Risk Of Acute Lung Injury Research Articles

The protective effect of carbamazepine on acute lung injury induced by hemorrhagic shock and resuscitation in rats.

Hemorrhagic shock and resuscitation (HSR) enhances the risk of acute lung injury (ALI). This study investigated the protective effect of carbamazepine (CBZ) on HSR-induced ALI in rats. Male Sprague-Dawley rats were allocated into five distinct groups through randomization: control (SHAM), saline + HSR (HSR), CBZ + HSR (CBZ/HSR), dimethyl sulfoxide (DMSO) + HSR (DMSO/HSR), and CBZ + chloroquine (CQ) + HSR (CBZ/CQ/HSR). Subsequently, HSR models were established. To detect tissue damage, we measured lung histological changes, lung injury scores, and wet/dry weight ratios. We measured neutrophil counts as well as assessed the expression of inflammatory factors using RT-PCR to determine the inflammatory response. We detected autophagy-related proteins LC3II/LC3I, P62, Beclin-1, and Atg12-Atg5 using western blotting. Pretreatment with CBZ improved histopathological changes in the lungs and reduced lung injury scores. The CBZ pretreatment group exhibited significantly reduced lung wet/dry weight ratio, neutrophil aggregation and number, and inflammation factor (TNF-α and iNOS) expression. CBZ changed the expression levels of autophagy-related proteins (LC3II/LC3I, beclin-1, Atg12-Atg5, and P62), suggesting autophagy activation. However, after injecting CQ, an autophagy inhibitor, the beneficial effects of CBZ were reversed. Taken together, CBZ pretreatment improved HSR-induced ALI by suppressing inflammation, at least in part, through activating autophagy. Thus, our study offers a novel perspective for treating HSR-induced ALI.

Discovery of peroxynitrite elevation in zinc ion-induced acute lung injury with an activatable near-infrared fluorogenic probe

Particulate matter derived from environmental pollution might contain zinc ions (Zn2+), and inhaling these particles exacerbates lung tissue's inflammatory response, impairing lung function and increasing the risk of acute lung injury (ALI). Zn2+ is known to contribute to oxidative stress, leading to elevated levels of reactive oxygen species such as peroxynitrite (ONOO-), which play a key role in the pathogenesis of ALI. Herein, a novel near-infrared fluorogenic probe, DCI-BT, was prepared for the specific detection of ONOO- based on the strategy of oxidative hydrolysis of imine to break into aldehyde. The response of DCI-BT to ONOO- was found to be extremely fast, and the addition of ONOO- would enhance its fluorescence intensity. Cell experiments showed that DCI-BT could efficiently indicate the changes in cellular ONOO- levels. Furthermore, employing DCI-BT, the Zn2+-induced endogenous ONOO- production in cells was successfully visualized, confirming that prolonged exposure to Zn2+ triggered cellular oxidative stress. Finally, the application of DCI-BT in the mice model of ALI was evaluated, and the results revealed that it had good biosafety and could effectively track the changes in ONOO- levels in the Zn2+-induced ALI model. Therefore, DCI-BT held promise as a valuable chemical tool for diagnosing and treating environmentally induced oxidative stress-related diseases.

Inflammatory signature-based theranostics for acute lung injury in acute type A aortic dissection.

Acute lung injury (ALI) is a serious adverse event in the management of acute type A aortic dissection (ATAAD). Using a large-scale cohort, we applied artificial intelligence-driven approach to stratify patients with different outcomes and treatment responses. A total of 2,499 patients from China 5A study database (2016-2022) from 10 cardiovascular centers were divided into 70% for derivation cohort and 30% for validation cohort, in which extreme gradient boosting algorithm was used to develop ALI risk model. Logistic regression was used to assess the risk under anti-inflammatory strategies in different risk probability. Eight top features of importance (leukocyte, platelet, hemoglobin, base excess, age, creatinine, glucose, and left ventricular end-diastolic dimension) were used to develop and validate an ALI risk model, with adequate discrimination ability regarding area under the receiver operating characteristic curve of 0.844 and 0.799 in the derivation and validation cohort, respectively. By the individualized treatment effect prediction, ulinastatin use was significantly associated with significantly lower risk of developing ALI (odds ratio [OR] 0.623 [95% CI 0.456, 0.851]; P = 0.003) in patients with a predicted ALI risk of 32.5-73.0%, rather than in pooled patients with a risk of <32.5 and >73.0% (OR 0.929 [0.682, 1.267], P = 0.642) (Pinteraction = 0.075). An artificial intelligence-driven risk stratification of ALI following ATAAD surgery were developed and validated, and subgroup analysis showed the heterogeneity of anti-inflammatory pharmacotherapy, which suggested individualized anti-inflammatory strategies in different risk probability of ALI.

Impact of interleukin 6 levels on acute lung injury risk and disease severity in critically ill sepsis patients.

Sepsis is a life-threatening condition characterized by a dysregulation of the host response to infection that can lead to acute lung injury (ALI) and multiple organ dysfunction syndrome (MODS). Interleukin 6 (IL-6) is a pro-inflammatory cytokine that plays a crucial role in the pathogenesis of sepsis and its complications. To investigate the relationship among plasma IL-6 levels, risk of ALI, and disease severity in critically ill patients with sepsis. This prospective and observational study was conducted in the intensive care unit of a tertiary care hospital between January 2021 and December 2022. A total of 83 septic patients were enrolled. Plasma IL-6 levels were measured upon admission using an enzyme-linked immunosorbent assay. The development of ALI and MODS was monitored during hospitalization. Disease severity was evaluated by Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores. Among the 83 patients with sepsis, 38 (45.8%) developed ALI and 29 (34.9%) developed MODS. Plasma IL-6 levels were significantly higher in patients who developed ALI than in those without ALI (median: 125.6 pg/mL vs 48.3 pg/mL; P < 0.001). Similarly, patients with MODS had higher IL-6 levels than those without MODS (median: 142.9 pg/mL vs 58.7 pg/mL; P < 0.001). Plasma IL-6 levels were strongly and positively correlated with APACHE II (r = 0.72; P < 0.001) and SOFA scores (r = 0.68; P < 0.001). Elevated plasma IL-6 levels in critically ill patients with sepsis were associated with an increased risk of ALI and MODS. Higher IL-6 levels were correlated with greater disease severity, as reflected by higher APACHE II and SOFA scores. These findings suggest that IL-6 may serve as a biomarker for predicting the development of ALI and disease severity in patients with sepsis.

Timing of intubation of pediatric hematopoietic cell transplant patients: an international survey.

Retrospective data suggest that pediatric hematopoietic cell transplant (HCT) patients placed on non-invasive ventilation (NIV) prior to intubation have increased risk of mortality compared to patients who are intubated earlier in their course. The HCT-CI subgroup of the PALISI Network set out to gain a better understanding of factors that influence clinician's decisions surrounding timing of intubation of pediatric HCT patients. We validated and distributed a brief survey exploring potential factors that may influence clinician's decisions around timing of intubation of pediatric HCT patients with acute lung injury (ALI). One hundred and four of the 869 PALISI Network's members responded to the survey; 97 of these respondents acknowledged caring for HCT patients and were offered the remainder of the survey. The majority of respondents were PICU physicians (96%), with a small number of Advanced Practice Providers and HCT physicians. As expected, poor prognosis categories were perceived as a factors that delay timing to intubation whereas need for invasive procedures was perceived as a factor shortening timing to intubation. Concerns for oxygen toxicity or NIV-associated lung injury were not believed to influence timing of intubation. Our survey indicates increased risk of ALI from prolonged NIV and oxygen toxicity in HCT patients are not a concern for most clinicians. Further education of pediatric ICU clinicians around these risk factors could lead to improvement in outcomes and demands further study. Additionally, clinicians identified concerns for the patient's poor prognosis as a common reason for delayed intubation.

Integrating UPLC-Q-Orbitrap MS with serum pharmacochemistry network and experimental verification to explore the pharmacological mechanisms of Cynanchi stauntonii rhizoma et radix against sepsis-induced acute lung injury.

Introduction: Patients with sepsis are at an incremental risk of acute lung injury (ALI). Baiqian, also known as Cynanchi stauntonii rhizoma et radix (Csrer), has anti-inflammatory properties and is traditionally used to treat cough and phlegm. This study aimed to demonstrate the multicomponent, multitarget, and multi-pathway regulatory molecular mechanisms of Csrer in treating lipopolysaccharide (LPS)-induced ALI. Methods: The bioactive components of Csrer were identified by ultrahigh-performance liquid chromatography Q-Orbitrap mass spectrometry (UPLC-Q-Orbitrap MS). Active targets predicted from PharmMapper. DrugBank, OMIM, TTD, and GeneCards were used to identify potential targets related to ALI. Intersection genes were identified for Csrer against ALI. The PPI network was analysed to identify prime targets. GO and KEGG analyses were performed. A drug-compound-target-pathway-disease network was constructed. Molecular docking and simulations evaluated the binding free energy between key proteins and active compounds. The protective effect and mechanism of Csrer in ALI were verified using an ALI model in mice. Western blot, Immunohistochemistry and TUNEL staining evaluated the mechanisms of the pulmonary protective effects of Csrer. Results: Forty-six bioactive components, one hundred and ninety-two potential cross-targets against ALI and ten core genes were identified. According to GO and KEGG analyses, the PI3K-Akt, apoptosis and p53 pathways are predominantly involved in the "Csrer-ALI" network. According to molecular docking and dynamics simulations, ten key genes were firmly bound by the principal active components of Csrer. The "Csrer-ALI" network was revealed to be mediated by the p53-mediated apoptosis and inflammatory pathways in animal experiments. Conclusion: Csrer is a reliable source for ALI treatment based on its practical components, potential targets and pathways.

Effects of tidal volume on physiology and clinical outcomes in patients with one‑lung ventilation undergoing surgery: A meta‑analysis of randomized controlled trials.

There is no detailed study on how tidal volume (VT) affects patients during one-lung ventilation (OLV). The present study conducted a meta-analysis to assess the effect of VT on physiology and clinical outcomes in OLV patients. Databases until February 2023 were retrieved from PubMed, Cochrane Library and Web of Science. Randomized controlled trials comparing the application of low and high VT ventilation in adults with OLV were performed. Demographic variables, VT, physiology, and clinical outcomes were retrieved. The random-effects model calculated the summary of odds ratios with 95% confidence intervals (CI) and mean difference with standard deviation. A total of 12 studies involving a total of 876 participants met the inclusion criteria. Low VT ventilation was associated with decreased risk of acute lung injury [relative risk 0.50, 95% CI (0.28, 0.88), P=0.02]. Low VT ventilation decreased the driving pressure (ΔP) and peak pressure (Ppeak) and improved arterial oxygen pressure (PaO2)/fraction of inspired oxygen (FiO2). Furthermore, the present study suggested that a significant difference in blood IL-6 was observed between low and high VT ventilation [mean difference, -35.51 pg/ml, 95% CI (-66.47, -4.54 pg/ml), P=0.02]. A decrease in the length of stay at the hospital occurred in the low VT group when set to 4-5 ml/kg. In the OLV patients, low VT ventilation decreased the risk of acute lung injury, blood IL-6, ΔP and Ppeak, and improved PaO2/FiO2. Furthermore, when low VT was set to 4-5 ml/kg, the length of stay at the hospital decreased.

Sivelestat in Patients at a High Risk of Postoperative Acute Lung Injury After Scheduled Cardiac Surgery: A Prospective Cohort Study.

Sivelestat, a neutrophil elastase inhibitor, is specifically developed to mitigate the occurrence of acute lung injury (ALI) in individuals who are undergoing cardiovascular surgery. However, its impact on patients who are at a heightened risk of developing ALI after scheduled cardiac surgery has yet to be determined. In order to address this knowledge gap, we undertook a study to assess the efficacy of sivelestat in protecting the lungs of these patients. We conducted a prospective cohort study involving 718 patients who were at high risk of developing postoperative acute lung injury (ALI) and underwent scheduled cardiac surgery between April 25th, 2022, and September 7th, 2023. Among them, 52 patients received sivelestat (administered at a dosage of 0.2mg/kg/h for 3 days), while 666 patients served as controls, not receiving sivelestat. The control conditions were the same for all patients, including ventilation strategy, extubating time, and fluid management. Subsequently, a propensity-score matched cohort was established, consisting of 40 patients in both the sivelestat and control groups. The primary outcome measure encompassed a composite of adverse outcomes, including 30-day mortality, ALI, acute respiratory distress syndrome (ARDS), and others. Secondary outcomes assessed included pneumonia, ventricular arrhythmias, mechanical ventilation (MV) time, and more. After conducting propensity matching in our study, we observed that there were no significant differences in 30-day mortality between the sivelestat and control groups (0% vs 2.5%, P=0.32). However, the use of sivelestat exhibited a significant reduction in the incidence of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) compared to the control group (0% vs 55%, P<0.01), pneumonia (0 vs 37.5%, P<0.01), MV time (median:8 hours, IQR:4-14.8 hours vs median: 15.2 hours, IQR:14-16.3 hours, P<0.01). Compared to the control group, the sivelestat could significantly decrease white cell count (P<0.01), neutrophile percentage (P<0.01) and C-reactive protein (P<0.01) in the period of postoperative 5 days. The prophylactic administration of sivelestat has shown promising results in reducing the occurrence of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) in patients with a heightened risk of developing these conditions after elective cardiac surgery. Our study findings indicate that sivelestat may provide protective effects by suppressing inflammation triggered by neutrophil activation, thereby safeguarding pulmonary function. ChiCTR2200059102, https://www.chictr.org.cn/showproj.html?proj=166643.

Perioperative Factors and Radiographic Severity Scores for Predicting the Duration of Mechanical Ventilation After Arterial Switch Surgery

ObjectivesCardiac surgery on cardiopulmonary bypass (CPB) during the neonatal period can cause perioperative organ injuries. The primary aim of this study was to determine the incidence and risk factors associated with postoperative mechanical ventilation duration and acute lung injury following arterial switch operation (ASO). The secondary aim was to examine the utility of the Brixia score for characterizing postoperative acute lung injury (ALI).Design: A retrospective study. SettingA single-center university hospital. ParticipantsA total of 93 neonates with transposition of great arteries with intact ventricular septum (dTGA/IVS) underwent ASO. InterventionsNone Measurements and Main ResultsFrom January 2015 to December 2022, 93 neonates with dTGA/IVS were included in the study. The cohort had a median age of 4.0 (3.0-5.0) days and a mean weight of 3.3 ± 0.5 kg. About 63% of patients had ≥ 48 hours postoperative mechanical ventilation after ASO. Risk factors included prematurity, post-CPB transfusion of salvaged red cells, platelets and cryoprecipitate, and postoperative fluid balance by univariate analysis. The larger transfused platelet volume was associated with the risk of ALI by multivariate analysis. The median baseline Brixia scores were 11.0 (9.0-12.0) and increased significantly in the postoperative day 1 in patients who developed moderate ALI 24 hours after admission to the intensive care unit (15.0 (13.0-16.0) vs. 12.0 (10.0-14.0), p = 0.046). ConclusionsArterial switch operation results in a high incidence of ≥ 48-hour postoperative mechanical ventilation. Blood component transfusion is a potentially modifiable risk factor. The Brixia scores may also be used to characterize postoperative acute lung injury.

ICAM-1 targeted and ROS-responsive nanoparticles for the treatment of acute lung injury.

Acute lung injury (ALI) is an inflammatory disease caused by multiple factors such as infection, trauma, and chemicals. Without effective intervention during the early stages, it usually quickly progresses to acute respiratory distress syndrome (ARDS). Since ordinary pharmaceutical preparations cannot precisely target the lungs, their clinical application is limited. In response, we constructed a γ3 peptide-decorated and ROS-responsive nanoparticle system encapsulating therapeutic dexamethasone (Dex/PSB-γ3 NPs). In vitro, Dex/PSB-γ3 NPs had rapid H2O2 responsiveness, low cytotoxicity, and strong intracellular ROS removal capacity. In a mouse model of ALI, Dex/PSB-γ3 NPs accumulated at the injured lung rapidly, alleviating pulmonary edema and cytokine levels significantly. The modification of NPs by γ3 peptide achieved highly specific positioning of NPs in the inflammatory area. The ROS-responsive release mechanism ensured the rapid release of therapeutic dexamethasone at the inflammatory site. This combined approach improves treatment accuracy, and drug bioavailability, and effectively inhibits inflammation progression. Our study could effectively reduce the risk of ALI progressing to ARDS and hold potential for the early treatment of ALI.

The Effect of Galantamine on Lipopolysaccharide-induced Acute Lung Injury During Neutropenia Recovery in Mice.

Acute lung injury (ALI) is associated with a high mortality rate and cancer patients who receive chemotherapy are at high risk of ALI during neutropenia recovery. Galantamine is a cholinesterase inhibitor used for Alzheimer's disease treatment. Previous studies have shown that galantamine reduced inflammatory response in lipopolysaccharide (LPS)-induced ALI in rats. Mer protein was negatively associated with inflammatory response. The aim of the study was to investigate whether galantamine is effective in LPS-induced ALI during neutropenia recovery and its effect on Mer tyrosine kinase (MerTK) expression in mice. Intraperitoneal cyclophosphamide was given to mice to induce neutropenia. After 7 days, LPS was administered by intratracheal instillation. Intraperitoneal galantamine was given once before LPS administration and in another group, galantamine was given twice before LPS administration. Galantamine attenuated LPS-induced ALI in histopathological analysis. The neutrophil percentage was lower in the group where galantamine was injected once, compared to the LPS group (p=0.007). MerTK expression was also higher in the group where galantamine was injected once but did not reach statistical significance (p=0.101). Galantamine attenuated inflammation in LPS-induced ALI during neutropenia recovery.

Macrophage-derived exosomal TNF-α promotes pulmonary surfactant protein expression in PM2.5-induced acute lung injury

Short-term high-concentration exposure to airborne fine particulate matter (PM2.5) is strongly associated with the risk of acute lung injury (ALI). It has been recently reported that exosomes (Exos) involve in the progression of respiratory diseases. However, the molecular mechanisms by which exosome-mediated intercellular signaling exacerbate PM2.5-induced ALI remains largely unaddressed. In the present study, we firstly investigated the effect of macrophage-derived exosomal tumor necrosis factor α (TNF-α) on pulmonary surfactant proteins (SPs) expression in epithelial MLE-12 cells after PM2.5 exposure. The higher levels of exosomes in the bronchoalveolar lavage fluid (BALF) of PM2.5-induced ALI mice were found. BALF-exosomes significantly up-regulated SPs expression in MLE-12 cells. Moreover, we found that remarkably high expression of TNF-α in exosomes secreted by PM2.5-treated RAW264.7 cells. Exosomal TNF-α promoted thyroid transcription factor-1 (TTF-1) activation and SPs expression in MLE-12 cells. Furthermore, intratracheal instillation of macrophage-derived TNF-α-containing exosomes increased epithelial cell SPs expression in the lungs of mice. Taken together, these results suggest that macrophages-secreted exosomal TNF-α can trigger epithelial cell SPs expression, which provides new insight and potential target in the mechanism of epithelial cell dysfunction in PM2.5-induced ALI.

WNT9A Affects Late-Onset Acute Respiratory Distress Syndrome and 28-Day Survival: Evidence from a Three-Step Multiomics Study.

Late-onset (more than 48 h after ICU admission) acute respiratory distress syndrome (ARDS) is associated with shorter survival time and higher mortality; however, the underlying molecular targets remain unclear. As the WNT gene family is known to drive inflammation, immunity, and tissue fibrosis, all of which are closely related to the pathogenesis and prognosis of ARDS, we aim to investigate the associations of the WNT family with late-onset ARDS and 28-day survival. Genetic (n = 380), epigenetic (n = 185), transcriptional (n = 160), and protein (n = 300) data of patients with ARDS were extracted from the MEARDS (Molecular Epidemiology of ARDS) cohort. We used sure independence screening to identify late onset-related genetic biomarkers and constructed a genetic score on the basis of eight SNPs, which was associated with risk for late-onset ARDS (odds ratio [OR], 2.72; P = 3.81 × 10-14) and survival (hazard ratio [HR], 1.28; P = 0.008). The associations were further externally validated in the iSPAAR (Identification of SNPs Predisposing to Altered Acute Lung Injury Risk) (ORlate onset, 2.49 [P = 0.006]; HRsurvival, 1.87 [P = 0.045]) and MESSI (Molecular Epidemiology of Severe Sepsis in the ICU) (ORlate onset, 4.12 [P = 0.026]; HRsurvival, 1.45 [P = 0.036]) cohorts. Furthermore, we functionally interrogated the six mapped genes of eight SNPs in the multiomics data and noted associations of WNT9A (WNT family member 9A) in epigenetic (ORlate onset, 2.95 [P = 9.91 × 10-4]; HRsurvival, 1.53 [P = 0.011]) and protein (ORlate onset, 1.42 [P = 0.035]; HRsurvival, 1.38 [P = 0.011]) data. The mediation analysis indicated that the effects of WNT9A on ARDS survival were mediated by late onset (HRindirect, 1.12 [P = 0.014] for genetic data; HRindirect, 1.05 [P = 0.030] for protein data). The essential roles of WNT9A in immunity and fibrosis may explain the different trajectories of recovery and dysfunction between early- and late-onset ARDS, providing clues for ARDS treatment.

Oxygen administration during surgery and postoperative organ injury: observational cohort study

ObjectiveTo examine whether supraphysiological oxygen administration during surgery is associated with lower or higher postoperative kidney, heart, and lung injury.DesignObservational cohort study.Setting42 medical centers across the United States participating in...

Pre-emptive intraoperative administration of PCC4 in cardiac surgery patients at high risk of bleeding: Apilot study.

Four-factor prothrombin complex (PCC4), a concentrate of factors II, VII, IX, and X and proteins C and S, has been used selectively for reversal of oral anticoagulation before surgery. There is data to support PCC4 as opposed to supplemental fresh frozen plasma (FFP) to manage postoperative bleeding following cardiac surgery. The preemptive, intraoperative use of PCC4 in cardiothoracic surgery has not been studied though it may prevent postoperative bleeding, the need for blood transfusion and the risk of transfusion-related acute lung injury, volume overload, and right ventricular (RV) heart failure. The purpose of this study is to evaluate the intraoperative administration of PCC4 to decrease bleeding and lower the rate of blood transfusion. A single institution retrospective chart review was conducted from May 2020 to November 2021 of patients who received PCC4 intraoperatively during cardiothoracic surgery of high-risk variety. Patients were evaluated for the type of surgery, demographics, baseline anticoagulation, PCC4 dose, type and quantity of blood transfusion within 72 hours (h) postoperatively, chest tube output, the incidence of RV failure, hypersensitivity reactions, acute kidney injury (AKI), thrombosis, acute lung injury, and mortality within 45 days of the operative dose of PCC4. Thirty-five patients received PCC4 at a mean dose of 2920 units (U). Sixty-fivepercent of cases were left ventricular assist devices(LVADs) or heart transplants. The protocol is to use PCC4 30 units (U)/kg immediately after the completion of protamine administration. Inclusion criteria are cardiothoracic surgery with increased risk of postoperative right heart failure commonly secondary to blood product transfusion, or cardiothoracic surgery associated with increased risk of bleeding, including heart transplant, LVAD implant, aortic dissection, and redo sternotomy (e.g., coronary artery bypass). Total chest tube output was recorded as a mean of 757 ml for 24 h after surgery (32 ml/h). Overall median event rates of FFPand red blood cell (RBC) transfusions were 0 (interquartile range [IQR]: 0-3 U) and 4 (IQR: 2-5 U). Overall, 43%and 89%of cases received FFP and RBC, respectively. There was one occurrence of RV failure, one occurrence of AKI requiring renal replacement therapy, one occurrence of venoarterial extracorporeal membrane oxygenation, one occurrence of venous thromboembolism related to a central venous access line, and one death unrelated to surgery or PCC4 that was attributed to advanced heart failure not amenable to advanced therapies. Overall patients received a low rate of blood transfusion, had minimal chest tube output, and there was a small incidence of right heart failure. Patients did not have an increased risk of adverse effects such as AKI or venous thromboembolism. A randomized controlled clinical trial comparing the observed dose and timing of PCC4 versus routine postoperative bleeding management with blood product transfusion is recommended.

Mechanisms of pulmonary endothelial permeability and inflammation caused by extracellular histone subunits H3 and H4.

Extracellular DNA-binding proteins such as histones are danger-associated molecular pattern released by the injured tissues in trauma and sepsis settings, which trigger host immune response and vascular dysfunction. Molecular events leading to histone-induced endothelial cell (EC) dysfunction remain poorly understood. This study performed comparative analysis of H1, H2A, H2B, H3, and H4 histone subunits effects on human pulmonary EC permeability and inflammatory response. Analysis of transendothelial electrical resistance and EC monolayer permeability for macromolecues revealed that H3 and H4, but not H1, H2A, or H2B caused dose-dependent EC permeability accompanied by disassembly of adherens junctions. At higher doses, H3 and H4 activated nuclear factor kappa B inflammatory cascade leading to upregulation EC adhesion molecules ICAM1, VCAM1, E-selectin, and release of inflammatory cytokines. Inhibitory receptor analysis showed that toll-like receptor (TLR) 4 but not TLR1/2 or receptor for advanced glycation end inhibition significantly attenuated deleterious effects of H3 and H4 histones. Inhibitor of Rho-kinase was without effect, while inhibition of Src kinase caused partial preservation of cell-cell junctions, H3/H4-induced permeability and inflammation. Deleterious effects of H3/H4 were blocked by heparin. Activation of Epac-Rap1 signaling restored EC barrier properties after histone challenge. Intravenous injection of histones in mice caused elevation of inflammatory markers and increased vascular leak. Post-treatment with pharmacological Epac/Rap1 activator suppressed injurious effects of histones in vitro and in vivo. These results identify H3 and H4 as key histone subunits exhibiting deleterious effects on pulmonary vascular endothelium via TLR4-dependent mechanism. In conclusion, elevation of circulating histones may represent a serious risk of exacerbated acute lung injury (ALI) and multiple organ injury during severe trauma and infection.

Prediction model for postoperative severe acute lung injury in patients undergoing acute type A aortic dissection surgery.

This study aimed to establish a risk assessment model to predict postoperative severe acute lung injury (ALI) risk in patients with acute type A aortic dissection (ATAAD). Consecutive patients with ATAAD admitted to our hospital were included in this retrospective assessment and placed in the postoperative severe ALI and nonsevere ALI groups based on the presence or absence of ALI within 72 h postoperatively (oxygen index [OI] ≤ 100 mmHg). Patients were then randomly divided into training and validation groups in a ratio of 8:2. Univariate and multivariate stepwise forward logistic regression analyses were used to statistically assess data and establish the prediction model. The prediction model's effectiveness was evaluated via 10-fold cross-validation of the validation group to facilitate the construction of a nomogram. After the screening, 479 patients were included in the study: 132 (27.6%) in the postoperative severe ALI group and 347 (72.4%) in the postoperative nonsevere ALI group. Based on multivariate logistics regression analyses, the following variables were included in the model: coronary heart disease, cardiopulmonary bypass (CPB) ≥ 257.5 min, left atrium diameter ≥ 35.5 mm, hemoglobin ≤ 139.5 g/L, preCPB OI ≤ 100 mmHg, intensive care unit OI ≤ 100 mmHg, left ventricular posterior wall thickness ≥ 10.5 mm, and neutrophilic granulocyte percentage ≥ 0.824. The area under the receiver operating characteristic (ROC) curve of the modeling group was 0.805 and differences between observed and predicted values were not deemed statistically significant via the Hosmer-Lemeshow test (χ2 = 6.037, df = 8, p = .643). For the validation group, the area under the ROC curve was 0.778, and observed and predicted value differences were insignificant when assessed using the Hosmer-Lemeshow test (χ2 = 3.3782, df = 7; p = .848). The average 10-fold cross-validation score was 0.756. This study established a prediction model and developed a nomogram to determine the risk of postoperative severe ALI after ATAAD. Variables used in the model were easy to obtain clinically and the effectiveness of the model was good.

COVID-19 and L-arginine Supplementations: Yet to Find the Missed Key.

Current coronavirus disease (COVID-19) is regarded as a primary respiratory and vascular disease leading to acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and endothelial dysfunction (ED) in severe cases. The causative virus of COVID-19 is SARS-CoV-2, which binds angiotensin-converting enzyme 2 (ACE2) for its entry. It has been shown that ED is linked to various COVID-19 complications since endothelial cells are regarded as the chief barrier against SARS-CoV- 2 invasion. SARS-CoV-2-indued ED leads to endotheliitis and thrombosis due to endothelial nitric oxide (NO) inhibition with subsequent vasoconstriction and tissue hypoxia. Loss of vasodilator NO and anti-thrombin factor from endothelial SARS-CoV-2 infection contribute to the progression of vascular dysfunction and coagulopathy. Therefore, NO restoration improves pulmonary function and hinders viral replication during respiratory viral infections, including COVID-19. L-arginine is a semiessential amino acid that has antiviral and immunomodulatory effects as well as improves the biosynthesis of NO in endothelial cells. L-arginine may reduce the risk of ALI through inhibition of generation of peroxynitrite and suppression of the release of proinflammatory cytokines from alveolar macrophages. Of interest, restoration of NO by L-arginine may attenuate SARS-CoV-2 infection through different mechanisms, including reduction binding of SARS-CoV-2 to ACE2, inhibition of transmembrane protease serine-type 2 (TMPRSS2), critical for the activation of SARS-CoV-2 spike protein and cellular entry, inhibition proliferation and replication of SARS-CoV-2, and prevention of SARS-CoV-2-induced coagulopathy. In conclusion, through antiviral and immunomodulatory effects, L-arginine and released NO have mutual and interrelated actions against SARS-CoV-2 infection.

Integrin Beta 4E Promotes Endothelial Phenotypic Changes and Attenuates Lung Endothelial Cell Inflammatory Responses.

We previously reported integrin beta 4 (ITGB4) is an important mediator of lung vascular protection by simvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A-reductase inhibitor. In this study, we report increased endothelial cell (EC) expression specifically of ITGB4E, an ITGB4 mRNA splice variant, by simvastatin with effects on EC protein expression and inflammatory responses. In initial experiments, human pulmonary artery ECs were treated using simvastatin (5 μM, 24 h) prior to immunoprecipitation of integrin alpha 6 (ITGA6), which associates with ITGB4, and Western blotting for full-length ITGB4 and ITGB4E, uniquely characterized by a truncated 114 amino acid cytoplasmic domain. These experiments confirmed a significant increase in both full-length ITGB4 and ITGB4E. To investigate the effects of increased ITGB4E expression alone, ECs were transfected with ITGB4E or control vector, and cells were seeded in wells containing Matrigel to assess effects on angiogenesis or used for scratch assay to assess migration. Decreased angiogenesis and migration were observed in ITGB4E transfected ECs compared with controls. In separate experiments, PCR and Western blots from transfected cells demonstrated significant changes in EC protein expression associated with increased ITGB4E, including marked decreases in platelet endothelial cell adhesion molecule-1 (PECAM-1) and vascular endothelial-cadherin (VE-cadherin) as well as increased expression of E-cadherin and N-cadherin along with increased expression of the Slug and Snail transcription factors that promote endothelial-to-mesenchymal transition (EndMT). We, then, investigated the functional effects of ITGB4E overexpression on EC inflammatory responses and observed a significant attenuation of lipopolysaccharide (LPS)-induced mitogen-activated protein kinase (MAPK) activation, including decreased phosphorylation of both extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), as well as reduced inflammatory cytokines (IL-6 and IL-8), expressed in the media of EC after either LPS or excessive cyclic stretch (CS). Finally, EC expression-increased ITGB4E demonstrated decreased barrier disruption induced by thrombin as measured by transendothelial electrical resistance. Our data support distinct EC phenotypic changes induced by ITGB4E that are also associated with an attenuation of cellular inflammatory responses. These findings implicate ITGB4E upregulation as an important mediator of lung EC protection by statins and may lead to novel therapeutic strategies for patients with or at risk for acute lung injury (ALI).

MAP2K2 Delays Recovery in Murine Models of Acute Lung Injury and Associates with Acute Respiratory Distress Syndrome Outcome.

Acute respiratory distress syndrome (ARDS) remains a significant problem in need of new pharmaceutical approaches to improve its resolution. Studies comparing gene expression signatures in rodents and humans with lung injury reveal conserved pathways, including MAPK (mitogen-activated protein kinase)/ERK (extracellular signal-related protein kinase) activation. In preclinical acute lung injury (ALI) models, inhibition of MAP2K1 (MAPK kinase 1)/MAP2K2 (MAPK kinase 2) improves measures of ALI. Myeloid cell deletion of MAP2K1 results in sustained MAP2K2 activation and nonresolving ALI, suggesting that MAP2K2 deactivation may be a key driver of ALI resolution. We used human genomic data from the iSPAAR (Identification of SNPs Predisposing to Altered Acute Lung Injury Risk) Consortium to assess genetic variants in MAP2K1 and MAP2K2 for association with mortality from ARDS. To determine the role of MAP2K2 in ALI recovery, we studied mice deficient in Map2k2 (Mek2-/-) and wild-type control mice in ALI models. We identified a MAP2K2 variant that was associated with death in ARDS and MAP2K2 expression. In Pseudomonas aeruginosa ALI, Mek2-/- mice had similar early alveolar neutrophilic recruitment but faster resolution of alveolar neutrophilia and vascular leak. Gene expression analysis revealed a role for MAP2K2 in promoting and sustaining select proinflammatory pathway activation in ALI. Bone marrow chimera studies indicate that leukocyte MAP2K2 is the key regulator of ALI duration. These studies implicate a role for MAP2K2 in ALI duration via transcriptional regulation of inflammatory programming with potential relevance to ARDS. Targeting leukocyte MAP2K2 may be an effective strategy to promote ALI resolution.