Sepsis-induced cardiac dysfunction: a review of pathophysiology

Complexities of cardiomyopathy in septic shock

PURPOSE OF REVIEW

This review highlights the complex pathophysiology of myocardial dysfunction in septic shock and emphasizes the need for early and repeated hemodynamic assessments to improve outcome.

RECENT FINDINGS

Septic cardiomyopathy is a complex, dynamic process driven by multiple mechanisms such as direct myocardial depression induced by host immune mediators (e.g., cytokines, nitric oxide) and/or bacterial toxins, and mitochondrial metabolic dysfunction. Recent echocardiography studies have described multiple unique hemodynamic clusters (phenotypes) that correlated with clinical outcomes. Similarly, serial echocardiography findings and mean arterial pressure abnormalities in patients with Streptococcal Toxic Shock Syndrome (StrepTSS) yielded three distinct hemodynamic groups that predicted mortality and morbidity. Because excessive use of fluids and/or vasopressors can be detrimental, especially in patients with microvascular injury or cardiomyopathy, application of the cardiovascular performance criteria of these different phenotypes could better inform management decisions in real time and improve outcome.

SUMMARY

Septic cardiomyopathy is a dynamic, multidimensional response of the myocardium to infection involving both normal and dysregulated immune responses in which the measurable changes in myocardial function predict outcomes. This current paradigm mandates that functional parameters of cardiac performance be measured early and repeatedly throughout the disease course using echocardiography to guide treatment and improve outcome.

The prognostic role of tricuspid annular plane systolic excursion in critically ill patients with septic shock

INTRODUCTION

The right ventricle (RV) may play a crucial role in predicting prognosis in critical settings. The value of the tricuspid annular plane systolic excursion (TAPSE) has been shown in the prognosis of cardiac patients, such as those with heart failure and pulmonary hypertension. The aim of this study was to evaluate the possible prognostic performance of RV dysfunction, as assessed by the TAPSE, in noncardiac septic shock patients.

METHODOLOGY

One hundred critically ill adult patients diagnosed with septic shock were enrolled directly after admission. The TAPSE was measured within 24 h. Patients were analyzed according to 28-day mortality and divided into non-survivors and survivors.

RESULTS

The overall 28-day mortality rate was 62%. TAPSE showed a strong negative correlation with APACHE-II (r = - 0.569, p < 0.001) and moderately negatively correlated with the SOFA score (r = - 0.448, p = 0.001). TAPSE (at a cutoff point of 2 cm) was a very good tool (area under curve = 0.887) for predicting 28-day mortality (95% confidence interval CI 0.770-0.980, p < 0.0001).

CONCLUSION

Early echocardiographic assessment of RV dysfunction to measure TAPSE might be of prognostic importance in noncardiac patients with septic shock, as a TAPSE less than 2 cm was useful for predicting poor outcomes.

TRIAL REGISTRATION

clinicaltrials.gov, NCT06008067. Registered 18 July 2023 registered. TAPSESEPTIC study.

The Role of Venoarterial Ecmo in the Management of Sepsis-Induced Cardiomyopathy and Refractory Shock: An Analytic Review

Sepsis-induced cardiomyopathy is a severe complication seen in patients with refractory septic shock, characterized by cardiac dysfunction due to an overwhelming inflammatory response secondary to infection. Despite its reversible nature, sepsis-induced cardiomyopathy (SIC) can significantly increase mortality in septic shock patients despite treating the underlying infection. Prompt recognition and aggressive intervention can potentially support the recovery of cellular injuries caused by inflammation and improve outcomes. Recently, venoarterial-extracorporeal membrane oxygenation (VA-ECMO) has gained attention as a potential mechanical support for managing these patients with SIC and cardiogenic shock. However, the lack of consensus in defining SIC and the variation in inclusion criteria for VA-ECMO implementation in acute sepsis-induced cardiogenic shock made it challenging to interpret the results of related studies. A more specific definition of SIC and careful selection of patients who may benefit from ECMO support could improve outcomes in this population. This analytic review discusses the mechanisms leading to cardiomyocyte injury and SIC, and summarizes recent studies including the efficacy of VA-ECMO in managing refractory septic shock due to SIC.

Evaluation of Presepsin for Early Diagnosis of Sepsis in the Emergency Department

Background: to date, there are no specific markers available for diagnosing sepsis. Diagnosis is, indeed, mainly determined by clinical suspicion and the evaluation of the patient's overall condition. This evaluation involves assessing various inflammatory markers, such as C-reactive protein (CRP) and procalcitonin (PCT), along with markers of tissue hypoxia, such as serum lactate. Additionally, it includes scores that account for complete blood count (CBC), organ function markers, and the patient's vital parameters, including SOFA, qSOFA, SIRS, and NEWS. Over the years, various potential biomarkers have been studied; among these presepsin appears to offer some significant advantages. Objective: Presepsin, which is the N-terminal fragment of the soluble component of CD14, is primarily elevated in infectious conditions. Its levels rise much earlier in the context of infection compared to currently used biomarkers. As a result, Presepsin shows promise for the early identification of septic patients and could aid in prognostic assessment, allowing clinicians to prioritize care for critically ill individuals. Methods: this study aims to evaluate the role of serum presepsin in the early diagnosis of sepsis in patients who present to the emergency room with a clinical suspicion of sepsis. The secondary objectives include comparing the diagnostic performance of presepsin with traditional biomarkers currently used for sepsis diagnosis and assessing its utility as a prognostic biomarker for mortality risk stratification, in comparison with validated severity prediction scores. Result: Presepsin had valuable diagnostic utility for sepsis (AUC 0.946, p < 0.001) comparable to PCT (AUC 0.905, p < 0.001). Conclusions: the combination of Presepsin, PCT, and EWS yielded the highest diagnostic accuracy for sepsis.

Human proteome distribution atlas for tissue-specific plasma proteome dynamics

The plasma proteome is maintained by the influx and efflux of proteins from surrounding organs and cells. To quantify the extent to which different organs and cells impact the plasma proteome in healthy and diseased conditions, we developed a mass-spectrometry-based proteomics strategy to infer the tissue origin of proteins detected in human plasma. We first constructed an extensive human proteome atlas from 18 vascularized organs and the 8 most abundant cell types in blood. The atlas was interfaced with previous RNA and protein atlases to objectively define proteome-wide protein-organ associations to infer the origin and enable the reproducible quantification of organ-specific proteins in plasma. We demonstrate that the resource can determine disease-specific quantitative changes of organ-enriched protein panels in six separate patient cohorts, including sepsis, pancreatitis, and myocardial injury. The strategy can be extended to other diseases to advance our understanding of the processes contributing to plasma proteome dynamics.

Roles and Therapeutic Targeting of Exosomes in Sepsis-Induced Cardiomyopathy

Sepsis-induced cardiomyopathy (SICM) is a complex and fatal manifestation of sepsis, characterised by myocardial dysfunction that exacerbates the clinical prognosis in septic patients. While the pathophysiology of SICM remains incompletely understood, emerging evidence highlights the multifaceted functions of exosomes, small membrane-bound extracellular vesicles, in mediating the inflammatory responses and cardiac dysfunction involved in this condition. During sepsis, exosomes are secreted by various cells, such as cardiomyocytes, endothelial cells and macrophages, which serve as critical messengers, transferring proteins, lipids and RNA molecules that influence recipient cells, thus affecting cellular functions and disease progression. This review summarises the pathophysiology of SICM and the basics of exosomes and focuses on exosome-mediated mechanisms in SICM, including their role in inflammation, oxidative stress, mitochondrial dysfunction and myocardial injury, offering novel insights into the exosome-based therapeutic strategies in SICM.

Micromeria congesta Alleviates LPS-Induced Inflammation, Apoptosis, Oxidative Stress and DNA Damage in Rat Heart and Kidneys

Life-threatening sepsis with high mortality and morbidity is an important cause of acute kidney injury and myocardial dysfunction. In this study, we investigated the protective effect of Micromeria congesta (MC) against kidney and heart damage caused by lipopolysaccharide (LPS) used as a sepsis model. Control, LPS, LPS + 25 mg/kg MC and LPS + 50 mg/kg MC groups were established from rats for the study. After the experiment, kidney and heart tissues obtained from the rats were stained with hematoxylin-eosin for histopathologic examination. Immunohistochemical staining was performed to determine inflammation, apoptosis, oxidative stress and DNA damage. IL-2 for inflammation, CASP-3 for apoptosis, HSP-27 for oxidative stress and 8-OHdG for DNA damage were used for immunopathologic examination. Histopathologic examination showed that the lesions in the kidney and heart tissues in the LPS group decreased with increasing doses of MC. Immunohistochemical examination showed that the expression of IL-2, CASP-3, HSP-27 and 8-OHdG was severe in the LPS group, but the severity of expression in these tissues decreased with increasing doses of MC. As a result of the study, it was histopathologically determined that MC reduced LPS-induced kidney and heart tissue damage. In addition, MC was found to protect against LPS by reducing LPS-induced inflammation, apoptosis, oxidative stress and DNA damage in kidney and heart tissue. In conclusion, it was seen that MC was effective in sepsis damage. However, it was concluded that MC could be an alternative in drug strategies developed for sepsis treatment with studies in vivo including more analyses.

Septic Cardiomyopathy: Difficult Definition, Challenging Diagnosis, Unclear Treatment

Sepsis is a systemic inflammatory response syndrome of suspected or confirmed infectious origin, which frequently culminates in multiorgan failure, including cardiac involvement. Septic cardiomyopathy (SCM) remains a poorly defined clinical entity, lacking a formal or consensus definition and representing a significant knowledge gap in critical care medicine. It is an often-underdiagnosed complication of sepsis. The only widely accepted aspect of its definition is that SCM is a transient myocardial dysfunction occurring in patients with sepsis, which cannot be attributed to ischemia or pre-existing cardiac disease. The pathogenesis of SCM appears to be multifactorial, involving inflammatory cytokines, overproduction of nitric oxide, mitochondrial dysfunction, calcium homeostasis dysregulation, autonomic imbalance, and myocardial edema. Diagnosis primarily relies on echocardiography, with advanced tools such as tissue Doppler imaging (TDI) and global longitudinal strain (GLS) providing greater sensitivity for detecting subclinical dysfunction and guiding therapeutic decisions. Traditional echocardiographic findings, such as left ventricular ejection fraction measured by 2D echocardiography, often reflect systemic vasoplegia rather than intrinsic myocardial dysfunction, complicating accurate diagnosis. Right ventricular (RV) dysfunction, identified as a critical component of SCM in many studies, has multifactorial pathophysiology. Factors including septic cardiomyopathy itself, mechanical ventilation, hypoxemia, and hypercapnia-particularly in cases complicated by acute respiratory distress syndrome (ARDS)-increase RV afterload and exacerbate RV dysfunction. The prognostic value of cardiac biomarkers, such as troponins and natriuretic peptides, remains uncertain, as these markers primarily reflect illness severity rather than being specific to SCM. Treatment focuses on the early recognition of sepsis, hemodynamic optimization, and etiological interventions, as no targeted therapies currently exist. Emerging therapies, such as levosimendan and VA-ECMO, show potential in severe SCM cases, though further validation is needed. The lack of standardized diagnostic criteria, combined with the heterogeneity of sepsis presentations, poses significant challenges to the effective management of SCM. Future research should focus on developing cluster-based classification systems for septic shock patients by integrating biomarkers, echocardiographic findings, and clinical parameters. These advancements could clarify the underlying pathophysiology and enable tailored therapeutic strategies to improve outcomes for SCM patients.

Is there a place for natural agents with anti-inflammatory and antioxidative properties in critically ill patients? Potential usefulness of Xanthohumol

Multi-organ dysfunction is a major issue in critically ill patients, where a significant inflammatory response appears to be the primary factor driving the degree of organ impairment, which correlates with the extent of organ injury. The management of inflammation requires a multidisciplinary approach, including antibiotics for infection control, circulatory and respiratory support, and correction of coagulation abnormalities. However, the use of anti-inflammatory treatments is typically restricted to a selected group of medications, with their effectiveness remaining the subject of extensive debate. Xanthohumol (Xn), a natural compound extracted from hops, possesses strong anti-inflammatory and antioxidative properties, with a mild anti-coagulation effect. Its biological activity is related to the inhibition of different inflammatory pathways, reduction in cytokine production and secretion, and an increase in antioxidative enzyme activity. This review examined the potential use of Xn as an adjuvant in the treatment of various pathologies in critically ill patients.

Silencing fatty acid-binding protein 4 improved sepsis-induced myocardial dysfunction through anti-apoptotic and antioxidant effects by mammalian target of rapamycin signaling pathway

Objective

One of the main complications of sepsis that is linked to poor clinical outcomes and high mortality is sepsis-induced myocardial dysfunction (SIMD). Fatty acid-binding protein 4 (FABP4) is a protein that is expressed in macrophages and adipose tissue and is involved in inflammation and apoptosis in various pathological processes. The purpose of this study was to investigate the role of FABP4 in SIMD.

Material and Methods

The H9c2 cell model of myocardial dysfunction induced by septicemia was established by lipopolysaccharide (LPS). Measurements of cell viability, apoptosis, reactive oxygen species levels, mitochondrial activity, and proinflammatory factor expression were used to assess FABP4's involvement in SIMD. In addition, the expression level of key proteins in the mammalian target of rapamycin (mTOR) signaling pathway was analyzed using Western blot. Finally, the combination of AZD-8055 further demonstrated the possibility of mTOR as a therapeutic target for SIMD.

Results

Silencing FABP4 expression drastically increased H9c2 cell viability and mitochondrial function. In addition, by upregulating B-cell lymphoma-2 (Bcl-2) and downregulating Bcl-2 associated X protein, FABP4 silencing improved LPS-induced anti-apoptosis of H9c2 cells. Finally, silencing FABP4 alleviated SIMD through the mTOR signaling pathway. However, the therapeutic effect was inhibited when FABP4 silencing was combined with the mTOR inhibitor AZD-8055.

Conclusion

Silencing FABP4 alleviates LPS-induced inflammatory response and apoptosis in H9c2 cells and enhances mitochondrial function through the mTOR signaling pathway.

Levosimendan for sepsis-induced myocardial dysfunction: friend or foe?

Sepsis-induced myocardial dysfunction (SIMD) involves reversible myocardial dysfunction. The use of inotropes can restore adequate cardiac output and tissue perfusion, but conventional inotropes, such as dobutamine and adrenaline, have limited efficacy in such situations. Levosimendan is a novel inotrope that acts in a catecholamine-independent manner. However, study results regarding the treatment of SIMD with levosimendan are inconsistent, and the use of levosimendan is highly controversial. In this review, we summarized the therapeutic mechanisms of levosimendan in SIMD and considered recent research on how to improve the efficacy of levosimendan in SIMD. We also analyzed the potential and limitations of levosimendan for the treatment of SIMD to provide ideas for future clinical trials and the clinical application of levosimendan in SIMD.

TLR4 Inhibition Attenuated LPS-Induced Proinflammatory Signaling and Cytokine Release in Mouse Hearts and Cardiomyocytes

BACKGROUND

Sepsis is associated with myocardial injury and early mortality. The innate immune receptor Toll-like receptor 4 (TLR4) can recognize pathogen-associated-molecular-patterns (PAMPs) and damage-associated molecular patterns (DAMPs); the latter are released during tissue injury. We hypothesized that TLR4 inhibition reduces proinflammatory signaling and cytokine release in: (1) LPS or Escherichia coli-treated isolated mouse heart; (2) LPS-treated mouse primary adult cardiomyocytes; and (3) the isolated heart during ischemia-reperfusion.

METHODS

Isolated C57BL/6N male mouse hearts were perfused for 120 min, with either LPS, E. coli, with and without CLI-095 (TLR4 inhibitor). Primary adult mouse cardiomyocytes were treated with LPS or LPS + CLI-095. Isolated hearts, exposed to 35 min of global ischemia, were treated with either vehicle or CLI-095 during reperfusion. Infarct size was quantified by triphenyltetrazolium staining. Cytokine expression was analyzed with ELISA, western blot analysis, and qPCR.

RESULTS

In isolated hearts, E. coli increased the expression of proinflammatory cytokines (IL-6 and CXCL2), which was not attenuated with TLR4 inhibition. TLR4 inhibition reduced expression (p = 0.004) and release of IL-6 (p < 0.0001) in LPS-exposed isolated hearts. LPS activated the nuclear-factor κ-light-chain-enhancer of activated B cells signaling pathway (NF-κB) in primary adult cardiomyocytes. Moreover, TLR4 inhibition reduced LPS-induced mRNA expression and release of IL-6 in primary adult cardiomyocytes. Isolated hearts treated with CLI-095 during reperfusion after ischemia (induced DAMPs release) showed reduced infarct size (39 ± 17% to 26 ± 8%, p = 0.034) and decreased IL-6 release (p = 0.006).

CONCLUSION

Inhibition of TLR4 reduced proinflammatory signaling and cytokine release in LPS-treated and ischemia-reperfused isolated mouse hearts and in primary adult murine cardiomyocytes.

Influence of liberal versus conservative oxygen therapies on the hemodynamic parameters of mechanically ventilated patients with sepsis: a randomized clinical trial

BACKGROUND

There is no significant evidence verifying the efficacy of liberal versus conservative oxygen therapy on hemodynamics in patients with sepsis. We investigated how liberal and conservative oxygen therapy influenced stroke volume, cardiac output, and vasopressor needs in patients with sepsis undergoing mechanical ventilation.

METHODS

This randomized clinical trial included 106 patients with an admission diagnosis of infection, a Sequential Organ Failure Assessment (SOFA) score of two points or higher and required invasive mechanical ventilation for at least 72 h. Patients were randomly assigned to one of two oxygenation strategies: liberal (n = 53) with a target SpO2 of ≥ 96% or conservative (n = 53) with a target SpO2 of 88-92%. Transthoracic Doppler echocardiography was done twice to measure stroke volume and cardiac output, initially upon enrollment in the trial and then 72 h later. The primary outcome was stroke volume. Secondary outcomes were cardiac output, vasopressor use, mechanical ventilation duration, ICU stay length, and adverse events.

RESULTS

Stroke volume and cardiac output measurements did not differ significantly between research groups after 72 h of oxygenation treatment (p = 0.459 and 0.637, respectively). Forty-five patients (84.9%) in the conservative oxygen therapy group needed vasopressors to maintain their mean arterial pressure above 65 mmHg, whereas 35 patients (66.0%) in the liberal group did (p = 0.024). A multivariate logistic regression analysis of the independent variables for vasopressor requirements revealed that patients in the conservative oxygen group were 3.83 times more likely to require vasopressors (AOR = 3.83, 95% CI: 1.31-11.18, p = 0.014) than those in the liberal group. Older patients (AOR = 1.03, 95% CI: 1.01-1.07, p = 0.038) and those with higher SOFA scores (AOR = 1.36, CI: 1.09-1.68, P = 0.005) were significantly more likely to need vasopressors.

CONCLUSIONS

Liberal or conservative oxygen therapy did not influence stroke volume or cardiac output measurements in mechanically ventilated patients with sepsis. Patients in the conservative oxygen group were more likely to require vasopressors than those in the liberal group.

TRIAL REGISTRATION

This study was approved by the Ethics Committee of Aswan University Hospital (approval number: Aswu/460/5/20) (registration date: 05/05/2020) and registered on ClinicalTrials.gov (NCT04824703) (03/30/2021).

Endothelial α1-adrenergic receptor activation improves cardiac function in septic mice via PKC-ERK/p38MAPK signaling pathway

Cardiomyopathy is particularly common in septic patients. Our previous studies have shown that activation of the alpha 1 adrenergic receptor (α1-AR) on cardiomyocytes inhibits sepsis-induced myocardial dysfunction. However, the role of cardiac endothelial α1-AR in septic cardiomyopathy has not been determined. Here, we identified α1-AR expression in mouse and human endothelial cells and showed that activation of α1-AR with phenylephrine (PE) improved cardiac function and survival by preventing cardiac endothelial injury in septic mice. Mechanistically, activating α1-AR with PE decreased the expression of ICAM-1, VCAM-1, iNOS, E-selectin, and p-p38MAPK, while promoting PKC and ERK1/2 phosphorylation in LPS-treated endothelial cells. These effects were abolished by a PKC inhibitor or α1-AR antagonist. PE also reduced p65 nuclear translocation, but this suppression is not blocked by PKC inhibition. Treatment with U0126 (a specific ERK1/2 inhibitor) reversed the effects of PE on p38MAPK phosphorylation. Our results demonstrate that cardiac endothelial α1-AR activation prevents sepsis-induced myocardial dysfunction in mice by inhibiting the endothelial injury via PKC-ERK/p38MAPK signaling pathway and a PKC-independent inhibition of p65 nuclear translocation. These findings offer a new perspective for septic patients with cardiac dysfunction by inhibiting cardiac endothelial cell injury through α1-AR activation.

Cecal necroptosis triggers lethal cardiac dysfunction in TNF-induced severe SIRS

Tumor necrosis factor (TNF) induces systemic inflammatory response syndrome (SIRS), and severe SIRS can serve as a model for studying animal death caused by organ failure. Through strategic cecectomy, we demonstrate that necroptosis in the cecum initiates the death process in TNF-treated mice, but it is not the direct cause of death. Instead, we show that it is the cardiac dysfunction downstream of cecum damage that ultimately leads to the death of TNF-treated mice. By in vivo and ex vivo physiological analyses, we reveal that TNF and the damage-associated molecular patterns (DAMPs) released from necroptotic cecal cells jointly target cardiac endothelial cells, triggering caspase-8 activation and subsequent cardiac endothelial damage. Cardiac endothelial damage is a primary cause of the deterioration of diastolic function in the heart of TNF-treated mice. Our research provides insights into the pathophysiological process of TNF-induced lethality.

The association between integrating echocardiography use in the management of septic shock patients and outcomes in the intensive care unit: a systematic review and meta-analysis

OBJECTIVES

Septic shock in critically ill patients can increases morbidity and mortality. We aimed to study the effect on outcomes when integrating point of care (POC) echocardiography in the management of septic shock patients in the Intensive Care Unit (ICU) who are being treated according to the Surviving Sepsis Campaign (SSC) guidelines.

METHODS

An electronic search of MEDLINE through PubMed, clinical trials.gov and google scholar was conducted for the period from January 1990-January 2024 to identify studies of septic shock adult and pediatric patients in the ICU managed according to SSC guidelines with or without POC echocardiography. Three reviewers extracted data independent of each other. Cochrane collaboration tool was used for bias assessment. Random effect meta-analysis used to pool data.

RESULTS

A total of 1701 articles identified. Seven studies included in the final report with a total of 3885 patients. POC echocardiography guided septic shock management was associated with lower in-hospital and 28-day mortality (sOR = 0.82 [95%CI: 0.71-0.95], p = 0.01), more frequent initiation of inotropic support (sOR = 2.42 [95%CI 1.92-3.03], p < 0.0001) and shorter time to achieve lactate clearance (SMD = - 0.87 h [95%CI - 1.23 h to - 0.51 h], p < 0.0001). Summary estimates did not achieve significance for effect of POC echocardiography on 24-h fluid intake (SMD = - 2.11 ml [95%CI - 5.93 ml to 1.72 ml], p = 0.28) on mechanical ventilation-free days (SMD = 0.03 days [95%CI - 0.04 to 0.10], p = 0.94). Shock reversal time analysis was less meaningful due to the small number of studies reporting outcome.

CONCLUSIONS

POC echocardiography guided management in septic shock patients in the ICU can lead to a decrease in mortality, increase in initiation of inotropic support, and a decrease in lactate clearance time. Larger cohort studies and data collection and analysis are needed for further understanding and optimizing standardization of protocols for POC echocardiography use in septic shock patients in the ICU.

Possible mechanisms of SARS-CoV-2-associated myocardial fibrosis: reflections in the post-pandemic era

Since December 2019, coronavirus disease 2019 (COVID-19) has been spreading worldwide with devastating immediate or long-term effects on people's health. Although the lungs are the primary organ affected by COVID-19, individuals infected with SARS-CoV-2 also develop systemic lesions involving multiple organs throughout the body, such as the cardiovascular system. Emerging evidence reveals that COVID-19 could generate myocardial fibrosis, termed "COVID-19-associated myocardial fibrosis." It can result from the activation of fibroblasts via the renin-angiotensin-aldosterone system (RAAS), transforming growth factor-β1 (TGF-β1), microRNAs, and other pathways, and can also occur in other cellular interactions with SARS-CoV-2, such as immunocytes, endothelial cells. Nonetheless, to gain a more profound insight into the natural progression of COVID-19-related myocardial fibrosis, additional investigations are necessary. This review delves into the underlying mechanisms contributing to COVID-19-associated myocardial fibrosis while also examining the antifibrotic potential of current COVID-19 treatments, thereby offering guidance for future clinical trials of these medications. Ultimately, we propose future research directions for COVID-19-associated myocardial fibrosis in the post-COVID-19 era, such as artificial intelligence (AI) telemedicine. We also recommend that relevant tests be added to the follow-up of COVID-19 patients to detect myocardial fibrosis promptly.

MMP-8 causes leftward shift in end-diastolic pressure-volume relationship and may explain the development of diastolic dysfunction in septic cardiomyopathy

Septic cardiomyopathy (SCM) with diastolic dysfunction carries a poor prognosis, and the mechanisms underlying the development of diastolic dysfunction remain unclear. Matrix metalloproteinase-8 (MMP-8) is released from neutrophils and degrades collagen I. MMP-8 levels correlate with SCM severity. We scrutinized, for the first time, the direct impact of MMP-8 on cardiac systolic and diastolic functions. Isolated rat hearts were perfused with Krebs-Henseleit solution in a Langendorff setup with computer-controlled filling pressures of both ventricles in an isovolumetric regime. The end-diastolic pressure (EDP) varied periodically between 3 and 20 mmHg. After baseline recordings, MMP-8 (100 µg/mL) was added to the perfusion. Short-axis views of both ventricles were continuously acquired by echocardiography. MMP-8 perfusion resulted in a progressive decline in peak systolic pressures (Psys) in both ventricles, but without significant changes in their end-systolic pressure-area relationships (ESPARs). Counterintuitively, conspicuous leftward shifts of the end-diastolic pressure-area relationships (EDPARs) were observed in both ventricles. The left ventricle (LV) end-diastolic area (EDA) decreased by 32.8 ± 5.7% (P = 0.008) at an EDP of 10.5 ± 0.4 mmHg, when LV Psys dropped by 20%. The decline of Psys was primarily due to the decrease in EDA, and restoring the baseline EDA by increasing EDP recovered 81.33 ± 5.87% of the pressure drop. Collagen I generates tensile (eccentric) stress, and its degradation by MMP-8 causes end-diastolic pressure-volume relationship (EDPVR) leftward shift, resulting in diastolic and systolic dysfunctions. The diastolic dysfunction explains the clinically observed fluid unresponsiveness, whereas the decrease in end-diastolic volume (EDV) diminishes the systolic functions. MMP-8 can explain the development of SCM with diastolic dysfunction.NEW & NOTEWORTHY MMP-8, released from activated neutrophils and macrophages, is markedly elevated in sepsis, correlating with sepsis severity and mortality. MMP-8 targets collagen I of the cardiac ECM and induces diastolic dysfunction with fluid unresponsiveness, associated with decreased EDV, reduced sarcomere length, and diminished systolic function. Unlike other MMPs that predominantly cleave collagen-III and contribute to cardiac dilatation, thereby increasing sarcomere length, MMP-8 leads to a leftward shift in the EDPVR, resulting in diastolic and systolic dysfunctions.

m6A methylation in myocardial tissue of septic mice analyzed using MeRIP/m6A-sequencing and RNA-sequencing

Septic cardiomyopathy is a secondary myocardial injury caused by sepsis. N6-methyl-adenosine (m6A) modification is involved in the pathological progression of septic cardiomyopathy; however, the pathological mechanism remains unclear. In this study, we identified the overall m6A modification pattern in septic myocardial injury and determined its potential interactions with differentially expressed genes (DEGs). A sepsis mouse model exhibiting septic symptoms and myocardial tissue damage was induced by lipopolysaccharide (LPS). LPS-induced septic myocardial tissues and control myocardial tissues were subjected to methylated RNA immunoprecipitation sequencing and RNA sequencing to screen for differentially expressed m6A peaks and DEGs. We identified 859 significantly m6A-modified genes in septic myocardial tissues, including 432 upregulated and 427 downregulated genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to explore the biological importance of differentially expressed m6A methylated genes and DEGs. Differentially expressed m6A methylated genes were enriched in immune- and inflammation-related pathways. Conjoint analysis revealed co-expression of differentially expressed m6A genes and DEGs, including genes that were upregulated or downregulated and those showing opposite trends. High expression of m6A-related genes (WTAP and IGF2BP2), interleukin-17, and interleukin-17 pathway-related genes (MAPK11 and TRAF3IP2) was verified using reverse transcription-quantitative PCR. We confirmed the presence of m6A modification of the transcriptome and m6A-mediated gene expression in septic myocardial tissues.

Hemodynamic goals in sepsis and septic shock resuscitation: An umbrella review of systematic reviews and meta-analyses with trial sequential analysis

OBJECTIVE

The objective of this study was to verify whether any parameter among those used as the target for haemodynamic optimisation (e.g., mean arterial pressure, central venous oxygen saturation, systolic or diastolic dysfunction, CO2 gap, lactates, right ventricular dysfunction, and PvaCO2/CavO2 ratio) is correlated with mortality in an undifferentiated population with sepsis or septic shock.

METHODS

An umbrella review, searching MEDLINE, the Cochrane Database of Systematic Reviews, Health Technology Assessment Database, and the JBI Database of Systematic Reviews and Implementation Reports, was performed. We included systematic reviews and meta-analyses enrolling a population of unselected patients with sepsis or septic shock. The main outcome was mortality. Two authors conducted data extraction and risk-of-bias assessments independently. We used a random-effects model to pool binary and continuous data and summarised estimates of effect using equivalent odds ratios (eORs). We used the ROBIS tool to assess risk of bias and the assessment of multiple systematic reviews 2 score to assess global quality.

DATA SYNTHESIS

17 systematic reviews and meta-analyses (15 828 patients) were included in the quantitative analysis. Diastolic dysfunction (eOR: 1.42; 95% confidence interval [CI]: 1.14-1.76), PvaCO2/CavO2 ratio (eOR: 2.15; 95% CI: 1.37-3.37), and CO2 gap (eOR: 1.86; 95% CI: 1.07-3.25) showed a significant correlation with mortality. Lactates were the parameter with highest inconsistency (I2 = 92%). Central venous oxygen saturation and right ventricle dysfunction showed significant statistical excess test of significance (p-value = 0.009 and 0.005, respectively). None of the considered parameters showed statistically significant publication bias.

CONCLUSIONS

According to this umbrella review, diastolic dysfunction is the haemodynamic variable that is most closely linked to the prognosis of septic patients. The PvaCO2/CavO2 ratio and the CO2gap are significantly related to the mortality of septic patients, but the poor quality of evidence or the low number of cases, studied so far, limit their clinical applicability.

CLINICAL TRIAL REGISTRATION

PROSPERO: International prospective register of systematic reviews, 2023, CRD42023432813 (Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023432813).

From Molecular Mechanisms to Clinical Therapy: Understanding Sepsis-Induced Multiple Organ Dysfunction

Sepsis-induced multiple organ dysfunction arises from the highly complex pathophysiology encompassing the interplay of inflammation, oxidative stress, endothelial dysfunction, mitochondrial damage, cellular energy failure, and dysbiosis. Over the past decades, numerous studies have been dedicated to elucidating the underlying molecular mechanisms of sepsis in order to develop effective treatments. Current research underscores liver and cardiac dysfunction, along with acute lung and kidney injuries, as predominant causes of mortality in sepsis patients. This understanding of sepsis-induced organ failure unveils potential therapeutic targets for sepsis treatment. Various novel therapeutics, including melatonin, metformin, palmitoylethanolamide (PEA), certain herbal extracts, and gut microbiota modulators, have demonstrated efficacy in different sepsis models. In recent years, the research focus has shifted from anti-inflammatory and antioxidative agents to exploring the modulation of energy metabolism and gut microbiota in sepsis. These approaches have shown a significant impact in preventing multiple organ damage and mortality in various animal sepsis models but require further clinical investigation. The accumulation of this knowledge enriches our understanding of sepsis and is anticipated to facilitate the development of effective therapeutic strategies in the future.

Nucleic acid-based nanotherapeutics for treating sepsis and associated organ injuries

In recent years, gene therapy has been made possible with the success of nucleic acid drugs against sepsis and its related organ dysfunction. Therapeutics based on nucleic acids such as small interfering RNAs (siRNAs), microRNAs (miRNAs), messenger RNAs (mRNAs), and plasmid DNAs (pDNAs) guarantee to treat previously undruggable diseases. The advantage of nucleic acid-based therapy against sepsis lies in the development of nanocarriers, achieving targeted and controlled gene delivery for improved efficacy with minimal adverse effects. Entrapment into nanocarriers also ameliorates the poor cellular uptake of naked nucleic acids. In this study, we discuss the current state of the art in nanoparticles for nucleic acid delivery to treat hyperinflammation and apoptosis associated with sepsis. The optimized design of the nanoparticles through physicochemical property modification and ligand conjugation can target specific organs-such as lung, heart, kidney, and liver-to mitigate multiple sepsis-associated organ injuries. This review highlights the nanomaterials designed for fabricating the anti-sepsis nanosystems, their physicochemical characterization, the mechanisms of nucleic acid-based therapy in working against sepsis, and the potential for promoting the therapeutic efficiency of the nucleic acids. The current investigations associated with nanoparticulate nucleic acid application in sepsis management are summarized in this paper. Noteworthily, the potential application of nanotherapeutic nucleic acids allows for a novel strategy to treat sepsis. Further clinical studies are required to confirm the findings in cell- and animal-based experiments. The capability of large-scale production and reproducibility of nanoparticle products are also critical for commercialization. It is expected that numerous anti-sepsis possibilities will be investigated for nucleic acid-based nanotherapeutics in the future.

NOVEL ECHOCARDIOGRAM ANALYSIS OF CARDIAC DYSFUNCTION IS ASSOCIATED WITH MORTALITY IN PEDIATRIC SEPSIS

ABSTRACT

Objectives: The objective of our study was to semiautomatically generate echocardiogram indices in pediatric sepsis using novel algorithms and determine which indices were associated with mortality. We hypothesized that strain and diastolic indices would be most associated with mortality. Design: Retrospective cohort study of children with sepsis from 2017 to 2022. Survivors and nonsurvivors were compared for echocardiogram indices. Multivariate Cox proportional hazard models were constructed for our primary outcome of in-hospital mortality. Linear regression was performed for secondary outcomes, which included multiple composite 28-day outcomes. Results: Of the 54 patients in the study, 9 (17%) died. Multiple echocardiogram indices of both right (RV) and left ventricles (LV) were associated with in-hospital mortality [RV GLS adjusted hazard ratio (aHR): 1.16 (1.03-1.29), P = 0.011; RV global longitudinal early diastolic strain rate (GLSre) aHR: 0.24 (0.07 to 0.75), P = 0.014; LV GLSre aHR: 0.33 (0.11-0.97), P = 0.044]. Impairment in GLS was associated with fewer ventilator-free days [RV GLS β-coefficient: -0.47 (-0.84 to -0.10), P = 0.013; LV GLS β-coefficient -0.62 (-1.07 to -0.17), P = 0.008], organ-support free days [RV GLS β-coefficient: -0.49 (-0.87 to -0.11), P = 0.013; LV GLS β-coefficient: -0.64 (-1.10 to -0.17), P = 0.008], and days free from ICU [RV GLS β-coefficient: -0.42 (-0.79 to -0.05), P = 0.026; LV GLS β-coefficient: -0.58 (-1.03 to -0.13), P = 0.012]. Systolic indices were not associated with mortality in this cohort. Conclusion: Our study demonstrates the feasibility of obtaining echocardiogram indices in a semiautomatic method using our algorithms. We showed that abnormal strain is associated with worse outcomes in a cohort of children with sepsis.

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.

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.

Epigallocatechin-3-gallate protects sepsis-induced myocardial dysfunction by inhibiting the nuclear factor-κB signaling pathway

Sepsis-induced myocardial dysfunction (SIMD) has become one of the most lethal complications of sepsis, while the treatment was limited by a shortage of pertinent drugs. Epigallocatechin-3-gallate (EGCG) is the highest content of active substances in green tea, and its application in cardiovascular diseases has broad prospects. This study was conducted to test the hypothesis that EGCG was able to inhibit lipopolysaccharide (LPS) induced myocardial dysfunction and investigate the underlying molecular mechanisms. The cardiac systolic function was assessed by echocardiography. The cardiomyocyte apoptosis was determined by TUNEL staining. The expression of inflammatory factors and apoptosis-related protein, cardiac markers were examined by Western Blot and qRT-PCR. EGCG effectively improve LPS-induced cardiac function damage, enhance left ventricular systolic function, and restore myocardial cell vitality. It can effectively inhibit the upregulation of TLR4 expression induced by LPS and inhibit IκB α/NF- κB/p65 signaling pathway, thereby inhibiting cardiomyocyte apoptosis and improving myocarditis. In conclusion, EGCG protects against SIMD through anti-inflammatory and anti-apoptosis effects; it was mediated by the inhibition of the TLR4/NF-κB signal pathway. Our results demonstrated that EGCG might be a possible medicine for SIMD prevention and treatment.

Effect of miR-412-5p-loaded exosomes in H9c2 cardiomyocytes via the MAPK pathway

Objectives

MicroRNAs (miRNAs) are small non-coding RNAs that function in all biological processes. Recent findings suggest that exosomes, which are small vesicles abundantly secreted by various cell types, can transport miRNAs to target cells. Here, we elucidated the effect of miRNA-loaded exosomes on lipopolysaccharide (LPS)-induced inflammation in H9c2 cardiomyocytes.

Materials and Methods

Exosomes were isolated from mesenchymal stem cells (MSC) and loaded with miR-412-5p. Additionally, the effect of the miR-412-5p-loaded exosomes on LPS-induced inflammation in H9c2 cardiomyocytes was evaluated by assessing the levels of nitric oxide (NO), reactive oxygen species (ROS), and prostaglandin E2 (PGE2). The expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), inflammatory cytokines, and mitogen-activated protein kinase (MAPK) signaling factors was evaluated using reverse transcription-quantitative PCR and western blotting.

Results

miR-412-5p-loaded exosomes inhibited LPS-induced secretion of inflammatory mediators (NO, PGE2, and ROS), pro-inflammatory cytokines (IL-1β and IL-6), and COX-2 and iNOS expression. Additionally, miR-412-5p-loaded exosomes significantly decreased the expression of MAPK signaling molecules, including p-extracellular signal-regulated kinase (ERK), p-p38, and p-Jun kinase (JNK), in H9c2 cardiomyocytes.

Conclusion

These findings showed that miR-412-5p-loaded exosomes ameliorated LPS-induced inflammation in H9c2 cardiomyocytes by inhibiting COX-2 and iNOS expression, inflammatory mediators, and pro-inflammatory cytokines via the MAPK pathway. The findings indicate that miR-412-5p-loaded exosomes may be effective for the prevention of myocardial injury.

Septic Cardiomyopathy

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis-induced myocardial dysfunction represents reversible myocardial dysfunction which ultimately results in left ventricular dilatation or both, with consequent loss of contractility. Studies on septic cardiomyopathy report a wide range of prevalence ranging from 10% to 70%. Myocardial damage occurs as a result of weakened myocardial circulation, direct myocardial depression, and mitochondrial dysfunction. Mitochondrial dysfunction is the leading problem in the development of septic cardiomyopathy and includes oxidative phosphorylation, production of reactive oxygen radicals, reprogramming of energy metabolism, and mitophagy. Echocardiography provides several possibilities for the diagnosis of septic cardiomyopathy. Systolic and diastolic dysfunction of left ventricular is present in 50-60% of patients with sepsis. Right ventricular dysfunction is present in 50-55% of cases, while isolated right ventricular dysfunction is present in 47% of cases. Left ventricle (LV) diastolic dysfunction is very common in septic shock, and it represents an early biomarker, it has prognostic significance. Right ventricular dysfunction associated with sepsis patients with worse early prognosis. Global longitudinal stress and magnetic resonance imaging (MRI) of the heart are sufficiently sensitive methods, but at the same time MRI of the heart is difficult to access in intensive care units, especially when dealing with critically ill patients. Previous research has identified two biomarkers as a result of the integrated mitochondrial response to stress, and these are fibroblast growth factor-21 (FGF-21) and growth differentiation factor-15 (GDF-15). Both of the mentioned biomarkers can be easily quantified in serum or plasma, but they are difficult to be specific in patients with multiple comorbidities. Mitochondrial dysfunction is also associated with reduced levels of miRNA (microRNA), some research showed significance of miRNA in sepsis-induced myocardial dysfunction, but further research is needed to determine the clinical significance of these molecules in septic cardiomyopathy. Therapeutic options in the treatment of septic cardiomyopathy are not specific, and include the optimization of hemodynamic parameters and the use of antibiotic thera-pies with targeted action. Future research aims to find mechanisms of targeted action on the initial mechanisms of the development of septic cardiomyopathy.

Sedation for Patients with Sepsis: Towards a Personalised Approach

This article looks at the challenges of sedoanalgesia for sepsis patients, and argues for a personalised approach. Sedation is a necessary part of treatment for patients in intensive care to reduce stress and anxiety and improve long-term prognoses. Sepsis patients present particular difficulties as they are at increased risk of a wide range of complications, such as multiple organ failure, neurological dysfunction, septic shock, ARDS, abdominal compartment syndrome, vasoplegic syndrome, and myocardial dysfunction. The development of any one of these complications can cause the patient's rapid deterioration, and each has distinct implications in terms of appropriate and safe forms of sedation. In this way, the present article reviews the sedative and analgesic drugs commonly used in the ICU and, placing special emphasis on their strategic administration in sepsis patients, develops a set of proposals for sedoanalgesia aimed at improving outcomes for this group of patients. These proposals represent a move away from simplistic approaches like avoiding benzodiazepines to more "objective-guided sedation" that accounts for a patient's principal pathology, as well as any comorbidities, and takes full advantage of the therapeutic arsenal currently available to achieve personalised, patient-centred treatment goals.

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.

The role of beta-blocker drugs in critically ill patients: a SIAARTI expert consensus statement

BACKGROUND

The role of β-blockers in the critically ill has been studied, and data on the protective effects of these drugs on critically ill patients have been repeatedly reported in the literature over the last two decades. However, consensus and guidelines by scientific societies on the use of β-blockers in critically ill patients are still lacking. The purpose of this document is to support the clinical decision-making process regarding the use of β-blockers in critically ill patients. The recipients of this document are physicians, nurses, healthcare personnel, and other professionals involved in the patient's care process.

METHODS

The Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care (SIAARTI) selected a panel of experts and asked them to define key aspects underlying the use of β-blockers in critically ill adult patients. The methodology followed by the experts during this process was in line with principles of modified Delphi and RAND-UCLA methods. The experts developed statements and supportive rationales in the form of informative text. The overall list of statements was subjected to blind votes for consensus.

RESULTS

The literature search suggests that adrenergic stress and increased heart rate in critically ill patients are associated with organ dysfunction and increased mortality. Heart rate control thus seems to be critical in the management of the critically ill patient, requiring careful clinical evaluation aimed at both the differential diagnosis to treat secondary tachycardia and the treatment of rhythm disturbance. In addition, the use of β-blockers for the treatment of persistent tachycardia may be considered in patients with septic shock once hypovolemia has been ruled out. Intravenous application should be the preferred route of administration.

CONCLUSION

β-blockers protective effects in critically ill patients have been repeatedly reported in the literature. Their use in the acute treatment of increased heart rate requires understanding of the pathophysiology and careful differential diagnosis, as all causes of tachycardia should be ruled out and addressed first.

Decoding molecular signature on heart of septic mice with distinct left ventricular ejection fraction

Dysregulated cardiac function after sepsis in intensive care unit is known to predict poor long-term outcome and increase mortality. Their pathological feature and molecular mechanism remain unclear. We observed that septic patients with depressed left ventricular ejection fraction (LVEF) have the highest in-hospital and 28 days mortality comparing to patients with hyperdynamic LVEF or with heart failure with preserved LVEF. Echocardiograms reveal that survivors post cecum ligation and puncture (CLP) on rodents have stable LVEF and non-survivors have fluctuated LVEF at CLP early phase. CLP-induced mice fall into three groups based on LVEF 24 h post-surgery: high-, low-, and normal-LVEF. Transcriptomic and proteomic analyses identify jointly and distinctively changed genes, proteins and biologically essential pathways in left ventricles from three CLP groups. Notably, transmission electron microscopy shows different mitochondrial and sarcomere defects associated with LVEF variances. Together, this study systematically characterizes the molecular, morphological, and functional alterations in CLP-induced cardiac injury.

Understanding yellow fever-associated myocardial injury: an autopsy study

BACKGROUND

Yellow fever (YF) is a viral hemorrhagic fever, endemic in parts of South America and Africa. There is scarce evidence about the pathogenesis of the myocardial injury. The objective of this study is to evaluate the cardiac pathology in fatal cases of YF.

METHODS

This retrospective autopsy study included cases from the São Paulo (Brazil) epidemic of 2017-2019. We reviewed medical records and performed cardiac tissue histopathological evaluation, electron microscopy, immunohistochemical assays, RT-qPCR for YF virus (YFV)-RNA, and proteomics analysis on inflammatory and endothelial biomarkers.

FINDINGS

Seventy-three confirmed YF cases with a median age of 48 (34-60) years were included. We observed myocardial fibrosis in 68 (93.2%) patients; cardiomyocyte hypertrophy in 68 (93.2%); endothelial alterations in 67 (91.8%); fiber necrosis in 50 (68.5%); viral myocarditis in 9 (12.3%); and secondary myocarditis in 5 (6.8%). Four out of five patients with 17DD vaccine-associated viscerotropic disease presented with myocarditis. The cardiac conduction system showed edema, hemorrhages and endothelial fibrinoid necrosis. Immunohistochemistry detected CD68-positive inflammatory interstitial cells and YFV antigens in endothelial and inflammatory cells. YFV-RNA was detected positive in 95.7% of the cardiac samples. The proteomics analysis demonstrated that YF patients had higher levels of multiple inflammatory and endothelial biomarkers in comparison to cardiovascular controls, and higher levels of interferon gamma-induced protein 10 (IP-10) in comparison to sepsis (p = 0.01) and cardiovascular controls (p < 0.001) in Dunn test.

INTERPRETATION

Myocardial injury is frequent in severe YF, due to multifactorial mechanisms, including direct YFV-mediated damage, endothelial cell injury, and inflammatory response, with a possible prominent role for IP-10.

FUNDING

This study was funded by Fundação de Amparo à Pesquisa do Estado de São Paulo, Bill and Melinda Gates Foundation, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.

Therapeutic S100A8/A9 blockade inhibits myocardial and systemic inflammation and mitigates sepsis-induced myocardial dysfunction

BACKGROUND AND AIMS

The triggering factors of sepsis-induced myocardial dysfunction (SIMD) are poorly understood and are not addressed by current treatments. S100A8/A9 is a pro-inflammatory alarmin abundantly secreted by activated neutrophils during infection and inflammation. We investigated the efficacy of S100A8/A9 blockade as a potential new treatment in SIMD.

METHODS

The relationship between plasma S100A8/A9 and cardiac dysfunction was assessed in a cohort of 62 patients with severe sepsis admitted to the intensive care unit of Linköping University Hospital, Sweden. We used S100A8/A9 blockade with the small-molecule inhibitor ABR-238901 and S100A9-/- mice for therapeutic and mechanistic studies on endotoxemia-induced cardiac dysfunction in mice.

RESULTS

In sepsis patients, elevated plasma S100A8/A9 was associated with left-ventricular (LV) systolic dysfunction and increased SOFA score. In wild-type mice, 5 mg/kg of bacterial lipopolysaccharide (LPS) induced rapid plasma S100A8/A9 increase and acute LV dysfunction. Two ABR-238901 doses (30 mg/kg) administered intraperitoneally with a 6 h interval, starting directly after LPS or at a later time-point when LV dysfunction is fully established, efficiently prevented and reversed the phenotype, respectively. In contrast, dexamethasone did not improve cardiac function compared to PBS-treated endotoxemic controls. S100A8/A9 inhibition potently reduced systemic levels of inflammatory mediators, prevented upregulation of inflammatory genes and restored mitochondrial function in the myocardium. The S100A9-/- mice were protected against LPS-induced LV dysfunction to an extent comparable with pharmacologic S100A8/A9 blockade. The ABR-238901 treatment did not induce an additional improvement of LV function in the S100A9-/- mice, confirming target specificity.

CONCLUSION

Elevated S100A8/A9 is associated with the development of LV dysfunction in severe sepsis patients and in a mouse model of endotoxemia. Pharmacological blockade of S100A8/A9 with ABR-238901 has potent anti-inflammatory effects, mitigates myocardial dysfunction and might represent a novel therapeutic strategy for patients with severe sepsis.

Baricitinib protects mice from sepsis-induced cardiac dysfunction and multiple-organ failure

Sepsis is one of the major complications of surgery resulting in high morbidity and mortality, but there are no specific therapies for sepsis-induced organ dysfunction. Data obtained under Gene Expression Omnibus accession GSE131761 were re-analyzed and showed an increased gene expression of Janus Kinase 2 (JAK2) and Signal Transducer and Activator of Transcription 3 (STAT3) in the whole blood of post-operative septic patients. Based on these results, we hypothesized that JAK/STAT activation may contribute to the pathophysiology of septic shock and, hence, investigated the effects of baricitinib (JAK1/JAK2 inhibitor) on sepsis-induced cardiac dysfunction and multiple-organ failure (MOF). In a mouse model of post-trauma sepsis induced by midline laparotomy and cecal ligation and puncture (CLP), 10-week-old male (n=32) and female (n=32) C57BL/6 mice received baricitinib (1mg/kg; i.p.) or vehicle at 1h or 3h post-surgery. Cardiac function was assessed at 24h post-CLP by echocardiography in vivo, and the degree of MOF was analyzed by determination of biomarkers in the serum. The potential mechanism underlying both the cardiac dysfunction and the effect of baricitinib was analyzed by western blot analysis in the heart. Trauma and subsequent sepsis significantly depressed the cardiac function and induced multiple-organ failure, associated with an increase in the activation of JAK2/STAT3, NLRP3 inflammasome and NF- κβ pathways in the heart of both male and female animals. These pathways were inhibited by the administration of baricitinib post the onset of sepsis. Moreover, treatment with baricitinib at 1h or 3h post-CLP protected mice from sepsis-induced cardiac injury and multiple-organ failure. Thus, baricitinib may be repurposed for trauma-associated sepsis.

Estradiol as the Trigger of Sirtuin-1-Dependent Cell Signaling with a Potential Utility in Anti-Aging Therapies

Aging entails the inevitable loss of the structural and functional integrity of cells and tissues during the lifetime. It is a highly hormone-dependent process; although, the exact mechanism of hormone involvement, including sex hormones, is unclear. The marked suppression of estradiol synthesis during menopause suggests that the hormone may be crucial in maintaining cell lifespan and viability in women. Recent studies also indicate that the same may be true for men. Similar anti-aging features are attributed to sirtuin 1 (SIRT1), which may possibly be linked at the molecular level with estradiol. This finding may be valuable for understanding the aging process, its regulation, and possible prevention against unhealthy aging. The following article summarizes the initial studies published in this field with a focus on age-associated diseases, like cancer, cardiovascular disease and atherogenic metabolic shift, osteoarthritis, osteoporosis, and muscle damage, as well as neurodegenerative and neuropsychiatric diseases.

Cardiac troponin as a prognosticator of mortality in patients with sepsis: A systematic review and meta-analysis

BACKGROUND

The impact of cardiac troponin on the short-term and long-term prognosis of patients with sepsis remains uncertain. Therefore, we conducted a meta-analysis to investigate the role of cardiac troponin as a potential indicator for sepsis mortality.

METHODS

We performed a comprehensive search for articles published before November 2022 using Google Scholar, PubMed, and Web of Science. Inclusion criteria for the studies were: (1) investigation of cardiac troponin, and (2) investigation of sepsis. Exclusion criteria included: (1) inability to obtain or calculate hazard ratio (HR) and 95% confidence interval (CI) for the relationship between cardiac troponin level and sepsis mortality, and (2) reviews, meta-analyses, and case reports. Analysis of HRs and 95% CIs for the association between cardiac troponin level and sepsis mortality was conducted using STATA 12.0 software.

RESULTS

Our study included 24 prospective studies (comprising 20,457 sepsis patients) and 4 retrospective studies (comprising 1416 sepsis patients). Meta-analysis demonstrated that elevated cardiac troponin levels were significantly associated with increased sepsis mortality using a random effects model (HR = 1.57, 95% CI 1.41-1.75). Moreover, elevated cardiac troponin levels were also significantly associated with increased hospital mortality of sepsis (HR = 1.35, 95% CI 1.19-1.53) and long-term mortality of sepsis (HR = 1.96, 95% CI 1.51-2.55) using the random effects model.

CONCLUSIONS

Overall, our finding revealed that elevated cardiac troponin for sepsis patients was a predictor of hospital and long-term mortality. Clinicians may treat septic patients with elevated cardiac troponin more cautious to avoid extra death. Moreover, large clinical studies are warranted to validate this association.

Xanthohumol ameliorates cardiac injury induced by sepsis in a mice model: role of toll-like receptor 4

Sepsis, a life-threatening condition arising from infection, often results in multi-organ failure, including cardiac dysfunction. This study investigated Xanthohumol, a natural compound, and its potential mechanism of action to enhance heart function following sepsis. A total of twenty-four adult male Swiss albino mice were allocated randomly to one of four equal groups (n=6): sham, CLP, vehicle Xanthohumol the same amount of DMSO injected IP 10 minutes before the CLP, and Xanthohumol group (0.4 mg/kg of Xanthohumol administered IP before the CLP process). Toll-like receptor 4, pro-inflammatory mediators, anti-inflammatory markers, oxidative stress indicators, apoptosis markers, and serum cardiac damage biomarkers were measured in the cardiac tissue using ELISA. Data with normal distribution were analyzed using t-test and ANOVA tests (p<0.05). In comparison to the sham group, the sepsis group had significantly higher levels of TLR-4, IL-6, TNF-α, MIF, F2-isoprostane, caspase-3, cTn-I, and CK-MB, while the pre-treated group with Xanthohumol had significantly lower levels (p<0.05) of these markers than the sepsis group. Bcl-2 showed no significant difference in Xanthohumol pre-treated group relative to the sepsis group, while IL-10 was significantly elevated. Xanthohumol dramatically reduced cardiac tissue injury (p<0.05) relative to the CLP group. By blocking the downstream signal transduction pathways of TLR-4 and NF-kB, Xanthohumol was shown to lessen cardiac damage in male mice during CLP-induced polymicrobial sepsis.

Effect of Sulforaphane on cardiac injury induced by sepsis in a mouse model: Role of toll-like receptor 4

As sepsis is associated with a 50% increase in mortality, sepsis-induced cardiomyopathy has become a critical topic. A multidisciplinary approach is required for the diagnosis and treatment of septic cardiomyopathy. This study looked at Sulforaphane, a natural product that aims to evaluate cardiac function after sepsis, and its likely mechanism of action. Twenty-four adult male Swiss albino mice were randomly divided into 4 equal groups (n=6): sham, CLP, vehicle Sulforaphane (the same amount of DMSO injected IP one hour before the CLP), and Sulforaphane group (one hour before the CLP, a 5mg/kg dose of Sulforaphane was injected). Cardiac tissue levels of toll-like receptor 4 (TLR-4), pro-inflammatory mediators, anti-inflammatory markers, oxidative stress markers, apoptosis markers, and serum cardiac damage biomarkers were assessed using ELISA. Statistical analyses, including t-tests and ANOVA tests, were performed with a significance level of 0.05 for normally distributed data. Compared to the sham group, the sepsis group had significantly elevated levels of TLR-4, IL-6, TNF-α, MIF, F2-isoprostane, caspase-3, cTn-I, and CK-MB (p<0.05). In contrast, the Sulforaphane pre-treated group demonstrated significantly lower levels of these markers (p<0.05). Additionally, Bcl-2 levels were significantly reduced (p<0.05) in the Sulforaphane group. Sulforaphane administration also significantly attenuated cardiac tissue injury (p<0.05). The findings suggest that Sulforaphane can decrease heart damage in male mice during CLP-induced polymicrobial sepsis by suppressing TLR-4/NF-kB downstream signal transduction pathways.

Role of Pellino-1 in Inflammation and Cardioprotection following Severe Sepsis: A Novel Mechanism in a Murine Severe Sepsis Model †

OBJECTIVES

Intra-abdominal sepsis is commonly diagnosed in the surgical population and remains the second most common cause of sepsis overall. Sepsis-related mortality remains a significant burden in the intensive care unit despite advances in critical care. Nearly a quarter of the deaths in people with heart failure are caused by sepsis. We have observed that overexpression of mammalian Pellino-1 (Peli1), an E3 ubiquitin ligase, causes inhibition of apoptosis, oxidative stress, and preservation of cardiac function in a myocardial infarction model. Given these manifold applications, we investigated the role of Peli1 in sepsis using transgenic and knockout mouse models specific to this protein. Therefore, we aimed to explore further the myocardial dysfunction seen in sepsis through its relation to the Peli 1 protein by using the loss of function and gain-of-function strategy.

METHODS

A series of genetic animals were created to understand the role of Peli1 in sepsis and the preservation of heart function. Wild-type, global Peli1 knock out (Peli1-/-), cardiomyocyte-specific Peli1 deletion (CP1KO), and cardiomyocyte-specific Peli1 overexpressing (alpha MHC (αMHC) Peli1; AMPEL1Tg/+) animals were divided into sham and cecal ligation and puncture (CLP) surgical procedure groups. Cardiac function was determined by two-dimensional echocardiography pre-surgery and at 6- and 24-h post-surgery. Serum IL-6 and TNF-alpha levels (ELISA) (6 h), cardiac apoptosis (TUNEL assay), and Bax expression (24 h) post-surgery were measured. Results are expressed as mean ± S.E.M.

RESULTS

AMPEL1Tg/+ prevents sepsis-induced cardiac dysfunction assessed by echocardiographic analysis, whereas global and cardiomyocyte-specific deletion of Peli1 shows significant deterioration of cardiac functions. Cardiac function was similar across the sham groups in all three genetically modified mice. ELISA assay displayed how Peli 1 overexpression decreased cardo-suppressive circulating inflammatory cytokines (TNF-alpha, IL-6) compared to both the knockout groups. The proportion of TUNEL-positive cells varied according to Peli1 expression, with overexpression (AMPEL1Tg/+) leading to a significant reduction and Peli1 gene knockout (Peli1-/- and CP1KO) leading to a significant increase in their presence. A similar trend was also observed with Bax protein expression. The improved cellular survival associated with Peli1 overexpression was again shown with the reduction of oxidative stress marker 4-Hydroxy-2-Nonenal (4-HNE).

CONCLUSION

Our results indicate that overexpression of Peli1 is a novel approach that not only preserved cardiac function but reduced inflammatory markers and apoptosis following severe sepsis in a murine genetic model.

Circulating protein and lipid markers of early sepsis diagnosis and prognosis: a scoping review

PURPOSE OF REVIEW

Sepsis is the extreme response to infection associated with high mortality, yet reliable biomarkers for its identification and stratification are lacking.

RECENT FINDINGS

Our scoping review of studies published from January 2017 to September 2022 that investigated circulating protein and lipid markers to inform non-COVID-19 sepsis diagnosis and prognosis identified interleukin (IL)-6, IL-8, heparin-binding protein (HBP), and angiopoietin-2 as having the most evidence. Biomarkers can be grouped according to sepsis pathobiology to inform biological data interpretation and four such physiologic processes include: immune regulation, endothelial injury and coagulopathy, cellular injury, and organ injury. Relative to proteins, the pleiotropic effects of lipid species' render their categorization more difficult. Circulating lipids are relatively less well studied in sepsis, however, low high-density lipoprotein (HDL) is associated with poor outcome.

SUMMARY

There is a lack of robust, large, and multicenter studies to support the routine use of circulating proteins and lipids for sepsis diagnosis or prognosis. Future studies will benefit from standardizing cohort design as well as analytical and reporting strategies. Incorporating biomarker dynamic changes and clinical data in statistical modeling may improve specificity for sepsis diagnosis and prognosis. To guide future clinical decisions at the bedside, point-of-care circulating biomarker quantification is needed.

Septic cardiomyopathy: A narrative review

Sepsis is a systemic inflammatory response syndrome of suspected or documented infectious origin, whose outcome is multiorgan failure. Sepsis-induced myocardial dysfunction (SIMD), present in more than 50% of septic patients, is characterized by (i) left ventricular (LV) dilatation with normal or low filling pressure, (ii) right and/or LV (systolic and/or diastolic) dysfunction and (iii) reversibility. Since the first definition proposed by Parker et al. in 1984, attempts have been made to define SIMD. Many parameters are used to assess cardiac function in septic patients, sometimes making it more difficult to measure due to the intrinsic hemodynamical changes in this condition. Nevertheless, with advanced echocardiographic techniques, such as speckle tracking analysis, it is possible to diagnose and assess systolic and diastolic dysfunction, even in the earliest stages of sepsis. Cardiac magnetic resonance imaging brings new insights into the reversibility of this condition. Many uncertainties still remain regarding the mechanisms, characteristics, treatment and even prognosis of this condition. There are also inconsistent conclusions from studies, therefore this review attempts to summarize our current knowledge of SIMD.

Mitochondrial transplantation protects against sepsis-induced myocardial dysfunction by modulating mitochondrial biogenesis and fission/fusion and inflammatory response

BACKGROUND

Sepsis-induced myocardial dysfunction is associated with worse clinical outcomes and high mortality, but no effective therapeutic intervention has been explored, reinforcing the urgent need to develop innovative strategies. Mitochondrial dysfunction underlies the pathogenesis of sepsis-induced myocardial dysfunction. Herein, we assessed the effect of mitochondrial transplantation on sepsis-induced myocardial dysfunction in a rat model of cecal ligation and puncture (CLP)-induced sepsis.

METHODS

Male Wistar rats (n = 80, 12 weeks old, 250-300 g) were divided into groups with/without CLP-induced sepsis receiving mitochondrial transplantation in single or two repetitive injections (1 h or 1 and 7 h post-CLP, respectively). Mitochondria were isolated from donor rats and injected intravenously (400 µl of mitochondrial suspension containing 7.5 × 10⁶ mitochondria/ml of respiration buffer) in recipient groups. Twenty-four hours post-operation, LDH and cTn-I levels, mitochondrial functional endpoints, expression of mitochondrial biogenesis (SIRT-1 and PGC-1α) and fission/fusion (Drp1/Mfn1 and Mfn2) genes, and inflammatory cytokines (TNF-α, IL-1β, and IL-6) levels were evaluated. Survival was tested over 72 h post-operation.

RESULTS

Mitotherapy significantly improved 72-hours survival (P < .05) and decreased LDH and cTn-I levels (P < .01). It also restored mitochondrial function and expression of mitochondrial biogenesis and fusion genes, and decreased the expression of mitochondrial fission gene and the levels of inflammatory cytokines (P < .05 to P < .01). Mitotherapy with repetitive injections at 1 and 7 h post-CLP provided noticeable mitoprotection in comparison with the group receiving mitotherapy at single injection.

CONCLUSION

Mitotherapy improved mitochondrial function, biogenesis, and dynamic associated with SIRT-1/PGC-1α network and suppressed inflammatory response in CLP-induced sepsis model, therefore, offers a promising strategy to overcome life-threatening sepsis challenge.

Extracellular Histone-Induced Protein Kinase C Alpha Activation and Troponin Phosphorylation Is a Potential Mechanism of Cardiac Contractility Depression in Sepsis

Reduction in cardiac contractility is common in severe sepsis. However, the pathological mechanism is still not fully understood. Recently it has been found that circulating histones released after extensive immune cell death play important roles in multiple organ injury and disfunction, particularly in cardiomyocyte injury and contractility reduction. How extracellular histones cause cardiac contractility depression is still not fully clear. In this work, using cultured cardiomyocytes and a histone infusion mouse model, we demonstrate that clinically relevant histone concentrations cause significant increases in intracellular calcium concentrations with subsequent activation and enriched localization of calcium-dependent protein kinase C (PKC) α and βII into the myofilament fraction of cardiomyocytes in vitro and in vivo. Furthermore, histones induced dose-dependent phosphorylation of cardiac troponin I (cTnI) at the PKC-regulated phosphorylation residues (S43 and T144) in cultured cardiomyocytes, which was also confirmed in murine cardiomyocytes following intravenous histone injection. Specific inhibitors against PKCα and PKCβII revealed that histone-induced cTnI phosphorylation was mainly mediated by PKCα activation, but not PKCβII. Blocking PKCα also significantly abrogated histone-induced deterioration in peak shortening, duration and the velocity of shortening, and re-lengthening of cardiomyocyte contractility. These in vitro and in vivo findings collectively indicate a potential mechanism of histone-induced cardiomyocyte dysfunction driven by PKCα activation with subsequent enhanced phosphorylation of cTnI. These findings also indicate a potential mechanism of clinical cardiac dysfunction in sepsis and other critical illnesses with high levels of circulating histones, which holds the potential translational benefit to these patients by targeting circulating histones and downstream pathways.

CLINICAL, MOLECULAR, AND EXOSOMAL MECHANISMS OF CARDIAC AND BRAIN DYSFUNCTION IN SEPSIS

ABSTRACT

Sepsis is a complex disease resulting from a dysregulated inflammatory response to an infection. Initiation of sepsis occurs from a localized infection that disseminates to the bloodstream placing all organ systems at risk. Septic shock is classically observed to manifest itself as systemic hypotension with hyporesponsiveness to vasopressor agents. Myocardial dysfunction occurs resulting in an inability to perfuse major organ systems throughout the body. Most importantly, the brain is hypoperfused creating an ischemic and inflammatory state resulting in the clinical observation of acute mental status changes and cognitive dysfunction commonly known as sepsis-associated encephalopathy. This short review describes the inflammatory molecular mechanisms of myocardial dysfunction, discusses the evidence of the dual roles of the microglia resulting in blood-brain barrier disruption, and suggests that septic-derived exosomes, endosome-derived lipid bilayer spheroids released from living cells, influence cardiac and neurological cellular function.

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.

Jujuboside A attenuates sepsis-induced cardiomyopathy by inhibiting inflammation and regulating autophagy

BACKGROUND

Jujuboside A (JuA), as a main effective component of Jujubogenin, has long been known as a sedative-hypnotic drug. The aim of the current study was to investigate the potential effect of JuA on sepsis-induced cardiomyopathy (SIC) induced by lipopolysaccharide (LPS).

METHOD

Wide type C57BL/6 mice and neonatal rat cardiomyocytes (NRCMs) were exposed to LPS to establish myocardial toxicity models. Cardiac function of septic mice was detected by echocardiography. Moreover, the survival rate was calculated for 7 days. ELISA assays were used to analyze inflammatory factors in serum. Furthermore, western blotting, flow cytometry and TUNEL staining were performed to assess cell apoptosis and transmission electron microscopy detect the number of autophagosomes in myocardium. Finally, the expression of proteins related to pyroptosis, autophagy and oxidative stress was analyzed by western blotting and immunohistochemistry staining.

RESULTS

Results showed that JuA pretreatment significantly improved the survival rate and cardiac function, and suppressed systemic inflammatory response in septic mice. Further study revealed that JuA could decrease cell apoptosis and pyroptosis; instead, it strengthened autophagy in SIC. Moreover, JuA also significantly decreased oxidative stress and nitrodative stress, as evidenced by suppressing the superoxide production and downregulating iNOS and gp91 expression in vivo. In addition, the autophagy inhibitor 3-MA significantly abolished the effect of JuA on autophagic activity in SIC.

CONCLUSION

In conclusion, the findings indicated that JuA attenuates cardiac function via blocking inflammasome-mediated apoptosis and pyroptosis, at the same time by enhancing autophagy in SIC, heralding JuA as a potential therapy for sepsis.

Tidy up - The unfolded protein response in sepsis

Pathogens, their toxic byproducts, and the subsequent immune reaction exert different forms of stress and damage to the tissue of the infected host. This stress can trigger specific transcriptional and post-transcriptional programs that have evolved to limit the pathogenesis of infectious diseases by conferring tissue damage control. If these programs fail, infectious diseases can take a severe course including organ dysfunction and damage, a phenomenon that is known as sepsis and which is associated with high mortality. One of the key adaptive mechanisms to counter infection-associated stress is the unfolded protein response (UPR), aiming to reduce endoplasmic reticulum stress and restore protein homeostasis. This is mediated via a set of diverse and complementary mechanisms, i.e. the reduction of protein translation, increase of protein folding capacity, and increase of polyubiquitination of misfolded proteins and subsequent proteasomal degradation. However, UPR is not exclusively beneficial since its enhanced or prolonged activation might lead to detrimental effects such as cell death. Thus, fine-tuning and time-restricted regulation of the UPR should diminish disease severity of infectious disease and improve the outcome of sepsis while not bearing long-term consequences. In this review, we describe the current knowledge of the UPR, its role in infectious diseases, regulation mechanisms, and further clinical implications in sepsis.

A case of sepsis-induced cardiomyopathy successfully treated with venoarterial extracorporeal membrane oxygenation

Introduction

Sepsis with concomitant acute pyelonephritis, secondary to urolithiasis, is common. We report a case of sepsis-induced cardiomyopathy with acute pyelonephritis, successfully managed with venoarterial extracorporeal membrane oxygenation.

Case presentation

A 64-year-old woman presented with fever and disturbed consciousness. Abdominal computed tomography revealed right hydronephrosis with ipsilateral ureteral stone. Despite ureteral stent placement and antibiotic treatment, her hemodynamics worsened. She was diagnosed with sepsis-induced cardiomyopathy and underwent venoarterial extracorporeal membrane oxygenation. Her hemodynamics improved rapidly; venoarterial extracorporeal membrane oxygenation was withdrawn on postoperative day-3. She was discharged from our hospital after sufficient antibiotic treatment.

Conclusion

Venoarterial extracorporeal membrane oxygenation may be initiated in patients with sepsis-induced cardiomyopathy. Evaluation of left ventricular ejection fraction via echocardiography is important to determine the indication for venoarterial extracorporeal membrane oxygenation.