Organ dysfunction as a new standard for defining sepsis

Evaluation of the efficacy of silymarin and dexmedetomidine on kidney and lung tissue in the treatment of sepsis in rats with cecal perforation

Sepsis is a systemic inflammatory response syndrome that develops in the host against microorganisms. This response develops away from the primary infection site and results in end-organ damage. The present study aimed to investigate the protective and therapeutic effects on lung and kidney tissue of silymarin (S) and dexmedetomidine (DEX) applied 1 h before and after sepsis induced by the cecal ligation and puncture (CLP) method in rats. A total of 62 rats was randomly divided into eight groups: i) Control (n=6); ii) cecal perforation (CLP; n=8); iii) S + CLP (n=8; S + CLP; S administered 1 h before CPL); iv) CLP + S (n=8; S administered 1 h after CLP); v) DEX + CLP (n=8; D + CLP; DEX administered 1 h before CLP); vi) CLP + D (n=8; DEX administered 1 h after CLP); vii) SD + CLP (n=8; S and DEX administered 1 h before CLP) and viii) CLP + SD (n=8; S and DEX administered 1 h after CLP). After the cecum filled with stool, it was tied with 3/0 silk under the ileocecal valve and the anterior surface of the cecum was punctured twice with an 18-gauge needle. A total of 100 mg/kg silymarin and 100 µg/kg DEX were administered intraperitoneally to the treatment groups. Lung and kidney tissue samples were collected to evaluate biochemical and histopathological parameters. In the histopathological examination, all parameters indicating kidney injury; interstitial edema, peritubular capillary dilatation, vacuolization, ablation of tubular epithelium from the basement membrane, loss of brush border in the proximal tubule epithelium, cell swelling and nuclear defragmentation; were increased in the CLP compared with the control group. Silymarin administration increased kidney damage, including ablation of tubular epithelium from the basement membrane, compared with that in the CLP group. DEX significantly reduced kidney damage compared with the CLP and silymarin groups. The co-administration of DEX + silymarin decreased kidney damage, although it was not as effective as DEX-alone. To conclude, intraperitoneal DEX ameliorated injury in CLP rats. DEX + silymarin partially ameliorated injury but silymarin administration increased damage. As a result, silymarin has a negative effects with this dosage and DEX has a protective effect. In the present study, it was determined that using the two drugs together had a greater therapeutic effect than silymarin and no differences in the effects were not observed any when the application times of the agents were changed.

Design, Synthesis, and Biological Evaluation of a Novel NIK Inhibitor with Anti-Inflammatory and Hepatoprotective Effects for Sepsis Treatment

NIK plays a crucial role in the noncanonical NF-κB signaling pathway associated with diverse inflammatory and autoimmune diseases. Our study presents compound 54, a novel NIK inhibitor, designed through a structure-based scaffold-hopping approach from the previously identified B022. Compound 54 demonstrates remarkable selectivity and potency against NIK both in vitro and in vivo, effectively suppressing pro-inflammatory cytokines and nitric oxide production. In mouse models, compound 54 protected against LPS-induced systemic sepsis, reducing AST, ALT, and AKP liver injury markers. Additionally, it also attenuates sepsis-induced lung and kidney damage. Mechanistically, compound 54 blocks the noncanonical NF-κB signaling pathway by targeting NIK, preventing p100 to p52 processing. This work reveals a novel class of NIK inhibitors with significant potential for sepsis therapy.

How well does peripheral blood neutrophil-to-lymphocyte ratio predict the severity and prognosis of hemorrhagic Stroke

OBJECTIVE

We explored the blood neutrophil-to-lymphocyte ratio (NLR) as a prognostic marker and its relation with mortality and Modified Rankin Scale (mRS) score at discharge and at 3 months following ICH and also compared NLR with intracerebral hemorrhage (ICH) score, Sequential Organ Failure Assessment (SOFA) score and National Institutes of Health Stroke Scale (NIHSS) score.

METHODS

The investigators calculated the NIHSS score, SOFA score, ICH score and NLR of 90 adult patients within 3 days of onset of stroke with evidence of hemorrhagic stroke in brain imaging and correlated it with in-hospital mortality, 3-month mortality and mRS at 3 months following stroke using regression analysis.

RESULTS

Out of 90 individuals, there were 54 (60%) males and 36 (40%) females. The mRS score at 3 months significantly related to the admission NLR ratio >7 and SOFA score. Similarly, the in-hospital death and 3-month mortality was related to the admission NLR ratio >7 and ICH score. However, at a cut off value of NLR>3 for assessing the prognosis of the patients, we did not get significant results for mRS at 3 months following stroke and for in-hospital and 3-month mortality.

CONCLUSION

A high NLR ratio >7 predicted worse outcomes in terms of mortality and morbidity at 3-months following haemorrhagic stroke. Hence, like ICH score, NLR can predict 3-month mortality following an acute haemorrhagic stroke and can also predict morbidity following 3 months of brain haemorrhage.

Nanoparticle-mediated co-delivery of inflammasome inhibitors provides protection against sepsis

The NLRP3 inflammasome, a multiprotein complex responsible for triggering the release of pro-inflammatory cytokines, plays a crucial role in inducing the inflammatory response associated with sepsis. While small molecule inhibitors of the NLRP3 inflammasome have been investigated for sepsis management, delivering NLRP3 inhibitors has been accompanied by several challenges, primarily related to the drug formulation, delivery route, stability, and toxicity. Many existing inflammasome inhibitors either show higher liver toxicity or require a high dosage to efficiently impede the inflammasome complex assembly. Moreover, the potential synergistic effects of combining multiple inflammasome inhibitors in sepsis therapy remain largely unexplored. Therefore, a rational approach is essential for presenting the potential administration of NLRP3 small molecule inhibitors to inhibit NLRP3 inflammasome activation effectively. In this context, we present a lipid nanoparticle-based dual-drug delivery system loaded with MCC 950 and disulfiram, demonstrating markedly higher efficiency compared to an equivalent amount of free-drug combinations and individual drug nanoparticles in vitro. This combination therapy substantially improved the in vivo survival rate of mice for LPS-induced septic peritonitis. Additionally, the synergistic approach illustrated a significant reduction in the expression of active caspase-1 as well as IL-1β inhibition integral components in the NLRP3 pathway. This study underscores the importance of integrating combination therapies facilitated by nanoparticle delivery to address the limitations of small molecule inflammasome inhibitors.

Pyroptotic Macrophage-Derived Microvesicles Accelerate Formation of Neutrophil Extracellular Traps via GSDMD-N-expressing Mitochondrial Transfer during Sepsis

Macrophage pyroptosis and neutrophil extracellular traps (NETs) play a critical role in sepsis pathophysiology; however, the role of macrophage pyroptosis in the regulation of NETs formation during sepsis is unknown. Here, we showed that macrophages transfer mitochondria to neutrophils through microvesicles following pyroptosis; this process induces mitochondrial dysfunction and triggers the induction of NETs formation through mitochondrial reactive oxygen species (mtROS)/Gasdermin D (GSDMD) axis. These pyroptotic macrophage-derived microvesicles can induce tissues damage, coagulation, and NETs formation in vivo. Disulfiram partly inhibits these effects in a mouse model of sepsis. Pyroptotic macrophage-derived microvesicles induce NETs formation through mitochondrial transfer, both in vitro and in vivo. Microvesicles-mediated NETs formation depends on the presence of GSDMD-N-expressing mitochondria in the microvesicles. This study elucidates a microvesicles-based pathway for NETs formation during sepsis and proposes a microvesicles-based intervention measure for sepsis management.

Organ dysfunction and mortality in preterm neonates with late-onset bloodstream infection

BACKGROUND

Organ dysfunction (ODF) in late-onset bloodstream infection (LBSI) is associated with increased risk of adverse outcomes. However, no established definition of ODF exists among preterm neonates. Our objective was to describe an outcome-based ODF definition for preterm infants, and assess factors associated with mortality.

METHODS

This is a six-year retrospective study of neonates <35 weeks gestational age, >72 h of age, with non-CONS bacterial/fungal LBSI. Discriminatory ability of each parameter for mortality was evaluated: base deficit ≤-8 mmol/L (BD8), renal dysfunction (urine output <1 cc/kg/h or creatinine ≥100 μmol/L), hypoxic respiratory failure (HRF, ventilated, FiO2 = 1.0), or vasopressor/inotrope use (V/I). Multivariable logistic regression analysis was performed to derive a mortality score.

RESULTS

One hundred and forty-eight infants had LBSI. BD8 had the highest individual predictive ability for mortality (AUROC = 0.78). The combination BD8 + HRF + V/I was used to define ODF (AUROC = 0.84). Fifty-seven (39%) infants developed ODF, among which 28 (49%) died. Mortality increased inversely relative to GA at LBSI-onset (aOR 0.81 [0.67, 0.98]) and directly relative to ODF occurrence (12.15 [4.48, 33.92]). Compared to no-ODF, ODF infants had lower GA and age at illness, and higher frequency of Gram-negative pathogen.

CONCLUSIONS

Among preterm neonates with LBSI, significant metabolic acidosis, HRF, and vasopressor/inotrope use may identify infants high risk for mortality. These criteria could help identify patients for future studies of adjunctive therapies.

IMPACT

Sepsis-related organ dysfunction is associated with increased risk of adverse outcomes. Among preterm neonates, significant metabolic acidosis, use of vasopressors/inotropes, and hypoxic respiratory failure may identify high-risk infants. This can be used to target research and quality improvement efforts toward the most vulnerable infants.

An Update on Toll-like Receptor 2, Its Function and Dimerization in Pro- and Anti-Inflammatory Processes

While a certain level of inflammation is critical for humans to survive infection and injury, a prolonged inflammatory response can have fatal consequences. Pattern recognition Toll-like receptors (TLRs) are key players in the initiation of an inflammatory process. TLR2 is one of the most studied pattern recognition receptors (PRRs) and is known to form heterodimers with either TLR1, TLR4, TLR6, and TLR10, allowing it to recognize a wide range of pathogens. Although a large number of studies have been conducted over the past decades, there are still many unanswered questions regarding TLR2 mechanisms in health and disease. In this review, we provide an up-to-date overview of TLR2, including its homo- and heterodimers. Furthermore, we will discuss the pro- and anti-inflammatory properties of TLR2 and recent findings in prominent TLR2-associated infectious and neurodegenerative diseases.

Evaluation of Sepsis-1 and Sepsis-3 Diagnostic Criteria in Patients with Sepsis in Intensive Care Unit

Background

The use of SIRS and SOFA criteria in diagnosing sepsis among patients has been characterized by increasingly growing criticism. Indeed, the definition of sepsis has attracted significant controversy in history across medical and academic realms.

Methods

The study used the Medical Information Mart for Intensive Care-III (MIMIC-III) database in assessing the effectiveness of the SIRS and SOFA diagnostic criteria. It ascertained the severity and specificity of sepsis infection in ICU patients. The Medical Information Mart for Intensive Care-III (MIMIC-III) database was established by the Beth Israel Deaconess Medical Center (BIDMC) and MIT's Computational Physiology Laboratory. The database is a voluminous single-center database containing information pertaining to 38,000 adults who were admitted to the BIDMC in the 11 years leading up to 2012. The identification of patients with sepsis was conducted using the International Classification of Diseases (ICD-10-CM) diagnosis codes.

Results

The analysis of data for this study was based on the chi-square test, which is significant in comparing the specificity, mortality, and sensitivity of the data. The process of screening the MIMIC-III database resulted in the identification of 21,368 patients with infections from the hospital admissions in the database. The results also indicate a significantly higher mortality rate within 28 days of admission in sepsis-3 patients compared with sepsis-1. In this experiment, we limited the study period to 28 days to restrict the potential of mortality caused by other factors. Additionally, we evaluated the clinical factors associated with the sepsis-1 or sepsis-3 and found out similar results in the analysis for sepsis-1 and sepsis-3.

Conclusions

The study results also portray numerous challenges in using the sepsis-3 criteria as a diagnostic tool. In particular, the ICD-10-CM diagnosis approach was limiting because it inhibited the measure of uncertainty of infection present at the beginning of the two diagnostic criteria of sepsis-1 and sepsis-3.

Application Prospect of the SOFA Score and Related Modification Research Progress in Sepsis

In 2016, the SOFA score was proposed as the main evaluation system for diagnosis in the definition of sepsis 3.0, and the SOFA score has become a new research focus in sepsis. Some people are skeptical about diagnosing sepsis using the SOFA score. Experts and scholars from different regions have proposed different, modified versions of SOFA score to make up for the related problems with the use of the SOFA score in the diagnosis of sepsis. While synthesizing the different improved versions of SOFA proposed by experts and scholars in various regions, this paper also summarizes the relevant definitions of sepsis put forward in recent years to build a clear, improved application framework of SOFA score. In addition, the comparison between machine learning and SOFA scores related to sepsis is described and discussed in the article. Taken together, by summarizing the application of the improved SOFA score proposed in recent years in the related definition of sepsis, we believe that the SOFA score is still an effective means of diagnosing sepsis, but in the process of the continuous refinement and development of sepsis in the future, the SOFA score needs to be further refined and improved to provide more accurate coping strategies for different patient populations or application directions regarding sepsis. Against the big data background, machine learning has immeasurable value and significance, but its future applications should add more humanistic references and assistance.

Sulfated Chinese Yam Polysaccharides Alleviate LPS-Induced Acute Inflammation in Mice through Modulating Intestinal Microbiota

This study aimed to test the preventive anti-inflammatory properties of Chinese yam polysaccharides (CYP) and sulfated Chinese yam polysaccharides (SCYP) on LPS-induced systemic acute inflammation in mice and investigate their mechanisms of action. The results showed that SCYP can efficiently reduce plasma TNF-α and IL-6 levels, exhibiting an obvious anti-inflammation ability. Moreover, SCYP reduced hepatic TNF-α, IL-6, and IL-1β secretion more effectively than CYP, and significantly altered intestinal oxidative stress levels. In addition, a 16S rRNA gene sequencing analysis showed that CYP regulated the gut microbiota by decreasing Desulfovibrio and Sutterella and increasing Prevotella. SCYP changed the gut microbiota by decreasing Desulfovibrio and increasing Coprococcus, which reversed the microbiota dysbiosis caused by LPS. Linear discriminant analysis (LDA) effect size (LEfSe) revealed that treatment with CYP and SCYP can produce more biomarkers of the gut microbiome that can promote the proliferation of polysaccharide-degrading bacteria and facilitate the intestinal de-utilization of polysaccharides. These results suggest that SCYP can differentially regulate intestinal flora, and that they exhibit anti-inflammatory effects, thus providing a new reference to rationalize the exploitation of sulfated yam polysaccharides.

Therapeutic potential of mesenchymal stromal/stem cells in critical-care patients with systemic inflammatory response syndrome

BACKGROUND

Despite notable advances in the support and treatment of patients admitted to the intensive care unit (ICU), the management of those who develop a systemic inflammatory response syndrome (SIRS) still constitutes an unmet medical need.

MAIN BODY

Both the initial injury (trauma, pancreatitis, infections) and the derived uncontrolled response promote a hyperinflammatory status that leads to systemic hypotension, tissue hypoperfusion and multiple organ failure. Mesenchymal stromal/stem cells (MSCs) are emerging as a potential therapy for severe ICU patients due to their potent immunomodulatory, anti-inflammatory, regenerative and systemic homeostasis-regulating properties. MSCs have demonstrated clinical benefits in several inflammatory-based diseases, but their role in SIRS needs to be further explored.

CONCLUSION

In the current review, after briefly overviewing SIRS physiopathology, we explore the potential mechanisms why MSC therapy could aid in the recovery of this condition and the pre-clinical and early clinical evidence generated to date.

The gut–liver axis in sepsis: interaction mechanisms and therapeutic potential

Sepsis is a potentially fatal condition caused by dysregulation of the body's immune response to an infection. Sepsis-induced liver injury is considered a strong independent prognosticator of death in the critical care unit, and there is anatomic and accumulating epidemiologic evidence that demonstrates intimate cross talk between the gut and the liver. Intestinal barrier disruption and gut microbiota dysbiosis during sepsis result in translocation of intestinal pathogen-associated molecular patterns and damage-associated molecular patterns into the liver and systemic circulation. The liver is essential for regulating immune defense during systemic infections via mechanisms such as bacterial clearance, lipopolysaccharide detoxification, cytokine and acute-phase protein release, and inflammation metabolic regulation. When an inappropriate immune response or overwhelming inflammation occurs in the liver, the impaired capacity for pathogen clearance and hepatic metabolic disturbance can result in further impairment of the intestinal barrier and increased disruption of the composition and diversity of the gut microbiota. Therefore, interaction between the gut and liver is a potential therapeutic target. This review outlines the intimate gut–liver cross talk (gut–liver axis) in sepsis.

Septic Shock: Management and Outcomes

The incidence rates of sepsis and septic shock as a complication have become more common over the past several decades. With this increase, sepsis remains the most common cause of intensive care unit (ICU) admissions and one of the most mortality factors, with a huge burden on healthcare facilities. Septic shock has devastating consequences on patients' lives, including organ failures and other long-term complications. Due to its dynamic clinical presentations, guidelines and tools have been established to improve the diagnosis and management effectively. However, there is still a need for evidence-based standardized procedures for the diagnosis, treatment, and follow-up of sepsis and septic shock patients due to the inconsistency of current guidelines and studies contrasting with each other. The standardization would help physicians better manage sepsis, minimize complications and reduce mortality. Septic shock is usually challenging to manage due to its variety of clinical characteristics and physiologic dynamics, affecting the outcomes. Therefore, this review presented the available data in the literature on septic shock diagnosis, management, and prognosis to have an overview of the updated best practice approach to septic shock.

Assessing organ-level immunoreactivity in a rat model of sepsis using TSPO PET imaging

There is current need for new approaches to assess/measure organ-level immunoreactivity and ensuing dysfunction in systemic inflammatory response syndrome (SIRS) and sepsis, in order to protect or recover organ function. Using a rat model of systemic sterile inflammatory shock (intravenous LPS administration), we performed PET imaging with a translocator protein (TSPO) tracer, [¹⁸F]DPA-714, as a biomarker for reactive immunoreactive changes in the brain and peripheral organs. In vivo dynamic PET/CT scans showed increased [¹⁸F]DPA-714 binding in the brain, lungs, liver and bone marrow, 4 hours after LPS injection. Post-LPS mean standard uptake values (SUV_mean) at equilibrium were significantly higher in those organs compared to baseline. Changes in spleen [¹⁸F]DPA-714 binding were variable but generally decreased after LPS. SUV_mean values in all organs, except the spleen, positively correlated with several serum cytokines/chemokines. In vitro measures of TSPO expression and immunofluorescent staining validated the imaging results. Noninvasive molecular imaging with [¹⁸F]DPA-714 PET in a rat model of systemic sterile inflammatory shock, along with in vitro measures of TSPO expression, showed brain, liver and lung inflammation, spleen monocytic efflux/lymphocytic activation and suggested increased bone marrow hematopoiesis. TSPO PET imaging can potentially be used to quantify SIRS and sepsis-associated organ-level immunoreactivity and assess the effectiveness of therapeutic and preventative approaches for associated organ failures, in vivo.

Ponciri Fructus Immaturus ethanol extract attenuates septic shock through inhibition of the STAT1 signaling pathway

Sepsis is a systemic inflammatory disease to infections and results in tissue damage and multiple organ failure. Ponciri Fructus Immaturus (PFI) is widely used in traditional medicine for allergic inflammation and gastrointestinal disorders. However, the effect of PFI on sepsis is still unknown. This study investigated the anti-inflammatory and antiseptic effects of PFI ethanol extract (PFIE) in LPS-stimulated J774 macrophages and mice with CLP- or LPS-induced sepsis, respectively. PFIE attenuates the LPS-induced production of the proinflammatory mediator NO by inhibiting the expression of iNOS in J774 cells. Real-time RT-PCR data and ELISA showed that the mRNA and protein levels of TNF-α, IL-1β, and IL-6 increased in LPS-stimulated J774 cells. However, this induction was significantly suppressed in PFIE pre-treated J774 cells. We also found that PFIE administration increased the survival rate of mice with LPS- and CLP-induced sepsis. Decreased serum levels of AST, ALT, and CK were observed after administration of PFIE, which was associated with reduced production of proinflammatory factors, such as NO, TNF-α, IL-1β, and IL-6. Moreover, PFIE suppressed the phosphorylation and nuclear translocation of STAT1 in LPS-stimulated J774 cells, suggesting that PFIE can inhibit LPS- and CLP-induced septic shock by suppressing the STAT1 activation. These findings provide the potential therapeutic relevance of PFIE in treating acute inflammatory disease.

Neutrophils restrain sepsis associated coagulopathy via extracellular vesicles carrying superoxide dismutase 2 in a murine model of lipopolysaccharide induced sepsis

Disseminated intravascular coagulation (DIC) is a complication of sepsis currently lacking effective therapeutic options. Excessive inflammatory responses are emerging triggers of coagulopathy during sepsis, but the interplay between the immune system and coagulation are not fully understood. Here we utilize a murine model of intraperitoneal lipopolysaccharide stimulation and show neutrophils in the circulation mitigate the occurrence of DIC, preventing subsequent septic death. We show circulating neutrophils release extracellular vesicles containing mitochondria, which contain superoxide dismutase 2 upon exposure to lipopolysaccharide. Extracellular superoxide dismutase 2 is necessary to induce neutrophils' antithrombotic function by preventing endothelial reactive oxygen species accumulation and alleviating endothelial dysfunction. Intervening endothelial reactive oxygen species accumulation by antioxidants significantly ameliorates disseminated intravascular coagulation improving survival in this murine model of lipopolysaccharide challenge. These findings reveal an interaction between neutrophils and vascular endothelium which critically regulate coagulation in a model of sepsis and may have potential implications for the management of disseminated intravascular coagulation.

Impact of indirect bilirubin and uric acid on outcomes of sepsis-associated acute kidney injury (sAKI)

BACKGROUND

Acute kidney injury (AKI) is one of the most frequent pathophysiologic disorders encountered in hospitalized patients, with sepsis frequently implicated in pathogenesis. Reactive oxygen species (ROS) seem to have a significant contribution to sepsis-induced AKI. Proposed mechanisms include induction of cell membrane lipid peroxidation, protein denaturing, and direct DNA damage, all of which have deleterious effect. These changes constitute oxidative injury to the kidneys.

OBJECTIVE

To evaluate the antioxidant actions of indirect bilirubin and uric acid on outcomes of sepsis-associated AKI.

METHODS

Ninety-eight patients admitted to the intensive care unit (ICU), at a large tertiary center, with sepsis and AKI were evaluated for serum levels of uric acid, bilirubin (primarily indirect), and procalcitonin. The primary endpoints studied were the need for hemodialysis and death.

RESULTS

Thirty-two (33%) patients developed AKI requiring hemodialysis (HD). These patients had higher SOFA scores (p < 0.001) and lower levels of indirect bilirubin (p < 0.001) compared to those not requiring HD. There was no statistically significant difference in serum uric acid levels. Logistic regression analysis identified creatinine level, total and indirect bilirubin levels, and leukocyte count as significant predictors of patient death.

CONCLUSION

Higher leukocyte counts and creatinine levels were independently associated with poor outcomes in ICU patients with sepsis. Additionally, lower indirect bilirubin levels were also noted to be associated with similar outcomes. The latter provides insights into oxidative stress as a major player in the pathogenesis of sepsis-induced AKI, with a potential protective role of indirect bilirubin.

Procalcitonin prognostic value in predicting mortality among adult patients with sepsis due to Gram-negative bacteria

BACKGROUND Sepsis is a leading cause of mortality and morbidity globally. Gram-negative bacteremia was reported to have a high risk of septic shock and poor prognosis. This study aimed to evaluate the role of procalcitonin in predicting mortality in patients with sepsis due to Gram-negative bacteria. METHODS This was a retrospective cohort study performed based on medical records and sepsis registry of Tropical and Infectious Disease Division, Department of Internal Medicine, Cipto Mangunkusumo Hospital. The inclusion criteria were patients aged ≥18 years diagnosed with sepsis due to Gram-negative bacteria based on blood culture on admission and hospitalized between March 2017 and October 2020. Data taken from medical records included subjects’ characteristics, laboratory parameters, and 28-day mortality outcomes during hospitalization. Receiver operating characteristic was used to determine the area under the curve (AUC) of procalcitonin and its accuracy. RESULTS A total of 128 patients were eligible. The cumulative survival of patients with Gram-negative bacteremia was 48.4% (standard error 0.96%). The AUC of procalcitonin to predict mortality was 0.45 (95% confidence interval 0.36–0.54). Escherichia coli was the predominant microorganism in blood culture (n = 38, 29.7%). CONCLUSIONS Procalcitonin has a poor performance in predicting mortality of patients with sepsis due to Gram-negative bacteria.

Erythrocyte-derived extracellular vesicles aggravate inflammation by promoting the proinflammatory macrophage phenotype through TLR4-MyD88-NF-κB-MAPK pathway

Transfusion of stored erythrocytes is associated with the increased risk of morbidity and mortality in critical infections, but the mechanism is incompletely understood. Previous studies have suggested that RBC-derived extracellular vesicles (EVs) may be potential risk factors for the occurrence of transfusion-related immunomodulation. The purpose of our study was to evaluate the effects of RBC-derived EVs under inflammatory conditions and explore the underlying mechanisms. In vivo, the activity of EVs was evaluated in cecal ligation and puncture (CLP)-induced sepsis. Our results showed that EVs significantly aggravated the inflammatory response to sepsis in serum and lung tissue by promoting the production of the proinflammatory factors tumor necrosis factor-α (TNF-α）-interleukin-6(IL-6), and interleukin-1β (IL-1β) and reduced the survival rate of septic mice in vivo. Importantly, adoptive transfer of EVs-pretreated bone marrow-derived macrophages (BMDMs) obviously aggravated systemic proinflammatory factors in mice after CLP surgery. In vitro, the proinflammatory properties of EVs were shown to elevate TNF-α, IL-6, and IL-1β levels in lipopolysaccharide (LPS)-stimulated BMDMs. Moreover, EVs promoted LPS-induced macrophage polarization into a proinflammatory phenotype. The underlying mechanism might involve EV-mediated up-regulation of TLR4-MyD88-NF-κB-MAPK activity to favor macrophage cytokine production.

Calming egress of inflammatory monocytes and related septic shock by therapeutic CCR2 silencing using macrophage-derived extracellular vesicles

Uncontrolled inflammation, featuring the aggravated mobilization of Ly6C^high inflammatory monocytes (Mos), may cause high morbidity and mortality in the pathogenesis of sepsis-associated immune disorders. Inspired by the similar membrane protein profile of extracellular vehicles (EVs) and their parent cells, EVs are generated from immortalized bone marrow-derived macrophages (Mps) for Mo/Mp-targeting drug delivery. Compared with MSC-EVs, Mac-EVs are more efficiently internalized by inflammatory Mo/Mps in vitro as well as by septic spleen in vivo. By loading with siRNA targeting the chemokine receptor CCR2, the mediator for chemotaxis of inflammatory Mo/Mps, Mac-EV^siCCR2 not only restrains chemotaxis of inflammatory Mo/Mps but also relieves septic symptoms in mice by limiting the mobilization of splenic inflammatory monocytes and calming the subsequent serum cytokine storm. The current study provides functional evidence for the successful therapeutic targeting of septic inflammatory Mos, mandating the clinical development of CCR2 inhibition in patients with infectious diseases.

Prevalence of New-Onset Atrial Fibrillation and Associated Outcomes in Patients with Sepsis: A Systematic Review and Meta-Analysis

Background: New-onset atrial fibrillation (NOAF) is a common complication in patients with sepsis, although its prevalence and impact on outcomes are still unclear. We aim to provide a systematic review and meta-analysis on the prevalence of NOAF in patients with sepsis, and its impact on in-hospital mortality and intensive care unit (ICU) mortality. Methods: PubMed and EMBASE were systematically searched on 26 December 2021. Studies reporting on the prevalence of NOAF and/or its impact on in-hospital mortality or ICU mortality in patients with sepsis or septic shock were included. The pooled prevalence and 95% confidence intervals (CI) were calculated, as well as the risk ratios (RR), 95%CI and 95% prediction intervals (PI) for outcomes. Subgroup analyses and meta-regressions were performed to account for heterogeneity. Results: Among 4988 records retrieved from the literature search, 22 articles were included. Across 207,847 patients with sepsis, NOAF was found in 13.5% (95%CI: 8.9–20.1%), with high heterogeneity between studies; significant subgroup differences were observed, according to the geographical location, study design and sample size of the included studies. A multivariable meta-regression model showed that sample size and geographical location account for most of the heterogeneity. NOAF patients showed an increased risk of both in-hospital mortality (RR: 1.69, 95%CI: 1.47–1.96, 95%PI: 1.15–2.50) and ICU mortality (RR: 2.12, 95%CI: 1.86–2.43, 95%PI: 1.71–2.63), with moderate to no heterogeneity between the included studies. Conclusions: NOAF is a common complication during sepsis, being present in one out of seven individuals. Patients with NOAF are at a higher risk of adverse events during sepsis, and may need specific therapeutical interventions.

Detecting Critical Functional Ingredients Group and Mechanism of Xuebijing Injection in Treating Sepsis

Sepsis is a systemic inflammatory reaction caused by various infectious or noninfectious factors, which can lead to shock, multiple organ dysfunction syndrome, and death. It is one of the common complications and a main cause of death in critically ill patients. At present, the treatments of sepsis are mainly focused on the controlling of inflammatory response and reduction of various organ function damage, including anti-infection, hormones, mechanical ventilation, nutritional support, and traditional Chinese medicine (TCM). Among them, Xuebijing injection (XBJI) is an important derivative of TCM, which is widely used in clinical research. However, the molecular mechanism of XBJI on sepsis is still not clear. The mechanism of treatment of "bacteria, poison and inflammation" and the effects of multi-ingredient, multi-target, and multi-pathway have still not been clarified. For solving this issue, we designed a new systems pharmacology strategy which combines target genes of XBJI and the pathogenetic genes of sepsis to construct functional response space (FRS). The key response proteins in the FRS were determined by using a novel node importance calculation method and were condensed by a dynamic programming strategy to conduct the critical functional ingredients group (CFIG). The results showed that enriched pathways of key response proteins selected from FRS could cover 95.83% of the enriched pathways of reference targets, which were defined as the intersections of ingredient targets and pathogenetic genes. The targets of the optimized CFIG with 60 ingredients could be enriched into 182 pathways which covered 81.58% of 152 pathways of 1,606 pathogenetic genes. The prediction of CFIG targets showed that the CFIG of XBJI could affect sepsis synergistically through genes such as TAK1, TNF-α, IL-1β, and MEK1 in the pathways of MAPK, NF-κB, PI3K-AKT, Toll-like receptor, and tumor necrosis factor signaling. Finally, the effects of apigenin, baicalein, and luteolin were evaluated by in vitro experiments and were proved to be effective in reducing the production of intracellular reactive oxygen species in lipopolysaccharide-stimulated RAW264.7 cells, significantly. These results indicate that the novel integrative model can promote reliability and accuracy on depicting the CFIGs in XBJI and figure out a methodological coordinate for simplicity, mechanism analysis, and secondary development of formulas in TCM.

The effect of exosomes derived from unrestricted somatic stem cells on murine model of sepsis

Sepsis is a systemic infection mainly caused by bacterial infections. Despite all efforts and advances in treatment of sepsis, it's still considered as one of the leading causes of death in the hospitalized patients. Today we have to use novel therapies and one of the most important is cell free therapy. Exosomes have been introduced to have all cell contents without compatible tissue complex proteins which is a good candidate for transplantation. Unrestricted somatic stem cells (USSC) also known as mesenchymal stem cell progenitors due to their high proliferative capacity and low immune response, which is a novel therapy for sepsis. In this study, the effect of USSC-derived exosomes on sepsis was investigated using a mouse model. USSCs were isolated from human cord blood and characterized by flow cytometry and multilineage differentiation. The exosomes were then harvested from USSCs and characterized by transmission electron microscopy, Western blotting, and dynamic light scattering. The harvested exosomes were injected into the mouse model of sepsis. Biochemical, histological, molecular, and survival studies were performed in different groups. Our observation showed that USSC-derived exosomes can reduce inflammation in septic mice. Histopathological and biochemical findings in the sham group obviously showed multiorgan involvement, but these changes disappeared after seven days of exosome administration. Moreover, the expression of IRAK-1 and TRAF-6 (main adapter molecules in signaling pathways of inflammation) was decreased through negative regulation by miR-146a after 72 h of exosome administration; finally, it leads to a 2-fold increase in the level of IL-10 and a 2-fold decrease in the levels of IL-6 and TNF-α . In conclusion, we reported that direct injection of USSC- derived exosomes can be one of the important methods for the treatment of various aspects of sepsis due to their immunomodulatory properties.

Comparison of the Clinical Effectiveness of AN69-oXiris versus AN69-ST Filter in Septic Patients: A Single-Centre Study

INTRODUCTION

The clinical effectiveness of AN69-oXiris remains unclear. This study aimed to compare the effects of AN69-oXiris and AN69-ST filters on cytokine levels and clinical improvement in septic patients.

METHODS

This prospective observational study recruited septic patients who underwent blood purification in the First Affiliated Hospital of Soochow University between December 2019 and May 2020. Patients were assigned to an AN69-oXiris (oXiris) or AN69-ST (ST) group based on their preferred filter. Patients' clinical data, cytokine levels, and prognostic indicators were analysed at baseline (T0), 24 h after treatment (T1), and at the end of the treatment (T2).

RESULTS

Forty-four patients participated in this study (22 patients in each group). Participants in both groups showed improvements in mean arterial pressure (MAP) values, oxygenation indices, and urinary output, and decreased vasoactive-inotropic scores (VISs), heart rates, lactic acid levels, and serum creatinine levels after blood purification. Reductions in cytokine levels were observed at T1 in both groups. Improvement the haemodynamic status was higher in the oXiris group than in the ST group at T2 (MAP: 79.0 [76.0, 85.0] vs. 77.0 [72.75, 79.25] mm Hg, p = 0.04; VISs: 9.10 [0.00, 16.69] vs. 19.05 [10.60, 26.33], p = 0.03, respectively). Patients in the oXiris group also had lower cytokine levels than those in the ST group at T1 (tumour necrosis factor-α: 24.55 [16.9, 30.15] vs. 30.15 [23.38, 34.13] pg/mL, p = 0.04; interleukin (IL)-6: 66.63 [46.21, 102.20] vs. 125.48 [79.73, 167.97] pg/mL, p = 0.01; IL-8: 53.59 [35.10, 66.01] vs. 63.60 [45.58, 83.37] pg/mL, p = 0.04; IL-10: 13.50 [10.35, 18.68] vs. 17.15 [13.80, 21.95] pg/mL, p = 0.04, respectively). There were no significant differences between the 2 groups regarding hospital mortality, intensive care unit length of stay (LOS), and hospital LOS.

CONCLUSION

Blood purification using the AN69-oXiris or AN69-ST filter proved useful for septic patients, which was associated with reduced cytokine levels and improved clinical condition. Patients treated with AN69-oXiris had a more remarkable improvement in haemodynamic status and lower cytokine levels than those treated with AN69-ST filter, but there were no differences in clinical outcomes. Further investigations are needed to prove this finding.

Mesenchymal stem cell and endothelial progenitor cells coinjection improves LPS-induced lung injury via Tie2 activation and downregulation of the TLR4/MyD88 pathway

Sepsis is one of the most important complications of infection with a high mortality rate. Recently, cell therapy has been widely used to reduce the symptoms of sepsis. It has been previously reported that mesenchymal stem cell (MSC) and endothelial progenitor cells (EPC) therapy have beneficial effects in experimental models of sepsis. The effects of coculture of MSC and EPC have not yet been used to treat sepsis. Therefore, the aim of this study was to investigate the therapeutic potential of EPC + MSC coculture on the residual effects of sepsis in a lipopolysaccharide (LPS)-induced mice model. Coinjections of EPC + MSC significantly enhanced the survival rate of LPS-induced mice, decreased concentrations of pro-inflammatory cytokines, and increased the level of anti-inflammatory cytokine. The LPS-induced mice that were treated with EPC + MSC showed a notable reduction in pulmonary edema, hepatic enzymes, and C-reactive protein level compared with the control group. Our results showed that coinjection of EPC + MSC up and downregulates Tie2 and TLR4/MyD88 signaling pathways in LPS-induced mice, respectively. Also, in vitro study showed that viability, adhesion, and migration in coculture cells is significantly decreased after being induced with 10 μg/ml LPS. Our results showed that LPS impaired the functional activity of the cocultured EPC + MSC via upregulation of the TLR4/MyD88 signaling pathway, which may be associated with decreased pTie2/Tie2 expression. In conclusion, coinjection of EPC and MSC modulated the TLR4/MyD88 signaling pathway that leads to reduce the inflammatory response. This study may provide promising results for the introduction of cocultured cells to manage infectious diseases and balance the immune response through immune regulatory function.

Predictive Value of C-Reactive Protein-to-Albumin Ratio for Neonatal Sepsis

Purpose

Previous studies have reported that C-reactive protein-to-albumin ratio (CAR) was a risk factor for sepsis in adults. However, little is known regarding the role of CAR in neonates with sepsis. The aim of this study was to explore the relationship between CAR and neonatal sepsis.

Patients and Methods

In this research, from January 2016 to February 2020, a total of 1076 neonates were enrolled at Henan Children’s Hospital in China. Complete clinical and laboratory data were collected. To identify the potential independent risk factor for neonatal sepsis, multivariate logistic regression analysis was performed. Receiver operating characteristic (ROC) curve analysis was used to evaluate the prediction accuracy of CAR in identifying neonatal sepsis.

Results

CAR levels were higher in neonates with sepsis and showed a gradual increase among the control group, mild sepsis group and severe sepsis group. The prevalence of neonates with overall sepsis, mild sepsis and severe sepsis increased significantly from CAR tertile 1 to tertile 3. Multiple logistic regression analysis showed that CAR was an independent risk factor for the presence of sepsis (OR = 10.144, 95% CI 4.151–24.790, P < 0.001) and severe sepsis (OR = 1.876, 95% CI 1.562–2.253, P < 0.001). ROC curve analysis showed that CAR had a well discriminatory power in predicting sepsis (area under curve (AUC) = 0.74, 95% CI, 0.71–0.77, P < 0.001) and severe sepsis (AUC = 0.70, 95% CI, 0.67–0.74, P < 0.001).

Conclusion

CAR was an independent predictor for the presence and severity of neonatal sepsis.

Umbilical cord mesenchymal stem cells enhance the therapeutic effect of imipenem by regulating myeloid-derived suppressor cells in septic mice

Background

Umbilical cord mesenchymal stem cells (UC-MSCs), which possess potent immunomodulatory effects and low immunogenicity, are considered to be a promising stem cell-based therapy for sepsis. In the current study, we aimed to investigate whether the combined use of UC-MSCs and imipenem has a better effect than imipenem alone in treating Escherichia coli (E. coli)-induced sepsis and to explore the mechanism by which UC-MSCs exert their therapeutic effect in septic mice.

Methods

We randomly divided mice into five groups with 10 mice in each group: the normal control group (control group), the sepsis group (vehicle group), the MSCs treatment group (MSCs group), the imipenem treatment group (imipenem group), and the imipenem plus MSCs treatment group (imipenem + MSCs group). We monitored the survival rate in each group every 12 h for 3 days. After observing the survival rate, another 50 mice were also randomly divided into five groups, and the mice were sacrificed after 24 h. Bacterial colonies from the blood and peritoneal lavage fluid were counted in a blinded manner. Organ injury was analyzed by hematoxylin and eosin (HE) staining. Frequencies of myeloid-derived suppressor cells (MDSCs) in the blood, spleen, and bone marrow (BM) were determined by flow cytometry. Plasma levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β, and IL-10 were detected by enzyme-linked immunosorbent assay (ELISA).

Results

Compared with imipenem treatment, the co-administration of UC-MSCs and imipenem dramatically improved the survival rate, decreased the bacterial load, and ameliorated organ injury. Furthermore, UC-MSCs treatment, either alone or in combination with imipenem, significantly increased plasma levels of IL-10 and the percentage of MDSCs by inducing arginase-1 in septic mice.

Conclusions

Our results indicated that UC-MSCs protect mice against sepsis by acting on MDSCs. Combination therapy of UC-MSCs and imipenem may be a new approach for the future clinical treatment of sepsis.

Undiagnosed Wilson's Disease and Fibromyalgia Masking Bowel Perforation

Wilson’s disease is a complex multi-organ disease characterized by impaired biliary excretion of copper and resulting deposition of excess copper in the liver and other organs. It has a wide range of clinical presentations, and diagnosis often requires a high degree of clinical suspicion, especially in patients with multiple other comorbidities.

We present the case of a 37-year-old woman with a complex medical and psychiatric history who was admitted for chronic diarrhea, hepatic enzyme elevation, electrolyte abnormalities, hyperammonemia, and methicillin-sensitive Staphylococcus aureus bacteremia. She was eventually found to have low serum ceruloplasmin level and elevated urine copper levels. Though confirmatory liver biopsy was not performed due to bowel wall rupture and septic shock, most of her symptoms and lab abnormalities could be explained by an underlying diagnosis of Wilson’s disease.

We present this case primarily as a cautionary tale. This patient was not lacking in medical attention prior to this prolonged hospitalization; however, her psychiatric issues and fibromyalgia management were the predominant foci during her frequent primary care office visits and likely distracted from the patient’s chronic laboratory abnormalities. More vigilant laboratory evaluation of underlying medical conditions in psychiatric patients may be warranted in order to prevent serious complications of such conditions.

CBP Bromodomain Inhibition Rescues Mice From Lethal Sepsis Through Blocking HMGB1-Mediated Inflammatory Responses

CREB binding protein (CBP), a transcriptional coactivator and acetyltransferase, is involved in the pathogenesis of inflammation-related diseases. High mobility group box-1 protein (HMGB1) is a critical mediator of lethal sepsis, which has prompted investigation for the development of new treatment for inflammation. Here, we report that the potent and selective inhibition of CBP bromodomain by SGC-CBP30 blocks HMGB1-mediated inflammatory responses in vitro and in vivo. Our data suggest that CBP bromodomain inhibition suppresses LPS-induced expression and release of HMGB1, when the inhibitor was given 8 h post LPS stimulation; moreover, CBP bromodomain inhibition attenuated pro-inflammatory activity of HMGB1. Furthermore, our findings provide evidence that SGC-CBP30 down-regulated rhHMGB1-induced activation of MAPKs and NF-κB signaling by triggering the reactivation of protein phosphatase 2A (PP2A) and the stabilization of MAPK phosphatase 1 (MKP-1). Collectively, these results suggest that CBP bromodomain could serve as a candidate therapeutic target for the treatment of lethal sepsis via inhibiting LPS-induced expression and release of HMGB1 and suppressing the pro-inflammatory activity of HMGB1.

Overexpression of Limb Bud and Heart Alleviates Sepsis-Induced Acute Lung Injury via Inhibiting the NLRP3 Inflammasome

Objective

Sepsis is a leading cause of acute lung injury (ALI). This study attempted to investigate the effects of limb bud and heart (LBH) on the development of sepsis-induced ALI and its underlying mechanism of action.

Methods

The sepsis-induced ALI mouse model was established by cecal ligation and puncture (CLP). The lung injury score and lung wet/dry weight (W/D) ratio were used to evaluate the lung injury. In vitro, ALI was simulated by lipopolysaccharide (LPS) treatment in A549 cells. The mRNA expression of LBH, NLRP3, ASC, and proinflammatory cytokines was measured by qRT-PCR. The viability of LPS-induced A549 cells was analyzed by MTT assay. Furthermore, western blot was performed to detect the protein expression of LBH, NLRP3, and ASC. LPS-induced A549 cells were treated with MCC950 (NLRP3 inflammasome inhibitor) to confirm the effect of LBH on NLRP3 inflammasome.

Results

The mRNA and protein expression of LBH was decreased in sepsis-induced ALI. LBH overexpression reduced the lung injury score, lung W/D ratio, expression of proinflammatory cytokines, and NLRP3 inflammasome activation in sepsis-induced ALI mouse model. Additionally, LBH upregulation increased the viability, while it decreased the proinflammatory cytokine expression and NLRP3 inflammasome activation of LPS-induced A549 cells. Moreover, MCC950 reversed the promoting effects of LBH silencing on proinflammatory cytokine expression and NLRP3 inflammasome activation in LPS-induced A549 cells.

Conclusions

LBH alleviated lung injury in sepsis-induced ALI mouse model by inhibiting inflammation and NLRP3 inflammasome, and restrained the inflammation by inhibiting NLRP3 inflammasome in LPS-induced A549 cells, providing a novel therapeutic target for ALI.

Clinical aspects for differential diagnosis of Kawasaki disease shock syndrome: a case control study

Background

Because of the absence of a specific diagnostic test and pathognomonic clinical features, physicians must rely on the presence of specific clinical criteria and laboratory data that support the diagnosis of KD. To help clinicians distinguish KD, KDSS, septic shock, and TSS earlier, we suggest differential diagnosis and treatment guideline.

Methods

Medical records of immunocompetent patients who were admitted to the pediatric department with a diagnosis of KDSS, septic shock or TSS (SS group) were retrospectively reviewed. In addition, KD patients were selected by seasonal matching to each case of KDSS patient by date of admission (± 2 weeks).

Results

There were 13 patients with KDSS, 35 patients with SS group, and 91 patients with KD. In comparison between KDSS and septic shock group, KDSS group had significantly higher rate of coronary aneurysm incidence, and higher left ventricle dysfunction rate. In comparison between KDSS and TSS, patients with KDSS had a significantly higher erythrocyte sedimentation rate (ESR) and significantly lower creatinine. Receiver operation characteristic curve revealed that the optimal ESR cut off value for determining the KDSS was 56.0 (sensitivity 75.0%, specificity of 100.0%) and the optimal creatinine cut off value for determining the TSS was 0.695 (sensitivity 76.9%, specificity 84.6%).

Conclusions

Clinical symptoms, laboratory finding, echocardiography, and culture studies can be used to differentiate KD, KDSS, septic shock and TSS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-020-02488-w.

Rubi Fructus Water Extract Alleviates LPS-Stimulated Macrophage Activation via an ER Stress-Induced Calcium/CHOP Signaling Pathway

Despite the availability of antibiotics and vaccines, many intractable infectious diseases still threaten human health across the globe. Uncontrolled infections can lead to systemic inflammatory response syndrome and the excessive production of inflammatory cytokines, known as a cytokine storm. As cytokines also play necessary and positive roles in fighting infections, it is important to identify nontoxic and anti-inflammatory natural products that can modulate cytokine production caused by infections. Rubi Fructus, the unripe fruits of Rubus coreanus Miquel, are known to possess antioxidative properties. In this study, the effect of the water extract of Rubi Fructus (RF) on the lipopolysaccharide (LPS)-induced inflammatory response in RAW 264.7 macrophages was investigated using biochemical and cell biology techniques. Our data indicated that RF inhibits p38 phosphorylation, intracellular calcium release, and the production of nitric oxide (NO), interleukin (IL)-6, monocyte chemotactic activating factor (MCP)-1, tumor necrosis factor (TNF)-α, leukemia inhibitory factor (LIF), lipopolysaccharide-induced CXC chemokine (LIX), granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF), macrophage colony-stimulating factor (M-CSF), macrophage inflammatory protein (MIP)-1α, MIP-1β, MIP-2, and regulated on activation, normal T cell expressed and secreted (RANTES) in LPS-treated macrophages. In addition, we observed decreasing mRNA expression of Chop, Camk2a, Stat1, Stat3, Jak2, Fas, c-Jun, c-Fos, Nos2, and Ptgs2 without cytotoxic effects. We concluded that RF demonstrated immunoregulatory activity on LPS-stimulated macrophages via an endoplasmic reticulum (ER) stress-induced calcium/CCAAT-enhancer-binding protein homologous protein (CHOP) pathway and the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway.

The Anti-Inflammatory Role of Bilirubin on "Two-Hit" Sepsis Animal Model

Introduction: Bilirubin is a product of the heme catabolism pathway, and it is excreted in bile and removed from the body through the urine. Bilirubin has potent antioxidant properties but also plays a role in anti-inflammation by protecting the body against endotoxin-induced lung inflammation, down-regulating the expression of adhesion molecules, and inhibiting the infiltration of inflammatory cells. Thus, bilirubin is a promising agent that could use in inflammation disease treatment. The application of bilirubin on the “two-hit” sepsis animal model has been, to date, unknown. Methods: we used lipopolysaccharide to induce initial insults in C57BL/6 mice. After 24 h, mice underwent cecal ligation and puncture to induce the “two-hit” sepsis model. Next, mice were administered 30 mg/kg bilirubin and we observed an improvement. Results: We observed that bilirubin inhibited the expression of pro-inflammatory cytokines, while the levels of anti-inflammatory cytokines were significantly augmented in the lung. Bilirubin improved the survival rate in the sepsis model. Furthermore, we suggest that bilirubin can modulate the accumulation of T-regulatory cells and myeloid-derived suppressor cells. Notably, bilirubin suppressed the activation and functions of T-cells. Conclusions: These results clarified that bilirubin might improve tissue injury in sepsis through anti-inflammatory mechanisms.

Association between right ventricle dysfunction and poor outcome in patients with septic shock

OBJECTIVE

Sepsis-induced myocardial dysfunction (SIMD) can involve both the left and right ventricles. However, the characteristics and outcomes across various manifestations of SIMD remain unknown.

METHODS

This was a retrospective cohort study using a prospective registry of septic shock from January 2011 and April 2017. Patients with clinically presumed cardiac dysfunction underwent echocardiography within 72 hours after admission and were enrolled (n=778). SIMD was classified as left ventricle (LV) systolic/diastolic and right ventricle (RV) dysfunction, which were defined based on the American Society of Echocardiography criteria. The primary outcome was 28-day mortality.

RESULTS

Of the 778 septic shock patients who underwent echocardiography, 270 (34.7%) showed SIMD. The median age was 67.0 years old, and the male was predominant (57.3%). Among them, 67.3% had LV systolic dysfunction, 40.7% had RV dysfunction and 39.3% had LV diastolic dysfunction. Although serum lactate level and sequential organ failure assessment score were not significantly different between groups, SIMD group showed higher troponin I (0.1 vs 0.1 ng/mL; p=0.02) and poor clinical outcomes, including higher 28-day mortality (35.9 vs 26.8%; p<0.01), longer intensive care unit length of stay (5 vs 2 days; p<0.01) and prolonged mechanical ventilation (9 vs 4 days; p<0.01). Multivariate analysis showed that isolated RV dysfunction was an independent risk factor of 28-day mortality (OR 2.26, 95% CI 1.04 to 4.91).

CONCLUSIONS

One-third of patients with septic shock showed various myocardial dysfunctions. LV systolic dysfunction was common; however, only RV dysfunction was associated with short-term mortality.

Role of β2 Integrins in Neutrophils and Sepsis

Sepsis remains medically challenging, with high morbidity and mortality. A novel intervention is urgently needed in the absence of specific, targeted therapy. Neutrophils act as double-edged swords in sepsis; they can help to eradicate microbes, but they also contribute to tissue injury. β2 integrins are critical adhesion molecules that regulate a number of neutrophil functions. β2 integrins consist of four members, namely, αLβ2, αMβ2, αXβ2, and αDβ2. Here, we review the role of each β2 integrin in neutrophils and sepsis and consider future direction for therapeutic intervention.

HDAC6 promotes sepsis development by impairing PHB1-mediated mitochondrial respiratory chain function

OBJECTIVE

This study was aimed at investigating the regulation of mitochondrial function by histone deacetylase 6 (HDAC6) and the role of HDAC6 in the development and progression of sepsis.

RESULTS

HDAC6 downregulated PHB1 and subsequently promoted the development of CLP-induced sepsis. Inhibition of HDAC6 significantly attenuated CLP-induced sepsis through inhibition of mitochondrial dysfunction and reduced oxidant production, thus protecting the rats from oxidative injury.

CONCLUSIONS

In this sepsis model, HDAC6 inhibits the expression and function of PHB1 and alters the function of the mitochondrial respiratory chain mediated by PHB1, thus enhancing the production of oxidants and increasing oxidative stress and thereby leading to severe oxidative injury in multiple organs.

METHODS

The expression of HDAC6 and prohibitin 1 (PHB1) in humans and in a rat model of sepsis was measured by quantitative reverse-transcription PCR and western blotting. Sepsis induction by cecal ligation and puncture (CLP) was confirmed by histological analysis. Concentrations of different sepsis markers were measured by an enzyme-linked immunosorbent assay, and mitochondrial function was assessed via the mitochondrial respiratory control rate.

Cellular Stress and General Pathological Processes

From the viewpoint of the general pathology, most of the human diseases are associated with a limited number of pathogenic processes such as inflammation, tumor growth, thrombosis, necrosis, fibrosis, atrophy, pathological hypertrophy, dysplasia and metaplasia. The phenomenon of chronic low-grade inflammation could be attributed to non-classical forms of inflammation, which include many neurodegenerative processes, pathological variants of insulin resistance, atherosclerosis, and other manifestations of the endothelial dysfunction. Individual and universal manifestations of cellular stress could be considered as a basic element of all these pathologies, which has both physiological and pathophysiological significance. The review examines the causes, main phenomena, developmental directions and outcomes of cellular stress using a phylogenetically conservative set of genes and their activation pathways, as well as tissue stress and its role in inflammatory and para-inflammatory processes. The main ways towards the realization of cellular stress and its functional blocks were outlined. The main stages of tissue stress and the classification of its typical manifestations, as well as its participation in the development of the classical and non-classical variants of the inflammatory process, were also described. The mechanisms of cellular and tissue stress are structured into the complex systems, which include networks that enable the exchange of information with multidirectional signaling pathways which together make these systems internally contradictory, and the result of their effects is often unpredictable. However, the possible solutions require new theoretical and methodological approaches, one of which includes the transition to integral criteria, which plausibly reflect the holistic image of these processes.

Protective effect of febuxostat in sepsis-induced liver and kidney injuries after cecal ligation and puncture with the impact of xanthine oxidase, interleukin 1β, and c-Jun N-terminal kinases

Sepsis is one of the most common causes of death among hospitalized patients. Activity of xanthine oxidase (XO), a reactive oxygen species-producing enzyme, is known to be elevated in septic patients. Our aim was to investigate the possible protective role of XO inhibitor, febuxostat (FEB), in a rat model of sepsis-induced liver and kidney injures. Adult male albino rats were divided into four groups (n = 12 each): sham control, sham + FEB, cecal ligation and puncture (CLP), and CLP + FEB groups. FEB (10 mg/kg per os (p.o.)) was given once daily for 2 days and 30 min prior to laparotomy with CLP. CLP was associated with a high mortality rate accompanied by significant liver and kidney injuries indicated by elevated serum alanine aminotransferase, aspartate aminotransferase, urea, and creatinine levels and confirmed by histopathological tissue injury. Moreover, there was an increase in neutrophil gelatinase-associated lipocalin, uric acid, malondialdehyde, and nitric oxide levels and with decreased superoxide dismutase activity and total antioxidant capacity. In addition, CLP caused increased expression of the inflammatory markers tumor necrosis factor alpha, interleukin 1beta protein levels, and nuclear factor kappa B immunoexpression. Finally, CLP operated rats exhibited an upregulation in the apoptotic mediators, caspase 3, and P-C-Jun N-terminal kinases (JNK) proteins. FEB treatment of CLP rats caused a significant improvement and normalization in all measured parameters. Moreover, FEB amerliorates degenerative histopathological changes and improves the overall survival rate. In conclusion, FEB exhibited a protective effect in sepsis-induced liver and kidney injuries most probably through its anti-inflammatory, antioxidant, and antiapoptotic properties and attenuating JNK signaling pathway secondary to its XO enzyme inhibitory activity.

Sepsis: From Historical Aspects to Novel Vistas. Pathogenic and Therapeutic Considerations

BACKGROUND

Sepsis is a clinical condition due to an infectious event which leads to an early hyper-inflammatory phase followed by a status of tolerance or immune paralysis. Hyper-inflammation derives from a massive activation of immune (neutrophils, monocytes/macrophages, dendritic cells and lymphocytes) and non-immune cells (platelets and endothelial cells) in response to Gram-negative and Gram-positive bacteria and fungi.

DISCUSSION

A storm of pro-inflammatory cytokines and reactive oxygen species accounts for the systemic inflammatory response syndrome. In this phase, bacterial clearance may be associated with a severe organ failure development. Tolerance or compensatory anti-inflammatory response syndrome (CARS) depends on the production of anti-inflammatory mediators, such as interleukin-10, secreted by T regulatory cells. However, once triggered, CARS, if prolonged, may also be detrimental to the host, thus reducing bacterial clearance.

CONCLUSION

In this review, the description of pathogenic mechanisms of sepsis is propaedeutic to the illustration of novel therapeutic attempts for the prevention or attenuation of experimental sepsis as well as of clinical trials. In this direction, inhibitors of NF-κB pathway, cell therapy and use of dietary products in sepsis will be described in detail.

Erastin Inhibits Septic Shock and Inflammatory Gene Expression via Suppression of the NF-κB Pathway

Sepsis is a life-threatening condition that is caused by an abnormal immune response to infection and can lead to tissue damage, organ failure, and death. Erastin is a small molecule capable of initiating ferroptotic cell death in cancer cells. However, the function of erastin in the inflammatory response during sepsis remains unknown. Here, we showed that erastin ameliorates septic shock induced by cecal ligation and puncture or lipopolysaccharides (LPS) in mice, which was associated with a reduced production of inflammatory mediators such as nitric oxide, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β. Pretreatment with erastin in bone marrow-derived macrophages (BMDMs) significantly attenuated the expression of inducible nitric oxide synthase, cyclooxygenase-2, TNF-α, and IL-1β mRNA in response to LPS treatment. Furthermore, we also showed that erastin suppresses phosphorylation of IκB kinase β, phosphorylation and degradation of IκBα, and nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in LPS-stimulated BMDMs. Our findings suggest that erastin attenuates the inflammatory response by suppressing the NF-κB signaling pathway, resulting in inhibition of sepsis development. This study provides new insights regarding the potential therapeutic properties of erastin in sepsis.

Assessment of Metabolic and Nutritional Imbalance in Mechanically Ventilated Multiple Trauma Patients: From Molecular to Clinical Outcomes

The critically ill polytrauma patient is characterized by a series of metabolic changes induced by inflammation, oxidative stress, sepsis, and primary trauma, as well as associated secondary injuries associated. Metabolic and nutritional dysfunction in the critically ill patient is a complex series of imbalances of biochemical and genetic pathways, as well as the interconnection between them. Therefore, the equation changes in comparison to other critical patients or to healthy individuals, in which cases, mathematical equations can be successfully used to predict the energy requirements. Recent studies have shown that indirect calorimetry is one of the most accurate methods for determining the energy requirements in intubated and mechanically ventilated patients. Current research is oriented towards an individualized therapy depending on the energy consumption (kcal/day) of each patient that also takes into account the clinical dynamics. By using indirect calorimetry, one can measure, in real time, both oxygen consumption and carbon dioxide production. Energy requirements (kcal/day) and the respiratory quotient (RQ) can be determined in real time by integrating these dynamic parameters into electronic algorithms. In this manner, nutritional therapy becomes personalized and caters to the patients’ individual needs, helping patients receive the energy substrates they need at each clinically specific time of treatment.

Effect of bovine lactoferrin as a novel therapeutic agent in a rat model of sepsis-induced acute lung injury

Sepsis is a serious clinical condition resulting from severe infection. High rates of mortality and tissue damage have been reported in intensive care unit (ICU) patients with sepsis. Bovine lactoferrin (BLF) is a well-known 80-kDa glycoprotein in the transferrin family that inhibits sepsis in low-birth-weight neonates. The present study investigated the protective effects of BLF in a rat model of sepsis-induced acute lung injury (ALI). The wet/dry ratio, lipid peroxidation, antioxidant markers, total protein, total cell count, inflammatory markers and myeloperoxidase (MPO) levels were assessed. Histopathological analysis was also carried out. BLF treatment reduced the wet/dry ratio of lung tissue by 30.7% and 61.3%, and lipid peroxidation by 22.3% and 67%, at concentrations of 100 and 200 mg/kg, respectively. Superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (Gpx) and catalase were increased by more than 50% under treatment with 200 mg/kg BLF. Inflammatory markers, neutrophils, lymphocytes and total cell count were reduced by more than 50% under treatment with 200 mg/kg BLF. BLF treatment significantly reduced MPO activity, by 28.2% and 74.3%, at concentrations of 100 and 200 mg/kg, respectively. Neutrophilic infiltration and edema were observed in control rats. However, BLF treatment restored intestinal microvilli to the normal range and reduced inflammatory cell invasion. Collectively, these results suggest that BLF is an effective therapeutic agent against sepsis-induced ALI.

High mobility group box protein 1 neutralization therapy in ovine bacteremia: Lessons learned from an ovine septic shock model incorporating intensive care support

Sepsis is a highly complex and often fatal syndrome which varies widely in its clinical manifestations, and therapies that target the underlying uncontrolled immune status in sepsis are needed. The failure of preclinical approaches to provide significant sepsis survival benefit in the clinic is often attributed to inappropriate animal disease models. It has been demonstrated that high mobility group box protein 1 (HMGB1) blockade can reduce inflammation, mortality and morbidity in experimental sepsis without promoting immunosuppression. Within this study, we explored the use of ovine anti-HMGB1 antibodies in a model of ovine septic shock incorporating intensive care supports (OSSICS). Results: Septic sheep exhibited elevated levels of HMGB1 within 12 h after the induction of sepsis. In this study, sepsis was induced in six anaesthetized adult Border Leicester × Merino ewes via intravenous instillation of E. coli and sheep monitored according to intensive care unit standard protocols for 26 h, with the requirement for noradrenaline as the primary endpoint. Septic sheep exhibited a hyperdynamic circulation, renal dysfunction, deranged coagulation profile and severe metabolic acidosis. Sheep were assigned a severity of illness score, which increased over time. While a therapeutic effect of intravenous anti-HMGB1 antibody could not be observed in this model due to limited animal numbers, a reduced bacterial dose induced a septic syndrome of much lower severity. With modifications including a reduced bacterial dose, a longer timeframe and broad spectrum antibiotics, the OSSICS model may become a robust tool for preclinical assessment of sepsis therapeutics.

Cargo-less nanoparticles program innate immune cell responses to toll-like receptor activation

Developing biomaterials to control the responsiveness of innate immune cells represents a clinically relevant approach to treat diseases with an underlying inflammatory basis, such as sepsis. Sepsis can involve activation of Toll-like receptor (TLR) signaling, which activates numerous inflammatory pathways. The breadth of this inflammation has limited the efficacy of pharmacological interventions that target a single molecular pathway. Here, we developed cargo-less particles as a single-agent, multi-target platform to elicit broad anti-inflammatory action against innate immune cells challenged by multiple TLR agonists. The particles, prepared from poly(lactic-co-glycolic acid) (PLGA) and poly(lactic acid) (PLA), displayed potent molecular weight-, polymer composition-, and charge-dependent immunomodulatory properties, including downregulation of TLR-induced costimulatory molecule expression and cytokine secretion. Particles prepared using the anionic surfactant poly(ethylene-alt-maleic acid) (PEMA) significantly blunted the responses of antigen presenting cells to TLR4 (lipopolysaccharide) and TLR9 (CpG-ODN) agonists, demonstrating broad inhibitory activity to both extracellular and intracellular TLR ligands. Interestingly, particles prepared using poly(vinyl alcohol) (PVA), a neutrally-charged surfactant, only marginally inhibited inflammatory cytokine secretions. The biochemical pathways modulated by particles were investigated using TRanscriptional Activity CEll aRrays (TRACER), which implicated IRF1, STAT1, and AP-1 in the mechanism of action for PLA-PEMA particles. Using an LPS-induced endotoxemia mouse model, administration of PLA-PEMA particles prior to or following a lethal challenge resulted in significantly improved mean survival. Cargo-less particles affect multiple biological pathways involved in the development of inflammatory responses by innate immune cells and represent a potentially promising therapeutic strategy to treat severe inflammation.

Cold-inducible RNA-binding Protein Induces Neutrophil Extracellular Traps in the Lungs during Sepsis

Extracellular cold-inducible RNA-binding protein (CIRP) exaggerates inflammation and tissue injury in sepsis. Neutrophil extracellular traps (NETs) are released by activated neutrophils during sepsis. NETs contribute to pathogen clearance, but excessive NET formation (NETosis) causes inflammation and tissue damage. Peptidylarginine deiminase 4 (PAD4) is associated with NETosis by increasing histone citrullination and chromatin decondensation. We hypothesized that CIRP induces NETosis in the lungs during sepsis via upregulating PAD4 expression. Sepsis was induced in C57BL/6 wild-type (WT) and CIRP^−/− mice by cecal ligation and puncture (CLP). After 20 h of CLP induction, NETs in the lungs of WT and CIRP^−/− mice were quantified by flow cytometry by staining the single cell suspensions with MPO and CitH3 Abs. PAD4 expression in the lungs of WT and CIRP^−/− mice after sepsis was assessed by Western blotting. In vitro effects of recombinant mouse (rm) CIRP for NETosis and PAD4 expression in the bone marrow-derived neutrophils (BMDN) were assessed by flow cytometry and Western blotting, respectively. After 20 h of CLP, NETosis in the lungs was significantly decreased in CIRP^−/− mice compared to WT mice, which also correlated with the decreased PAD4 expression. Intratracheal administration of rmCIRP into WT mice significantly increased NETosis and PAD4 expression in the lungs compared to vehicle-injected mice. In vitro culture of BMDN with rmCIRP significantly increased NETosis and PAD4 expression compared to PBS-treated control. Fluorescence microscopy revealed typical web-like structures consistent with NETs in rmCIRP-treated BMDN. Thus, CIRP serves as a novel inducer of NETosis via PAD4 during sepsis.

Dexmedetomidine Attenuates Lung Injury by Promoting Mitochondrial Fission and Oxygen Consumption

BACKGROUND Sepsis is among the major antecedents of lung injury characterized by mitochondrial dysfunction. The functional integrity of the cell is influenced by mitochondrial dynamics. The present investigation evaluated the protective effects of dexmedetomidine against lung injury and speculates on the possible mechanism underlying its effects on mitochondrial function. MATERIAL AND METHODS Lung injury was induced by cecal ligation and puncture (CLP) in mice treated with 0.1, 0.3, or 0.5 mg/kg intravenous dexmedetomidine after a 30-minute surgery. The effects of dexmedetomidine were determined by the oxygenation index and the wet/dry weight ratio of the lung. The expression of mitochondrial protein was assessed by western blot analyses and real-time polymerase chain reaction, to determine the effects of dexmedetomidine on mitochondrial dynamics. The histopathology of the lung tissue was determined by hematoxylin and eosin staining, and TUNEL-positive cells were counted in TUNEL assays. Activity of caspase-3, caspase-8, and caspase-9 enzymes were determined by colorimetric assay. RESULTS Treatment with dexmedetomidine significantly attenuated changes in the oxygenation index and the wet/dry weight ratio in mice with CLP-induced lung injury. There was a significant decrease in pro-inflammatory mediators and markers of oxidative stress in the lung tissue of the dexmedetomidine-treated group compared to the negative control group. Moreover, treatment with dexmedetomidine attenuated the altered gene expression caused by mitochondrial fusion and fission in the lung tissue of mice with CLP-induced lung injury. The number of TUNEL-positive cells was significantly reduced in the dexmedetomidine-treated group compared to the negative control group. Moreover, dexmedetomidine ameliorated the altered activity of caspase-3, caspase-8, and caspase-9 enzyme in the lung tissues of CLP-induced lung injure mice. CONCLUSIONS Dexmedetomidine protected mice against CLP-induced lung injury by attenuating changes in mitochondrial fusion and fission.

Risk Factors for Same Pathogen Sepsis Readmission Following Hospitalization for Septic Shock

(1) Background: Septic shock survivors frequently readmit because of subsequent infection. This study aimed to determine the rate and risk factors for same pathogen sepsis readmissions following hospitalization for septic shock. (2) Methods: We performed this retrospective study using data from a prospective septic shock registry at a single urban tertiary center. All the patients were treated with a protocol-driven resuscitation bundle therapy between 2011 and 2016. We collected data from adult (older than 18 years) patients readmitted with sepsis within 90 days of discharge following hospitalization for septic shock. (3) Results: Among 2062 septic shock patients, 690 were readmitted within 90 days of discharge. After excluding scheduled and non-sepsis admissions, we analyzed the data from 274 (13.3%) patients readmitted for sepsis. Most of the readmissions following septic shock were new infections rather than relapses of the initial infection. The culture-negative rate was 51.4% (141/274), while the same pathogen was isolated in 25% of cases (69/274). Multivariate analysis revealed that previous gram-negative bacteremia (OR, 9.902; 95% CI, 2.843⁻34.489), urinary tract infection (OR, 4.331; 95% CI, 1.723⁻10.882) and same site infection (OR, 6.894; 95% CI, 2.390⁻19.886) were significantly associated with readmission for sepsis caused by the same pathogen. (4) Conclusions: The sepsis readmission rate following the previous hospitalization for septic shock was 13.3% and one-quarter of those patients had the same pathogen isolated. Previous gram-negative bacteremia, and/or same site infection are predisposing factors for recurrent same-pathogen sepsis.