor (TLR) 4/solute carrier family 7 member 11 (SLC7A11) signaling pathway. Twenty-four male SD rats were randomly divided into control, Nic (nicorandil), LPS (lipopolysaccharide), and LPS + Nic groups and given echocardiography. A detection kit was applied to measure the levels of lactic dehydrogenase (LDH), cardiac troponin I (cTnI), and creatine kinase-MB (CK-MB); HE staining and the levels of glutathione (GSH), malondialdehyde (MDA), total iron, and Fe2+ of myocardial tissues were detected. Moreover, the expression of TLR4 and SLC7A11 were measured by qRT-PCR and the proteins regulating ferroptosis (TLR4, SLC7A11, GPX4, ACSL4, DMT1, Fpn, and TfR1) were checked by western blot. Myocardial cells (H9C2) were induced with lipopolysaccharide (LPS) and transfected with si-TLR4 or SLC7A11-OE. Then, the viability, ferroptosis, and TLR4/SLC7A11 signaling pathway of cells were examined. Nicorandil could significantly increase left ventricular (LV) ejection fraction (LVEF) while reduce LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV). Also, it greatly reduced the levels of LDH, cTnI, and CK-MB; alleviated the pathological changes of myocardial injury; notably decreased MDA, total iron, and Fe2+ levels in myocardial tissues; and significantly increased GSH level. Besides, nicorandil obviously raised protein levels of GPX4, Fpn, and SLC7A11, and decreased protein levels of ACSL4, DMT1, TfR1, and TLR4. After knockdown of TLR4 or overexpression of SLC7A11, the inhibition effect of nicorandil on ferroptosis was strengthened in LPS-induced H9C2 cells. Therefore, nicorandil may regulate ferroptosis through TLR4/SLC7A11 signaling, thereby alleviating septic cardiomyopathy.

Herpes virus entry mediator signaling blockade produces mortality in neonatal sepsis through induced cardiac dysfunction

Introduction

Sepsis remains a major source of morbidity and mortality in neonates, and characterization of immune regulation in the neonatal septic response remains limited. HVEM is a checkpoint regulator which can both stimulate or inhibit immune responses and demonstrates altered expression after sepsis. We hypothesized that signaling via HVEM would be essential for the neonatal response to sepsis, and that therefore blockade of this pathway would improve survival to septic challenge.

Methods

To explore this, neonatal mice were treated with cecal slurry (CS), CS with Anti-HVEM antibody (CS-Ab) or CS with isotype (CS-IT) and followed for 7-day survival. Mice from all treatment groups had thymus, lung, kidney and peritoneal fluid harvested, weighed, and stained for histologic evaluation, and changes in cardiac function were assessed with echocardiography.

Results

Mortality was significantly higher for CS-Ab mice (72.2%) than for CS-IT mice (22.2%). CS resulted in dysregulated alveolar remodeling, but CS-Ab lungs demonstrated significantly less dysfunctional alveolar remodeling than CS alone (MCL 121.0 CS vs. 87.6 CS-Ab), as well as increased renal tubular vacuolization. No morphologic differences in alveolar septation or thymic karyorrhexis were found between CS-Ab and CS-IT. CS-Ab pups exhibited a marked decrease in heart rate (390.3 Sh vs. 342.1 CS-Ab), stroke volume (13.08 CS-IT vs. 8.83 CS-Ab) and ultimately cardiac output (4.90 Sh vs. 3.02 CS-Ab) as well as a significant increase in ejection fraction (73.74 Sh vs. 83.75 CS-Ab) and cardiac strain (40.74 Sh vs. 51.16 CS-Ab) as compared to CS-IT or Sham animals.

Discussion

While receptor ligation of aspects of HVEM signaling, via antibody blockade, appears to mitigate aspects of lung injury and thymic involution, stimulatory signaling via HVEM still seems to be necessary for vascular and hemodynamic resilience and overall neonatal mouse survival in response to this experimental polymicrobial septic insult. This dissonance in the activity of anti-HVEM neutralizing antibody in neonatal animals speaks to the differences in how septic cardiac dysfunction should be considered and approached in the neonatal population.

Current Perspectives of Mitochondria in Sepsis-Induced Cardiomyopathy

Sepsis-induced cardiomyopathy (SICM) is one of the leading indicators for poor prognosis associated with sepsis. Despite its reversibility, prognosis varies widely among patients. Mitochondria play a key role in cellular energy production by generating adenosine triphosphate (ATP), which is vital for myocardial energy metabolism. Over recent years, mounting evidence suggests that severe sepsis not only triggers mitochondrial structural abnormalities such as apoptosis, incomplete autophagy, and mitophagy in cardiomyocytes but also compromises their function, leading to ATP depletion. This metabolic disruption is recognized as a significant contributor to SICM, yet effective treatment options remain elusive. Sepsis cannot be effectively treated with inotropic drugs in failing myocardium due to excessive inflammatory factors that blunt β-adrenergic receptors. This review will share the recent knowledge on myocardial cell death in sepsis and its molecular mechanisms, focusing on the role of mitochondria as an important metabolic regulator of SICM, and discuss the potential for developing therapies for sepsis-induced myocardial injury.

Neonatal sepsis and cardiovascular dysfunction I: mechanisms and pathophysiology

The highest incidence of sepsis across all age groups occurs in neonates leading to substantial mortality and morbidity. Cardiovascular dysfunction frequently complicates neonatal sepsis including biventricular systolic and/or diastolic dysfunction, vasoregulatory failure, and pulmonary arterial hypertension. The haemodynamic response in neonatal sepsis can be hyperdynamic or hypodynamic and the underlying pathophysiological mechanisms are heterogeneous. The diagnosis and definition of both neonatal sepsis and cardiovascular dysfunction complicating neonatal sepsis are challenging and not consensus-based. Future developments in neonatal sepsis management will be facilitated by common definitions and datasets especially in neonatal cardiovascular optimisation. IMPACT: Cardiovascular dysfunction is common in neonatal sepsis but there is no consensus-based definition, making calculating the incidence and designing clinical trials challenging. Neonatal cardiovascular dysfunction is related to the inflammatory response, which can directly target myocyte function and systemic haemodynamics.

Nutrition care for the adult post-intestinal transplant patient

Intestinal transplantation has emerged as an accepted treatment choice for individuals experiencing irreversible intestinal failure. This treatment is particularly relevant for those who are not candidates or have poor response to autologous gut reconstruction or trophic hormone therapy, and who can no longer be sustained on parenteral nutrition. One of the main goals of transplant is to eliminate the need for parenteral support and its associated complications, while safely restoring complete nutrition autonomy. An intestinal transplant is a complex process that goes beyond merely replacing the intestines to provide nourishment and ceasing parenteral support. It requires an integrated management approach in the pretransplant and posttransplant setting, and high-quality nutrition treatment is one of the cornerstones leading to favorable outcomes and long-term management. Since the outset of intestinal transplant in the early 2000s, there is observed improvement of achieving nutrition autonomy sooner in the initial posttransplant phase; however, the development of nutrition complications in the chronic posttransplant period remains a long-term risk. This review delineates the decision-making process and clinical protocols used to nutritionally manage and monitor pre- and post-intestine transplant patients.

Cardiac injury in hospitalized patients with severe fever and thrombocytopenia syndrome

Severe fever with thrombocytopenia syndrome (SFTS), an emerging infectious disease with a high fatality rate. Cardiac injury in SFTS patients is a major concern. This study aimed to evaluate the prevalence of cardiac injury and its association with mortality in hospitalized patients infected with novel Bunyavirus. Cardiac injury was defined as the presence of any of the following abnormalities: (1) blood levels of cardiac biomarkers (creatine kinase-MB, troponin-I, B-type natriuretic peptide or N-terminal pro-B-type natriuretic peptide); (2) new abnormalities in electrocardiography. The 203 SFTS patients were included in the final analysis. The proportion of SFTS patients developing cardiac injury during hospitalization was 71.4% (145/203). Compared with the uninjured group, the cardiac injury group had the severity of cardiac injury was underscored by higher median hospital costs (31420 vs. 12911, p < 0.001), higher proportion of intensive care units admissions (13.1% vs. 3.4%, p = 0.041), and higher hospital mortality rate (33.8% vs. 6.9%, p < 0.001). Multivariable-adjusted Cox proportional hazards regression analysis showed that cardiac injury was associated with higher mortality during hospitalization (hazards ratio, 7.349; 95% CI: 2.352-22.960). Cardiac injury is common among hospitalized SFTS patients, and it is associated with higher risk of mortality.

Exploring potential therapeutic agents for lipopolysaccharide-induced septic cardiomyopathy based on transcriptomics using bioinformatics

Septic cardiomyopathy (SCM) is a common and severe complication of sepsis, characterized by left ventricular dilation and reduced ejection fraction leading to heart failure. The pathogenesis of SCM remains unclear. Understanding the SCM pathogenesis is essential in the search for effective therapeutic agents for SCM. This study was to investigate the pathophysiology of SCM and explore new therapeutic drugs by bioinformatics. An SCM rat model was established by injection of 10 mg/kg lipopolysaccharide (LPS) for 24 h, and the myocardial tissues were collected for RNA sequencing. The differentially expressed genes (DEGs) between LPS rats and control (Ctrl) with the thresholds of |log2fold change|≥ 1 and P < 0.05. A protein-protein interaction (PPI) network was constructed based on the DEGs. The hub genes were identified using five algorithms of Cytoscape in the PPI networks and validated in the GSE185754 dataset and by RT-qPCR. The hub genes were analyzed by Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG), as well as Gene set enrichment analyses (GSEA). In addition, the miRNAs of hub genes were predicted through miRWalk, and the candidate therapeutic drugs were identified using the Connectivity Map (CMAP) database. This study revealed the identified hub genes (Itgb1, Il1b, Rac2, Vegfa) and key miRNAs (rno-miR-541-5p, rno-miR-487b-3p, rno-miR-1224, rno-miR-378a-5p, rno-miR-6334, and rno-miR-466b-5p), which were potential biological targets and biomarkers of SCM. Anomalies in cytokine-cytokine receptor interactions, complement and coagulation cascades, chemokine signaling pathways, and MAPK signaling pathways also played vital roles in SCM pathogenesis. Two high-confidence candidate compounds (KU-0063794 and dasatinib) were identified from the CMAP database as new therapeutic drugs for SCM. In summary, these four identified hub genes and enrichment pathways may hold promise for diagnosing and treating SCM.

Identification of key genes in sepsis-induced cardiomyopathy based on integrated bioinformatical analysis and experiments in vitro and in vivo

Introduction

Sepsis is a life-threatening disease that damages multiple organs and induced by the host's dysregulated response to infection with high morbidity and mortality. Heart remains one of the most vulnerable targets of sepsis-induced organ damage, and sepsis-induced cardiomyopathy (SIC) is an important factor that exacerbates the death of patients. However, the underlying genetic mechanism of SIC disease needs further research.

Methods

The transcriptomic dataset, GSE171564, was downloaded from NCBI for further analysis. Gene expression matrices for the sample group were obtained by quartile standardization and log2 logarithm conversion prior to analysis. The time series, protein-protein interaction (PPI) network, and functional enrichment analysis via Gene Ontology and KEGG Pathway Databases were used to identify key gene clusters and their potential interactions. Predicted miRNA-mRNA relationships from multiple databases facilitated the construction of a TF-miRNA-mRNA regulatory network. In vivo experiments, along with qPCR and western blot assays, provided experimental validation.

Results

The transcriptome data analysis between SIC and healthy samples revealed 221 down-regulated, and 342 up-regulated expressed genes across two distinct clusters. Among these, Tpt1, Mmp9 and Fth1 were of particular significance. Functional analysis revealed their role in several biological processes and pathways, subsequently, in vivo experiments confirmed their overexpression in SIC samples. Notably, we found TPT1 play a pivotal role in the progression of SIC, and silencing TPT1 showed a protective effect against LPS-induced SIC.

Conclusion

In our study, we demonstrated that Tpt1, Mmp9 and Fth1 have great potential to be biomarker of SIC. These findings will facilitated to understand the occurrence and development mechanism of SIC.

Impact of norepinephrine on immunity and oxidative metabolism in sepsis

Sepsis is a major health problem in the United States (US), constituting a leading contributor to mortality among critically ill patients. Despite advances in treatment the underlying pathophysiology of sepsis remains elusive. Reactive oxygen species (ROS) have a significant role in antimicrobial host defense and inflammation and its dysregulation leads to maladaptive responses because of excessive inflammation. There is growing evidence for crosstalk between the central nervous system and the immune system in response to infection. The hypothalamic-pituitary and adrenal axis and the sympathetic nervous system are the two major pathways that mediate this interaction. Epinephrine (Epi) and norepinephrine (NE), respectively are the effectors of these interactions. Upon stimulation, NE is released from sympathetic nerve terminals locally within lymphoid organs and activate adrenoreceptors expressed on immune cells. Similarly, epinephrine secreted from the adrenal gland which is released systemically also exerts influence on immune cells. However, understanding the specific impact of neuroimmunity is still in its infancy. In this review, we focus on the sympathetic nervous system, specifically the role the neurotransmitter norepinephrine has on immune cells. Norepinephrine has been shown to modulate immune cell responses leading to increased anti-inflammatory and blunting of pro-inflammatory effects. Furthermore, there is evidence to suggest that norepinephrine is involved in regulating oxidative metabolism in immune cells. This review attempts to summarize the known effects of norepinephrine on immune cell response and oxidative metabolism in response to infection.

Role of toll-like receptor-mediated pyroptosis in sepsis-induced cardiomyopathy

Sepsis, a life-threatening dysregulated status of the host response to infection, can cause multiorgan dysfunction and mortality. Sepsis places a heavy burden on the cardiovascular system due to the pathological imbalance of hyperinflammation and immune suppression. Myocardial injury and cardiac dysfunction caused by the aberrant host responses to pathogens can lead to cardiomyopathy, one of the most critical complications of sepsis. However, many questions about the specific mechanisms and characteristics of this complication remain to be answered. The causes of sepsis-induced cardiac dysfunction include abnormal cardiac perfusion, myocardial inhibitory substances, autonomic dysfunction, mitochondrial dysfunction, and calcium homeostasis dysregulation. The fight between the host and pathogens acts as the trigger for sepsis-induced cardiomyopathy. Pyroptosis, a form of programmed cell death, plays a critical role in the progress of sepsis. Toll-like receptors (TLRs) act as pattern recognition receptors and participate in innate immune pathways that recognize damage-associated molecular patterns as well as pathogen-associated molecular patterns to mediate pyroptosis. Notably, pyroptosis is tightly associated with cardiac dysfunction in sepsis and septic shock. In line with these observations, induction of TLR-mediated pyroptosis may be a promising therapeutic approach to treat sepsis-induced cardiomyopathy. This review focuses on the potential roles of TLR-mediated pyroptosis in sepsis-induced cardiomyopathy, to shed light on this promising therapeutic approach, thus helping to prevent and control septic shock caused by cardiovascular disorders and improve the prognosis of sepsis patients.

In-hospital Outcomes of Aspiration Pneumonia Hospitalizations With Acute Heart Failure: A Nationwide Analysis

Background and Objectives

There is a paucity of data regarding the impact of acute heart failure (AHF) on the outcomes of aspiration pneumonia (AP).

Methods

Using National Inpatient Sample datasets (2016 to 2019), we identified admissions for AP with AHF vs. without AHF using relevant International Classification of Diseases, Tenth Revision codes. We compared the demographics, comorbidities, and outcomes between the two groups.

Results

Out of the 121,097,410 weighted adult hospitalizations, 488,260 had AP, of which 13.25% (n=64,675) had AHF. The AHF cohort consisted predominantly of the elderly (mean age 80.4 vs. 71.1 years), females (47.8% vs. 42.2%), and whites (81.6% vs. 78.5%) than non-AHF cohort (all p<0.001). Complicated diabetes and hypertension, dyslipidemia, obesity, chronic pulmonary disease, and prior myocardial infarction were more frequent in AHF than in the non-AHF cohort. AP-AHF cohort had similar adjusted odds of all-cause mortality (adjusted odds ratio [AOR], 0.9; 95% confidence interval [CI], 0.78-1.03; p=0.122), acute respiratory failure (AOR, 1.0; 95% CI, 0.96-1.13; p=0.379), but higher adjusted odds of cardiogenic shock (AOR, 2.2; 95% CI, 1.30-3.64; p=0.003), and use of mechanical ventilation (MV) (AOR, 1.3; 95% CI, 1.17-1.56; p<0.001) compared to AP only cohort. AP-AHF cohort more frequently required longer durations of MV and hospital stays with a higher mean cost of the stay.

Conclusions

Our study from a nationally representative database demonstrates an increased morbidity burden, worsened complications, and higher hospital resource utilization, although a similar risk of all-cause mortality in AP patients with AHF vs. no AHF.

Research progress on the activation mechanism of NLRP3 inflammasome in septic cardiomyopathy

Sepsis is an uncontrolled host response to infection, resulting in a clinical syndrome involving multiple organ dysfunctions. Cardiac damage is the most common organ damage in sepsis. Uncontrolled inflammatory response is an important mechanism in the pathogenesis of septic cardiomyopathy (SCM). NLRP3 inflammasome promotes inflammatory response by controlling the activation of caspase-1 and the release of pro-inflammatory cytokines interleukin IL-1β and IL-18. The role of NLRP3 inflammasome has received increasing attention, but its activation mechanism and regulation of inflammation in SCM remain to be investigated.

Clinical analysis of AN69ST membrane continuous venous hemofiltration in the treatment of severe sepsis

We aimed to investigate the clinical efficacy of blood purification technology based on cytokine adsorption in the treatment of sepsis. Sixty patients with sepsis were randomly divided into control (n = 30) and experimental (n = 30) groups. Both groups were given routine treatment and continuous venovenous hemofiltration, and on this basis, the experimental group received acrylonitrile/sodium methacrylate (AN69ST) blood purification. The levels of C-reactive protein, procalcitonin, white blood cell count, albumin, platelets, total bilirubin, creatinine, lactic acid, and APACE II score, as well as secretion of inflammatory factors interleukin (IL)-6 and tumor necrosis factor (TNF-α) were compared. The hospitalization time, mechanical ventilation (MV) time, drug use time, and mortality were analyzed. After treatment, the secretion levels of IL-6 and TNF-α were decreased, and other indicators were significantly improved compared with those before treatment (P < 0.05), especially in the experimental group (P < 0.05). The hospitalization time, MV time, and drug use time in the experimental group were significantly lower than those of the control group (P < 0.05), and the mortality was lower than that in the control group (P < 0.05). In conclusion, blood purification technology based on cytokine adsorption can significantly improve various indicators of sepsis patients, reduce hospitalization time, reduce mortality, and improve the prognosis.

Lipid oxidation dysregulation: an emerging player in the pathophysiology of sepsis

Sepsis is a life-threatening organ dysfunction caused by abnormal host response to infection. Millions of people are affected annually worldwide. Derangement of the inflammatory response is crucial in sepsis pathogenesis. However, metabolic, coagulation, and thermoregulatory alterations also occur in patients with sepsis. Fatty acid mobilization and oxidation changes may assume the role of a protagonist in sepsis pathogenesis. Lipid oxidation and free fatty acids (FFAs) are potentially valuable markers for sepsis diagnosis and prognosis. Herein, we discuss inflammatory and metabolic dysfunction during sepsis, focusing on fatty acid oxidation (FAO) alterations in the liver and muscle (skeletal and cardiac) and their implications in sepsis development.

Resolving neutrophils due to TRAM deletion renders protection against experimental sepsis

OBJECTIVE

Proper inflammation resolution is crucial to prevent runaway inflammation during sepsis and reduce sepsis-related mortality/morbidity. Previous studies suggest that deleting TRAM, a key TLR4 signaling adaptor, can reprogram the first inflammatory responder cell-neutrophil from an inflammatory state to a resolving state. In this study, we aim to examine the therapeutic potential of TRAM-deficient neutrophils in vivo with recipient mice undergoing experimental sepsis.

MATERIAL AND METHODS

Wild-type or Tram-/- mice were intraperitoneally injected with cecal slurry to induce either severe or mild sepsis. Phenotypic examinations of sepsis and neutrophil characteristics were examined in vivo and ex vivo. The propagations of resolution from donor neutrophils to recipient cells such as monocytes, T cells, and endothelial cells were examined through co-culture assays in vitro. The efficacies of Tram-/- neutrophils in reducing inflammation were studied by transfusing either wild-type or Tram-/- neutrophils into septic recipient mice.

RESULTS

Tram-/- septic mice had improved survival and attenuated injuries within the lung and kidney tissues as compared to wild-type septic mice. Wild-type septic mice transfused with Tram-/- resolving neutrophils exhibited reduced multi-organ damages and improved cellular homeostasis. In vitro co-culture studies revealed that donor Tram-/- neutrophils can effectively propagate cellular homeostasis to co-cultured neighboring monocytes, neutrophils, T cells as well as endothelial cells.

CONCLUSIONS

Neutrophils with TRAM deletion render effective reprogramming into a resolving state beneficial for ameliorating experimental sepsis, with therapeutic potential in propagating cellular and tissue homeostasis as well as treating sepsis.

Acute Respiratory Distress Syndrome in Patients with Cardiovascular Disease

Heart and lung interaction within the thoracic cavity is well known during inhalation and exhalation, both spontaneously and during mechanical ventilation. Disease and dysfunction of one organ affect the function of the other. A review of the cause-and-effect relationship between cardiovascular disease and acute respiratory distress syndrome (ARDS) is of significance, as the disease burden of both conditions has both a national and global impact on health care. This literature review examines the relationship between cardiovascular disease and ARDS over the past 25 years.

Comparative Analysis of Whole Transcriptome Profiles in Septic Cardiomyopathy: Insights from CLP- and LPS-Induced Mouse Models

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, with septic cardiomyopathy being a common and severe complication. Despite its significant clinical impact, the molecular mechanisms underlying sepsis-induced cardiomyopathy (SICM) remain incompletely understood. In this study, we performed a comparative analysis of whole transcriptome profiles using RNA sequencing in mouse hearts in two widely used mouse models of septic cardiomyopathy. CLP-induced sepsis was achieved by surgical cecal ligation and puncture, while LPS-induced sepsis was induced using a 5 mg/kg intraperitoneal (IP) injection of lipopolysaccharide (LPS). For consistency, we utilized sham-operated mice as the control for septic models. Our aim was to identify key genes and pathways involved in the development of septic cardiomyopathy and to evaluate the similarities and differences between the two models. Our findings demonstrated that both the CLP and lipopolysaccharide LPS methods could induce septic heart dysfunction within 24 h. We identified common transcriptional regulatory regions in the septic hearts of both models, such as Nfkb1, Sp1, and Jun. Moreover, differentially expressed genes (DEGs) in comparison to control were involved in shared pathways, including regulation of inflammatory response, regulation of reactive oxygen species metabolic process, and the JAK-STAT signaling pathway. However, each model presented distinctive whole transcriptome expression profiles and potentially diverse pathways contributing to sepsis-induced heart failure. This extensive comparison enhances our understanding of the molecular basis of septic cardiomyopathy, providing invaluable insights. Accordingly, our study also contributes to the pursuit of effective and personalized treatment strategies for SICM, highlighting the importance of considering the specific causative factors.

Zataria multiflora and its constituent, carvacrol, counteract sepsis-induced aortic and cardiac toxicity in rat: Involvement of nitric oxide and oxidative stress

BACKGROUND

Zataria multiflora and carvacrol showed various pharmacological properties including anti-inflammatory and anti-oxidant effects. However, up to now no studies have explored its potential benefits in ameliorating sepsis-induced aortic and cardiac injury. Thus, this study aimed to investigate the effects of Z. multiflora and carvacrol on nitric oxide (NO) and oxidative stress indicators in lipopolysaccharide (LPS)-induced aortic and cardiac injury.

METHODS

Adult male Wistar rats were assigned to: Control, lipopolysaccharide (LPS) (1 mg/kg, intraperitoneal (i.p.)), and Z. multiflora hydro-ethanolic extract (ZME, 50-200 mg/kg, oral)- and carvacrol (25-100 mg/kg, oral)-treated groups. LPS was injected daily for 14 days. Treatment with ZME and carvacrol started 3 days before LPS administration and treatment continued during LPS administration. At the end of the study, the levels of malondialdehyde (MDA), NO, thiols, and antioxidant enzymes were evaluated.

RESULTS

Our findings showed a significant reduction in the levels of superoxide dismutase (SOD), catalase (CAT), and thiols in the LPS group, which were restored by ZME and carvacrol. Furthermore, ZME and carvacrol decreased MDA and NO in cardiac and aortic tissues of LPS-injected rats.

CONCLUSIONS

The results suggest protective effects of ZME and carvacrol on LPS-induced cardiovascular injury via improved redox hemostasis and attenuated NO production. However, additional studies are needed to elucidate the effects of ZME and its constituents on inflammatory responses mediated by LPS.

Inflammatory mechanisms and intervention strategies for sepsis-induced myocardial dysfunction

Sepsis-induced myocardial dysfunction (SIMD) is the leading cause of death in patients with sepsis in the intensive care units. The main manifestations of SIMD are systolic and diastolic dysfunctions of the myocardium. Despite our initial understanding of the SIMD over the past three decades, the incidence and mortality of SIMD remain high. This may be attributed to the large degree of heterogeneity among the initiating factors, disease processes, and host states involved in SIMD. Previously, organ dysfunction caused by sepsis was thought to be an impairment brought about by an excessive inflammatory response. However, many recent studies have shown that SIMD is a consequence of a combination of factors shaped by the inflammatory responses between the pathogen and the host. In this article, we review the mechanisms of the inflammatory responses and potential novel therapeutic strategies in SIMD.

RIP2 inhibition alleviates lipopolysaccharide-induced septic cardiomyopathy via regulating TAK1 signaling

PURPOSE

RIP2 is a member of the receptor-interacting protein family that has been associated with various pathophysiological processes, including immunity, apoptosis, and autophagy. However, no studies have hitherto reported the role of RIP2 in lipopolysaccharide (LPS)-induced septic cardiomyopathy (SCM). This study was designed to illustrate the role of RIP2 in LPS-induced SCM.

METHODS

C57 and RIP2 knockout mice received intraperitoneal injections of LPS to establish models of SCM. Echocardiography was used to assess the cardiac function of the mice. Real-time-PCR, cytometric bead array and immunohistochemical staining were used to detect the inflammatory response. Immunoblotting was used to determine the protein expression of relevant signaling pathways. Our findings were validated by treatment with a RIP2 inhibitor. Neonatal rats cardiomyocytes (NRCMs) and cardiac fibroblasts (CFs) were transfected with Ad-RIP2 to further explore the role of RIP2 in vitro.

RESULTS

RIP2 expression was upregulated in our mice models of septic cardiomyopathy and LPS-stimulated cardiomyocytes and fibroblasts. RIP2 knockout or RIP2 inhibitors attenuated LPS-induced cardiac dysfunction and reduced the inflammatory response in mice. Overexpression of RIP2 in vitro enhanced the inflammatory response, and TAK1 inhibitors attenuated the inflammatory response caused by overexpression of RIP2.

CONCLUSION

Our findings substantiate that RIP2 induces an inflammatory response by regulating the TAK1/IκBα/NF-κB signaling pathway. RIP2 inhibition by genetic or pharmacological approaches has huge prospects for application as a potential treatment strategy for inhibiting inflammation, alleviating cardiac dysfunction, and improving survival.

SILENCING M 6 A READER YTHDC1 REDUCES INFLAMMATORY RESPONSE IN SEPSIS-INDUCED CARDIOMYOPATHY BY INHIBITING SERPINA3N EXPRESSION

ABSTRACT

Sepsis-induced cardiomyopathy (SIC) is one of the most common complications of infection-induced sepsis. An imbalance in inflammatory mediators is the main factor leading to SIC . N 6 -methyladenosine (m 6 A) is closely related to the occurrence and development of sepsis. N 6 -methyladenosine reader YTH domain containing 1 (YTHDC1) is an m 6 A N 6 -methyladenosine recognition protein. However, the role of YTHDC1 in SIC remains unclear. Herein, we demonstrated that YTHDC1-shRNA inhibits inflammation, reduces inflammatory mediators, and improves cardiac function in a LPS-induced SIC mouse model. Based on the Gene Expression Omnibus database analysis, serine protease inhibitor A3N is a differential gene of SIC. Furthermore, RNA immunoprecipitation indicated that serine protease inhibitor A3N (SERPINA3N) mRNA can bind to YTHDC1, which regulates the expression of SERPINA3N. Serine protease inhibitor A3N-siRNA reduced LPS-induced inflammation of cardiac myocytes. In conclusion, the m 6 A reader YTHDC1 regulates SERPINA3N mRNA expression to mediate the levels of inflammation in SIC. Such findings add to the relationship between m 6 A reader YTHDC1 and SIC, providing a new research avenue for the therapeutic mechanism of SIC.

Rnf144b alleviates the inflammatory responses and cardiac dysfunction in sepsis

AIMS

Sepsis is an inflammatory disease with high mortality and morbidity. Inflammation plays an essential role in sepsis, and suppressing inflammation has been shown to ameliorate sepsis. Rnf144b is an ubiquitin E3 ligation with anti-inflammation activities. Its precise roles in sepsis remain unknown. Here, we explored the function of Rnf144b in sepsis.

METHODS AND RESULTS

We generated conditional knockout mice with Rnf144b deficiency in the myeloid cells. We monitored the Rnf144b expression in peripheral blood mononuclear cells from healthy donor and patients with sepsis, and in lipopolysaccharides (LPS)-treated bone marrow-derived macrophages (BMDMs). The cytokine expression between wild-type BMDMs and Rnf144b-deficient BMDMs after LPS and CpG treatments was compared. The survival rate and cardiac function were monitored. The activation of TANK binding kinase 1 and nuclear factor kappa-B was examined by Western blot and real-time PCR. Up-regulated expression of Rnf144b was observed in peripheral blood mononuclear cells from patients with sepsis. LPS induced the expression of Rnf144b in BMDMs. Rnf144b-deficient BMDMs produced more inflammatory cytokines after LPS or CpG stimulation. Septic mice with Rnf144b deficiency in myeloid cells had higher mortality and exacerbated cardiac dysfunction. Rnf144b interacted with TANK binding kinase 1 and Rnf144b deficiency resulted in impaired activation of TBK1 but enhanced activation of nuclear factor kappa-B.

CONCLUSIONS

Rnf144b prevents inflammatory responses and cardiac dysfunction in sepsis.

Cardiac RGS Proteins in Human Heart Failure and Atrial Fibrillation: Focus on RGS4

The regulator of G protein signaling (RGS) proteins are crucial for the termination of G protein signals elicited by G protein-coupled receptors (GPCRs). This superfamily of cell membrane receptors, by far the largest and most versatile in mammals, including humans, play pivotal roles in the regulation of cardiac function and homeostasis. Perturbations in both the activation and termination of their G protein-mediated signaling underlie numerous heart pathologies, including heart failure (HF) and atrial fibrillation (AFib). Therefore, RGS proteins play important roles in the pathophysiology of these two devasting cardiac diseases, and several of them could be targeted therapeutically. Although close to 40 human RGS proteins have been identified, each RGS protein seems to interact only with a specific set of G protein subunits and GPCR types/subtypes in any given tissue or cell type. Numerous in vitro and in vivo studies in animal models, and also in diseased human heart tissue obtained from transplantations or tissue banks, have provided substantial evidence of the roles various cardiomyocyte RGS proteins play in cardiac normal homeostasis as well as pathophysiology. One RGS protein in particular, RGS4, has been reported in what are now decades-old studies to be selectively upregulated in human HF. It has also been implicated in protection against AFib via knockout mice studies. This review summarizes the current understanding of the functional roles of cardiac RGS proteins and their implications for the treatment of HF and AFib, with a specific focus on RGS4 for the aforementioned reasons but also because it can be targeted successfully with small organic molecule inhibitors.

6-Formylindolo(3,2-b)carbazole Dampens Inflammation and Reduces Endotoxin-Induced Kidney Injury via Nrf2 Activation

Patients with sepsis are at a high risk of morbidity and mortality due to multiple organ injuries caused by pathological inflammation. Although sepsis is accompanied by multiple organ injuries, acute renal injury is a significant contributor to sepsis morbidity and mortality. Thus, dampening inflammation-induced renal injury may limit severe consequences of sepsis. As several studies have suggested that 6-formylindolo(3,2-b)carbazole (FICZ) is beneficial for treating various inflammatory diseases, we aimed to examine the potential protective effect of FICZ on the acute endotoxin-induced sepsis model of kidney injury. To test this, male C57Bl/6N mice were injected with FICZ (0.2 mg/kg) or vehicle 1 h prior to an injection of either lipopolysaccharides (LPS) (10 mg/kg), to induce sepsis, or phosphate-buffered saline for 24 h. Thereafter, gene expression of kidney injury and pro-inflammatory markers, circulating cytokines and chemokines, and kidney morphology were assessed. Our results show that FICZ reduced LPS-induced acute injury in kidneys from LPS-injected mice. Furthermore, we found that FICZ dampens both renal and systemic inflammation in our sepsis model. Mechanistically, our data indicated that FICZ significantly upregulates NAD(P)H quinone oxidoreductase 1 and heme oxygenase 1 via aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2-related factor 2 (Nrf2) in the kidneys to lessen inflammation and improve septic acute kidney injury. Overall, the data of our study show that FICZ possesses a beneficial reno-protective effect against sepsis-induced renal injury via dual activation of AhR/Nrf2.

Associations of the Serum Total Carbon Dioxide Level with Long-Term Clinical Outcomes in Sepsis Survivors

INTRODUCTION

Sepsis is characterized by a dysregulated host response to infection that leads to multiple organ dysfunction and often complicated with metabolic acidosis. However, the associations between serum total carbon dioxide level (TCO₂) and long-term clinical outcomes in sepsis survivors remains unknown.

METHODS

A total of 7212 sepsis survivors aged ≥ 20 years who were discharged from January  1, 2008 to December 31, 2018 were included in our analyses. The sepsis survivors were further divided into high TCO₂ (≥ 18 mmol/L) and low TCO₂ (< 18 mmol/L) groups, comprising 5023 and 2189 patients, respectively. The following outcomes of interest were included: all-cause mortality, myocardial infarction, ischemic stroke, hospitalization for heart failure, ventricular arrhythmia, and end-stage renal disease (ESRD).

RESULTS

After propensity score matching, the low TCO₂ group was at higher risks of all-cause mortality (hazard ratio [HR] 1.28, 95% confidence interval [95% CI] 1.18-1.39), myocardial infarction (HR 1.83, 95% CI 1.39-2.43), and ESRD (HR 1.38, 95% CI 1.16-1.64) than the high TCO₂ group. The results remained similar after considering death as a competing risk.

CONCLUSION

Patients discharged from hospitalization for sepsis have higher risks of worse long-term clinical outcomes. Physicians may need to pay more attention to sepsis survivors whose TCO₂ was low.

The therapeutic potential of targeting cardiac RGS4

G protein-coupled receptors (GPCRs) play pivotal roles in regulation of cardiac function and homeostasis. To function properly, every cell needs these receptors to be stimulated only when a specific extracellular stimulus is present, and to be silenced the moment that stimulus is removed. The regulator of G protein signaling (RGS) proteins are crucial for the latter to occur at the cell membrane, where the GPCR normally resides. Perturbations in both activation and termination of G protein signaling underlie numerous heart pathologies. Although more than 30 mammalian RGS proteins have been identified, each RGS protein seems to interact only with a specific set of G protein subunits and GPCR types/subtypes in any given tissue or cell type, and this applies to the myocardium as well. A large number of studies have provided substantial evidence for the roles various RGS proteins expressed in cardiomyocytes play in cardiac physiology and heart disease pathophysiology. This review summarizes the current understanding of the functional roles of cardiac RGS proteins and their implications for the treatment of specific heart diseases, such as heart failure and atrial fibrillation. We focus on cardiac RGS4 in particular, since this isoform appears to be selectively (among the RGS protein family) upregulated in human heart failure and is also the target of ongoing drug discovery efforts for the treatment of a variety of diseases.

Assessing the performance of genetic risk score for stratifying risk of post-sepsis cardiovascular complications

Background

Patients with sepsis are at increased risk for cardiovascular complications, including myocardial infarction (MI), ischemic stroke (IS), and venous thromboembolism (VTE). Our objective is to assess whether genetic risk score (GRS) can differentiate risk for these complications.

Methods

A population-based prospective cohort of 483,177 subjects, derived from the UK Biobank, was followed for diagnosis of sepsis and its complications (MI, IS, and VTE) after the study recruitment. GRS for each complication was calculated based on established risk-associated single nucleotide polymorphisms (SNPs). Time to incident MI, IS, and VTE was compared between subjects with or without sepsis and GRS risk groups using Kaplan-Meier log-rank test and Cox-regression analysis.

Results

During an average of 12.6 years of follow-up, 10,757 (2.23%) developed sepsis. Patients with sepsis had an overall higher risk than non-sepsis subjects for each complication, but the risk differed by time after a sepsis diagnosis; exceedingly high in short-term (0-30 days), considerably high in mid-term (31 days to 2 years), and reduced in long-term (>2 years). Furthermore, in White subjects, GRS was a significant predictor of complications, independent of sepsis and other risk factors. For example, GRS_MI further differentiated their risk in patients with sepsis; 3.49, 4.73, and 9.03% in those with low- (<0.5), intermediate- (0.5-1.99), high- GRS_MI (≥2.0), P_trend  < 0.001.

Conclusion

Risk for post-sepsis cardiovascular complications differed considerably by time after a sepsis diagnosis and GRS. These findings, if confirmed in other ancestry-specific populations, may guide personalized management for preventing post-sepsis cardiovascular complications.

DAMPs Released from Proinflammatory Macrophages Induce Inflammation in Cardiomyocytes via Activation of TLR4 and TNFR

Cardiac dysfunction is a life-threatening complication in sepsis. Upon infection and cardiac stress, the cardiac macrophage population expands. Recruited macrophages exhibit a predominantly proinflammatory phenotype and release danger-associated molecular patterns (DAMPs) that contribute to cardiac dysfunction. However, the underlying pathomechanisms are highly complex and not fully understood. Here, we utilized an indirect macrophage-cardiomyocyte co-culture model to study the effects of proinflammatory macrophages on the activation of different cardiac receptors (TLR3, TLR4, and TNFR) and their role in cardiac inflammation and caspase-3/7 activation. The stimulation of cardiomyocytes with conditioned medium of LPS-stimulated macrophages resulted in elevated IL-6 protein concentrations and relative IL-6 and TNFα mRNA levels. Conditioned medium from LPS-stimulated macrophages also induced NFκB translocation and increased caspase-3/7 activation in cardiomyocytes. Analyzing the role of different cardiac receptors, we found that TLR4 and TNFR inhibition reduces cardiac inflammation and that the inhibition of TNFR prevents NFκB translocation into the nuclei of cardiomyocytes, induced by exposure to conditioned medium of proinflammatory macrophages. Moreover, we demonstrated that TLR3 inhibition reduces macrophage-mediated caspase-3/7 activation. Our results suggest that the immune response of macrophages under inflammatory conditions leads to the release of DAMPs, such as eRNA and cytokines, which in turn induce cardiomyocyte dysfunction. Thus, the data obtained in this study contribute to a better understanding of the pathophysiological mechanisms of cardiac dysfunction.