Shared Features of Endothelial Dysfunction between Sepsis and Its Preceding Risk Factors (Aging and Chronic Disease)

The effect of thyme essential oil and endothelial progenitor stem cells on lipopolysaccharide-induced sepsis in C57BL/6 mice

Sepsis is a potentially fatal syndrome related to severe systemic inflammation developed by infection. Despite different antimicrobial therapies, morbidity and mortality rates remain high. Herbs along with cell therapy have been introduced as a promising option to improve the symptoms of sepsis. The present study aimed to evaluate the therapeutic effect of simultaneous administration of thyme essential oil (TEO) and endothelial progenitor stem cells (EPCs) on lipopolysaccharide (LPS)-induced sepsis in C57BL/6 mice. Sepsis was induced in C57Bl/6J mice by intraperitoneal injection of LPS, followed 2 h later by an intravenous injection of EPCs or oral administration of TEO or simultaneous administration of TEO and EPCs. After 10 days, the complete blood cell, renal and liver factors, serum levels of inflammatory cytokines, and angiogenic factors were measured. Simultaneous treatment with EPCs and TEO significantly increased the survival of mice with sepsis and modulated the inflammatory response by reducing the serum levels of pro-inflammatory cytokines. Moreover, this treatment significantly reduced the level of white blood cells and neutrophils and increased the number of red blood cells, the percentage of hematocrit, and hemoglobin. The combination of TEO with EPCs decreased organ injuries and was assessed by lower levels of the liver enzymes alanine aminotransferase and aspartate aminotransferase compared to the sepsis group. Administration of EPCs and TEO also significantly improved angiogenic factors, lung function, and toll-like receptor 4 expression. EPCs in combination with TEO increase survival in the LPS-induced sepsis mice model by acting on several targets. Thus, the combination of TEO with EPCs can be a feasible approach for the future clinical treatment and control of sepsis.

Improvement of renal functions in mice with septic acute kidney injury using secretome of mesenchymal stem cells

Background

A potentially fatal complication of sepsis is septic acute kidney injury. Stem cell therapy is a potential new method of treating sepsis and has been applied to treat some human diseases.

Objectives

This study investigated the effects of secretome-MSCs on NGAL, CRP, NF-κB, and MMP-9 proteins, and histopathology in mice with septic AKI.

Methods

A post-test-only group design was conducted in 30 Balb/C male mice, which were randomly assigned to five groups: the control group was intraperitoneally injected with 0.5 ml of 0.9 % NaCl, the septic AKI, and the treatment groups (T1, T2, and T3) were intraperitoneally injected with 0.5 ml of 0.9 % NaCl and 0.3 mg/kg BW LPS single dose for three days. Three-day treatments of 150, 300, and 600 µl secretome-MSCs were administered intraperitoneally into the treatment groups. Furthermore, kidney and blood samples were collected for biochemical and histopathological analyses.

Results

The T1, T2, and T3 groups had lower expression of NF-κB and MMP-9 and significantly lower CRP and NGAL levels than that of septic AKI group. T1 (1.21 ± 0.19), T2 (0.75 ± 0.22), and T3 (0.38 ± 0.14) groups demonstrated lower average scores for inflammation, necrosis, hemorrhage, and degeneration compared to septic AKI group (2.17 ± 0.13).

Conclusions

Administration of 600 µl/20 g BW secretome-MSCs suppresses NF-κB and MMP-9 expression and reduces CRP and NGAL levels. Meanwhile, the 150 and 300 µl/20 g BW doses also indicated a greater improvement in renal tissue damage of mice with septic AKI.

Assessment of Sepsis Risk at Admission to the Emergency Department: Clinical Interpretable Prediction Model

This study aims to develop an interpretable prediction model based on explainable artificial intelligence to predict bacterial sepsis and discover important biomarkers. A total of 1572 adult patients, 560 of whom were sepsis positive and 1012 of whom were negative, who were admitted to the emergency department with suspicion of sepsis, were examined. We investigated the performance characteristics of sepsis biomarkers alone and in combination for confirmed sepsis diagnosis using Sepsis-3 criteria. Three different tree-based algorithms-Extreme Gradient Boosting (XGBoost), Light Gradient Boosting Machine (LightGBM), Adaptive Boosting (AdaBoost)-were used for sepsis prediction, and after examining comprehensive performance metrics, descriptions of the optimal model were obtained with the SHAP method. The XGBoost model achieved accuracy of 0.898 (0.868-0.929) and area under the ROC curve (AUC) of 0.940 (0.898-0.980) with a 95% confidence interval. The five biomarkers for predicting sepsis were age, respiratory rate, oxygen saturation, procalcitonin, and positive blood culture. SHAP results revealed that older age, higher respiratory rate, procalcitonin, neutrophil-lymphocyte count ratio, C-reactive protein, plaque, leukocyte particle concentration, as well as lower oxygen saturation, systolic blood pressure, and hemoglobin levels increased the risk of sepsis. As a result, the Explainable Artificial Intelligence (XAI)-based prediction model can guide clinicians in the early diagnosis and treatment of sepsis, providing more effective sepsis management and potentially reducing mortality rates and medical costs.

The mitochondrial signature of cultured endothelial cells in sepsis: Identifying potential targets for treatment

Sepsis is the most common cause of death from infection in the world. Unfortunately, there is no specific treatment for patients with sepsis, and management relies on infection control and support of organ function. A better understanding of the underlying pathophysiology of this syndrome will help to develop innovative therapies. In this regard, it has been widely reported that endothelial cell activation and dysfunction are major contributors to the development of sepsis. This review aims to provide a comprehensive overview of emerging findings highlighting the prominent role of mitochondria in the endothelial response in in vitro experimental models of sepsis. Additionally, we discuss potential mitochondrial targets that have demonstrated protective effects in preclinical investigations against sepsis. These promising findings hold the potential to pave the way for future clinical trials in the field.

PDE4 Phosphodiesterases in Cardiovascular Diseases: Key Pathophysiological Players and Potential Therapeutic Targets

3',5'-cyclic adenosine monophosphate (cAMP) is a second messenger critically involved in the control of a myriad of processes with significant implications for vascular and cardiac cell function. The temporal and spatial compartmentalization of cAMP is governed by the activity of phosphodiesterases (PDEs), a superfamily of enzymes responsible for the hydrolysis of cyclic nucleotides. Through the fine-tuning of cAMP signaling, PDE4 enzymes could play an important role in cardiac hypertrophy and arrhythmogenesis, while it decisively influences vascular homeostasis through the control of vascular smooth muscle cell proliferation, migration, differentiation and contraction, as well as regulating endothelial permeability, angiogenesis, monocyte/macrophage activation and cardiomyocyte function. This review summarizes the current knowledge and recent advances in understanding the contribution of the PDE4 subfamily to cardiovascular function and underscores the intricate challenges associated with targeting PDE4 enzymes as a therapeutic strategy for the management of cardiovascular diseases.

The role of the microcirculation and integrative cardiovascular physiology in the pathogenesis of ICU-acquired weakness

Skeletal muscle dysfunction after critical illness, defined as ICU-acquired weakness (ICU-AW), is a complex and multifactorial syndrome that contributes significantly to long-term morbidity and reduced quality of life for ICU survivors and caregivers. Historically, research in this field has focused on pathological changes within the muscle itself, without much consideration for their in vivo physiological environment. Skeletal muscle has the widest range of oxygen metabolism of any organ, and regulation of oxygen supply with tissue demand is a fundamental requirement for locomotion and muscle function. During exercise, this process is exquisitely controlled and coordinated by the cardiovascular, respiratory, and autonomic systems, and also within the skeletal muscle microcirculation and mitochondria as the terminal site of oxygen exchange and utilization. This review highlights the potential contribution of the microcirculation and integrative cardiovascular physiology to the pathogenesis of ICU-AW. An overview of skeletal muscle microvascular structure and function is provided, as well as our understanding of microvascular dysfunction during the acute phase of critical illness; whether microvascular dysfunction persists after ICU discharge is currently not known. Molecular mechanisms that regulate crosstalk between endothelial cells and myocytes are discussed, including the role of the microcirculation in skeletal muscle atrophy, oxidative stress, and satellite cell biology. The concept of integrated control of oxygen delivery and utilization during exercise is introduced, with evidence of physiological dysfunction throughout the oxygen delivery pathway - from mouth to mitochondria - causing reduced exercise capacity in patients with chronic disease (e.g., heart failure, COPD). We suggest that objective and perceived weakness after critical illness represents a physiological failure of oxygen supply-demand matching - both globally throughout the body and locally within skeletal muscle. Lastly, we highlight the value of standardized cardiopulmonary exercise testing protocols for evaluating fitness in ICU survivors, and the application of near-infrared spectroscopy for directly measuring skeletal muscle oxygenation, representing potential advancements in ICU-AW research and rehabilitation.

Relationship between severe acute respiratory syndrome coronavirus 2 and diabetes mellitus (review)

Infections caused by SARE-CoV-2 are complicated with the concurrent pathologies, to name hypertension, diabetes mellitus and cardiovascular diseases. High level of glucose in blood weakens the immunity and increase the SARS-CoV-2 replication. Diabetes mellitus aggravates the COVID-19 outcome. The intrusion of SARS-CoV-2 into a host-cell occurs by means of its association with the angiotensin-converting enzyme-2 (ACE 2). Stimulating immune responses the COVID-19 infection causes the cytokine storm, and may result in the lethal outcome in the diabetics.

Recent laboratory studies demonstrated that the type1 and type2 diabetes mellitus is the main consequence in 14% of the patients after corona infection. Thus, in 2% of 14% diabetes started progressing due to the corona virus. In the other, diabetes debut occurred as the direct and negative consequence of the disease. Hyperglycemia results in the formation of protein molecules known as the advanced glycation end products (AGEs). The AGEs and their receptors (RAGE) are of high significance in the host-cell’s virus invasion. Consequently, more strict glucose control is necessary for optimal outcome and reduction in mortality. The better control for the COVID-19 course can be provided by the targeted effect on the RAGE axis. The review helps elucidate the molecular mechanism underlying the exacerbation of pathophysiology in the diabetic COVID-19 patients.

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.

Hepatoprotective functions of jujuboside B

Jujuboside B (JB) found in the seeds of Zizyphi Spinosi Semen possesses pharmacological functions, such as anti-inflammatory, antiplatelet aggregation, and antianxiety potentials. This study evaluated the effect of JB on liver failure in cecal ligation and puncture (CLP)-induced sepsis. First, we observed histopathological changes in the liver by optical microscopy and the activity of enzymes in serum such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). We further measured the levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, nitric oxide (NO), and antioxidative parameters in liver homogenate. The expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), and glucocorticoid receptor (GR) in the liver was observed by Western blotting. CLP enhanced the migration of inflammatory cells, ALT and AST concentrations, and necrosis, which were reduced by JB. In addition, JB reduced 11β-HSD2 expression and levels of inflammatory mediators (TNF-α, IL-1β, and NO) in the liver, increased GR expression, enhanced endogenous antioxidative capacity. These results further suggest that JB may protect the liver against CLP-induced damage by regulating anti-inflammatory responses, downregulating 11β-HSD2 expression and antioxidation, and up-regulating GR expression.

Endogenous humoral determinants of vascular endothelial dysfunction as triggers of acute poisoning complications

The vascular endothelium is not only the semipermeable membrane that separates tissue from blood but also an organ that regulates inflammation, vascular tone, blood clotting, angiogenesis and synthesis of connective tissue proteins. It is susceptible to the direct cytotoxic action of numerous xenobiotics and to the acute hypoxia that accompanies acute poisoning. This damage is superimposed on the preformed state of the vascular endothelium, which, in turn, depends on many humoral factors. The probability that an exogenous toxicant will cause life-threatening dysfunction of the vascular endothelium, thereby complicating the course of acute poisoning, increases with an increase in the content of endogenous substances in the blood that disrupt endothelial function. These include ammonia, bacterial endotoxin, indoxyl sulfate, para-cresyl sulfate, trimethylamine N-oxide, asymmetric dimethylarginine, glucose, homocysteine, low-density and very-low-density lipoproteins, free fatty acids and products of intravascular haemolysis. Some other endogenous substances (albumin, haptoglobin, haemopexin, biliverdin, bilirubin, tetrahydrobiopterin) or food-derived compounds (ascorbic acid, rutin, omega-3 polyunsaturated fatty acids, etc.) reduce the risk of lethal vascular endothelial dysfunction. The individual variability of the content of these substances in the blood contributes to the stochasticity of the complications of acute poisoning and is a promising target for the risk reduction measures. Another feasible option may be the repositioning of drugs that affect the function of the vascular endothelium while being currently used for other indications.

Transcriptome profiling of colorectal tumors from patients with sepsis reveals an ethnic basis for viral infection risk and sepsis progression

Mortality from cancer-associated sepsis varies by cancer site and host responses to sepsis are heterogenous. Native Hawaiians have the highest mortality risk from cancer-associated sepsis and colorectal cancer (CRC), even though they demonstrate lower CRC incidence compared to other ethnicities. We conducted a retrospective transcriptomic analysis of CRC tumors and adjacent non-tumor tissue from adult patients of Native Hawaiian and Japanese ethnicity who died from cancer-associated sepsis. We examined differential gene expression in relation to patient survival and sepsis disease etiology. Native Hawaiian CRC patients diagnosed with sepsis had a median survival of 5 (IQR 4-49) months, compared to 117 (IQR 30-146) months for Japanese patients. Transcriptomic analyses identified two distinct sepsis gene signatures classified as early response and late response sepsis genes that were significantly altered in the Native Hawaiian cohort. Analysis of canonical pathways revealed significant up and downregulation in mechanisms of viral exit from host cells (p = 4.52E-04) and epithelial junction remodeling (p = 4.01E-05). Key genes including elongation initiation factor pathway genes, GSK3B, and regulatory associated protein of mTOR (RPTOR) genes that protect cells from infection were significantly downregulated in Native Hawaiians. Genes promoting sepsis progression including CLOCK, PPBP and Rho family GTPASE 2 (RND2) were upregulated in Native Hawaiian patients. Our transcriptomic approach advances understanding of sepsis heterogeneity by revealing a role of genetic background and defining patient subgroups with altered early and late biological responses to sepsis. This study is the first to investigate differential gene expression in CRC-associated sepsis patients in relation to ethnicity. Our findings may lead to personalized approaches in stratifying patient mortality risk for sepsis and in the development of effective targeted therapies for sepsis.

Defibrotide Therapy for SARS-CoV-2 ARDS

BACKGROUND

SARS-CoV-2-related ARDS is associated with endothelial dysfunction and profound dysregulation of the thrombotic-fibrinolytic pathway. Defibrotide is a polyanionic compound with fibrinolytic, antithrombotic, and antiinflammatory properties.

RESEARCH QUESTION

What is the safety and tolerability of defibrotide in patients with severe SARS-CoV-2 infections?

STUDY DESIGN AND METHODS

We report a prospective, open-label, single-center safety trial of defibrotide for the management of SARS-CoV-2-related ARDS. Eligible participants were 18 years of age or older with clinical and radiographic signs of ARDS, no signs of active bleeding, a serum D-dimer of more than twice upper limit of normal, and positive polymerase chain reaction-based results for SARS-CoV-2. Defibrotide (6.25 mg/kg/dose IV q6h) was administered for a planned 7-day course, with serum D-dimer levels and respiratory function monitored daily during therapy.

RESULTS

Twelve patients (median age, 63 years) were treated, with 10 patients receiving mechanical ventilation and 6 receiving vasopressor support at study entry. The median D-dimer was 3.25 μg/ml (range, 1.33-12.3) at study entry. The median duration of therapy was 7 days. No hemorrhagic or thrombotic complications occurred during therapy. No other adverse events attributable to defibrotide were noted. Four patients met the day 7 pulmonary response parameter, all four showing a decrease in serum D-dimer levels within the initial 72 h of defibrotide therapy. Three patients died of progressive pulmonary disease 11, 17, and 34 days after study entry. Nine patients (75%) remain alive 64 to 174 days after initiation of defibrotide. Day 30 all-cause mortality was 17% (95% CI, 0%-35%). All patients with a baseline Pao₂ to Fio₂ ratio of ≥ 125 mm Hg survived, whereas the three patients with a baseline Pao₂ to Fio₂ ratio of < 125 mm Hg died.

INTERPRETATION

The use of defibrotide for management of SARS-CoV-2-related ARDS proved safe and tolerable. No hemorrhagic or thrombotic complications were reported during therapy, with promising outcomes in a patient population with a historically high mortality rate.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT04530604; URL: www.

CLINICALTRIALS

gov.

Secondary Dysfunction of the Intestinal Barrier in the Pathogenesis of Complications of Acute Poisoning

The last decade has been marked by an exponential increase in the number of publications on the physiological role of the normal human gut microbiota. The idea of a symbiotic relationship between the human organism and normal microbiota of its gastrointestinal tract has been firmly established as an integral part of the current biomedical paradigm. However, the type of this symbiosis varies from mutualism to parasitism and depends on the functional state of the host organism. Damage caused to the organism by external agents can lead to the emergence of conditionally pathogenic properties in the normal gut microbiota, mediated by humoral factors and affecting the outcome of exogenous exposure. Among the substances produced by symbiotic microbiota, there are an indefinite number of compounds with systemic toxicity. Some occur in the intestinal chyme in potentially lethal amounts in the case they enter the bloodstream quickly. The quick entry of potential toxicants is prevented by the intestinal barrier (IB), a set of structural elements separating the intestinal chyme from the blood. Hypothetically, severe damage to the IB caused by exogenous toxicants can trigger a leakage and subsequent systemic redistribution of toxic substances of bacterial origin. Until recently, the impact of such a redistribution on the outcome of acute exogenous poisoning remained outside the view of toxicology. The present review addresses causal relationships between the secondary dysfunction of the IB and complications of acute poisoning. We characterize acute systemic toxicity of such waste products of the normal gut microflora as ammonia and endotoxins, and demonstrate their involvement in the formation of such complications of acute poisoning as shock, sepsis, cerebral insufficiency and secondary lung injuries. The principles of assessing the functional state of the IB and the approaches to its protection in acute poisoning are briefly considered.

Sepsis-associated brain injury: underlying mechanisms and potential therapeutic strategies for acute and long-term cognitive impairments

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis causes cerebral dysfunction in the short and long term and induces disruption of the blood–brain barrier (BBB), neuroinflammation, hypoperfusion, and accumulation of amyloid β (Aβ) and tau protein in the brain. White matter changes and brain atrophy can be detected using brain imaging, but unfortunately, there is no specific treatment that directly addresses the underlying mechanisms of cognitive impairments in sepsis. Here, we review the underlying mechanisms of sepsis-associated brain injury, with a focus on BBB dysfunction and Aβ and tau protein accumulation in the brain. We also describe the neurological manifestations and imaging findings of sepsis-associated brain injury, and finally, we propose potential therapeutic strategies for acute and long-term cognitive impairments associated with sepsis. In the acute phase of sepsis, we suggest using antibiotics (such as rifampicin), targeting proinflammatory cytokines, and preventing ischemic injuries and hypoperfusion. In the late phase of sepsis, we suggest targeting neuroinflammation, BBB dysfunction, Aβ and tau protein phosphorylation, glycogen synthase kinase-3 beta (GSK3β), and the receptor for advanced glycation end products (RAGE). These proposed strategies are meant to bring new mechanism-based directions for future basic and clinical research aimed at preventing or ameliorating acute and long-term cognitive impairments in patients with sepsis.

Soluble IL-2R Levels at Baseline Predict the Development of Severe Respiratory Failure and Mortality in COVID-19 Patients

Risk stratification of coronavirus disease-19 (COVID-19) patients by simple markers is critical to guide treatment. We studied the predictive value of soluble interleukin-2 receptor (sIL-2R) for the early identification of patients at risk of developing severe clinical outcomes. sIL-2R levels were measured in 197 patients (60.9% males; median age 61 years; moderate disease, n = 65; severe, n = 132, intubated and/or died, n = 42). All patients received combined immunotherapies (anakinra ± corticosteroids ± intravenous immunoglobulin ± tocilizumab) according to our local treatment algorithm. The endpoint was the composite event of intubation due to severe respiratory failure (SRF) or mortality. Median (interquartile range) sIL-2R levels were significantly higher in patients with severe disease, compared with those with moderate disease (6 (6.2) vs. 5.2 (3.4) ng/mL, p = 0.017). sIL-2R was the strongest laboratory predictive factor for intubation/death (hazard ratio 1.749, 95%CI 1.041–2.939, p = 0.035) after adjustment for other known risk factors. Youden’s index revealed optimal sIL-2R cut-off for predicting intubation/death at 9 ng/mL (sensitivity: 67%; specificity: 86%; positive and negative predictive value: 57% and 91%, respectively). Delta sIL-2R between the day of event or discharge minus admission date was higher in patients that intubated/died than in those who did not experience an event (2.91 (10.42) vs. 0.44 (2.88) ng/mL; p = 0.08)). sIL-2R on admission and its dynamic changes during follow-up may reflect disease severity and predict the development of SRF and mortality.

[Pathophysiology of septic shock]

Sepsis and septic shock result from an inadequate host response to an infection, which causes organ dysfunction. The progression of this condition is manifested by the occurrence of successive clinical stages, resulting from the systemic inflammatory response secondary to the activation of different inflammatory mediators, leading to organ dysfunction. There is a high burden of evidence on the role of endotoxin in the pathogenesis of sepsis and its crucial role in triggering the inflammatory response in sepsis caused by gram-negative bacteria. The coagulation cascade activation in sepsis patients is part of the host's adaptive immune response to infection. The endothelium is the main target in sepsis, which is metabolically active and can.

Role of Age-Related Changes in DNA Methylation in the Disproportionate Susceptibility and Worse Outcomes of Sepsis in Older Adults

Sepsis, a complex multisystem disorder, is among the top causes of hospitalization and mortality in older adults. However, the mechanisms underlying the disproportionate susceptibility to sepsis and worse outcomes in the elderly are not well understood. Recently, changes in DNA methylation have been shown to be linked to aging processes and age-related diseases. Thus, we postulated that age-related changes in DNA methylation may play a role in the onset and prognosis of sepsis in elderly patients. Here, we performed genome-wide methylation profiling of peripheral blood from patients with sepsis and controls. Among the CpG sites whose methylation changes may contribute to an increase in sepsis susceptibility or mortality, 241 sites that possessed age-related changes in DNA methylation in controls may partly explain the increased risk of sepsis in older adults, and 161 sites whose methylation significantly correlated with age in sepsis group may be the potential mechanisms underlying the worse outcomes of elderly septic patients. Finally, an independent cohort was used to validate our findings. Together, our study demonstrates that age-related changes in DNA methylation may explain in part the disproportionate susceptibility and worse outcomes of sepsis in older adults.

MiR-29b-3p Inhibits the Inflammation Injury in Human Umbilical Vein Endothelial Cells by Regulating SEC23A

This study aims to investigate the effects of miR-29b-3p on the inflammation injury of human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS) and explore the underlying mechanisms. The effects of different concentrations of LPS (0, 1, 5 and 10 μg/mL) on inflammation injury in HUVECs are detected by ELISA, CCK-8, EdU, flow cytometry and western blot analyses to determine the optimal stimulus concentration. After stimulating HUVECs with 10 μg/mL LPS, the expression levels of miR-29b-3p are detected, and the effects of miR-29b-3p on inflammation injury are detected by ELISA, CCK-8, EdU, flow cytometry and western blot analyses. Bioinformatic analysis, luciferase reporter assay and confirmatory experiments are applied to identify the target gene bound with miR-29b-3p. Rescue experiments have verified the roles of miR-29b-3p and the target gene in inflammation injury. We found that pro-inflammatory factor was increased, apoptosis was promoted, and cell proliferation was inhibited after the treatment of LPS in HUVECs. Overexpression of miR-29b-3p inhibited LPS-induced inflammatory response and apoptosis while promoting proliferation in HUVECs. Besides, bioinformatics analysis indicated that SEC23A was the target gene of miR-29b-3p and the confirmatory experiments showed that SEC23A was negatively correlated with miR-29b-3p and positively correlated with LPS concentration. Rescue experiments revealed that overexpression of SEC23A partially enhanced the inflammation injury effects in LPS-induced HUVECs with overexpression of miR-29b-3p. Hence, miR-29b-3p repressed inflammatory response, cell apoptosis and promoted cell proliferation in LPS-induced HUVECs by targeting SEC23A, providing a potential target for treating sepsis.

The spike protein of SARS-CoV-2 induces endothelial inflammation through integrin α5β1 and NF-κB signaling

Vascular endothelial cells (ECs) form a critical interface between blood and tissues that maintains whole-body homeostasis. In COVID-19, disruption of the EC barrier results in edema, vascular inflammation, and coagulation, hallmarks of this severe disease. However, the mechanisms by which ECs are dysregulated in COVID-19 are unclear. Here, we show that the spike protein of SARS-CoV-2 alone activates the EC inflammatory phenotype in a manner dependent on integrin ⍺5β1 signaling. Incubation of human umbilical vein ECs with whole spike protein, its receptor-binding domain, or the integrin-binding tripeptide RGD induced the nuclear translocation of NF-κB and subsequent expression of leukocyte adhesion molecules (VCAM1 and ICAM1), coagulation factors (TF and FVIII), proinflammatory cytokines (TNF⍺, IL-1β, and IL-6), and ACE2, as well as the adhesion of peripheral blood leukocytes and hyperpermeability of the EC monolayer. In addition, inhibitors of integrin ⍺5β1 activation prevented these effects. Furthermore, these vascular effects occur in vivo, as revealed by the intravenous administration of spike, which increased expression of ICAM1, VCAM1, CD45, TNFα, IL-1β, and IL-6 in the lung, liver, kidney, and eye, and the intravitreal injection of spike, which disrupted the barrier function of retinal capillaries. We suggest that the spike protein, through its RGD motif in the receptor-binding domain, binds to integrin ⍺5β1 in ECs to activate the NF-κB target gene expression programs responsible for vascular leakage and leukocyte adhesion. These findings uncover a new direct action of SARS-CoV-2 on EC dysfunction and introduce integrin ⍺5β1 as a promising target for treating vascular inflammation in COVID-19.

Piceatannol alleviates glucolipotoxicity induced vascular barrier injury through inhibition of the ROS/NF-kappa B signaling pathway

Vascular barrier dysfunction is considered as the initial and critical event in atherosclerosis progression. Recent studies have revealed that treatment with piceatannol (PIC) alleviates both acute and chronic responses to vascular injury. We investigated whether PIC treatment would have beneficial effects on glucolipotoxicity-induced endothelial barrier dysfunction. Target proteins of PIC were identified from several online databases. Then, we confirmed the effect of PIC on endothelial barrier function. PIC treatment mitigated the impairment of endothelial cell motility, adhesion and migration ability associated with high glucose/lipid stimulation. PIC stabilized cytoskeletal reorganization and expression of cell cytoskeletal associated proteins GTPase. PIC reversed changes in critical vascular junction proteins and thus preserved endothelial barrier function and permeability. Finally, we confirmed that reducing of nuclear factor kappa B (NF-κB)/p65 activation and elimination of reactive oxygen species (ROS) were involved in the protective effect of PIC against glucolipotoxicity-induced vascular barrier injury. We identify PIC as a promising therapeutic strategy for glucolipotoxicity-induced endothelial barrier injury.

Immune response to SARS-CoV-2 Variants: A focus on severity, susceptibility, and preexisting immunity

The heterogeneous phenotypes among patients with coronavirus disease 2019 (COVID-19) has drawn worldwide attention, especially those with severe symptoms without comorbid conditions. Immune responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative virus of COVID-19, occur mainly by the innate immune response via the interferon (IFN)-mediated pathways, and the adaptive immunity via the T lymphocyte and the antibody mediated pathways. The ability of the original Wuhan SARS-CoV-2 strain, and possibly more so with new emerging variants, to antagonize IFN-mediated antiviral responses can be behind the higher early viral load, higher transmissibility, and milder symptoms compared to SARS-CoV and are part of the continued clinical evolution of COVID-19. Since it first emerged, several variants of SARS-CoV-2 have been circulating worldwide. Variants that have the potential to elude natural or vaccine-mediated immunity are variants of concern. This review focuses on the main host factors that may explain the immune responses to SARS-CoV-2 and its variants in the context of susceptibility, severity, and preexisting immunity.

Role of heparinase in the gastrointestinal dysfunction of sepsis (Review)

Heparinase (HPA) is a β-D glucuronidase that belongs to the endoglycosidase enzyme family, and plays an important role in numerous pathological and physiological processes, including inflammation, angiogenesis and tumor metastasis. When the expression of HPA is abnormally high, the side chain of heparin sulfate proteoglycans degrades, destroying the cell barrier and leading to the occurrence and development of inflammation, with systemic inflammation occurring in severe cases. Sepsis is a major cause of mortality in critically ill patients. In sepsis, the gastrointestinal tract is the first and most frequently involved target organ, which often leads to gastrointestinal dysfunction. HPA overexpression has been determined to accelerate sepsis progression and gastrointestinal dysfunction; thus, it was hypothesized that HPA may play an important role and may serve as an index for the diagnosis of gastrointestinal dysfunction in sepsis. HPA inhibitors may therefore become applicable as targeted drugs for the treatment of gastrointestinal dysfunction in patients with sepsis. The present review mainly discussed the role of HPA in gastrointestinal dysfunction of sepsis.

AICAR Protects Vascular Endothelial Cells from Oxidative Injury Induced by the Long-Term Palmitate Excess

Hyperlipidemia manifested by high blood levels of free fatty acids (FFA) and lipoprotein triglycerides is critical for the progression of type 2 diabetes (T2D) and its cardiovascular complications via vascular endothelial dysfunction. However, attempts to assess high FFA effects in endothelial culture often result in early cell apoptosis that poorly recapitulates a much slower pace of vascular deterioration in vivo and does not provide for the longer-term studies of endothelial lipotoxicity in vitro. Here, we report that palmitate (PA), a typical FFA, does not impair, by itself, endothelial barrier and insulin signaling in human umbilical vein endothelial cells (HUVEC), but increases NO release, reactive oxygen species (ROS) generation, and protein labeling by malondialdehyde (MDA) hallmarking oxidative stress and increased lipid peroxidation. This PA-induced stress eventually resulted in the loss of cell viability coincident with loss of insulin signaling. Supplementation with 5-aminoimidazole-4-carboxamide-riboside (AICAR) increased endothelial AMP-activated protein kinase (AMPK) activity, supported insulin signaling, and prevented the PA-induced increases in NO, ROS, and MDA, thus allowing to maintain HUVEC viability and barrier, and providing the means to study the long-term effects of high FFA levels in endothelial cultures. An upgraded cell-based model reproduces FFA-induced insulin resistance by demonstrating decreased NO production by vascular endothelium.

Modulation of oxidative and nitrosative stress attenuates microvascular hyperpermeability in ovine model of Pseudomonas aeruginosa sepsis

In sepsis, microvascular hyperpermeability caused by oxidative/nitrosative stress (O&NS) plays an important role in tissue edema leading to multi-organ dysfunctions and increased mortality. We hypothesized that a novel compound R-107, a modulator of O&NS, effectively ameliorates the severity of microvascular hyperpermeability and preserves multi-organ function in ovine sepsis model. Sepsis was induced in twenty-two adult female Merino sheep by intravenous infusion of Pseudomonas aeruginosa (PA) (1 × 10¹⁰ CFUs). The animals were allocated into: 1) Control (n = 13): intramuscular injection (IM) of saline; and 2) Treatment (n = 9): IM of 50 mg/kg R-107. The treatment was given after the PA injection, and monitored for 24-h. R-107 treatment significantly reduced fluid requirement (15-24 h, P < 0.05), net fluid balance (9-24 h, P < 0.05), and water content in lung/heart/kidney (P = 0.02/0.04/0.01) compared to control. R-107 treatment significantly decreased lung injury score/modified sheep SOFA score at 24-h (P = 0.01/0.04), significantly lowered arterial lactate (21-24 h, P < 0.05), shed syndecan-1 (3-6 h, P < 0.05), interleukin-6 (6-12 h, P < 0.05) levels in plasma, and significantly attenuated lung tissue 3-nitrotyrosine and vascular endothelial growth factor-A expressions (P = 0.03/0.002) compared to control. There was no adverse effect in R-107 treatment. In conclusion, modulation of O&NS by R-107 reduced hyperpermeability markers and improved multi-organ function.

Management of pneumonia in critically ill patients

Severe pneumonia is associated with high mortality (short and long term), as well as pulmonary and extrapulmonary complications. Appropriate diagnosis and early initiation of adequate antimicrobial treatment for severe pneumonia are crucial in improving survival among critically ill patients. Identifying the underlying causative pathogen is also critical for antimicrobial stewardship. However, establishing an etiological diagnosis is challenging in most patients, especially in those with chronic underlying disease; those who received previous antibiotic treatment; and those treated with mechanical ventilation. Furthermore, as antimicrobial therapy must be empiric, national and international guidelines recommend initial antimicrobial treatment according to the location's epidemiology; for patients admitted to the intensive care unit, specific recommendations on disease management are available. Adherence to pneumonia guidelines is associated with better outcomes in severe pneumonia. Yet, the continuing and necessary research on severe pneumonia is expansive, inviting different perspectives on host immunological responses, assessment of illness severity, microbial causes, risk factors for multidrug resistant pathogens, diagnostic tests, and therapeutic options.

Low serum levels of promatrix metalloproteinase-2 and -9 occur during acute Babesia canis infection in dogs

Inflammation is a hallmark of the acute Babesia canis infection. Promatrix metalloproteinase (proMMP)-2 and -9 are involved in inflammation, but their levels have not been analyzed in canine babesiosis. We hypothesized that in dogs infected with B. canis, serum proMMP-2 and -9 levels change between presentation and recovery. Degree of the change differs if dogs develop systemic inflammatory response syndrome (SIRS). This study included 24 dogs with an acute B. canis infection, at presentation and after two weeks. We used routine hematology and biochemistry methods, spectrophotometry for the acute-phase proteins, microscopy for parasitemia and zymography for (pro)MMPs. In vitro endothelial cells and leukocyte short-term cultures, and platelet lysates were used to detect specific MMP activity. Statistical analyses included Wilcoxon test for paired samples, Mann-Whitney U test and Spearman's rank correlation. Our results showed that endothelial cells, leukocytes and platelets are the source of proMMP-2 and proMMP-9. Furthermore, both proMMPs were lower at presentation than after recovery (p < 0.001). At presentation, proMMP-9 levels correlated with parasitemia (rho = -0.616, p = 0.009), total leukocyte (rho = 0.704, p < 0.001) and neutrophil counts (rho = 0.741, p < 0.001). Extent of alterations in proMMP-2 levels between presentation and recovery was lower (p = 0.038) in dogs with SIRS than in non-SIRS dogs, while levels of proMMP-9 were comparable between these groups. Our conclusion is that during the acute B. canis infection, low serum levels of proMMP-2 and proMMP-9 at presentation reflect thrombocytopenia and leukopenia. Decreased proMMP-2 level could be associated with SIRS.

Is It All About Endothelial Dysfunction and Thrombosis Formation? The Secret of COVID-19

The world is in a hard battle against COVID-19. Endothelial cells are among the most critical targets of SARS-CoV-2. Dysfunction of endothelium leads to vascular injury following by coagulopathies and thrombotic conditions in the vital organs increasing the risk of life-threatening events. Growing evidences revealed that endothelial dysfunction and consequent thrombotic conditions are associated with the severity of outcomes. It is not yet fully clear that these devastating sequels originate directly from the virus or a side effect of virus-induced cytokine storm. Due to endothelial dysfunction, plasma levels of some biomarkers are changed and relevant clinical manifestations appear as well. Stabilization of endothelial integrity and supporting its function are among the promising therapeutic strategies. Other than respiratory, COVID-19 could be called a systemic vascular disease and this aspect should be scrutinized in more detail in order to reduce related mortality. In the present investigation, the effects of COVID-19 on endothelial function and thrombosis formation are discussed. In this regard, critical players, laboratory findings, clinical manifestation, and suggestive therapies are presented.

SARS-CoV-2 Coronavirus Spike Protein-Induced Apoptosis, Inflammatory, and Oxidative Stress Responses in THP-1-Like-Macrophages: Potential Role of Angiotensin-Converting Enzyme Inhibitor (Perindopril)

A purified spike (S) glycoprotein of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) coronavirus was used to study its effects on THP-1 macrophages, peripheral blood mononuclear cells (PBMCs), and HUVEC cells. The S protein mediates the entry of SARS-CoV-2 into cells through binding to the angiotensin-converting enzyme 2 (ACE2) receptors. We measured the viability, intracellular cytokine release, oxidative stress, proinflammatory markers, and THP-1-like macrophage polarization. We observed an increase in apoptosis, ROS generation, MCP-1, and intracellular calcium expression in the THP-1 macrophages. Stimulation with the S protein polarizes the THP-1 macrophages towards proinflammatory futures with an increase in the TNFα and MHC-II M1-like phenotype markers. Treating the cells with an ACE inhibitor, perindopril, at 100 µM reduced apoptosis, ROS, and MHC-II expression induced by S protein. We analyzed the sensitivity of the HUVEC cells after the exposure to a conditioned media (CM) of THP-1 macrophages stimulated with the S protein. The CM induced endothelial cell apoptosis and MCP-1 expression. Treatment with perindopril reduced these effects. However, the direct stimulation of the HUVEC cells with the S protein, slightly increased HIF1α and MCP-1 expression, which was significantly increased by the ACE inhibitor treatment. The S protein stimulation induced ROS generation and changed the mitogenic responses of the PBMCs through the upregulation of TNFα and interleukin (IL)-17 cytokine expression. These effects were reduced by the perindopril (100 µM) treatment. Proteomic analysis of the S protein stimulated THP-1 macrophages with or without perindopril (100 µM) exposed more than 400 differentially regulated proteins. Our results provide a mechanistic analysis suggesting that the blood and vascular components could be activated directly through S protein systemically present in the circulation and that the activation of the local renin angiotensin system may be partially involved in this process.

Graphical

Suggested pathways that might be involved at least in part in S protein inducing activation of inflammatory markers (red narrow) and angiotensin-converting enzyme inhibitor (ACEi) modulation of this process (green narrow).

"The possible implication of endothelin in the pathology of COVID-19-induced pulmonary hypertension"

COVID-19 pandemic has changed the world dramatically since was first reported in Wuhan city, China [1]. Not only as a respiratory illness that could lead to fatal respiratory failure, but also some evidences suggest that it can propagate as a chronic disease associated with a variety of persistent post COVID-19 pathologies that affect patients' life [2,3]. Pulmonary hypertension (PH) is one of the challenging diseases that may develop as a consequence of SARS-COV-2 infection in some COVID-19 survivors [4,5]. The vasopressor, proliferative, proinflammatory, and prothrombotic actions of endothelin [6] may be encountered in the COVID-19-induced PH pathology. And so, endothelin blockers may have an important role to restrict the development of serious PH outcomes with special precautions considering patients with significant hypoxemia.

Kansuinine A Ameliorates Atherosclerosis and Human Aortic Endothelial Cell Apoptosis by Inhibiting Reactive Oxygen Species Production and Suppressing IKKβ/IκBα/NF-κB Signaling

Reactive oxygen species (ROS)-induced vascular endothelial cell apoptosis is strongly associated with atherosclerosis progression. Herein, we aimed to examine whether Kansuinine A (KA), extracted from Euphorbia kansui L., prevents atherosclerosis development in a mouse model and inhibits cell apoptosis through oxidative stress reduction. Atherosclerosis development was analyzed in apolipoprotein E-deficient (ApoE^-/-) mice fed a high-fat diet (HFD) using Oil Red O staining and H&E staining. Human aortic endothelial cells (HAECs) were treated with KA, followed by hydrogen peroxide (H₂O₂), to investigate the KA-mediated inhibition of ROS-induced oxidative stress and cell apoptosis. Oil Red O staining and H&E staining showed that atherosclerotic lesion size was significantly smaller in the aortic arch of ApoE^-/- mice in the HFD+KA group than that in the aortic arch of those in the HFD group. Further, KA (0.1-1.0 μM) blocked the H₂O₂-induced death of HAECs and ROS generation. The H₂O₂-mediated upregulation of phosphorylated IKKβ, phosphorylated IκBα, and phosphorylated NF-κB was suppressed by KA. KA also reduced the Bax/Bcl-2 ratio and cleaved caspase-3 expression, preventing H₂O₂-induced vascular endothelial cell apoptosis. Our results indicate that KA may protect against ROS-induced endothelial cell apoptosis and has considerable clinical potential in the prevention of atherosclerosis and cardiovascular diseases.

Apolipoprotein M and its impact on endothelial dysfunction and inflammation in the cardiovascular system

Apolipoprotein M (apoM) is a member of the lipocalin superfamily and is predominantly associated with high-density lipoprotein (HDL). It was found that apoM is the chaperon to the bioactive sphingolipid, sphingosine-1-phosphate (S1P). Several studies have since contributed to expand the knowledge on apoM, S1P, and the apoM/S1P-complex in cardiovascular diseases. For instance, the HDL-bound apoM/S1P complex serves as a bridge between HDL and endothelial cells, maintaining a healthy endothelial barrier. Evidence indicates, however, that the apoM/S1P complex may has both protective and harmful effects on the cardiovascular system, which suggests the need for more research to understand the interplay between these molecules. This review aims to shed light on the most recent findings on apoM/S1P-signaling and its impact on endothelial dysfunction, inflammation, and cardiovascular diseases. Finally, it will be discussed whether drugs that target apoM and/or S1P-signaling may be beneficial to patients with cardiovascular and inflammatory diseases.

Lymphopenia and lung complications in patients with coronavirus disease-2019 (COVID-19): A retrospective study based on clinical data

A rapid outbreak of novel coronavirus, coronavirus disease-2019 (COVID-19), has made it a global pandemic. This study focused on the possible association between lymphopenia and computed tomography (CT) scan features and COVID-19 patient mortality. The clinical data of 596 COVID-19 patients were collected from February 2020 to September 2020. The patients' serological survey and CT scan features were retrospectively explored. The median age of the patients was 56.7 ± 16.4 years old. Lung involvement was more than 50% in 214 COVID-19 patients (35.9%). The average blood lymphocyte percentage was 20.35 ± 10.16 (normal range, 20%-50%). Although the levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were high in more than 80% of COVID-19 patients; CRP, ESR, and platelet-to-lymphocyte ratio (PLR) may not indicate the in-hospital mortality of COVID-19. Patients with severe lung involvement and lymphopenia were found to be significantly associated with increased odds of death (odds ratio, 9.24; 95% confidence interval, 4.32-19.78). These results indicated that lymphopenia < 20% along with pulmonary involvement >50% impose a multiplicative effect on the risk of mortality. The in-hospital mortality rate of this group was significantly higher than other COVID-19 hospitalized cases. Furthermore, they meaningfully experienced a prolonged stay in the hospital (p = .00). Lymphocyte count less than 20% and chest CT scan findings with more than 50% involvement might be related to the patient's mortality. These could act as laboratory and clinical indicators of disease severity, mortality, and outcome.

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.

Nationwide case-control study of risk factors and outcomes for community-acquired sepsis

Sepsis is the main cause of death in the intensive care units (ICU) and increasing incidences of ICU admissions for sepsis are reported. Identification of patients at risk for sepsis and poor outcome is therefore of outmost importance. We performed a nation-wide case-control study aiming at identifying and quantifying the association between co-morbidity and socio-economic factors with intensive care admission for community-acquired sepsis. We also explored 30-day mortality. All adult patients (n = 10,072) with sepsis admitted from an emergency department to an intensive care unit in Sweden between 2008 and 2017 and a control population (n = 50,322), matched on age, sex and county were included. In the sepsis group, 69% had a co-morbid condition at ICU admission, compared to 31% in the control group. Multivariable conditional logistic regression analysis was performed and there was a large variation in the influence of different risk factors associated with ICU-admission, renal disease, liver disease, metastatic malignancy, substance abuse, and congestive heart failure showed the strongest associations. Low income and low education level were more common in sepsis patients compared to controls. The adjusted OR for 30-day mortality for sepsis patients was 132 (95% CI 110-159) compared to controls.

Novel insights into the pathogenesis of virus-induced ARDS: review on the central role of the epithelial-endothelial barrier

Introduction: Respiratory viruses can directly or indirectly damage the pulmonary defense barrier, potentially contributing to acute respiratory distress syndrome (ARDS). Despite developments in the understanding of the pathogenesis of ARDS, the underlying pathophysiology still needs to be elucidated.Areas covered: The PubMed database was reviewed for relevant papers published up to 2021. This review summarizes the currently immunological and clinical studies to provide a systemic overview of the epithelial-endothelial barrier, given the recently published immunological profiles upon viral pneumonia, and the potentially detrimental contribution to respiratory function caused by damage to this barrier.Expert opinion: The biophysical structure of host pulmonary defense is intrinsically linked with the ability of alveolar epithelial and capillary endothelial cells, known as the epithelial-endothelial barrier, to respond to, and instruct the delicate immune system to protect the lungs from infections and injuries. Recently published immunological profiles upon viral infection, and its contributions to the damage of respiratory function, suggest a central role for the pulmonary epithelial and endothelial barrier in the pathogenesis of ARDS. We suggest a central role and common pathways by which the epithelial-endothelial barrier contributes to the pathogenesis of ARDS.

Endothelial Dysfunction and Neutrophil Degranulation as Central Events in Sepsis Physiopathology

Sepsis is a major health problem worldwide. It is a time-dependent disease, with a high rate of morbidity and mortality. In this sense, an early diagnosis is essential to reduce these rates. The progressive increase of both the incidence and prevalence of sepsis has translated into a significant socioeconomic burden for health systems. Currently, it is the leading cause of noncoronary mortality worldwide and represents one of the most prevalent pathologies both in hospital emergency services and in intensive care units. In this article, we review the role of both endothelial dysfunction and neutrophil dysregulation in the physiopathology of this disease. The lack of a key symptom in sepsis makes it difficult to obtain a quick and accurate diagnosis of this condition. Thus, it is essential to have fast and reliable diagnostic tools. In this sense, the use of biomarkers can be a very important alternative when it comes to achieving these goals. Both new biomarkers and treatments related to endothelial dysfunction and neutrophil dysregulation deserve to be further investigated in order to open new venues for the diagnosis, treatment and prognosis of sepsis.

Long Noncoding RNA: Regulatory Mechanisms and Therapeutic Potential in Sepsis

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection and is characterized by a hyperinflammatory state accompanied by immunosuppression. Long noncoding RNAs (lncRNAs) are noncoding RNAs longer than 200 nucleotides and have important roles in mediating various biological processes. Recently, lncRNAs were found to exert both promotive and inhibitory immune functions in sepsis, thus participating in sepsis regulation. Additionally, several studies have revealed that lncRNAs are involved in sepsis-induced organ dysfunctions, including cardiovascular dysfunction, acute lung injury, and acute kidney injury. Considering the lack of effective biomarkers for early identification and specific treatment for sepsis, lncRNAs may be promising biomarkers and even targets for sepsis therapies. This review systematically highlights the recent advances regarding the roles of lncRNAs in sepsis and sheds light on their use as potential biomarkers and treatment targets for sepsis.

MR-proADM as marker of endotheliitis predicts COVID-19 severity

BACKGROUND

Early identification of patients at high risk of progression to severe COVID-19 constituted an unsolved challenge. Although growing evidence demonstrates a direct association between endotheliitis and severe COVID-19, the role of endothelial damage biomarkers has been scarcely studied. We investigated the relationship between circulating mid-regional proadrenomedullin (MR-proADM) levels, a biomarker of endothelial dysfunction, and prognosis of SARS-CoV-2-infected patients.

METHODS

Prospective observational study enrolling adult patients with confirmed COVID-19. On admission to emergency department, a blood sample was drawn for laboratory test analysis. Primary and secondary endpoints were 28-day all-cause mortality and severe COVID-19 progression. Area under the curve (AUC) and multivariate regression analysis were employed to assess the association of the biomarker with the established endpoints.

RESULTS

A total of 99 patients were enrolled. During hospitalization, 25 (25.3%) cases progressed to severe disease and the 28-day mortality rate was of 14.1%. MR-proADM showed the highest AUC to predict 28-day mortality (0.905; [CI] 95%: 0.829-0.955; P < .001) and progression to severe disease (0.829; [CI] 95%: 0.740-0.897; P < .001), respectively. MR-proADM plasma levels above optimal cut-off (1.01 nmol/L) showed the strongest independent association with 28-day mortality risk (hazard ratio [HR]: 10.470, 95% CI: 2.066-53.049; P < .005) and with progression to severe disease (HR: 6.803, 95% CI: 1.458-31.750; P = .015).

CONCLUSION

Mid-regional proadrenomedullin was the biomarker with highest performance for prognosis of death and progression to severe disease in COVID-19 patients and represents a promising predictor for both outcomes, which might constitute a potential tool in the assessment of prognosis in early stages of this disease.

Coenzyme Q10 supplement rescues postovulatory oocyte aging by regulating SIRT4 expression

BACKGROUND

High-quality of the oocyte is crucial for embryo development and the success of human assisted reproduction. The postovulatory aged oocytes lose the developmental competence with mitochondrial dysfunction and oxidative stress. Coenzyme Q10 (CoQ10) is widely distributed in the membranes of cells, and has an important role in the mitochondrial respiration chain, against oxidative stress and modulation of gene expression.

OBJECTIVE

To investigate the functions and mechanisms of CoQ10 on delaying postovulatory oocyte aging.

METHODS

Quantitative real-time PCR and Immunofluorescence staining were used to determine the expression patterns of the biogenesis genes of CoQ10 in postovulatory aged oocytes compared with fresh oocytes. The mitochondrial function, apoptosis, reactive oxygen species (ROS) accumulation and spindle abnormalities were investigated after treatment with 10 μM CoQ10 in aged groups. SIRT4 siRNA or capped RNA was injected into oocytes to investigate the function of SIRT4 on postovulatory oocyte aging and the relationship between CoQ10 and SIRT4.

RESULTS

Multiple CoQ10 biosynthesis enzymes are insufficient, and supplement of CoQ10 can improve oocyte quality and elevate the development competency of postovulatory aged oocytes. CoQ10 can attenuate the aging-induced abnormalities including mitochondrial dysfunction, ROS accumulation, spindle abnormalities, and apoptosis in postovulatory aged oocytes. Furthermore, SIRT4, which was first found to be up-regulated in postovulatory aged oocytes, decreased following CoQ10 treatment. Finally, knockdown of SIRT4 can rescue aging-induced dysfunction of mitochondria, and the efficiency of CoQ10 rescuing dysfunction of mitochondria can be weakened by SIRT4 overexpression.

CONCLUSION

Supplement of CoQ10 protects oocytes from postovulatory aging by inhibiting SIRT4increase.

Transcriptional Regulation of Thrombin-Induced Endothelial VEGF Induction and Proangiogenic Response

Thrombin, the ligand of the protease-activated receptor 1 (PAR1), is a well-known stimulator of proangiogenic responses in vascular endothelial cells (ECs), which are mediated through the induction of vascular endothelial growth factor (VEGF). However, the transcriptional events underlying this thrombin-induced VEGF induction and angiogenic response are less well understood at present. As reported here, we conducted detailed promotor activation and signal transduction pathway studies in human microvascular ECs, to decipher the transcription factors and the intracellular signaling events underlying the thrombin and PAR-1-induced endothelial VEGF induction. We found that c-FOS is a key transcription factor controlling thrombin-induced EC VEGF synthesis and angiogenesis. Upon the binding and internalization of its G-protein-coupled PAR-1 receptor, thrombin triggers ERK1/2 signaling and activation of the nuclear AP-1/c-FOS transcription factor complex, which then leads to VEGF transcription, extracellular secretion, and concomitant proangiogenic responses of ECs. In conclusion, exposure of human microvascular ECs to thrombin triggers signaling through the PAR-1–ERK1/2–AP-1/c-FOS axis to control VEGF gene transcription and VEGF-induced angiogenesis. These observations offer a greater understanding of endothelial responses to thromboinflammation, which may help to interpret the results of clinical trials tackling the conditions associated with endothelial injury and thrombosis.

SARS-Cov-2 and COVID-19, Basic and Clinical Aspects of the Human Pandemic: A Review

In the last two decades, we have witnessed three major epidemics of the coronavirus human disease namely, severe acute respiratory syndrome (SARS), Middle Eastern respiratory syndrome, and more recently an ongoing global pandemic of coronavirus disease 2019 (COVID-19). Iran, a country of nearly 84 million, in the Middle East, severely involved with the COVID-19 disease. A documented multidimensional approach to COVID-19 disease is therefore mandatory to provide a well-balanced platform for the concerned medical community in our county and beyond. In this review, we highlight the disease status in Iran and attempt to provide a multilateral view of the fundamental and clinical aspects of the disease including the clinical features of the confirmed cases, virology, pathogenesis, epidemiology, and laboratory methods needed for diagnosis.

Lymphopenia Is Associated With Poor Outcomes of Patients With Community-Acquired Pneumonia and Sepsis

Background

Lymphopenia is a marker of poor prognosis in patients with community-acquired pneumonia (CAP), yet its impact on outcomes in patients with CAP and sepsis remains unknown. We aim to investigate the impact of lymphopenia on outcomes, risk of intensive care unit (ICU) admission, and mortality in CAP patients with sepsis.

Methods

This was a retrospective, observational study of prospectively collected data from an 800-bed tertiary teaching hospital (2005–2019).

Results

Of the 2203 patients with CAP and sepsis, 1347 (61%) did not have lymphopenia, while 856 (39%) did. When compared with the nonlymphopenic group, patients with sepsis and lymphopenia more frequently required ICU admission (P = .001), had a longer hospital length of stay (P ˂ .001), and presented with a higher rate of in-hospital (P ˂ .001) and 30-day mortality (P = .001). Multivariable analysis showed that C-reactive protein ≥15 mg/dL, lymphopenia, pleural effusion, and acute respiratory distress syndrome within 24 hours of admission were risk factors for ICU admission; age ≥80 years was independently associated with decreased ICU admission. In addition, age ≥80 years, chronic renal disease, chronic neurologic disease, being a nursing home resident, lymphopenia, and pleural effusion were independently associated with increased 30-day mortality, whereas pneumococcal vaccination, diabetes mellitus, and fever were independently associated with reduced 30-day mortality.

Conclusions

Lymphopenia was independently associated with risk of ICU admission and higher in-hospital and 30-day mortality in patients with CAP and sepsis. Early identification of lymphopenia could help identify septic patients with CAP who require or will shortly require critical care.

Endothelial activation and dysfunction in COVID-19: from basic mechanisms to potential therapeutic approaches

On 12 March 2020, the outbreak of coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization. As of 4 August 2020, more than 18 million confirmed infections had been reported globally. Most patients have mild symptoms, but some patients develop respiratory failure which is the leading cause of death among COVID-19 patients. Endothelial cells with high levels of angiotensin-converting enzyme 2 expression are major participants and regulators of inflammatory reactions and coagulation. Accumulating evidence suggests that endothelial activation and dysfunction participate in COVID-19 pathogenesis by altering the integrity of vessel barrier, promoting pro-coagulative state, inducing endothelial inflammation, and even mediating leukocyte infiltration. This review describes the proposed cellular and molecular mechanisms of endothelial activation and dysfunction during COVID-19 emphasizing the principal mediators and therapeutic implications.

Assessment of Endothelial Injury and Pro-Coagulant Activity Using Circulating Microvesicles in Survivors of Allogeneic Hematopoietic Cell Transplantation

(1) Background: survivors of allogeneic hematopoietic cell transplantation (alloHCT) suffer from morbidity and mortality due to cardiovascular events. We hypothesized that vascular injury and pro-coagulant activity are evident in alloHCT survivors without existing alloHCT complications or relapse. (2) Methods: we enrolled consecutive adult alloHCT survivors without established cardiovascular disease and control individuals matched for traditional cardiovascular risk factors (January-December 2019). Circulating microvesicles (MVs) of different cellular origins (platelet, erythrocyte, and endothelial) were measured by a standardized flow cytometry protocol as novel markers of vascular injury and pro-coagulant activity. (3) Results: we recruited 45 survivors after a median of 2.3 (range 1.1-13.2) years from alloHCT, and 45 controls. The majority of patients suffered from acute (44%) and/or chronic (66%) graft-versus-host disease (GVHD). Although the two groups were matched for traditional cardiovascular risk factors, alloHCT survivors showed significantly increased platelet and erythrocyte MVs compared to controls. Within alloHCT survivors, erythrocyte MVs were significantly increased in patients with a previous history of thrombotic microangiopathy. Interestingly, endothelial MVs were significantly increased only in alloHCT recipients of a myeloablative conditioning. Furthermore, MVs of different origins showed a positive association with each other. (4) Conclusions: endothelial dysfunction and increased thrombotic risk are evident in alloHCT recipients long after alloHCT, independently of traditional cardiovascular risk factors. An apparent synergism of these pathophysiological processes may be strongly involved in the subsequent establishment of cardiovascular disease.

Analysis of Peripheral Blood IL-6 and Leukocyte Characteristics in 364 COVID-19 Patients of Wuhan

SARS-CoV-2, the pathogen of COVID-19, is spreading around the world. Different individuals infected with COVID-19 have different manifestations. It is urgent to determine the risk factors of disease progress of COVID-19. 364 patients diagnosed with COVID-19, who were admitted to Wuhan Pulmonary Hospital from February 3, 2020 to March 16, 2020, were divided into mild, ordinary, severe, and critical groups, according to Chinese novel coronavirus pneumonia diagnosis and treatment plan. Peripheral blood IL-6 and leukocyte characteristics were analyzed, to evaluate the correlation with the severity of COVID-19. The levels of peripheral blood IL-6 were 2.35 ± 0.46 pg/ml (mild), 6.48 ± 1.13 pg/ml (ordinary), 20.30 ± 5.15 pg/ml (severe), and 123.48 ± 44.31 pg/ml (critical). The leukocytes were 5.70 ± 0.41×10⁹/L (mild), 6.21 ± 0.14×10⁹/L (ordinary), 6.37 ± 0.26×10⁹/L (severe), and 10.03 ± 1.43×10⁹/L (critical). The lymphocytes were 1.46 ± 0.19×10⁹/L (mild), 1.89 ± 0.14×10⁹/L (ordinary), 1.26 ± 0.07×10⁹/L (severe), and 1.17 ± 0.23×10⁹/L (critical). The neutrophils were 3.63 ± 0.36×10⁹/L (mild), 3.78 ± 0.11×10⁹/L (ordinary), 4.47 ± 0.25×10⁹/L (severe), and 7.92 ± 1.19×10⁹/L (critical). The monocytes were 0.42 ± 0.05×10⁹/L (mild), 0.44 ± 0.01×10⁹/L (ordinary), 0.46 ± 0.02×10⁹/L (severe), and 0.78 ± 0.25×10⁹/L (critical). Conclusively, increase of peripheral blood IL-6 and decrease of lymphocytes can be used as the indicators of severe COVID-19. The increase of neutrophils and monocytes was noticed in critical cases of COVID-19, suggesting that the increase of neutrophils and monocytes should be considered as risk factors of critical cases of COVID-19. Peripheral blood IL-6 and leukocyte characteristics were also analyzed in different age groups. The increase of serum IL-6, decrease of lymphocytes, and increase of neutrophils were noticed in patients over 60 years old.

COVID-19 and Microvascular Disease: Pathophysiology of SARS-CoV-2 Infection With Focus on the Renin-Angiotensin System

The recently described severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected millions of people, with thousands of fatalities. It has prompted global efforts in research, with focus on the pathophysiology of coronavirus disease-19 (COVID-19), and a rapid surge of publications. COVID-19 has been associated with a myriad of clinical manifestations, including the lungs, heart, kidneys, central nervous system, gastrointestinal system, skin, and blood coagulation abnormalities. The endothelium plays a key role in organ dysfunction associated with severe infection, and current data suggest that it is also involved in SARS-CoV-2-induced sepsis. This critical review aimed to address a possible unifying mechanism underlying the diverse complications of COVID-19: microvascular dysfunction, with emphasis on the renin-angiotensin system. In addition, research perspectives are suggested in order to expand understanding of the pathophysiology of the infection.

The Glycocalyx and Its Role in Vascular Physiology and Vascular Related Diseases

Purpose

In 2007 the two senior authors wrote a review on the structure and function of the endothelial glycocalyx layer (Weinbaum in Annu Rev Biomed Eng 9:121–167, 2007). Since then there has been an explosion of interest in this hydrated gel-like structure that coats the luminal surface of endothelial cells that line our vasculature due to its important functions in (A) basic vascular physiology and (B) vascular related diseases. This review will highlight the major advances that have occurred since our 2007 paper.

Methods

A literature search mainly focusing on the role of the glycocalyx in the two major areas described above was performed using electronic databases.

Results

In part (A) of this review, the new formulation of the century old Starling principle, now referred to as the Michel–Weinbaum glycoclayx model or revised Starling hypothesis, is described including new subtleties and physiological ramifications. New insights into mechanotransduction and release of nitric oxide due to fluid shear stress sensed by the glycocalyx are elaborated. Major advances in understanding the organization and function of glycocalyx components, and new techniques for measuring both its thickness and spatio-chemical organization based on super resolution, stochastic optical reconstruction microscopy (STORM) are presented. As discussed in part (B) of this review, it is now recognized that artery wall stiffness associated with hypertension and aging induces glycocalyx degradation, endothelial dysfunction and vascular disease. In addition to atherosclerosis and cardiovascular diseases, the glycocalyx plays an important role in lifestyle related diseases (e.g., diabetes) and cancer. Infectious diseases including sepsis, Dengue, Zika and Corona viruses, and malaria also involve the glycocalyx. Because of increasing recognition of the role of the glycocalyx in a wide range of diseases, there has been a vigorous search for methods to protect the glycocalyx from degradation or to enhance its synthesis in disease environments.

Conclusion

As we have seen in this review, many important developments in our basic understanding of GCX structure, function and role in diseases have been described since the 2007 paper. The future is wide open for continued GCX research.

The Immune System in Cushing's Syndrome

Cushing's syndrome (CS), or chronic hypercortisolism, induces a variety of alterations in the immune system, often leading to severe clinical complications such as sepsis and opportunistic infections. Prolonged exposure to high levels of glucocorticoids (GC), changes in the circadian rhythm, and the comorbidities associated therewith all combine to cause profound changes in the immune profile of affected patients. While traditionally associated with generalized immune suppression, such changes actually comprise a much more complex scenario, sharing traits with chronic inflammatory disorders. Persistently increased levels of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNFα) and adipose tissue infiltration by immune cells lead to a chronic, nonresolving, inflammatory state. The combination of low-grade inflammation and selectively impaired immune response is thought to play a major role in the pathogenesis of clinical complications of CS, including diabetes, lipodystrophy, visceral adiposity, atherosclerosis, osteoporosis, and cognitive impairment. This dysregulation also explains rebound phenomena when CS is treated, involving new clinical complications sustained by an excessive immune response and autoimmunity. The aim of this review is to summarize the available evidence on the immune system in chronic hypercortisolism, while describing the main mechanisms of immune derangement and their role in the increased mortality and morbidity seen in this complex disease. A better understanding of immune system alterations in CS could help improve risk stratification, offer novel biomarkers, and provide the basis for more tailored therapies and post-remission follow-up.