Markers of endothelial damage in organ dysfunction and sepsis

Associations between serum albumin level trajectories and clinical outcomes in sepsis patients in ICU: insights from longitudinal group trajectory modeling

Background

Sepsis triggers a strong inflammatory response, often leading to organ failure and high mortality. The role of serum albumin levels in sepsis is critical but not fully understood, particularly regarding the significance of albumin level changes over time. This study utilized Group-based Trajectory Modeling (GBTM) to investigate the patterns of serum albumin changes and their impact on sepsis outcomes.

Methods

We conducted a retrospective analysis on ICU patients from West China Hospital (2015-2022), employing GBTM to study serum albumin fluctuations within the first week of ICU admission. The study factored in demographics, clinical parameters, and comorbidities, handling missing data through multiple imputation. Outcomes assessed included 28-day mortality, overall hospital mortality, and secondary complications such as AKI and the need for mechanical ventilation.

Results

Data from 1,950 patients revealed four serum albumin trajectories, showing distinct patterns of consistently low, increasing, moderate, and consistently high levels. These groups differed significantly in mortality, with the consistently low level group experiencing the highest mortality. No significant difference in 28-day mortality was observed among the other groups. Subgroup analysis did not alter these findings.

Conclusion

The study identified four albumin trajectory groups in sepsis patients, highlighting that those with persistently low levels had the worst outcomes, while those with increasing levels had the best. Stable high levels above 30 g/L did not change outcomes significantly. These findings can inform clinical decisions, helping to identify high-risk patients early and tailor treatment approaches.

Protective effect of pregabalin on renal and renal endothelial damage in sepsis induced by lipopolysaccharide

OBJECTIVE

We investigated the protective effects of pregabalin (PRG) on kidney and renal endothelial damage in sepsis induced by Lipopolysaccharide (LPS).

MATERIALS AND METHODS

Rats were randomly divided into three groups as control, LPS and LPS+PRG. Saline solution was administered 30 mg/kg orally and 5 mg/kg intraperitoneally (i.p.) to the control group. LPS was applied as 5 mg/kg, i.p. to the LPS group. In the LPS+PRG group, PRG at 30 mg/kg orally and one hour before LPS administration, one hour later 5 mg/kg i.p. LPS was applied. Rats were sacrificed 6 hours after LPS administration.

RESULTS

White Blood Cell (WBC), granulocyte, Blood Urea Nitrogen (BUN), creatinine, uric asid, Total Oxidant Status (TOS) and Oxidative Stress Index (OSI) significantly increased (p<0.05); platelets (PLT), activated partial thromboplastin time (aPTT) and Total Antioxidant Status (TAS) significantly decreased in the LPS group compared to the control group (p<0.05). In the LPS+PRG group WBC, granulocyte, BUN, creatinine, uric asid, TOS and OSI significantly decreased (p<0.05); PLT, aPTT and TAS significantly increased compared to the LPS group(p<0.05). Histopathological examinations showed that kidney and renal endothelial damage in the LPS group decreased in the LPS+PRG group. Immunohistochemically IL1-β, IL-6, IL-10, TNF-α expressions in kidney tissue and Toll-Like Receptors-4 (TLR-4) and NF-κB expressions in the renal endothelial tissue significantly increased in the LPS group compared to the control group and significantly decreased in the LPS+PRG group compared to the LPS group (p<0.001).

CONCLUSIONS

Sepsis causes kidney and renal endothelial damage and PRG reduces this damage. Therefore PRG can be used in prophylactic treatment in sepsis, supported by more studies.

Impact of Treatment with Antioxidants as an Adjuvant to Standard Therapy in Patients with Septic Shock: Analysis of the Correlation between Cytokine Storm and Oxidative Stress and Therapeutic Effects

Cellular homeostasis is lost or becomes dysfunctional during septic shock due to the activation of the inflammatory response and the deregulation of oxidative stress. Antioxidant therapy administered alongside standard treatment could restore this lost homeostasis. We included 131 patients with septic shock who were treated with standard treatment and vitamin C (Vit C), vitamin E (Vit E), N-acetylcysteine (NAC), or melatonin (MT), in a randomized trial. Organ damage quantified by Sequential Organ Failure Assessment (SOFA) score, and we determined levels of Interleukins (IL) IL1β, Tumor necrosis factor alpha (TNFα), IL-6, monocyte chemoattractant protein-1 (MCP-1), Transforming growth factor B (TGFβ), IL-4, IL-10, IL-12, and Interferon-γ (IFNγ). The SOFA score decreased in patients treated with Vit C, NAC, and MT. Patients treated with MT had statistically significantly reduced of IL-6, IL-8, MCP-1, and IL-10 levels. Lipid peroxidation, Nitrates and nitrites (NO3- and NO2-), glutathione reductase, and superoxide dismutase decreased after treatment with Vit C, Vit E, NAC, and MT. The levels of thiols recovered with the use of Vit E, and all patients treated with antioxidants maintained their selenium levels, in contrast with controls (p = 0.04). The findings regarding oxidative stress markers and cytokines after treatment with antioxidants allow us to consider to future the combined use of antioxidants in a randomized clinical trial with a larger sample to demonstrate the reproducibility of these beneficial effects.

Ultrasonographic assessment of brachial artery reactivity as a predictor of adverse outcome in patients undergoing emergency laparotomy for perforated peritonitis - Prospective observational study

Background and Aims

This study aimed to assess if pre- and postoperative parameters of brachial artery reactivity (BAR), like flow-mediated dilation (FMD) and hyperaemic velocity (HV), could predict in-hospital mortality in perforation peritonitis patients undergoing emergency laparotomy.

Methods

In this prospective observational study, adult patients with perforation peritonitis undergoing emergency laparotomy were recruited. FMD and HV were measured preoperatively, postoperatively and at 24 and 48 h post-surgery. Adult patients undergoing elective laparotomy served as the control group. The primary outcome was in-hospital mortality. Baseline and BAR parameters were compared between survivors and non-survivors. Risk factors for mortality were identified by univariate analysis. Prognostic performances of BAR parameters were assessed by different models using logistic regression. All statistical analyses were performed on STATA version 13 for Mac OS.

Results

Seventy-six emergency laparotomy patients were recruited, and 26 died during the hospital stay. FMD and HV were comparable at all time points between survivors and non-survivors, except that HV was higher in survivors at 48 h post-surgery (median [interquartile range] 1.28 [1.16-1.49] vs. 1.16 [0.86-1.35], P = 0.010]. HV at 48 h predicted mortality (adjusted odds ratio [OR] [95% confidence interval] 21.05 [1.04-422.43], P = 0.046), and a model consisting of age, Acute Physiology and Chronic Health Evaluation (APACHE) score and HV at 48 h was the best predictor of mortality (area under the receiver operating characteristic (AUROC) curve 0.82).

Conclusion

HV, as measured by ultrasonography of the brachial artery at 48 h postoperatively, is a good predictor of mortality in patients undergoing emergency laparotomy for perforation peritonitis.

The Intricate Role of Non-Coding RNAs in Sepsis-Associated Disseminated Intravascular Coagulation

Disseminated Intravascular Coagulation (DIC) is a type of tissue and organ dysregulation in sepsis, due mainly to the effect of the inflammation on the coagulation system. Unfortunately, the underlying molecular mechanisms that lead to this disorder are not fully understood. Moreover, current biomarkers for DIC, including biological and clinical parameters, generally provide a poor diagnosis and prognosis. In recent years, non-coding RNAs have been studied as promising and robust biomarkers for a variety of diseases. Thus, their potential in the diagnosis and prognosis of DIC should be further studied. Specifically, the relationship between the coagulation cascade and non-coding RNAs should be established. In this review, microRNAs, long non-coding RNAs, and circular RNAs are studied in relation to DIC. Specifically, the axis between these non-coding RNAs and the corresponding affected pathway has been identified, including inflammation, alteration of the coagulation cascade, and endothelial damage. The main affected pathway identified is PI3K/AKT/mTOR axis, where several ncRNAs participate in its regulation, including miR-122-5p which is sponged by circ_0005963, ciRS-122, and circPTN, and miR-19a-3p which is modulated by circ_0000096 and circ_0063425. Additionally, both miR-223 and miR-24 were found to affect the PI3K/AKT pathway and were regulated by lncGAS5 and lncKCNQ1OT1, respectively. Thus, this work provides a useful pipeline of inter-connected ncRNAs that future research on their impact on DIC can further explore.

Endogenous Glycosaminoglycans in Various Pathologic Plasma Samples as Measured by a Fluorescent Quenching Method

Endogenous glycosaminoglycans (GAGs) with a similar structure to heparin are widely distributed in various tissues. A fluorescence probe, namely Heparin Red, can detect polyanionic GAGs in plasma samples. The purpose of this study is to measure endogenous GAGs in various plasma samples obtained from different pathologic states in comparison to healthy controls utilizing this method. Plasma samples were obtained from patient groups including atrial fibrillation (AF), end-stage-renal-disease (ESRD), diabetes mellitus (DM), sepsis, cancer, liver disease (LD), and pulmonary embolism (PE). Normal human plasma (NHP) was used as healthy controls. The Heparin Red kit from Red Probes (Münster, Germany) was used for the quantification of endogenous GAGs in each sample before and after heparinase I degradation. All results were compiled as group means  ±  SD for comparison. NHP was found to have relatively low levels of endogenous GAGs with a mean concentration of 0.06 μg/mL. The AF, ESRD, DM, and sepsis patient samples had a mean endogenous GAG concentration of 0.55, 0.72, 0.92, and 0.94 μg/mL, respectively. The levels of endogenous GAGs were highest in cancer, LD, and PE patient plasma samples with a mean concentration of 1.95, 2.78, and 2.83 μg/mL, respectively. Heparinase I degradation resulted in a decline in GAG levels in plasma samples. These results clearly show that detectable Heparin Red sensitive endogenous GAGs are present in circulating plasma at varying levels in various patient groups. Additional studies are necessary to understand this complex pathophysiology.

Role of SARS-CoV-2-induced Cytokine Storm in Multi-Organ Failure: Molecular Pathways and Potential Therapeutic Options

Coronavirus disease 2019 (COVID-19) outbreak has become a global public health emergency and has led to devastating results. Mounting evidence proposes that the disease causes severe pulmonary involvement and influences different organs, leading to a critical situation named multi-organ failure. It is yet to be fully clarified how the disease becomes so deadly in some patients. However, it is proven that a condition called “cytokine storm” is involved in the deterioration of COVID-19. Although beneficial, sustained production of cytokines and overabundance of inflammatory mediators causing cytokine storm can lead to collateral vital organ damages. Furthermore, cytokine storm can cause post-COVID-19 syndrome (PCS), an important cause of morbidity after the acute phase of COVID-19. Herein, we aim to explain the possible pathophysiology mechanisms involved in COVID-19-related cytokine storm and its association with multi-organ failure and PCS. We also discuss the latest advances in finding the potential therapeutic targets to control cytokine storm wishing to answer unmet clinical demands for treatment of COVID-19.

von Willebrand factor links primary hemostasis to innate immunity

The plasma multimeric glycoprotein von Willebrand factor (VWF) plays a critical role in primary hemostasis by tethering platelets to exposed collagen at sites of vascular injury. Recent studies have identified additional biological roles for VWF, and in particular suggest that VWF may play an important role in regulating inflammatory responses. However, the molecular mechanisms through which VWF exerts its immuno-modulatory effects remain poorly understood. In this study, we report that VWF binding to macrophages triggers downstream MAP kinase signaling, NF-κB activation and production of pro-inflammatory cytokines and chemokines. In addition, VWF binding also drives macrophage M1 polarization and shifts macrophage metabolism towards glycolysis in a p38-dependent manner. Cumulatively, our findings define an important biological role for VWF in modulating macrophage function, and thereby establish a novel link between primary hemostasis and innate immunity.

Disseminated Intravascular Coagulation: The Past, Present, and Future Considerations

Disseminated intravascular coagulation (DIC) has been understood as a consumptive coagulopathy. However, impaired hemostasis is a component of DIC that occurs in a progressive manner. The critical concept of DIC is systemic activation of coagulation with vascular endothelial damage. DIC is the dynamic coagulation/fibrinolysis disorder that can proceed from compensated to decompensated phases, and is not simply impaired hemostasis, a misunderstanding that continues to evoke confusion among clinicians. DIC is a critical step of disease progression that is important to monitor over time. Impaired microcirculation and subsequent organ failure due to pathologic microthrombi formation are the pathophysiologies in sepsis-associated DIC. Impaired hemostasis due to coagulation factor depletion from hemodilution, shock, and hyperfibrinolysis occurs in trauma-associated DIC. Overt-DIC diagnostic criteria have been used clinically for more than 20 years but may not be adequate to detect the compensated phase of DIC, and due to different underlying causes, there is no "one-size-fits-all criteria." Individualized criteria for heterogeneous conditions continue to be proposed to facilitate the diagnosis. We believe that future research will provide therapeutics using new diagnostic criteria. Finally, DIC is also classified as either acute or chronic, and acute DIC results from progressive coagulation activation over a short time and requires urgent management. In this review, we examine the advances in research for DIC.

Endothelial Poldip2 regulates sepsis-induced lung injury via Rho pathway activation

AIMS

Sepsis-induced lung injury is associated with significant morbidity and mortality. Previously, we showed that heterozygous deletion of polymerase δ-interacting protein 2 (Poldip2) was protective against sepsis-induced lung injury. Since endothelial barrier disruption is thought to be the main mechanism of sepsis-induced lung injury, we sought to determine if the observed protection was specifically due to the effect of reduced endothelial Poldip2.

METHODS AND RESULTS

Endothelial-specific Poldip2 knock-out mice (EC-/-) and their wild-type littermates (EC+/+) were injected with saline or lipopolysaccharide (18 mg/kg) to model sepsis-induced lung injury. At 18 h post-injection mice, were euthanized and bronchoalveolar lavage (BAL) fluid and lung tissue were collected to assess leucocyte infiltration. Poldip2 EC-/- mice showed reduced lung leucocyte infiltration in BAL (0.21 ± 0.9×106 vs. 1.29 ± 1.8×106 cells/mL) and lung tissue (12.7 ± 1.8 vs. 23 ± 3.7% neutrophils of total number of cells) compared to Poldip2 EC+/+ mice. qPCR analysis of the lung tissue revealed a significantly dampened induction of inflammatory gene expression (TNFα 2.23 ± 0.39 vs. 4.15 ± 0.5-fold, IκBα 4.32 ± 1.53 vs. 8.97 ± 1.59-fold), neutrophil chemoattractant gene expression (CXCL1 68.8 ± 29.6 vs. 147 ± 25.7-fold, CXCL2 65 ± 25.6 vs. 215 ± 27.3-fold) and a marker of endothelial activation (VCAM1 1.25 ± 0.25 vs. 3.8 ± 0.38-fold) in Poldip2 EC-/- compared to Poldip2 EC+/+ lungs. An in vitro model using human pulmonary microvascular endothelial cells was used to assess the effect of Poldip2 knock-down on endothelial activation and permeability. TNFα-induced endothelial permeability and VE-cadherin disruption were significantly reduced with siRNA-mediated knock-down of Poldip2 (5 ± 0.5 vs. 17.5 ± 3-fold for permeability, 1.5 ± 0.4 vs. 10.9 ± 1.3-fold for proportion of disrupted VE-cadherin). Poldip2 knock-down altered expression of Rho-GTPase-related genes, which correlated with reduced RhoA activation by TNFα (0.94 ± 0.05 vs. 1.29 ± 0.01 of relative RhoA activity) accompanied by redistribution of active-RhoA staining to the centre of the cell.

CONCLUSION

Poldip2 is a potent regulator of endothelial dysfunction during sepsis-induced lung injury, and its endothelium-specific inhibition may provide clinical benefit.

Stress conditions induced circRNAs profile of extracellular vesicles in brain microvascular endothelial cells

Cerebral ischemia causes hypoxic injury and inflammation, and brain microvascular endothelial cells (BMVECs) dysfunction is an initial stage of blood-brain barrier disruption. Endothelial cells secrete extracellular vesicles (EVs) that are involved in intercellular signal transduction. EVs contain a variety of RNAs, proteins, and metabolites. Circular RNA (circRNA) is a member of the non-coding RNA. The expression profile and potential function of circRNAs in BMVECs are unknown. Here, human BMVECs have undergone hypoxia or TNF-α induction, and the changes in circRNAs were measured by RNA sequencing. A total of 70 circRNAs showed differential expression, including 43 previously unrecorded circRNAs and 27 recorded circRNAs. Since astrocyte end-feet encircle endothelial cells, they are considered the main targets of the EVs from BMVEC. The miRNA sequence data and bioinformatics were used to predict the circRNA-miRNA-mRNA networks in astrocytes. The gene ontology (GO) analysis showed the main downstream targets of circRNAs are DNA transcription regulation and protein kinase-related signaling pathways. These results suggest that altering circRNAs may be a potential therapeutic target for cerebral ischemia induced hypoxic injury and inflammation.

Sepsis-Associated Encephalopathy: A Mini-Review of Inflammation in the Brain and Body

Sepsis is defined as a life-threatening multi-organ dysfunction triggered by an uncontrolled host response to infectious disease. Systemic inflammation elicited by sepsis can cause acute cerebral dysfunction, characterized by delirium, coma, and cognitive dysfunction, known as septic encephalopathy. Recent evidence has reported the underlying mechanisms of sepsis. However, the reasons for the development of inflammation and degeneration in some brain regions and the persistence of neuroinflammation remain unclear. This mini-review describes the pathophysiology of region-specific inflammation after sepsis-associated encephalopathy (SAE), clinical features, and future prospects for SAE treatment. The hippocampus is highly susceptible to inflammation, and studies that perform treatments with antibodies to cytokine receptors, such as interleukin-1β, are in progress. Future development of clinically applicable therapies is expected.

Eosinopenia and increased markers of endothelial damage are characteristic of COVID-19 infection at time of hospital admission

In December 2019, a new virus has been discovered, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), leading to coronavirus disease 2019 (COVID-19). COVID-19 has been defined as an evolving disease with different phases. It starts with a mild or asymptomatic phase in which there is minimal disease. Thereafter, most patients recover, however, in 20% of the cases the infection worsens. It is hypothesized that eosinopenia, endothelial injury and the presence of smooth muscle autoantibodies are associated with the severity of the COVID-19. In a subset of 75 blood samples of patients with a SARS-CoV-2 infection at time of hospitalization and 30 healthy control samples concentrations of eosinophils, VEGF, VCAM, endothelin and smooth muscle autoantibodies were determined with hemocytometry, ELISA and immunofluorescence assays. In the group of patients with COVID-19 eosinophils (IQR = 0.0-0.01*10⁹/L) were significantly decreased (p < .001), whereas markers of endothelial damage VCAM (IQR = 740-1120 ng/mL) and endothelin (IQR = 2.0-3.4 pg/mL) were significantly increased (p < .001) compared to the group of healthy controls (eosinophils IQR = 0.09-0.19*10⁹/L, VCAM IQR = 362-561 ng/mL, endothelin IQR = 0.5-1.0 pg/mL). From the multivariate analysis, it is concluded that at time of hospitalization a combination of eosinopenia and increased markers of endothelial damage VCAM and endothelin are characteristic of COVID-19.

Clinical significance and role of CXCL16 in anti-neutrophil cytoplasmic autoantibody-associated vasculitis

Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is a group of potentially life-threatening autoimmune diseases. The kidney and lung are the most common and most severely affected organs. Previous studies have shown that the chemokine ligand CXCL16 and its receptor CXCR6 play an important role in kidney disease. However, whether CXCL16/CXCR6 is involved in the pathogenesis of AAV remains elusive. In this study, the levels of CXCL16 and its specific receptor CXCR6 were investigated. According to kidney outcome, patients were divided into two groups, specifically one with high CXCL16 levels and one with low CXCL16 levels, by cut-off values using receiver operating characteristic (ROC) curves. The clinical parameters and histological features were further compared between the two groups. The ability of CXCL16 to induce neutrophil chemotaxis was analysed using a Transwell migration assay in a coculture system of conditional immortalized human glomerular endothelial cells (ciGEnCs) and neutrophils. We observed that the levels of CXCL16 were significantly increased in the circulation, along with the expression in renal tissue of AAV patients compared to healthy controls (HCs). CXCR6 expression on neutrophils was significantly higher in patients with AAV than in HCs. There were positive correlations between the levels of CXCL16 and serum creatinine, IL-6, CRP, and TNF-α and negative correlations with eGFR. The serum levels of CXCL16 could act as a predictive biomarker of renal outcome in AAV. CXCL16 secretion was upregulated in ciGEnCs treated with AAV serum. CXCL16 released from ciGEnCs contributed to neutrophil migration. Furthermore, neutrophil migration was attenuated by silencing CXCL16 expression via transfection with short hairpin RNA (shRNA) sequences and lentivirus. Taken together, these data suggest that the inhibition of the CXCL16/CXCR6 axis may provide new therapeutic strategies targeting AAV.

A Thrombomodulin Promoter Gene Polymorphism, rs2239562, Influences Both Susceptibility to and Outcome of Sepsis

Objective: Disseminated intravascular coagulation plays a key role in the pathophysiology of sepsis. Thrombomodulin is essential in the protein C system of coagulation cascade, and functional polymorphisms influence the human thrombomodulin gene (THBD). Therefore, we conducted a multicenter study to evaluate the influence of such polymorphisms on the pathophysiology of sepsis. Methods: A collaborative case-control study in the intensive care unit (ICU) of each of five tertiary emergency centers. The study included 259 patients (of whom 125 displayed severe sepsis), who were admitted to the ICU of Chiba University Hospital, Chiba, Japan between October 2001 and September 2008 (discovery cohort) and 793 patients (of whom 271 patients displayed severe sepsis), who were admitted to the five ICUs between October 2008 and September 2012 (multicenter validation cohort). To assess the susceptibility to severe sepsis, we further selected 222 critically ill patients from the validation cohort matched for age, gender, morbidity, and severity with the patients with severe sepsis, but without any evidence of sepsis. Results: We examined whether the eight THBD single nucleotide polymorphisms (SNPs) were associated with susceptibility to and/or mortality of sepsis. Higher mortality on severe sepsis in the discovery and combined cohorts was significantly associated with the CC genotype in a THBD promoter SNP (-1920^*C/G; rs2239562) [odds ratio [OR] 2.709 (1.067-6.877), P = 0.033 and OR 1.768 (1.060-2.949), P = 0.028]. Furthermore, rs2239562 SNP was associated with susceptibility to severe sepsis [OR 1.593 (1.086-2.338), P = 0.017]. Conclusions: The data demonstrate that rs2239562, the THBD promoter SNP influences both the outcome and susceptibility to severe sepsis.

Endothelial Dysfunction Criteria in Critically Ill Children: The PODIUM Consensus Conference

OBJECTIVES

To review, analyze, and synthesize the literature on endothelial dysfunction in critically ill children with multiple organ dysfunction syndrome and to develop a consensus biomarker-based definition and diagnostic criteria.

DATA SOURCES

Electronic searches of PubMed and Embase were conducted from January 1992 to January 2020, using a combination of medical subject heading terms and key words to define concepts of endothelial dysfunction, pediatric critical illness, and outcomes.

STUDY SELECTION

Studies were included if they evaluated critically ill children with endothelial dysfunction, evaluated performance characteristics of assessment/scoring tools to screen for endothelial dysfunction, and assessed outcomes related to mortality, functional status, organ-specific outcomes, or other patient-centered outcomes. Studies of adults or premature infants (≤36 weeks gestational age), animal studies, reviews or commentaries, case series with sample size ≤10, and non-English language studies with the inability to determine eligibility criteria were excluded.

DATA EXTRACTION

Data were abstracted from each eligible study into a standard data extraction form along with risk of bias assessment.

DATA SYNTHESIS

We identified 62 studies involving 84 assessments of endothelial derived biomarkers indirectly linked to endothelial functions including leukocyte recruitment, inflammation, coagulation, and permeability. Nearly all biomarkers studied lacked specificity for vascular segment and organ systems. Quality assessment scores for the collected literature were low.

CONCLUSIONS

The Endothelial Subgroup concludes that there exists no single or combination of biomarkers to diagnose endothelial dysfunction in pediatric multiple organ dysfunction syndrome. Future research should focus on biomarkers more directly linked to endothelial functions and with specificity for vascular segment and organ systems.

Thrombo-inflammatory biomarkers and D-dimer in a biracial cohort study

BACKGROUND

Higher D-dimer is a risk factor for cardiovascular diseases and venous thromboembolism. In the general population, D-dimer and other thrombo-inflammatory biomarkers are higher among Black individuals, who also have higher risk of these conditions compared to White people.

OBJECTIVE

To assess whether Black individuals have an exaggerated correlation between D-dimer and thrombo-inflammatory biomarkers characteristic of cardiovascular diseases.

METHODS

Linear regression was used to assess correlations of 11 thrombo-inflammatory biomarkers with D-dimer in a cross-sectional study of 1068 participants of the biracial Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort.

RESULTS

Adverse levels of most biomarkers, especially fibrinogen, factor VIII, C-reactive protein, N-terminal pro-B-type natriuretic peptide, and interleukin (IL)-6, were associated with higher D-dimer. Several associations with D-dimer differed significantly by race. For example, the association of factor VIII with D-dimer was more than twice as large in Black compared to White participants. Specifically, D-dimer was 26% higher per standard deviation (SD) higher factor VIII in Black adults and was only 11% higher per SD higher factor VIII in White adults. In Black but not White adults, higher IL-10 and soluble CD14 were associated with higher D-dimer.

CONCLUSIONS

Findings suggest that D-dimer might relate to Black/White differences in cardiovascular diseases and venous thromboembolism because it is a marker of amplified thrombo-inflammatory response in Black people. Better understanding of contributors to higher D-dimer in the general population is needed.

Pleiotropic actions of factor Xa inhibition in cardiovascular prevention: mechanistic insights and implications for anti-thrombotic treatment

Atherosclerosis is a chronic inflammatory disease in which atherothrombotic complications lead to cardiovascular morbidity and mortality. At advanced stages, myocardial infarction, ischaemic stroke, and peripheral artery disease, including major adverse limb events, are caused either by acute occlusive atherothrombosis or by thromboembolism. Endothelial dysfunction, vascular smooth muscle cell activation, and vascular inflammation are essential in the development of acute cardiovascular events. Effects of the coagulation system on vascular biology extend beyond thrombosis. Under physiological conditions, coagulation proteases in blood are pivotal in maintaining haemostasis and vascular integrity. Under pathological conditions, including atherosclerosis, the same coagulation proteases (including factor Xa, factor VIIa, and thrombin) become drivers of atherothrombosis, working in concert with platelets and vessel wall components. While initially atherothrombosis was attributed primarily to platelets, recent advances indicate the critical role of fibrin clot and plasma coagulation factors. Mechanisms of atherothrombosis and hypercoagulability vary depending on plaque erosion or plaque rupture. In addition to contributing to thrombus formation, factor Xa and thrombin can affect endothelial dysfunction, oxidative stress, vascular smooth muscle cell function as well as immune cell activation and vascular inflammation. By these mechanisms, they promote atherosclerosis and contribute to plaque instability. In this review, we first discuss the postulated vasoprotective mechanisms of protease-activated receptor signalling induced by coagulation enzymes under physiological conditions. Next, we discuss preclinical studies linking coagulation with endothelial cell dysfunction, thromboinflammation, and atherogenesis. Understanding these mechanisms is pivotal for the introduction of novel strategies in cardiovascular prevention and therapy. We therefore translate these findings to clinical studies of direct oral anticoagulant drugs and discuss the potential relevance of dual pathway inhibition for atherothrombosis prevention and vascular protection.

Endothelium Activation Markers in Severe Hospitalized COVID-19 Patients: Role in Mortality Risk Prediction

Introduction  Endothelial damage and hypercoagulability are major players behind the hemostatic derangement of SARS-CoV-2 infection.

Aim  In this prospective study we assessed endothelial and inflammatory biomarkers in a cohort of COVID-19 patients, aiming to identify predictive factors of in-hospital mortality.

Methods  COVID-19 patients hospitalized in intensive care (ICU) and non-ICU units at 2 Bergamo (Italy) hospitals from March 23 to May 30, 2020, were enrolled. Markers of endothelium activation including von-Willebrand factor (vWF), soluble thrombomodulin (sTM), and fibrinolytic proteins (t-PA and PAI-1) were measured. Additionally, D-dimer, Fibrinogen, FVIII, nucleosomes, C reactive protein (CRP) and procalcitonin were assessed.

Results  Sixty-three (45 ICU, and 18 non-ICU) patients, with a median age of 62 years were analyzed. Increased plasma levels of D-dimer, FVIII, fibrinogen, nucleosomes, CRP, and procalcitonin were observed in the whole cohort. Extremely elevated vWF levels characterized all patients (highest values in ICU-subjects). After a median time of 30 days, death occurred in 13 (21%) patients. By multivariable analysis, vWF-activity, neutrophil-count and PaO2/FiO2 were significantly associated with death. Using these variables, a linear score with 3-risk groups was generated that provided a cumulative incidence of death of 0% in the low-, 32% in the intermediate-, and 78% in the high-risk group.

Conclusions  COVID-19-induced hemostatic abnormalities are exacerbated by the severity of the disease and strongly correlate with the inflammatory status, underlying the link between coagulation, endothelial activation, and inflammation. Our study provides evidence for a role of vWF, together with neutrophils and PaO2/FiO2, as a significant predictor of in-hospital mortality by SARSCoV-2 infection.

Up-to-date information on polymyxin B-immobilized fiber column direct hemoperfusion for septic shock

Endotoxin adsorption therapy by polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) has been used for the treatment of septic shock patients. Endotoxin, an outer membrane component of Gram-negative bacteria, plays an important role in the pathogenesis of septic shock. Endotoxin triggers a signaling cascade for leukocytes, macrophage, and endothelial cells to secrete various mediators including cytokines and nitric oxide, leading to septic shock and multiple organ dysfunction syndrome. PMX-DHP directly adsorbed not only endotoxin but also monocytes and anandamide. It reduced blood levels of inflammatory cytokines such as interleukin (IL)-1, IL-6, tumor necrosis factor-alpha and IL-17A, adhesion molecules, plasminogen activator inhibitor 1, and high mobility group box-1. As a result, PMX-DHP increased blood pressure and reduced the dose of vasoactive-inotropic agents. PMX-DHP improved monocyte human leukocyte antigen-DR expression in patients with severe sepsis and septic shock. A post hoc analysis of EUPHRATES (Evaluating the Use of Polymyxin B Hemoperfusion in Randomized Controlled Trial of Adults Treated for Endotoxemia and Septic Shock) trial has shown that PMX-DHP significantly reduced 28-day mortality compared with the control group in septic shock patients with endotoxin activity assay level between 0.60 and 0.89. Longer duration of PMX-DHP may be another strategy to bring out the beneficial effects of PMX-DHP. Further studies are needed to confirm the efficacy of PMX-DHP treatment for septic shock.

Influence of Fucoidan Extracts from Different Fucus Species on Adult Stem Cells and Molecular Mediators in In Vitro Models for Bone Formation and Vascularization

Fucoidans, sulfated polysaccharides extracted from brown algae, are marine products with the potential to modulate bone formation and vascularization processes. The bioactivity and safety of fucoidans are highly associated with their chemical structure, which may vary with algae species and extraction method. Thus, in depth evaluation of fucoidan extracts in terms of endotoxin content, cytotoxicity, and their detailed molecular biological impact on the individual cell types in bone is needed. In this study, we characterized fucoidan extracts from three different Fucus species including Fucus vesiculosus (Fv), Fucus serratus (Fs), and Fucus distichus subsp. evanescens (Fe) for their chemical features, endotoxin content, cytotoxicity, and bioactive effects on human outgrowth endothelial cells (OEC) and human mesenchymal stem cells (MSC) as in vitro models for bone function and vascularization. Extracts contained mainly high molecular weight (HMW) fucoidans and were free of endotoxins that may cause inflammation or influence vascularization. OEC tolerated fucoidan concentrations up to 200 µg/mL, and no indication of cytotoxicity was observed. The inflammatory response, however, investigated by real-time PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) and endothelial barrier assessed by impedance measurement differed for the individual extracts. MSC in comparison with endothelial cells were more sensitive to fucoidans and showed partly reduced metabolic activity and proliferation at higher doses of fucoidans. Further results for MSC indicated impaired osteogenic functions in alkaline phosphatase and calcification assays. All tested extracts consistently lowered important molecular mediators involved in angiogenesis, such a VEGF (vascular endothelial growth factor), ANG-1 (angiopoietin 1), and ANG-2 (angiopoietin 2), as indicated by RT-PCR and ELISA. This was associated with antiangiogenic effects at the functional level using selected extracts in co-culture models to mimic bone vascularization processes during bone regeneration or osteosarcoma.

Severe mesenteric traction syndrome is associated with increased systemic inflammatory response, endothelial dysfunction, and major postoperative morbidity

This study aimed to determine if mesenteric traction syndrome (MTS) triggers increased systemic inflammation and endothelial cell dysfunction. Patients developing severe MTS had pronounced early IL6 elevations followed by endothelial cell damage. Furthermore, these processes were associated with increased postoperative morbidity.

OBJECTIVE

To determine whether mesenteric traction syndrome (MTS) leads to increased systemic inflammation and dysfunction of the glycocalyx and endothelial cell and whether this correlates with the degree of postoperative morbidity.

INTRODUCTION

Severe MTS is associated with increased postoperative morbidity following major gastrointestinal surgery, but the pathophysiological mechanism has not been previously explored. Systemic inflammatory response and impaired glycocalyx and endothelial cells may be responsible for the development of symptoms.

METHODS

The study analyzed prospectively collected data from two cohorts (n = 67). The severity of the MTS response was graded intraoperatively and blood samples for PGI₂, catecholamines, IL6, and endothelial biomarkers obtained at predefined time points.

RESULTS

Patients undergoing either esophagectomy (n = 45) or gastrectomy (n = 22) were included. Surgery led to significantly increased plasma concentrations of all biomarkers. Yet, patients who developed severe MTS had higher baseline epinephrine levels (p < 0.05) and higher levels of PGI₂ (p < 0.05), Syndecan-1 (p < 0.001), and sVEGFR1 (p < 0.001). Peak values of IL6, Syndecan-1, sVEGFR1, and sTM all correlated to peak PGI₂. Lastly, patients with high postoperative morbidity had higher baseline epinephrine (p = 0.009) and developed higher plasma IL6 (p = 0.007) and sTM (p = 0.022).

CONCLUSION

The development of severe MTS during upper gastrointestinal surgery is associated with preoperative elevated plasma epinephrine and further a more pronounced proinflammatory response and damage to the vascular endothelium. The increased postoperative morbidity seen in patients with severe MTS may thus, in part, be explained by an inherent susceptibility towards an inappropriate secretion of PGI₂, which leads to an increased surgical stress response and endothelial damage. These findings must be confirmed in a new prospective cohort.

The effects of sepsis on endothelium and clinical implications

ABSTRACT

Sepsis accounts for nearly 700 000 deaths in Europe annually and is caused by an overwhelming host response to infection resulting in organ failure. The endothelium is an active contributor to sepsis and as such represents a major target for therapy. During sepsis, endothelial cells amplify the immune response and activate the coagulation system. They are both a target and source of inflammation and serve as a link between local and systemic immune responses. In response to cytokines produced by immune cells, the endothelium expresses adhesion molecules and produces vasoactive compounds, inflammatory cytokines, and chemoattractants, thus switching from an anticoagulant to procoagulant state. These responses contribute to local control of infection, but systemic activation can lead to microvascular thrombosis, capillary permeability, hypotension, tissue hypoxia, and ultimately tissue damage. This review focuses on the role of the endothelium in leucocyte adhesion and transmigration as well as production of reactive oxygen and nitrogen species, microRNAs and cytokines, formation of signalling microparticles, and disseminated intravascular coagulation. We also discuss alterations in endothelial permeability and apoptosis. Finally, we review the diagnostic potential of endothelial markers and endothelial pathways as therapeutic targets for this devastating disease.

Therapeutic Plasma Exchange Protects Patients with Sepsis-Associated Disseminated Intravascular Coagulation by Improving Endothelial Function

The mortality rate of sepsis-associated disseminated intravascular coagulation (DIC) is high. This study aimed to explore the efficacy of therapeutic plasma exchange (TPE) in sepsis-associated DIC patients by improving endothelial function. A total of 112 sepsis-associated DIC patients were randomly divided into the TPE group (n = 40), the heparin (HP) group (n = 36), and the SHAM group (n = 36). The SHAM group received conventional treatment; the HP group was treated with HP based on conventional treatment; and the TPE group received conventional treatment plus TPE. The differences in thromboelastogram (TEG), platelet (PLT), coagulation function, and the endothelial cell (EC) injury biomarkers at 6 h, 24 h, 48 h, 72 h, and 7 days after TPE were compared among the three groups, and the three groups were compared in terms of Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Sepsis-Related Organ Failure Assessment (SOFA) score, the length of intensive care unit (ICU) hospitalization, 28-day mortality rate, 28-day cumulative survival rate, the incidence of bleeding events, the incidence of acute kidney injury (AKI), and acute respiratory distress syndrome (ARDS). The efficacy of TPE is superior to the HP in increasing PLT, improving coagulation function, increasing the 28-day cumulative survival rate, and reducing the length of ICU hospitalization, 28-day mortality, and the incidence of bleeding events, AKI, and ARDS with statistically significant differences (P < .05). Moreover, the effect of TPE outperforms HP on the EC injury biomarkers with statistically significant differences (P < .05). Our results suggest that TPE may be more effective than HP in the treatment of patients with sepsis-associated DIC. The possible mechanism is via improving endothelial function.

A Novel STAT3-Mediated GATA6 Pathway Contributes to tert-Butylhydroquinone- (tBHQ-) Protected TNFα-Activated Vascular Cell Adhesion Molecule 1 (VCAM-1) in Vascular Endothelium

The activation of vascular cell adhesion molecule 1 (VCAM-1) in vascular endothelial cells has been well considered implicating in the initiation and processing of atherosclerosis. Oxidative stress is mechanistically involved in proatherosclerotic cytokine-induced VCAM-1 activation. tert-Butylhydroquinone (tBHQ), a synthetic phenolic antioxidant used for preventing lipid peroxidation of food, possesses strongly antioxidant capacity against oxidative stress-induced dysfunction in various pathological process. Here, we investigated the protective role of tBHQ on tumor necrosis factor alpha- (TNFα-) induced VCAM-1 activation in both aortic endothelium of mice and cultured human vascular endothelial cells and uncovered its potential mechanisms. Our data showed that tBHQ treatment significantly reversed TNFα-induced activation of VCAM-1 at both transcriptional and protein levels. The mechanistic study revealed that inhibiting neither nuclear factor (erythroid-derived 2)-like 2 (Nrf2) nor autophagy blocked the beneficial role of tBHQ. Alternatively, tBHQ intervention markedly alleviated TNFα-increased GATA-binding protein 6 (GATA6) mRNA and protein expressions and its translocation into nucleus. Further investigation indicated that tBHQ-inhibited signal transducer and activator of transcription 3 (STAT3) but not mitogen-activated protein kinase (MAPK) pathway contributed to its protective role against VCAM-1 activation via regulating GATA6. Collectively, our data demonstrated that tBHQ prevented TNFα-activated VCAM-1 via a novel STAT3/GATA6-involved pathway. tBHQ could be a potential candidate for the prevention of proatherosclerotic cytokine-caused inflammatory response and further dysfunctions in vascular endothelium.

Docked severe acute respiratory syndrome coronavirus 2 proteins within the cutaneous and subcutaneous microvasculature and their role in the pathogenesis of severe coronavirus disease 2019

The purpose of this study was to examine the deltoid skin biopsy in twenty-three patients with coronavirus disease 2019 (COVID-19), most severely ill, for vascular complement deposition and correlate this with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA and protein localization and ACE2 expression. Deltoid skin microvascular complement screening has been applied to patients with various systemic complement-mediated microvascular syndromes, best exemplified by atypical hemolytic uremic syndrome. In 21 of 23 cases, substantial microvascular deposition of complement components was identified. The two patients without significant complement deposition included one patient with moderate disease and a severely ill patient who although on a ventilator for a day was discharged after 3 days. The dominant microvascular complement immunoreactant identified was the terminal membranolytic attack complex C5b-9. Microvascular complement deposition strongly colocalized in situ with the SARS-CoV-2 viral proteins including spike glycoproteins in the endothelial cells as well as the viral receptor ACE2 in lesional and nonlesional skin; viral RNA was not evident. Microvascular SARS-CoV-2 viral protein, complement, and ACE2 expression was most conspicuous in the subcutaneous fat. Although the samples from severely ill patients with COVID-19 were from grossly normal skin, light microscopically focal microvascular abnormalities were evident that included endothelial cell denudement, basement membrane zone reduplication, and small thrombi. It is concluded that complement activation is common in grossly normal skin, especially in the subcutaneous fat which may provide a link between severe disease and obesity, in people with severe COVID-19, and the strong colocalization with the ACE2 receptor and viral capsid proteins without viral RNA suggests that circulating viral proteins (ie, pseudovirions) may dock onto the endothelial of these microvessels and induce complement activation.

The predisposing factors of AKI for prophylactic strategies in burn care

Background

Acute kidney injury (AKI) is one of the most severe complications of burn injury. AKI with severe burn injury causes high mortality. This study aims to investigate the incidence of and predisposing factors for AKI in burn patients.

Methods

This is a single-center, retrospective, descriptive criterion standard study conducted from June 27, 2015, to March 8, 2016. We used Kidney Disease Improving Global Outcomes criteria to define and select patients with AKI. The study was conducted by recruiting in hospital patients who suffered from the flammable cornstarch-based powder explosion and were treated under primary care procedures. A total of 49 patients who suffered from flammable dust explosion-related burn injury were enrolled and admitted on June 27, 2015. The patients with more than 20% total body surface area of burn were transferred to the intensive care unit. Patients received fluid resuscitation in the first 24 hours based on the Parkland formula. The primary measurements were the incidence of and predisposing factors for AKI in these patients. Demographic characteristics, laboratory data, and inpatient outcomes were also evaluated. The incidence of AKI in this cohort was 61.2% (n = 30). The mortality rate was 2.0% (n = 1) during a 59-day follow-up period. The multivariate analysis revealed inhalation injury (adjusted OR = 22.0; 95% CI [1.4–358.2]) and meeting ≥3 American Burn Association (ABA) sepsis criteria (adjusted OR = 13.7; 95% CI [1.7–110.5]) as independent risk factors for early advanced AKI.

Conclusions

The incidence rate of AKI was higher in this cohort than in previous studies, possibly due to the flammable dust explosion-related burn injury. However, the mortality was lower than that expected. In clinical practice, indicators of inflammation, including ABA sepsis criteria may help in predicting the risk of AKI in patients with burn injury.

3,4,5-Trihydroxycinnamic Acid Inhibits LPS-Induced Inflammatory Response by Increasing SIRT1 Expression in Human Umbilical Vein Endothelial Cells

3,4,5-Trihydroxycinnamic acid (THC) has been demonstrated to exert anti-inflammatory activities in LPS-induced RAW264.7 murine macrophage cells and in LPS-induced septic mice. However, the effect of THC on the inflammatory response in vascular endothelial cells has not been clearly examined. The goal of the present study was to elucidate the anti-inflammatory properties of THC and its underlying mechanism in LPS-challenged human umbilical vein endothelial cells (HUVECs). THC significantly suppressed LPS-induced interleukin-1β production and intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression and significantly decreased LPS-induced nuclear factor-κB activation by attenuating p65 phosphorylation and inhibitor of kappa B degradation. To understand the underlying mechanism of the anti-inflammatory effect of THC, the involvement of the sirtuin 1 (SIRT1) signaling pathway was examined. THC resulted in increased expression of SIRT1 in LPS-challenged HUVECs. Among the downstream molecular targets of SIRT1, the level of LPS-induced acetylated p53 was significantly decreased by THC treatment, whereas no noticeable change was observed in the levels of forkhead box O3 and peroxisome proliferator activated receptor gamma coactivator 1 alpha. In conclusion, the results clearly demonstrate that THC possesses anti-inflammatory properties by increasing SIRT1 expression and subsequent suppression of p53 activation in LPS-challenged HUVECs.

The role of optical coherence tomography and other intravascular imaging modalities in cardiac allograft vasculopathy

Orthotopic heart transplantation (OHT) is the standard-of-care for end-stage heart disease. Although a significant improvement in the prognosis of patients after OHT has been observed in recent years, their overall mortality remains relatively high, with a median survival of approximately 10 years after transplantation. One of the primary causes of death in patients after OHT is cardiac allograft vasculopathy (CAV), the condition developing specifically in the coronary vasculature after OHT, the pathophysiology of which is still inadequately known. It is estimated that CAV development and progression is responsible for approximately 30% of deaths within five years post-OHT. According to the International Society for Heart and Lung Transplantation (ISHLT) Nomenclature for CAV, its presence should be assessed primarily by the coronary angiography performed routinely after OHT, mostly due to its wide availability, reproducibility, and low complication rate. However, the analysis of CAV in coronary angiography has limitations, mostly concerning its - sometimes inadequate - sensitivity and specificity. Hence, there is a growing need for the introduction of more accurate methods of CAV assessment, such as intravascular imaging, which through a thorough evaluation of the arterial wall structure and thickness allows the drawbacks of routine angiography to be minimised. The aim of the article was to critically summarise the current findings derived from the analysis of CAV by optical coherence tomography, the other intravascular imaging modalities, such as intravascular ultrasound (IVUS) and IVUS-derived virtual histology, along with physiological assessment with the use of the fractional flow reserve.

Physiological Roles of the von Willebrand Factor-Factor VIII Interaction

Von Willebrand factor (VWF) and coagulation factor VIII (FVIII) circulate as a complex in plasma and have a major role in the hemostatic system. VWF has a dual role in hemostasis. It promotes platelet adhesion by anchoring the platelets to the subendothelial matrix of damaged vessels and it protects FVIII from proteolytic degradation. Moreover, VWF is an acute phase protein that has multiple roles in vascular inflammation and is massively secreted from Weibel-Palade bodies upon endothelial cell activation. Activated FVIII on the other hand, together with coagulation factor IX forms the tenase complex, an essential feature of the propagation phase of coagulation on the surface of activated platelets. VWF deficiency, either quantitative or qualitative, results in von Willebrand disease (VWD), the most common bleeding disorder. The deficiency of FVIII is responsible for Hemophilia A, an X-linked bleeding disorder. Here, we provide an overview on the role of the VWF-FVIII interaction in vascular physiology.

Suppressive Effects of GSS on Lipopolysaccharide-Induced Endothelial Cell Injury and ALI via TNF-α and IL-6

Background. Under septic conditions, LPS induced lung vascular endothelial cell (EC) injury, and the release of inflammatory mediator launches and aggravates acute lung injury (ALI). There are no effective therapeutic options for ALI. Genistein-3'-sodium sulfonate (GSS) is a derivative of native soy isoflavone, which exhibits neuroprotective effects via its antiapoptosis property. However, whether GSS protect against sepsis-induced EC injury and release of inflammatory mediators has not been determined. In this study, we found that GSS not only downregulated the levels of TNF-α and IL-6 in the lung and serum of mice in vivo but also inhibited the expression and secretion of TNF-α and IL-6 in ECs. Importantly, we also found that GSS blocked LPS-induced TNF-α and IL-6 expression in ECs via the Myd88/NF-κB signaling pathway. Taken together, our results demonstrated that GSS might be a promising candidate for sepsis-induced ALI via its regulating effects on inflammatory response in lung ECs.

Renal Tubular Glucagon-Like Peptide-1 Receptor Expression Is Increased in Early Sepsis but Reduced in Chronic Kidney Disease and Sepsis-Induced Kidney Injury

Acute kidney injury (AKI) is common in patients with sepsis and causes renal ischemia. Glucagon-like peptide-1 (GLP-1) protects the vascular system and the kidney, and GLP-1 receptor (GLP-1R) is expressed in the kidney. Renal GLP-1R activity is decreased in chronic kidney disease (CKD), but is increased by the inflammatory response; however, the effect of AKI on GLP-1R expression is unknown. We investigated the role of GLP-1 by assessing GLP-1R expression in the renal cortex in animals with AKI-related sepsis, CKD, and CKD-with-sepsis. We generated a model of CKD by 5/6 nephrectomy, and sepsis induced by cecal perforation, in male Sprague-Dawley rats. We compared renal GLP-1R expression at 3, 6, 12, 24, and 72 h after cecal perforation, and in CKD and CKD-with-sepsis. We performed blood and urine tests, western blotting (WB), and immunohistochemistry (IHC) to assay GLP-1R expression in renal tubules. The CKD-with-sepsis group showed the lowest kidney function, urine volume, and serum glucose and albumin levels. GLP-1R expression in renal tubules was decreased at 3 h, increased at 24 h, and decreased at 72 h after sepsis induction. GLP-1R expression was decreased at 8 weeks after CKD and was lowest in the CKD-with-sepsis group. The WB results were verified against those obtained by IHC. GLP-1R expression in renal tubules is increased in early sepsis, which may explain the protective effect of endogenous GLP-1 against sepsis-related inflammation.

E-selectin as a prognostic factor of patients hospitalized due to acute inflammatory respiratory diseases: a single institutional study

When examining patients with acute inflammatory respiratory diseases, it is difficult to distinguish between infectious pneumonia and interstitial pneumonia and predict patient prognosis at the beginning of treatment. In this study, we assessed whether endothelial selectin (E-selectin) predicts the outcome of patients with acute inflammatory respiratory diseases. We measured E-selectin serum levels in 101 patients who were admitted to our respiratory care unit between January 2013 and December 2013 because of acute inflammatory respiratory diseases that were eventually diagnosed as interstitial pneumonia (n = 38) and lower respiratory tract infection (n = 63). Seven of these patients (n = 101) died. The pneumonia severity score was significantly higher and the oxygen saturation of arterial blood measured by pulse oximeter (SpO₂)/fraction of inspiratory oxygen (FiO₂) was significantly lower in the deceased patients than in the surviving patients. There were significantly fewer peripheral lymphocytes and significantly higher E-selectin serum levels in the deceased patients than in the surviving patients. In the multiple logistic regression analysis, the E-selectin serum levels and SpO₂/FiO₂ ratio were independent predictive factors of prognosis. The risk of death during acute respiratory disease was determined using a receiver operating characteristic (ROC) curve analysis. The area under the curve (AUC) was 0.871 as calculated from the ES, and the cutoff value was 6453.04 pg/ml, with a sensitivity of 1.00 and a specificity of 0.72 (p = 0.0027). E-selectin may be a useful biomarker for predicting the prognosis of patients with acute inflammatory respiratory diseases.

Thrombomodulin, Plasminogen Activator Inhibitor-1 and Protein C Levels, and Organ Dysfunction in Sepsis

Since endothelial function is closely related to organ dysfunction in sepsis and the relationship among endothelial injury, organ dysfunction, and other biomarkers remains unclear, we aimed to evaluate the correlation among endothelial injury, organ dysfunction, and several biomarkers in patients with sepsis.

Design

This was a retrospective observational study.

Setting

The study was conducted in a university hospital with 14 mixed ICU beds.

Patients

ICU patients with sepsis from June 2011 to December 2017 were enrolled in this study.

Interventions

Endothelial biomarkers (soluble thrombomodulin, plasminogen activator inhibitor-1, and protein C) and markers of inflammation and coagulation were evaluated during the ICU stay. Sequential Organ Failure Assessment scores were assessed for 7 days after ICU admission to determine organ dysfunction. Variables were compared among five stratified groups according to the Sequential Organ Failure Assessment score (0-2, 3-5, 6-8, 9-12, and 13-24). Regression analysis and 95% CIs were used to evaluate trends in biomarkers.

Measurements and Main Results

The patients were divided into five stratified groups (Sequential Organ Failure Assessment 0-2, n = 159 [20.5%]; Sequential Organ Failure Assessment 3-5, n = 296 [38.2%]; Sequential Organ Failure Assessment 6-8, n = 182 [23.5%]; Sequential Organ Failure Assessment 9-12, n = 75 [9.7%]; Sequential Organ Failure Assessment 13-24, n = 31 [4.0%]). Protein C activity was significantly correlated with the severity of organ dysfunction. It was lower on day 1, increased upon successful treatment, and was significantly higher in groups with lower Sequential Organ Failure Assessment scores.

Conclusions

Trends and activity of protein C were superior in predicting organ dysfunction compared with other endothelial biomarkers. Monitoring the level of protein C activity is an ideal tool to monitor organ dysfunctions in patients with sepsis.

Advance in the Management of Sepsis-Induced Coagulopathy and Disseminated Intravascular Coagulation

Coagulopathy commonly occurs in sepsis as a critical host response to infection that can progress to disseminated intravascular coagulation (DIC) with an increased mortality. Recent studies have further defined factors responsible for the thromboinflammatory response and intravascular thrombosis, including neutrophil extracellular traps, extracellular vesicles, damage-associated molecular patterns, and endothelial glycocalyx shedding. Diagnosing DIC facilitates sepsis management, and is associated with improved outcomes. Although the International Society on Thrombosis and Haemostasis (ISTH) has proposed criteria for diagnosing overt DIC, these criteria are not suitable for early detection. Accordingly, the ISTH DIC Scientific Standardization Committee has proposed a new category termed "sepsis-induced coagulopathy (SIC)" to facilitate earlier diagnosis of DIC and potentially more rapid interventions in these critically ill patients. Therapy of SIC includes both treatment of the underlying infection and correcting the coagulopathy, with most therapeutic approaches focusing on anticoagulant therapy. Recently, a phase III trial of recombinant thrombomodulin was performed in coagulopathic patients. Although the 28-day mortality was improved by 2.6% (absolute difference), it did not reach statistical significance. However, in patients who met entry criteria for SIC at baseline, the mortality difference was approximately 5% without increased risk of bleeding. In this review, we discuss current advances in managing SIC and DIC.

The Role of Tyrosine Phosphorylation of Protein Kinase C Delta in Infection and Inflammation

Protein Kinase C (PKC) is a family composed of phospholipid-dependent serine/threonine kinases that are master regulators of inflammatory signaling. The activity of different PKCs is context-sensitive and these kinases can be positive or negative regulators of signaling pathways. The delta isoform (PKCδ) is a critical regulator of the inflammatory response in cancer, diabetes, ischemic heart disease, and neurodegenerative diseases. Recent studies implicate PKCδ as an important regulator of the inflammatory response in sepsis. PKCδ, unlike other members of the PKC family, is unique in its regulation by tyrosine phosphorylation, activation mechanisms, and multiple subcellular targets. Inhibition of PKCδ may offer a unique therapeutic approach in sepsis by targeting neutrophil-endothelial cell interactions. In this review, we will describe the overall structure and function of PKCs, with a focus on the specific phosphorylation sites of PKCδ that determine its critical role in cell signaling in inflammatory diseases such as sepsis. Current genetic and pharmacological tools, as well as in vivo models, that are used to examine the role of PKCδ in inflammation and sepsis are presented and the current state of emerging tools such as microfluidic assays in these studies is described.

Extract from Bougainvillea xbuttiana (Variety Orange) Inhibits Production of LPS-Induced Inflammatory Mediators in Macrophages and Exerts a Protective Effect In Vivo

BACKGROUND

Different pharmacological properties, such as antioxidant, antiproliferative, and anti-inflammatory properties, have been described among natural products. We previously described that the Bougainvillea xbuttiana (Variety Orange) ethanolic extract (BxbO) has an anti-inflammatory effect; however, this action is not fully understood. In this study, the action of the BxbO extract on the secretion of inflammatory mediators in two experimental models, in vitro and in vivo, after LPS challenge was evaluated.

METHODS

Peritoneal macrophages were obtained from female BALB/c mice and LPS-challenged with or without the BxbO extract. For the evaluation of mediators, the supernatants at 0, 12, 24, 36, and 48 hours were collected. For in vivo estimation, groups of female BALB/c mice were first intraperitoneously injected with different amounts of LPS and later administered the oral BxbO extract (v.o.) for 144 hours. To understand the mechanism of action, sera obtained from mice were collected at 0, 2, 4, 8, 12, and 24 hours after LPS challenge (with or without BxbO) for the detection of mediators.

RESULTS

The results showed that, in both peritoneal macrophages and sera of mice treated with the BxbO extract 1 hour before or together with LPS challenge, proinflammatory cytokines and nitric oxide release were unquestionably repressed. In contrast, in both systems studied here, the IL-10 levels were elevated to 5 to 9 times. At lethal doses of LPS, the BxbO extract treatment was found to protect animals from death.

CONCLUSIONS

The results revealed that the inhibitory, protective, and benign effects of the BxbO extract were due to its capacity to balance the secretion of mediators.

Inflammasomes: Pandora's box for sepsis

Sepsis was known to ancient Greeks since the time of great physician Hippocrates (460-377 BC) without exact information regarding its pathogenesis. With time and medical advances, it is now considered as a condition associated with organ dysfunction occurring in the presence of systemic infection as a result of dysregulation of the immune response. Still with this advancement, we are struggling for the development of target-based therapeutic approach for the management of sepsis. The advancement in understanding the immune system and its working has led to novel discoveries in the last 50 years, including different pattern recognition receptors. Inflammasomes are also part of these novel discoveries in the field of immunology which are <20 years old in terms of their first identification. They serve as important cytosolic pattern recognition receptors required for recognizing cytosolic pathogens, and their pathogen-associated molecular patterns play an important role in the pathogenesis of sepsis. The activation of both canonical and non-canonical inflammasome signaling pathways is involved in mounting a proinflammatory immune response via regulating the generation of IL-1β, IL-18, IL-33 cytokines and pyroptosis. In addition to pathogens and their pathogen-associated molecular patterns, death/damage-associated molecular patterns and other proinflammatory molecules involved in the pathogenesis of sepsis affect inflammasomes and vice versa. Thus, the present review is mainly focused on the inflammasomes, their role in the regulation of immune response associated with sepsis, and their targeting as a novel therapeutic approach.

Troponin I at admission in the intensive care unit predicts the need of dialysis in septic patients

Background

In a previous study we showed that troponin I (TnI) > 0.42 ng/mL predicted the need of dialysis in a group of 29 septic patients admitted to the intensive care unit (ICU). We aimed to confirm such finding in a larger independent sample.

Methods

All septic patients admitted to an ICU from March 2016 to February 2017 were included if age between 18 and 90 years, onset of sepsis < 24 h, normal left ventricular ejection fraction, and no previous coronary or kidney diseases. TnI was measured on day 1. Patients were followed by 30 days or until death.

Results

A total of 120 patients were included (51% male, 74 ± 13 years old). At ICU admission, 70 patients had TnI > 0.42 ng/mL. These patients had serum creatinine slightly higher (1.66 ± 0.34 vs. 1.32 ± 0.39 mg/dL; P <  0.0001) than those with lower TnI and similar urine output (1490 ± 682 vs. 1406 ± 631 mL; P = 0.44). At the end of the follow-up period, 70.0% of the patients with lower TnI were alive in comparison with 38.6% of those with higher TnI (p = 0.0014). After 30 days, 69.3 and 2.9% of the patients with lower and higher TnI levels remained free of dialysis, respectively (p <  0.0001). In a Cox regression model, after adjustment for gender, age, Charlson comorbidity index, serum creatinine, potassium, pH, brain natriuretic peptide and urine output, TnI > 0.42 ng/mL persisted as a strong predictor of dialysis need (hazard ratio 3.48 [95%CI 1.69–7.18]).

Conclusions

TnI levels at ICU admission are a strong independent predictor of dialysis need in sepsis.

A systems biology network analysis of nutri(epi)genomic changes in endothelial cells exposed to epicatechin metabolites

Although vasculo-protective effects of flavan-3-ols are widely accepted today, their impact on endothelial cell functions and molecular mechanisms of action involved is not completely understood. The aim of this study was to characterize the potential endothelium-protective effects of circulating epicatechin metabolites and to define underlying mechanisms of action by an integrated systems biology approach. Reduced leukocyte rolling over vascular endothelium was observed following epicatechin supplementation in a mouse model of inflammation. Integrative pathway analysis of transcriptome, miRNome and epigenome profiles of endothelial cells exposed to epicatechin metabolites revealed that by acting at these different levels of regulation, metabolites affect cellular pathways involved in endothelial permeability and interaction with immune cells. In-vitro experiments on endothelial cells confirmed that epicatechin metabolites reduce monocyte adhesion and their transendothelial migration. Altogether, our in-vivo and in-vitro results support the outcome of a systems biology based network analysis which suggests that epicatechin metabolites mediate their vasculoprotective effects through dynamic regulation of endothelial cell monocyte adhesion and permeability. This study illustrates complex and multimodal mechanisms of action by which epicatechin modulate endothelial cell integrity.

Driving-pressure-independent protective effects of open lung approach against experimental acute respiratory distress syndrome

Background

The open lung approach (OLA) reportedly has lung-protective effects against acute respiratory distress syndrome (ARDS). Recently, lowering of the driving pressure (ΔP), rather than improvement in lung aeration per se, has come to be considered as the primary lung-protective mechanism of OLA. However, the driving pressure-independent protective effects of OLA have never been evaluated in experimental studies. We here evaluated whether OLA shows protective effects against experimental ARDS even when the ΔP is not lowered.

Methods

Lipopolysaccharide was intratracheally administered to rats to establish experimental ARDS. After 24 h, rats were mechanically ventilated and randomly allocated to the OLA or control group. In the OLA group, 5 cmH₂O positive end-expiratory pressure (PEEP) and recruitment maneuver (RM) were applied. Neither PEEP nor RM was applied to the rats in the control group. Dynamic ΔP was kept at 15 cmH₂O in both groups. After 6 h of mechanical ventilation, rats in both groups received RM to inflate reversible atelectasis of the lungs. Arterial blood gas analysis, lung computed tomography, histological evaluation, and comprehensive biochemical analysis were performed.

Results

OLA significantly improved lung aeration, arterial oxygenation, and gas exchange. Even after RM in both groups, the differences in these parameters between the two groups persisted, indicating that the atelectasis-induced respiratory dysfunction observed in the control group is not an easily reversible functional problem. Lung histological damage was severe in the dorsal dependent area in both groups, but was attenuated by OLA. White blood cell counts, protein concentrations, and tissue injury markers in the broncho-alveolar lavage fluid (BALF) were higher in the control than in the OLA group. Furthermore, levels of CXCL-7, a platelet-derived chemokine, were higher in the BALF from the control group, indicating that OLA protects the lungs by suppressing platelet activation.

Conclusions

OLA shows protective effects against experimental ARDS, even when the ΔP is not decreased. In addition to reducing ΔP, maintaining lung aeration seems to be important for lung protection in ARDS.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2154-2) contains supplementary material, which is available to authorized users.

Differential Mechanisms of Septic Human Pulmonary Microvascular Endothelial Cell Barrier Dysfunction Depending on the Presence of Neutrophils

Sepsis is characterized by injury of pulmonary microvascular endothelial cells (PMVEC) leading to barrier dysfunction. Multiple mechanisms promote septic PMVEC barrier dysfunction, including interaction with circulating leukocytes and PMVEC apoptotic death. Our previous work demonstrated a strong correlation between septic neutrophil (PMN)-dependent PMVEC apoptosis and pulmonary microvascular albumin leak in septic mice in vivo; however, this remains uncertain in human PMVEC. Thus, we hypothesize that human PMVEC apoptosis is required for loss of PMVEC barrier function under septic conditions in vitro. To assess this hypothesis, human PMVECs cultured alone or in coculture with PMN were stimulated with PBS or cytomix (equimolar interferon γ, tumor necrosis factor α, and interleukin 1β) in the absence or presence of a pan-caspase inhibitor, Q-VD, or specific caspase inhibitors. PMVEC barrier function was assessed by transendothelial electrical resistance (TEER), as well as fluoroisothiocyanate-labeled dextran and Evans blue-labeled albumin flux across PMVEC monolayers. PMVEC apoptosis was identified by (1) loss of cell membrane polarity (Annexin V), (2) caspase activation (FLICA), and (3) DNA fragmentation [terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)]. Septic stimulation of human PMVECs cultured alone resulted in loss of barrier function (decreased TEER and increased macromolecular flux) associated with increased apoptosis (increased Annexin V, FLICA, and TUNEL staining). In addition, treatment of septic PMVEC cultured alone with Q-VD decreased PMVEC apoptosis and prevented septic PMVEC barrier dysfunction. In septic PMN-PMVEC cocultures, there was greater trans-PMVEC macromolecular flux (both dextran and albumin) vs. PMVEC cultured alone. PMN presence also augmented septic PMVEC caspase activation (FLICA staining) vs. PMVEC cultured alone but did not affect septic PMVEC apoptosis. Importantly, pan-caspase inhibition (Q-VD treatment) completely attenuated septic PMN-dependent PMVEC barrier dysfunction. Moreover, inhibition of caspase 3, 8, or 9 in PMN-PMVEC cocultures also reduced septic PMVEC barrier dysfunction whereas inhibition of caspase 1 had no effect. Our data demonstrate that human PMVEC barrier dysfunction under septic conditions in vitro (cytomix stimulation) is clearly caspase-dependent, but the mechanism differs depending on the presence of PMN. In isolated PMVEC, apoptosis contributes to septic barrier dysfunction, whereas PMN presence enhances caspase-dependent septic PMVEC barrier dysfunction independently of PMVEC apoptosis.

Endotoxemia Results in Trapping of Transfused Red Blood Cells in Lungs with Associated Lung Injury

BACKGROUND

Red blood cell (RBC) transfusion is associated with organ failure, in particular in the critically ill. We hypothesized that endotoxemia contributes to increased trapping of RBCs in organs. Furthermore, we hypothesized that this effect is more pronounced following transfusion of stored RBCs compared with fresh RBCs.

METHODS

Adult male Sprague-Dawley rats were randomized to receive injection with lipopolysaccharide from E coli or vehicle and transfusion with fresh or stored biotinylated RBCs. After 24 h, the amount of biotinylated RBCs in organs was measured by flow cytometry, as well as the 24-h post-transfusion recovery. Markers of organ injury and histopathology of organs were assessed.

RESULTS

Endotoxemia resulted in systemic inflammation and organ injury. Following RBC transfusion, donor RBCs were recovered from the lung and kidney of endotoxemic recipients (1.2 [0.8-1.6]% and 2.2 [0.4-4.4]% of donor RBCs respectively), but not from organs of healthy recipients. Trapping of donor RBCs in the lung was associated with increased lung injury, but not with kidney injury. Stored RBCs induced organ injury in the spleen and yielded a lower 24-h post-transfusion recovery, but other effects of storage time were limited.

CONCLUSION

Endotoxemia results in an increased percentage of donor RBCs recovered from the lung and kidney, which is associated with lung injury following transfusion.

Evaluation of capillary leakage after vasopressin resuscitation in a hemorrhagic shock model

Background

Hemorrhagic shock (HS) is a major threat to patients with trauma and spontaneous bleeding. The aim of the study was to investigate early effects of vasopressin on metabolic and hemodynamic parameters and endothelium permeability by measuring capillary leakage compared to those of other resuscitation strategies in a HS model.

Methods

Forty-five Sprague-Dawley rats were randomized into five groups: S group (n = 5), sham-operated rats without shock or resuscitation; HS group (n = 10), HS and no resuscitation; RL group (n = 10), HS and resuscitation with Ringer’s lactate (RL); RLB group (n = 10), HS and resuscitation with two-third shed blood plus RL; and vasopressin group (n = 10), HS and resuscitation with RL, followed by continuous infusion of 0.04 U/kg/min vasopressin. The effects of resuscitation on hemodynamic parameters [mean arterial pressure (MAP), superior mesenteric artery blood flow (MBF), and mesenteric vascular resistances (MVR)], arterial blood gases, bicarbonate, base deficit, and lactate levels as well as on capillary leakage in the lung, ileum, and kidney were investigated. Capillary leakage was evaluated with Evans blue dye extravasation.

Results

In the vasopressin group, the MAP was higher than in the RL and RLB groups (p < 0.001), while MBF was decreased (p < 0.001). MVR were increased only in the vasopressin group (p < 0.001). Capillary leakage was increased in the lungs of the animals in the vasopressin group compared to that in the lungs of animals in the RLB group (p < 0.05); this increase was associated with the lowest partial pressure of oxygen (p < 0.05). Conversely, decreased capillary leakage was observed with vasopressin in the ileum (p < 0.05). Increased capillary leakage was observed in the kidney in the RLB and vasopressin groups (p < 0.05). Lastly, vasopressin use was associated with higher base deficit and lactate levels when compared to the RL and RLB groups (p < 0.001).

Conclusion

Although vasopressin was proposed as a vasoactive drug for provisional hemodynamic optimization in the early phase of HS resuscitation, the overall findings of this experimental study focus on the possible critical side effects of vasopressin on metabolic parameters and endothelium permeability.

Endothelial Damage Signals Refractory Acute Kidney Injury in Critically Ill Patients

Critically ill patients with acute kidney injury (AKI) are heterogeneous on pathophysiology and prognosis. The role of endothelial damage in the pathogenesis of refractory AKI has not been clarified. The aim was to determine if biomarkers of endothelial damage, independently of the inflammatory insult on the kidney, can predict recovery of acute kidney injury.

METHODS

From the "Procalcitonin And Survival Study" multicenter intensive care unit cohort, followed for 28 days after admission, we included patients without chronic kidney disease, who survived >24 h after admission and with plasma samples at admission available for biomarker analysis. We defined AKI by the "Kidney Disease: Improving Global Outcomes" guidelines and recovery of prior kidney function as alive for five consecutive days after admission with no need for renal replacement therapy and creatinine levels consistently below ×1.5 the level before admission. We adjusted models for age, gender, vasopressor treatment, mechanical ventilation and levels of creatinine, procalcitonin, platelets, and bilirubin at admission.

RESULTS

Of a total 213 with AKI at admission, 99 recovered prior kidney function during follow-up. Endothelial damage on admission, measured by Soluble Thrombomodulin (sTM), was the strongest predictor of a reduced chance of recovery of prior kidney function (sTM in the highest vs. three lower quartiles hazard ratio 0.39; 95% confidence interval 0.21-0.73, P = 0.003). In contrast, the degree of the initial inflammatory insult on the kidney, measured by neutrophil gelatinase-associated lipocalin (NGAL), failed to predict this outcome (NGAL in highest vs. three lower quartiles hazard ratio = 1.20; 95% CI 0.72-2.00; P = 0.48). Procalcitonin, a specific marker of bacterial infection, was also associated with the rate of recovery (PCT in highest vs. three lower quartiles hazard ratio = 0.59; 95% CI 0.36-0.98; P = 0.04).

CONCLUSION

AKI patients with high levels of sTM had a reduced chance of recovering prior renal function. Our findings support disintegration of the endothelium as a critical point in the pathogenesis of AKI that is refractory to treatment.

Markers and Biomarkers of Endothelium: When Something Is Rotten in the State

Endothelium is a community of endothelial cells (ECs), which line the blood and lymphatic vessels, thus forming an interface between the tissues and the blood or lympha. This strategic position of endothelium infers its indispensable functional role in controlling vasoregulation, haemostasis, and inflammation. The state of endothelium is simultaneously the cause and effect of many diseases, and this is coupled with modifications of endothelial phenotype represented by markers and with biochemical profile of blood represented by biomarkers. In this paper, we briefly review data on the functional role of endothelium, give definitions of endothelial markers and biomarkers, touch on the methodological approaches for revealing biomarkers, present an implicit role of endothelium in some toxicological mechanistic studies, and survey the role of reactive oxygen species (ROS) in modulation of endothelial status.