The acute respiratory distress syndrome: pathogenesis and treatment

Evaluation of hypoxia pathway genes and serum parameters in new coronavirus pneumonia (COVID-19)

BACKGROUND

Coronavirus disease-2019 (COVID-19) causes severe hypoxemia. Unlike normal pneumonia, pneumonia due to COVID-19 causes oxygen deprivation without breathing difficulties (i.e., silent hypoxia). We evaluated the relationship between COVID-19 and hypoxemia and examined possible mechanisms of pneumonia from the perspective of gene expression (HIF1A, vascular endothelial growth factor [VEGF], NF-kB, MEKK1, and EGFR) using real-time PCR and ELISA for serum parameters.

METHODS

We evaluated 100 individuals (50 patients and 50 controls). The patients were individuals with respiratory symptoms and pneumonia who were COVİD-19 positive. The relative quantification of standardized samples wa s calculated according to the formula 2 -ΔΔCT. Receiver operating curve (ROC) analysis was made to define the diagnostic power of the genes. The expression changes of four genes in the hypoxia pathway were significant (excluding VEGF) and upregulated in the patients' serums.

RESULTS

The fold change values of the HIF1A, VEGF, NF-kB, MEKK1, and EGFR genes were 0.048, 0.688, 0.168, 0.207, and 0.171, respectively, in the cases checked against to the controls. The areas under the ROC values indicating the diagnostic power of the genes were 0.727, 0.538, 0.815, 0.734, and 0.936, respectively. Some serum parameters were significant (age, PCR, urea, LDH, WBC, ferritin, and pO2).

CONCLUSIONS

The upregulation of some genes in the hypoxia pathway in COVID-19 pneumonia shows that these genes and protein products are candidates for treatment targets. At the same time, the high discriminative power of two genes (NF-κB and EGFR) in patients compared to controls indicates their diagnostic potential in serum samples.

Postoperative Complications in Lung Cancer

Most of the complications can occur after lung resection for lung cancer. Most of complications occur in the early postoperative period but delayed complications are also recognized. Respiratory and cardiovascular complications predominate after lung surgery. Nonspecific clinical manifestations can make these complications challenging to diagnose. Imaging plays a vital role in recognizing and treating these complications in a timely manner. Hence, it is important to understand the expected anatomic alterations following lung cancer resection, and the spectrum of postsurgical complications and their respective imaging manifestations to avoid misinterpretations or delay in diagnosis.

A genetic variant associated with aquaporin 3 expression is correlated to in-hospital death in COVID-19 patients with extracellular hyperosmolality

Hyperosmolality is increasingly recognized as a factor contributing to severe COVID-19. Recently, a genetic variant near the aquaporin 3 (AQP3) water channel was associated with severe COVID-19 [rs60840586:G; odds ratio (OR): 1.07, P = 2.5 × 10-9]. The variant is known to increase gene expression of AQP3 in several organs, including the lung [normalized expression scores (NES) = 0.33, P = 4.1 × 10-20] in GTEx. In this study, we investigated 576 patients in the Biobanque Quebecoise de la COVID-19 (BQC-19) with both genetic and clinical data available. We estimated plasma osmolality using the formula: eOSM = 2 × [Na+] + 2 × [K+] + [Urea] + [Glucose]. Using a logistic regression of mortality against eOSM, genotype at rs60840586, sex, age, and the first 10 genetic principal components, we confirm that hyperosmolality is associated with COVID-19 mortality (OR = 2.06 [95% CI = 1.62-2.65], P = 9.13 × 10-9). Interestingly, we found that the risk of death linked to hyperosmolality is influenced by the AQP3 variant rs60840586:G genotype (OR = 1.95 [95% CI = 1.22-3.28], P = 0.0075). However, the rs60840586 genotype did not independently affect mortality in this cohort. These findings suggest that the body's ability to regulate and accommodate hyperosmolality may be disrupted by overexpression of AQP3, potentially worsening outcomes in COVID-19. Given the role of AQP3 in water transport and homeostasis, further defining the functionality of its variants may provide key insights into COVID-19 severity and guide clinical management strategies, particularly in critically ill patients with hyperosmolality.NEW & NOTEWORTHY A genetic variant near water channel AQP3, linked to severe COVID-19, amplifies the risk of death in patients with elevated plasma osmolality. In patients hospitalized with COVID-19, we show that although the variant does not affect systemic osmolality directly, it interacts with hyperosmolality to increase mortality risk. These findings highlight a potential mechanism where AQP3 overexpression disrupts cellular water handling during critical illness, offering new insight into the role of water balance in COVID-19 pathophysiology.

Chlorogenic acid targets SLC37A2 to inhibit macrophage activation via ER-dependent NF-κB and NLRP3 signaling pathways against sepsis-induced acute lung injury

Sepsis-induced acute lung injury (SI-ALI) requires urgent treatment due to severe inflammation. Our study found chlorogenic acid (CGA) suppressed LPS-induced macrophage activation by lowering NO, TNF-α, and IL-6. TPP-based strategies identified SLC37A2 as the direct target of CGA, validated by CETSA/MST. Molecular docking indicated CGA-SLC37A2 hydrogen bonding. CGA alleviated endoplasmic reticulum stress via SLC37A2, inhibiting TLR4/NF-κB and NLRP3 pathways to reduce inflammation. In SI-ALI mice and zebrafish models, CGA mitigated lung injury through these mechanisms taken together. This work highlights the therapeutic potential of CGA for SI-ALI and the critical role of SLC37A2 in combating infectious pneumonia.

Predictive Modeling of ARDS Mortality Integrating Biomarker/Cytokine, Clinical and Metabolomic Data

Acute Respiratory Distress Syndrome (ARDS), characterized by the rapid onset of respiratory failure and mortality rates of ∼40%, remains a significant challenge in critical care medicine. Despite advances in supportive care, accurate prediction of ARDS mortality remains challenging, resulting in delayed delivery of targeted interventions and effective disease management. Traditional critical illness severity scores lack specificity for ARDS, underscoring the need for more precise prognostic tools for ARDS mortality. To address this crucial gap, we employed a multimodal approach to predict ARDS patients utilizing a comprehensive dataset comprised of integrated clinical, metabolomic, and biochemical/cytokine data from ARDS patients (collected within hours of ICU admission) to develop and validate predictive models of ARDS mortality risk. The most robust multimodal data model generated demonstrated superior predictive capability with an area under the curve (AUC) of 0.868 on the test set and 0.959 on the validation set. Notably, this model achieved perfect specificity in identifying non-survivors in the validation cohort, highlighting potential utility in guiding early and targeted interventions in ICU settings. Metabolomic analysis revealed significant alterations in crucial pathways associated with ARDS mortality with tryptophan metabolism, particularly the kynurenine pathway, emerging as the most significantly enriched metabolic route, as well as the NAD+ metabolism/ nicotinamide phosphoribosyltransferase (NAMPT) and glycosaminoglycan biosynthesis pathways. These metabolic derangements were strongly confirmed by lipidomic/metabolomic analysis of lung tissues from a porcine sepsis/ARDS model. Together, these findings demonstrate the promise of integrating multimodal data to improve ARDS prognostication and to provide important insights into the complex metabolic derangements underlying severe ARDS. Identification of metabolic signatures, such as kynurenine and NAD+ metabolism/NAMPT pathways, may serve as a foundation for developing personalized and effective targeted interventions and management strategies for ARDS patients.

Archaea-inspired deoxyribonuclease I liposomes prevent multiple organ dysfunction in sepsis

Neutrophil extracellular traps (NETs) and circulating cell-free DNA (cfDNA) are pivotal in driving excessive inflammation and organ damage during sepsis, with their levels correlating positively with sepsis severity in both patients and murine models. Despite the ability of deoxyribonuclease I (DNase I) to degrade NETs and cfDNA, its short half-life and rapid degradation limit its therapeutic effectiveness. To address this challenge, we developed a methyl-branched liposome fused with a red blood cell membrane for the systemic delivery of DNase I (DNase I/Rm-Lipo). The efficacy of DNase I/Rm-Lipo was evaluated in the stimulated immune cells and septic model. The data confirmed that DNase I/Rm-Lipo efficiently removed excess NETs and cfDNA in activated neutrophils. Following injection, DNase I/Rm-Lipo exhibited an extended circulation time, effectively suppressing neutrophil activation and regulating macrophage polarization to mitigate inflammation and prevent organ dysfunction in septic mice. These findings highlight the therapeutic potential of DNase I/Rm-Lipo as a promising candidate for sepsis management by targeting the degradation of NETs and cfDNA.

The Role of Post-Translational Modifications in Necroptosis

Necroptosis, a distinct form of regulated necrosis implicated in various human pathologies, is orchestrated through sophisticated signaling pathways. During this process, cells undergoing necroptosis exhibit characteristic necrotic morphology and provoke substantial inflammatory responses. Post-translational modifications (PTMs)-chemical alterations occurring after protein synthesis that critically regulate protein functionality-constitute essential regulatory components within these complex signaling cascades. This intricate crosstalk between necroptotic pathways and PTM networks presents promising therapeutic opportunities. Our comprehensive review systematically analyzes the molecular mechanisms underlying necroptosis, with particular emphasis on the regulatory roles of PTMs in signal transduction. Through systematic evaluation of key modifications including ubiquitination, phosphorylation, glycosylation, methylation, acetylation, disulfide bond formation, caspase cleavage, nitrosylation, and SUMOylation, we examine potential therapeutic applications targeting necroptosis in disease pathogenesis. Furthermore, we synthesize current pharmacological strategies for manipulating PTM-regulated necroptosis, offering novel perspectives on clinical target development and therapeutic intervention.

Experimental and clinical perspectives on glycocalyx integrity and its relation to acute respiratory distress syndrome

The development of microcirculation imaging devices has significantly advanced our comprehension of the capillary environment's dynamics. Early research suggested that erythrocytes did not contact the vessel's inner surface due to the Fåhraeus effect, implying the presence of a covering on the endothelial cell surface. Subsequent electron microscopy studies revealed this layer to be a complex part of the vessel wall, now known as the endothelial glycocalyx (EG). The EG is a network of proteoglycans and glycoproteins bound to the endothelial membrane, incorporating soluble molecules from the endothelium and plasma. Over time, studies have elucidated the structure, function, and therapeutic targets of the glycocalyx, underscoring its pivotal role in vascular biology. The presence of cellular extensions of lung tissue cells in both vascular and nonvascular areas demonstrates the pivotal role of the glycocalyx in pulmonary vascular leak, surfactant dysfunction, impaired lung compliance and gas exchange abnormalities, which are hallmarks of acute respiratory distress syndrome (ARDS). It is of the utmost importance to elucidate the mechanisms underlying alveolocapillary glycocalyx degradation to develop efficacious treatments for ARDS, which has a mortality rate of 35 %. An understanding of the glycocalyx's role in vascular integrity provides a foundation for exploring new therapeutic avenues to mitigate lung injury and improve clinical outcomes in ARDS patients.

CIRP contributes to multiple organ damage in acute pancreatitis by increasing endothelial permeability

Acute pancreatitis can lead to systemic inflammation and multiple organ damage. Increased endothelial permeability is a hallmark of systemic inflammation. Several studies have demonstrated that cold-inducible RNA-binding protein (CIRP) functions as a proinflammatory factor in various diseases. However, its role in endothelial barrier dysfunction during acute pancreatitis remains unknown. To study this, acute pancreatitis was induced by two hourly intraperitoneal injections of 4.0 g/kg L-arginine in wild-type (WT) or CIRP knockout mice. Our results showed that CIRP levels in the pancreas, small intestine, lung, and liver were upregulated at 72 h after the induction of acute pancreatitis in WT mice. CIRP deficiency significantly attenuated tissue injury, edema, and extravasation of Evans blue in the pancreas, small intestine, lung, and liver at 72 h after L-arginine injection. Administration of C23, a specific antagonist of CIRP, at 2 h after the last injection of L-arginine also produced similar protective effects as CIRP knockout in mice. In vitro studies showed that recombinant CIRP caused a significant reduction in transcellular electric resistance in HUVEC monolayers. Immunocytochemical analysis of endothelial cells exposed to CIRP revealed an increased formation of actin stress fibers. VE-cadherin and β-catenin staining showed intercellular gaps were formed in CIRP-stimulated cells. Western blot analysis showed that CIRP induced SRC phosphorylation at TYR416. Exposure to the SRC inhibitor PP2 reduced CIRP-induced endothelial barrier dysfunction in HUVEC monolayers. In conclusion, blocking CIRP mitigates acute pancreatitis-induced multiple organ damage by alleviating endothelial hyperpermeability. Targeting CIRP may be a potential therapeutic option for acute pancreatitis.

Platelet distribution width in patients with influenza A virus-induced acute respiratory distress syndrome: An old indicator with promising clinical application

This study aims to investigate the predictive value of platelet distribution width (PDW) in patients with influenza A virus (IAV) infection. The clinical data of 105 IAV-infected patients was collected and analyzed. We found that creatine kinase (CK), Acute Physiology and Chronic Health Evaluation (APACHE) II score, PDW, and red blood cell distribution width (RDW) were independent risk factors for acute respiratory distress syndrome (ARDS) development. PDW was more effective in predicting ARDS development than CK and RDW, and comparable to APACHE II score. Among ARDS patients, PDW showed a positive correlation with duration of invasive ventilation, APACHE II score, and Sequential Organ Failure Assessment (SOFA) score, and a negative correlation with the arterial pressure of oxygen/inspiratory fraction of oxygen (PaO2/FiO2) level. Furthermore, PDW showed high predictive efficiency for septic shock and 28-day mortality. Taken together, this study demonstrated a promising clinical value of PDW in patients with IAV-induced ARDS.

Combating sepsis-induced acute lung injury: PARP1 inhibition mediates oxidative stress mitigation and miR-135a-5p/SMAD5/Nanog axis drives regeneration

PURPOSE

The purpose of this study was to investigate the therapeutic potential of Poly (ADP-ribose) polymerase 1 (PARP1) inhibition combined with microRNA miR-135a-5p overexpression in sepsis-induced acute lung injury (ALI). Specifically, we aimed to elucidate combinatorial therapeutic potential of PARP1 inhibition in mitigating oxidative stress and inflammation across different models, simultaneously miR-135a-5p overexpression promoting regeneration through the SMAD5/Nanog axis.

METHOD

We used C57BL/6 mice to create Cecal Ligation Puncture (CLP) model of Sepsis-induced Acute Lung Injury. RAW264.7 murine macrophages and MLE12 (Mouse Lung Epithelial) cells were stimulated through Lipopolysaccharide (LPS) to induce inflammation. miR-135a-5p mimic Transfection confirmed using one-step Real time quantitative PCR (RT-qPCR). PARP1 inhibition confirmed by western blotting using Poly (ADP-ribose) (PAR) expression. Reactive oxygen Species (ROS) generation measured through Dichlorofluorescein diacetate (DCF-DA) dye using fluorescent microscopy and Nitric Oxide (NO) via spectrophotometry. Bronchoalveolar Lavage Fluid (BALF) cytokine analysis was done using Enzyme-linked immunosorbent assay (ELISA). miRNA mediated signaling, inflammatory markers and cytokines were determined using immunoblotting, RT-qPCR, and immunohistochemistry. miR-135a-5p target validation using dual-luciferase assay.

RESULTS

Our results demonstrated that PARP1 inhibition significantly reduced oxidative stress (**P < 0.01) and inflammatory markers in sepsis-induced lung injury models. Specifically, we observed decreased protein levels of inducible nitric oxide synthase (iNOS) (***P < 0.001), cyclooxygenase-2 (COX2) (*P < 0.05), phospho-Akt (*P < 0.05), and Tumor necrosis factor-Alpha (TNF-α) (*P < 0.05) mRNA expression. We observed significant reduction in ROS and NO generation in macrophages. Moreover, histopathological evidence suggested improved lung health. Concurrently, miR-135a-5p overexpression decreased the expression of SMAD5 (*P < 0.05) which in turns increased the expression of Nanog and related pluripotency genes in epithelial cells and mice, thus promoting regeneration and repair.

CONCLUSION

The combination of PARP1 inhibition and miR-135a-5p overexpression showed significant potential as a therapeutic intervention by reducing inflammation alongside stimulating regenerative environment in Sepsis-induced ALI.

Sinensetin attenuates LPS-induced acute pulmonary inflammation in mice and RAW264.7 cells by modulating NF-κB p65-mediated immune resistance and STAT3-mediated tissue resilience

Acute pulmonary inflammation is a severe lower respiratory tract infection. Sinensetin (SIN), a polymethoxyflavone with strong anti-inflammatory properties, is known to ameliorate LPS-induced acute inflammatory lung injury, but its molecular mechanisms are not fully understood. This study aimed to provide insight into the pharmacological mechanisms of SIN in attenuating acute pulmonary inflammation. In LPS-induced inflammation assays in vivo and in vitro, SIN significantly reduced the mRNA levels of inflammatory genes including MCP-1, ICAM1, Ccl3, Ccl4, Ccl5, Ccl7, Cxcl9, Cxcl10, IL1α, IL1β, IL6, IL11, IL18, IL27, TNF-α, IFN-γ, TLR4, MyD88, F4/80, COX2, iNOS, NLRP3, ASC, JAK2, STAT3, STAT4, and Bcl2l1, as well as increased the mRNA levels of anti-inflammatory genes such as IL4, IL10, and IL12α. Besides, SIN markedly decreased the expression of CD68, TLR4, MyD88, phospho-IκBα (S32/S36), phospho-NF-κB p65 (S536), MCP-1, ICAM1, phospho-JAK2 (Tyr1008), phospho-STAT1 (S727), phospho-STAT3 (Y705), and phospho-STAT4 (Y693), inhibited NF-κB p65 translocation into the nucleus, thereby blocking in combination with STAT transcription factors to induce target gene expression. Further GC-MS/MS and LC-MS/MS metabolomic analysis revealed that SIN significantly increased the abundance of anti-inflammatory metabolites, such as L-alanine, L-carnitine, L-glutamic acid, Glycine, and L-cysteine. In conclusion, the results indicated that SIN attenuated LPS-induced acute pulmonary inflammation by modulating NF-κB p65-mediated immune resistance and STAT3-mediated tissue resilience. All these favorable findings presented critical insights into the remarkable abilities and health benefits of SIN in ameliorating inflammatory lung disease.

The value of heparin-binding protein in bronchoalveolar lavage fluid in acute respiratory distress syndrome

Background

Heparin-binding protein (HBP) is recognized as a significant factor in the development of Acute Respiratory Distress Syndrome (ARDS). Although plasma levels of HBP have been identified as a predictive biomarker for ARDS, the role and value of HBP in bronchoalveolar lavage fluid (BALF) remain unexplored.

Methods

Our study utilized a cecum ligation and puncture (CLP) method to induce an ARDS model in mice, examining the correlations between plasma and BALF HBP levels, lung injury severity, lung wet-to-dry (WD) ratio, and BALF total protein levels. Additionally, we conducted a comparative analysis of BALF and plasma HBP levels in 44 ARDS patients and 38 patients with cardiogenic pulmonary edema (CPE), investigating their correlations.

Results

In the animal study, CLP-induced mice demonstrated significantly higher lung WD ratios, BALF protein, BALF HBP, and plasma HBP levels compared to the control group. Notably, both BALF and plasma HBP levels were significantly correlated with lung injury severity. In human subjects, significant differences in BALF HBP, BALF protein, and plasma HBP levels were observed between ARDS and CPE patients, along with notable correlations between these markers and the severity of lung injury. Particularly, BALF HBP levels exhibited a stronger correlation with lung injury compared to plasma HBP levels.

Conclusion

The study indicates that both BALF and plasma HBP levels are significantly elevated in the context of lung injury in both animal models and human ARDS patients. More importantly, BALF HBP levels show a stronger correlation with the severity of lung injury, suggesting that BALF HBP could serve as a valuable biomarker for diagnosing and guiding the treatment of ARDS.

Role of C5aR2 in prognosis of patients with acute respiratory distress syndrome through negative modulation of C5a: A prospective observational study

Objective

Diverse inflammatory pathology is involved in acute respiratory distress syndrome (ARDS). This study aimed to assess the role of complement component fragment 5a (C5a) receptor 2 (C5aR2) in prognosis of patients with ARDS.

Methods

A total of 64 adult patients diagnosed with ARDS were prospectively recruited to the study over a period of one year after obtaining the informed consent. The serum C5a and C5aR2were determined using ELISA Kit sandwich method. Area under receiver operating characteristic (AUROC) was used to analyse the prognostic performance of C5a, C5R2, and C5a/C5R2 ratio using MedCalc. The relationship of these biomarkers with the parameters of poor prognosis (non-recovery, hospitalization, ventilation and ICU admission) was analysed through regression using SPSSv20.

Results

The mean age of the included participants was 49.17 (SD:14.81) years. C5a/C5aR2 ratio had better discrimination (AUC: 0.707 vs 0.699 vs 0.511) and higher specificity (78.1 vs 71.9 vs 3.1) than C5R2 and C5a in predicting the poor prognosis among ARDS patients. The increased level of C5aR2 (OR: 0.225; p = 0.009) was significantly associated with better recovery and the high C5a/C5aR2 ratio (OR: 3.281; p = 0.036) was significantly associated with non-recovery in moderate to severe patients. Additionally, steroid treatment significantly associated with better recovery in patients with a high C5a/C5aR2 ratio (OR: 0.104; p = 0.007).

Conclusion

The current evidence indicates that a higher levels of C5aR2 significantly associated with better recovery, whereas high levels of C5a/C5aR2 significantly associated to poor prognosis in moderate to severe ARDS patients. However, adequately powered studies are required to confirm these findings in future.

Tomographic features of lung damage associate with D-Dimer levels and further clinical outcome in patients with acute respiratory distress syndrome due to COVID-19

BACKGROUND

Rapid progression of symptoms and development of Acute Respiratory Distress Syndrome (ARDS) frequently occurred during COVID-19 pandemic, while CT-Scan was useful to assess severity of lung damage, with classic patterns like early Ground Glass Opacity and/or late consolidation. Likewise, lung injury has been related to activation of the coagulation-fibrinolysis systems and pro-inflammatory mediators; where D-Dimer acquires prognostic relevance. The present study aimed to evaluate whether the extent of lung involvement and pattern of lung injury, as determined by chest CT-scan, are related with D-Dimer; and further impact clinical prognosis in patients with ARDS due to COVID-19.

METHODS

Longitudinal, prospective, observational, multi-center study. Patients diagnosed with ARDS due to COVID-19, without previous lung damage, clotting disorder and/or anticoagulants use, who were attended at the Intensive Care Unit and Internal Medicine Department from March to June 2020. Tomographic extent of lung involvement was analyzed by image software, as well as damage patterns, assessed by experienced radiologists. Endpoints included relation of lung injury with coagulopathy markers like D-Dimer, and prognostic outcome including mortality, mechanical ventilation and hospitalization time.

RESULTS

One-hundred and four patients mean aged 55 years old, 66% males, main comorbidities obesity, hypertension and diabetes mellitus. Larger lung damage was associated with older age, male gender and higher pro-inflammatory mediators like leukocytes and ferritin; whilst consolidation pattern was related to higher Body Mass Index. Higher values of D-Dimer were related either to a larger extent of lung involvement or late consolidation pattern. In addition, the extent of lung involvement was related with longer hospital stay, higher requirement of mechanical ventilation (HR 0.12, p < 0.01) and mortality rate (HR 0.13, p < 0.01); whereas late consolidation was mainly associated with requirement of mechanical ventilation (HR 0.23, p < 0.01).

CONCLUSION

Tomographic extent of lung involvement and the pattern of lung injury are related with coagulopathy severity markers like D-Dimer, and own prognostic clinical ability in ARDS.

ADSCs-derived exosomes suppress macrophage ferroptosis via the SIRT1/NRF2 signaling axis to alleviate acute lung injury in sepsis

Acute lung injury being one of the earliest and most severe complications during sepsis and macrophages play a key role in this process. To investigate the regulatory effects and potential mechanisms of adipose mesenchymal stem cell derived-exosomes (ADSC-exo) on macrophages and septic mice, ADSCs-exo was administrated to both LPS-induced macrophage and cecal ligation and puncture (CLP) induced sepsis mice. ADSCs-exo was confirmed to inhibit M1 polarization of macrophages and to reduce excessive inflammation. The use of ADSCs-exo in CLP mice and in LPS-induced macrophages relieved oxidative stress, cellular damage, and acute lung injury. During this process, ADSCs-exo increased the nuclear translocation of Nrf2, significantly upregulating the activation of the antioxidant pathway Nrf2/HO-1. Concurrently, they enhanced the expression of SIRT1 in macrophages. Further SIRT1 interference experiments demonstrated that ADSCs-exo mitigated macrophage inflammatory responses and LPS-induced ferroptosis by upregulating SIRT1. In the LPS-induced macrophage model, after SIRT1 was interfered with, ADSCs-exo failed to upregulate the Nrf2/HO-1 signaling pathway, leading to enhanced ferroptosis. Finally, in a CLP sepsis mouse model with myeloid-specific SIRT1 knockout, ADSCs-exo was observed to reduce lung tissue injury, oxidative stress damage, and ferroptosis. Still, these beneficial effects were reversed due to the myeloid-specific knockout of SIRT1, while co-administration of a ferroptosis inhibitor rescued this situation, alleviating lung injury and significantly reducing tissue levels of oxidative stress. In conclusion, this study elucidated a novel potential therapeutic mechanism wherein ADSCs-exo upregulates the levels of SIRT1 in macrophages through a non-delivery approach.

Proof of Concept: Effects of an Immune-Enhancing Formula on Clinical Markers of Critical Coronavirus Disease 2019 Cases

Background/Objectives: The rapid viral spread observed in coronavirus disease 2019 (COVID-19) is capable of inducing the secretion of excessive inflammatory cytokines. The resulting multi-organ damage is a severe complication that can be attenuated through adequate nutrition. Formulae enhanced with either glutamine or arginine are conditionally essential amino acids that have been proven to improve the condition of hospitalized patients. This retrospective study aimed to investigate the effects of administering an immune-enhancing enteral formula enhanced with arginine and glutamine on the clinical signs and biomarkers of patients with severe COVID-19. Methods: After checking the data of 232 patients enrolled in the biobank for completeness and eligibility, 31 patients with severe COVID-19 in the intensive care unit at Taipei Tzu Chi Hospital were grouped based on the type of enteral formula used: 16 patients received the control formula, and 15 patients received the immune-enhancing formula. Baseline characteristics, clinical signs, and inflammatory markers were analyzed for differences. Results: An increase in IL-10 levels in the intervention group was observed (p = 0.048). Changes in other inflammatory cytokine levels were insignificant. Conclusions: Providing an enteral formula enriched with glutamine and arginine to severe COVID-19 patients may help improve their anti-inflammatory marker levels. Further interventional study utilizing enteral formula enriched with glutamine and arginine is needed to confirm the findings of this study.

The role of neutrophilia in hyperlactatemia, blood acidosis, impaired oxygen transport, and mortality outcome in critically ill COVID-19 patients

Introduction

COVID-19 severity and high in-hospital mortality are often associated with severe hypoxemia, hyperlactatemia, and acidosis, yet the key players driving this association remain unclear. It is generally assumed that organ damage causes toxic acidosis, but since neutrophil numbers in severe COVID-19 can exceed 80% of the total circulating leukocytes, we asked if metabolic acidosis mediated by the glycolytic neutrophils is associated with lung damage and impaired oxygen delivery in critically ill patients.

Methods

Based on prospective mortality outcome, critically ill COVID-19 patients were divided into ICU- survivors and ICU-non-survivors. Samples were analyzed to explore if correlations exist between neutrophil counts, lung damage, glycolysis, blood lactate, blood pH, hemoglobin oxygen saturation, and mortality outcome. We also interrogated isolated neutrophils, platelets, and PBMCs for glycolytic activities.

Results

Arterial blood gas analyses showed remarkable hypoxemia in non-survivors with no consistent differences in PCO2 or [HCO3 -]. The hemoglobin oxygen dissociation curve revealed a right-shift, consistent with lower blood-pH and elevated blood lactate in non-survivors. Metabolic analysis of different blood cells revealed increased glycolytic activity only when considering the total number of neutrophils.

Conclusion

This indicates the role of neutrophilia in hyperlactatemia and lung damage, subsequently contributing to mortality outcomes in severe SARS-CoV-2 infection.

IDENTIFYING POTENTIAL KEY FERROPTOSIS-RELATED GENES AND THERAPEUTIC DRUGS IN SEPSIS-INDUCED ARDS BY BIOINFORMATICS AND EXPERIMENTAL VERIFICATION

ABSTRACT

Background: Acute respiratory distress syndrome (ARDS) is a serious pathological process with high mortality. Ferroptosis is pivotal in sepsis, whose regulatory mechanisms in sepsis-induced ARDS remains unknown. We aimed to determine key ferroptosis-related genes in septic ARDS and investigate therapeutic traditional Chinese medicine. Method: Sepsis-induced ARDS dataset obtained from Gene Expression Omnibus was analyzed to identify ferroptosis-related differentially expressed genes. Enrichment analysis and protein-protein interaction network construction were performed to identify hub genes. Immune cells infiltration was analyzed and competitive endogenous RNA network was constructed. The diagnostic value of hub genes in septic ARDS was analyzed and the occurrence of ferroptosis and the expression of hub genes were detected. Traditional Chinese medicine targeting hub genes was predicted via SymMap database and was verified. Results: Sixteen ferroptosis-related differentially expressed genes were obtained, among which the top four genes ( IL1B , TXN , MAPK3 , HSPB1 ) were selected as hub genes, which may be potential diagnostic markers of septic ARDS. Immunoassay showed that sepsis-induced ARDS and hub genes were closely related to immune cells. The competitive endogenous RNA network showed 26 microRNAs and 38 long noncoding RNA. Ferroptosis occurred and the expressions of IL1B , MAPK3 , and TXN were increased in septic ARDS mice and LPS-challenged human pulmonary alveolar epithelial cells. Sea buckthorn alleviated septic lung injury and affected hub genes expression. Conclusions: Ferroptosis-related genes of IL1B , MAPK 3, and TXN serve as potential diagnostic genes for sepsis-induced ARDS. Sea buckthorn may be therapeutic medication for ARDS. This study provides a new direction for septic ARDS treatment.

Sedation modality in acute respiratory distress syndrome: does method of sedation affect length of stay, outcomes, or adverse events? A systematic review

INTRODUCTION

Acute respiratory distress syndrome (ARDS) is a life-threatening, diffuse inflammatory pulmonary condition characterised by the Berlin criteria. Incidence of ARDS is estimated at 2.5-19% globally with high mortality and morbidity. Interest has been increasing in the use of inhaled sedatives because of a more rapid awakening and fewer adverse effects compared with intravenous propofol. The primary aim of this systematic review protocol is to investigate the length of critical care stay between ARDS patients who have been mechanically ventilated with inhaled anaesthetic sedatives (ie, sevoflurane and isoflurane) compared with those patients who are prescribed conventional sedatives (ie, propofol).

METHODS AND ANALYSIS

Cochrane Central Register of Controlled Trials, Ovid (Embase, MEDLINE), PubMed, EBSCO (CINAHL Plus), Google Scholar will be searched and stratified by the reviewers. The literature search will be limited to English articles. Published full text peer-reviewed articles will be included.The International Prospective Register of Systematic Reviews (PROSPERO) Registration number is: CRD42023390988.

ETHICS AND DISSEMINATION

Ethics approval is not required for this systematic review. The results will be presented at local/regional meetings and dissemination will occur through peer-reviewed publication.

Viral sepsis: diagnosis, clinical features, pathogenesis, and clinical considerations

Sepsis, characterized as life-threatening organ dysfunction resulting from dysregulated host responses to infection, remains a significant challenge in clinical practice. Despite advancements in understanding host-bacterial interactions, molecular responses, and therapeutic approaches, the mortality rate associated with sepsis has consistently ranged between 10 and 16%. This elevated mortality highlights critical gaps in our comprehension of sepsis etiology. Traditionally linked to bacterial and fungal pathogens, recent outbreaks of acute viral infections, including Middle East respiratory syndrome coronavirus (MERS-CoV), influenza virus, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), among other regional epidemics, have underscored the role of viral pathogenesis in sepsis, particularly when critically ill patients exhibit classic symptoms indicative of sepsis. However, many cases of viral-induced sepsis are frequently underdiagnosed because standard evaluations typically exclude viral panels. Moreover, these viruses not only activate conventional pattern recognition receptors (PRRs) and retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) but also initiate primary antiviral pathways such as cyclic guanosine monophosphate adenosine monophosphate (GMP-AMP) synthase (cGAS)-stimulator of interferon genes (STING) signaling and interferon response mechanisms. Such activations lead to cellular stress, metabolic disturbances, and extensive cell damage that exacerbate tissue injury while leading to a spectrum of clinical manifestations. This complexity poses substantial challenges for the clinical management of affected cases. In this review, we elucidate the definition and diagnosis criteria for viral sepsis while synthesizing current knowledge regarding its etiology, epidemiology, and pathophysiology, molecular mechanisms involved therein as well as their impact on immune-mediated organ damage. Additionally, we discuss clinical considerations related to both existing therapies and advanced treatment interventions, aiming to enhance the comprehensive understanding surrounding viral sepsis.

The impact of glucose metabolism on inflammatory processes in sepsis-induced acute lung injury

Acute lung injury (ALI) is a prevalent and critical complication of sepsis, marked by high incidence and mortality rates, with its pathogenesis still not being fully elucidated. Recent research has revealed a significant correlation between the metabolic reprogramming of glucose and sepsis-associated ALI (S-ALI). Throughout the course of S-ALI, immune cells, including macrophages and dendritic cells, undergo metabolic shifts to accommodate the intricate demands of immune function that emerge as sepsis advances. Indeed, glucose metabolic reprogramming in S-ALI serves as a double-edged sword, fueling inflammatory immune responses in the initial stages and subsequently initiating anti-inflammatory responses as the disease evolves. In this review, we delineate the current research progress concerning the pathogenic mechanisms linked to glucose metabolic reprogramming in S-ALI, with a focus on the pertinent immune cells implicated. We encapsulate the impact of glucose metabolic reprogramming on the onset, progression, and prognosis of S-ALI. Ultimately, by examining key regulatory factors within metabolic intermediates and enzymes, We have identified potential therapeutic targets linked to metabolic reprogramming, striving to tackle the inherent challenges in diagnosing and treating Severe Acute Lung Injury (S-ALI) with greater efficacy.

Liang-Ge-San Decoction Ameliorates Acute Respiratory Distress Syndrome via Suppressing p38MAPK-NF-κ B Signaling Pathway

OBJECTIVE

To explore the potential effects and mechanisms of Liang-Ge-San (LGS) for the treatment of acute respiratory distress syndrome (ARDS) through network pharmacology analysis and to verify LGS activity through biological experiments.

METHODS

The key ingredients of LGS and related targets were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. ARDS-related targets were selected from GeneCards and DisGeNET databases. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed using the Metascape Database. Molecular docking analysis was used to confirm the binding affinity of the core compounds with key therapeutic targets. Finally, the effects of LGS on key signaling pathways and biological processes were determined by in vitro and in vivo experiments.

RESULTS

A total of LGS-related targets and 496 ARDS-related targets were obtained from the databases. Network pharmacological analysis suggested that LGS could treat ARDS based on the following information: LGS ingredients luteolin, wogonin, and baicalein may be potential candidate agents. Mitogen-activated protein kinase 14 (MAPK14), recombinant V-Rel reticuloendotheliosis viral oncogene homolog A (RELA), and tumor necrosis factor alpha (TNF-α) may be potential therapeutic targets. Reactive oxygen species metabolic process and the apoptotic signaling pathway were the main biological processes. The p38MAPK/NF-κ B signaling pathway might be the key signaling pathway activated by LGS against ARDS. Moreover, molecular docking demonstrated that luteolin, wogonin, and baicalein had a good binding affinity with MAPK14, RELA, and TNF α. In vitro experiments, LGS inhibited the expression and entry of p38 and p65 into the nucleation in human bronchial epithelial cells (HBE) cells induced by LPS, inhibited the inflammatory response and oxidative stress response, and inhibited HBE cell apoptosis (P<0.05 or P<0.01). In vivo experiments, LGS improved lung injury caused by ligation and puncture, reduced inflammatory responses, and inhibited the activation of p38MAPK and p65 (P<0.05 or P<0.01).

CONCLUSION

LGS could reduce reactive oxygen species and inflammatory cytokine production by inhibiting p38MAPK/NF-κ B signaling pathway, thus reducing apoptosis and attenuating ARDS.

Liang-Ge-San protects against viral infection-induced acute lung injury through inhibiting α7nAChR-mediated mitophagy

BACKGROUND

Acute lung injury (ALI) is the main cause of death in clinical respiratory virus infection. Liang-Ge-San (LGS), a famous traditional Chinese formula, has been proved to be effective in treating ALI caused by lipopolysaccharide. However, the effects of LGS on ALI induced by viral infections remain uncertain.

PURPOSE

To investigate the effect and mechanism of action of LGS on viral infection-induced ALI.

METHODS

The inhibitory effects of LGS on virus-induced inflammation in vitro were evaluated by qRT-PCR and ELISA. The protein expression of α7nAChR was examined by Western blotting. α7nAChR was inhibited by the transfection of siRNA or methyllycaconitine citrate (MLA, an α7nAChR inhibitor) to investigate the role of α7nAChR in the anti-inflammatory effect of LGS. Adoptive culture and co-culture systems of macrophages RAW264.7 and alveolar epithelial cells MLE-12 were established to mimic their interaction. Western blotting, immunofluorescence, flow cytometry and transmission electron microscopy were used to examine the effects of LGS on mitophagy inhibition. In vivo, ALI mouse models induced by SARS-CoV-2, H1N1 or Poly(I:C) infection were established to explore the therapeutic effect and mechanism of LGS.

RESULTS

LGS reduced the release of IL-6, TNF-α and IL-1β and increased the expression of α7nAChR in virus-infected RAW264.7 cells. The blockage of α7nAChR counteracted the anti-inflammatory effect of LGS. Moreover, LGS significantly inhibited autophagy in MLE-12 cells induced by Poly(I:C) in adoptive culture and co-culture systems of RAW264.7 and MLE-12 cells, which could be attenuated after the inhibition of α7nAChR in RAW264.7 cells by decreasing the secretion of IL-6, TNF-α and IL-1β. Further study showed that LGS suppressed TNF-α-induced mitochondrial damage and mitophagy by inhibiting the generation of ROS in MLE-12 cells. In vivo, LGS significantly prolonged the survival time, alleviated pathological injury and acute inflammation of ALI mice induced by SARS-CoV-2, H1N1 or Poly(I:C) infection which were associated with the inhibition of α7nAChR-mediated mitophagy.

CONCLUSION

This study first demonstrates that LGS inhibits virus infection-induced inflammation in RAW246.7 cells by increasing the expression of α7nAChR, thereby inhibiting mitophagy induction in MLE-12 cells to alleviate ALI. This work indicates that LGS may serve as a candidate drug for treating ALI/ARDS caused by viral infection.

Ursodeoxycholic acid alleviates fat embolism syndrome-induced acute lung injury by inhibiting the p38 MAPK/NF-κB signalling pathway through FXR

Acute lung injury (ALI) caused by fat embolism syndrome (FES) is a disease with high mortality. This study aimed to explore the roles of ursodeoxycholic acid (UDCA) in FES-induced ALI and its underlying mechanisms. An ALI mouse model was established by allografting mouse perinephric fat. For in vitro experiments, human pulmonary microvascular endothelial cells (HPMEC) were treated with FFAs. The effects of UDCA on the expression of farnesoid X receptor (FXR) and the inflammatory response in endothelial cells were investigated. UDCA significantly inhibited the inflammatory response and the expression of proinflammatory markers during FES-induced ALI. UDCA markedly decreased TNF-α and IL-1β expression in vitro. UDCA administration markedly upregulated FXR expression and significantly reduced the phosphorylation of p38 MAPK and NF-κB p65. Knock down FXR expression decreased the effect of UDCA in vivo. Furthermore, knock down FXR expression and overexpressing FXR increased and decreased the inflammatory response, respectively, in vitro. Moreover, administration of a p38 MAPK activator reversed the anti-inflammatory effect of FXR overexpression. UDCA ameliorated inflammation during FES-induced ALI by suppressing p38 MAPK/NF-κB signalling and activating FXR. These findings provide new evidence for the potential of UDCA for FES-induced ALI treatment.

Acute respiratory distress syndrome caused by demulsifier poisoning: A case report

BACKGROUND

This case report emphasizes the potential pulmonary toxicity of demulsifier gas, which is a widely used chemical. To our knowledge, this is the first documented instance of acute respiratory distress syndrome (ARDS) induced by inhalation of demulsifier gas. This report underscores the need for increased workplace safety and awareness regarding health risks associated with demulsifiers, particularly in industrial settings. Timely diagnosis and management of ARDS are crucial for improving patient outcomes, thus making this report significant for clinical practice and occupational health literature.

CASE SUMMARY

We present a rare case of acute demulsifier poisoning leading to ARDS in a previously healthy 69-year-old man. He presented with chest discomfort, shortness of breath, and dyspnea following a 30-minute exposure to demulsifier fumes in a poorly ventilated area. Chest computed tomography revealed bilateral diffuse infiltrative shadows. Based on his exposure history and clinical findings, a diagnosis of ARDS due to demulsifier poisoning was confirmed. The patient required high-flow oxygen and intravenous norepinephrine upon admission and was subsequently intubated for mechanical ventilation. Following timely and effective multidisciplinary treatment interventions including emergency care, intensive care, and respiratory medicine, he achieved positive outcomes and was ultimately discharged.

CONCLUSION

This case underscores the critical importance of recognizing chemical exposure risks and their potential to cause severe respiratory complications.

Association Between Albumin Levels and Neonatal Acute Respiratory Distress Syndrome in Newborn Pneumoniae

Objective

This study aims to investigate the relationship between serum albumin levels and neonatal acute respiratory distress syndrome (NARDS) in patients with newborn pneumonia, providing new insights for clinical interventions targeting NARDS.

Methods

A retrospective analysis of medical records of neonatal pneumonia patients admitted to the neonatal intensive care unit (NICU) at a tertiary medical institution from January 2021 to December 2023 was conducted. Patients were stratified based on hypoalbuminemia (defined as serum albumin levels < 35 g/L), clinical thresholds, and albumin level quartiles. To eliminate the impact of potential confounding factors on the results, multivariable logistic regression and propensity score matching (PSM) analyses were performed to calculate the adjusted odds ratio (OR) and 95% confidence interval (95% CI) for the occurrence of NARDS in these patients. Additionally, subgroup analyses were conducted to explore interaction effects.

Results

In this retrospective cohort study, a total of 342 patients with neonatal pneumonia admitted to the NICU were included. The multivariable logistic regression analysis revealed that the incidence of NARDS in patients with hypoalbuminemia was significantly higher than in those with normal albumin levels (OR = 2.16, 95% CI 1.47-4.06, p = 0.017). Compared to patients in quartile Q1 (≥39 g/L), those in quartile Q4 (≤33 g/L) exhibited a significantly increased risk of NARDS (OR = 4.40, 95% CI 1.53-12.63, p = 0.006). After conducting PSM, these associations remained significant. Furthermore, treating serum albumin levels as a continuous variable revealed that each 1 g/L increase was associated with a 17% reduction in NARDS risk (95% CI, 1.08-1.15).

Conclusion

Low serum albumin levels in patients with neonatal pneumonia are closely associated with NARDS, indicating a significant dose-response relationship between the two.

Reduced microRNA-744 expression in mast cell-derived exosomes triggers epithelial cell ferroptosis in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a critical disorder characterized by immune-related damage to epithelial cells; however, its underlying mechanism remains elusive. This study investigated the effects of alterations in microRNA (miRNA) expression in mast cell-derived exosomes on human bronchial epithelial (HBE) cells and ARDS development in cellular and mouse models challenged with lipopolysaccharide. Lipopolysaccharide-treated mast cell-derived exosomes reduced glutathione peroxidase 4 (GPX4) expression and increased long-chain acyl-CoA synthetase 4 (ACSL4), 15-lipoxygenase (ALOX15), and inflammatory mediator levels in HBE cells. miRNA sequencing revealed a reduction in mast cell-derived exosomal miR-744 levels, which was associated with the regulation of ACSL4, ALOX15, and GPX4 expression. This downregulation of exosomal miR-744 expression reduced miR-744 levels and promoted ferroptosis in HBE cells, whereas the experimental upregulation of miR-744 reversed these adverse effects. Down-regulation of miR-744 induced the expression of markers for ferroptosis and inflammation in HBE cells and promoted pulmonary ferroptosis, inflammation, and injury in LPS-stimulated mice. In vivo, treatment with ACSL4, ALOX15, and GPX4 inhibitors mitigated these effects, and experimental miR-744 expression rescued the lipopolysaccharide-induced changes in HBE cells and mouse lungs. Notably, miR-744 levels were reduced in the plasma and exosomes of patients with ARDS. We concluded that decreased mast cell-derived exosomal miR-744 levels trigger epithelial cell ferroptosis, promoting lung inflammation and damage in ARDS. This study provides new mechanistic insights into the development and sustained pulmonary damage associated with ARDS and highlights potential therapeutic strategies.

Identifying risk factors for acute respiratory distress syndrome in critically ill patients: a retrospective study

Background

Acute respiratory distress syndrome (ARDS) is a life-threatening condition that can develop in critically ill patients. Early identification of risk factors associated with ARDS development is essential for timely intervention and improved patient outcomes. This study aimed to investigate the potential predictors of ARDS in critically ill patients admitted to the intensive care unit (ICU).

Methods

We conducted a retrospective study involving 502 critically ill patients admitted to the ICUs of three hospitals. Demographic and clinical data, including laboratory test results, were collected during their ICU stay. Multivariable logistic regression analysis was performed to identify independent risk factors associated with the development of ARDS.

Results

Among the 502 critically ill patients, 104 (20.7%) patients developed ARDS during their ICU stay, with a median time to development of 5.2 days. Multivariable logistic regression analysis revealed that age (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.01-1.13; P = 0.002), C-reactive protein (CRP) levels (OR, 1.11; 95% CI, 1.05-1.17; P = 0.013), T lymphocyte count (OR, 0.82; 95% CI, 0.69-0.93; P = 0.011), and interleukin-6 (IL-6) levels (OR, 1.17; 95% CI, 1.08-1.23; P = 0.003) were independently associated with the development of ARDS in critically ill patients.

Conclusions

Our study identified age, CRP, T lymphocyte count, and IL-6 as independent predictors of ARDS in critically ill patients admitted to the ICU. These findings highlight the importance of monitoring these parameters in critically ill patients to identify those at high risk of developing ARDS. Early recognition and intervention based on these risk factors may improve patient outcomes in the ICU setting. Further prospective studies are warranted to validate these results and develop a reliable predictive model for ARDS in critically ill patients.

Risk factors for acute respiratory distress syndrome in sepsis patients: A meta-analysis

Background

Acute Respiratory Distress Syndrome (ARDS) is a critical complication of sepsis, associated with high morbidity and mortality. Identifying risk factors for ARDS among sepsis patients is essential for early intervention and improving outcomes.

Methods

We conducted a comprehensive meta-analysis, reviewing studies that examined the association between various risk factors and ARDS development in sepsis patients. Databases such as PubMed, EMBASE, Cochrane Library, Medline, CINAHL, and Web of Science were searched up to January 2024, without language restrictions. Eligible studies included observational cohorts and case-control studies. Pooled odds ratios (ORs) and standardized mean differences (SMDs) were calculated using a random-effects model. Heterogeneity was assessed through I2 statistics, and publication bias was evaluated via the Luis Furuya-Kanamori (LFK) index.

Results

15 studies with more than 40,000 participants were analyzed. Significant risk factors for ARDS included pulmonary infection (OR: 2.696, 95 % CI: 1.655 to 4.390), septic shock (OR: 2.627, 95 % CI: 1.850 to 3.731), and pancreatitis (OR: 3.734, 95 % CI: 2.958 to 4.712). No significant associations were found between the development of ARDS in septic patients and the following risk factors: sex (OR: 1.106, 95%CI: 0.957-1.279), smoking status (OR: 1.214, 95%CI: 0.835-1.765), or steroid use (OR: 0.901, 95%CI: 0.617-1.314). APACHE-II and SOFA scores were predictive of ARDS development, emphasizing their utility in clinical assessments.

Conclusion

Pulmonary infection, septic shock, and pancreatitis significantly increase ARDS risk in sepsis patients. Our findings advocate for targeted management of these risk factors to mitigate ARDS development, emphasizing the importance of personalized care in sepsis management.

The involvement of HDAC3 in the pathogenesis of lung injury and pulmonary fibrosis

Acute lung injury (ALI) and its severe counterpart, acute respiratory distress syndrome (ARDS), are critical respiratory conditions with high mortality rates due primarily to acute and intense pulmonary inflammation. Despite significant research advances, effective pharmacological treatments for ALI and ARDS remain unavailable, highlighting an urgent need for therapeutic innovation. Notably, idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease characterized by the irreversible progression of fibrosis, which is initiated by repeated damage to the alveolar epithelium and leads to excessive extracellular matrix deposition. This condition is further complicated by dysregulated tissue repair and fibroblast dysfunction, exacerbating tissue remodeling processes and promoting progression to terminal pulmonary fibrosis. Similar to that noted for ALI and ARDS, treatment options for IPF are currently limited, with no specific drug therapy providing a cure. Histone deacetylase 3 (HDAC3), a notable member of the HDAC family with four splice variants (HD3α, -β, -γ, and -δ), plays multiple roles. HDAC3 regulates gene transcription through histone acetylation and adjusts nonhistone proteins posttranslationally, affecting certain mitochondrial and cytoplasmic proteins. Given its unique structure, HDAC3 impacts various physiological processes, such as inflammation, apoptosis, mitochondrial homeostasis, and macrophage polarization. This article explores the intricate role of HDAC3 in ALI/ARDS and IPF and evaluates its therapeutic potential the treatment of these severe pulmonary conditions.

Mitochondrial Extracellular Vesicles: A Promising Avenue for Diagnosing and Treating Lung Diseases

Mitochondria, pivotal organelles governing cellular biosynthesis, energy metabolism, and signal transduction, maintain dynamic equilibrium through processes such as biogenesis, fusion, fission, and mitophagy. Growing evidence implicates mitochondrial dysfunction in a spectrum of respiratory diseases including acute lung injury/acute respiratory distress syndrome, bronchial asthma, pulmonary fibrosis, chronic obstructive pulmonary disease, and lung cancer. Consequently, identifying methods capable of ameliorating damaged mitochondrial function is crucial for the treatment of pulmonary diseases. Extracellular vesicles (EVs), nanosized membrane vesicles released by cells into the extracellular space, facilitate intercellular communication by transferring bioactive substances or signals between cells or organs. Recent studies have identified abundant mitochondrial components within specific subsets of EVs, termed mitochondrial extracellular vesicles (mitoEVs), whose contents and compositions vary with disease progression. Moreover, mitoEVs have demonstrated reparative mitochondrial functions in injured recipient cells. However, a comprehensive understanding of mitoEVs is currently lacking, limiting their clinical translation prospects. This Review explores the biogenesis, classification, functional mitochondrial cargo, and biological effects of mitoEVs, with a focus on their role in pulmonary diseases. Emphasis is placed on their potential as biological markers and innovative therapeutic strategies in pulmonary diseases, offering fresh insights for mechanistic studies and drug development in various pulmonary disorders.

Neutrophils: a key component in ECMO-related acute organ injury

Extracorporeal membrane oxygenation (ECMO), as an extracorporeal life support technique, can save the lives of reversible critically ill patients when conventional treatments fail. However, ECMO-related acute organ injury is a common complication that increases the risk of death in critically ill patients, including acute kidney injury, acute brain injury, acute lung injury, and so on. In ECMO supported patients, an increasing number of studies have shown that activation of the inflammatory response plays an important role in the development of acute organ injury. Cross-cascade activation of the complement system, the contact system, and the coagulation system, as well as the mechanical forces of the circuitry are very important pathophysiological mechanisms, likely leading to neutrophil activation and the production of neutrophil extracellular traps (NETs). NETs may have the potential to cause organ damage, generating interest in their study as potential therapeutic targets for ECMO-related acute organ injury. Therefore, this article comprehensively summarized the mechanism of neutrophils activation and NETs formation following ECMO treatment and their actions on acute organ injury.

Methylprednisolone alleviates lung injury in sepsis by regulating miR-151-5p/USP38 pathway

BACKGROUND

Acute lung injury (ALI) is manifested by increased blood vessel permeability within the lungs and subsequent impairment of alveolar gas exchange. Methylprednisolone (MP) is commonly used as a treatment for ALI to reduce inflammation, yet its molecular mechanism remains unclear. This study aims to explore the underlying mechanisms of MP on ALI in a model induced by lipopolysaccharide (LPS).

MATERIAL AND METHODS

The proliferation, viability, apoptosis, and miR-151-5p expression of alveolar type II epithelial cells (AECII) were detected using the cell EdU assay, Annexin V/PI Apoptosis Kit, counting kit-8 (CCK-8) assay, and RT-qPCR. Western blot analysis was used to detect the Usp38 protein level. IL-6 and TNF-α were measured by ELISA. The combination of miR-151-5p and USP38 was determined by chromatin immunoprecipitation (ChIP)-PCR and dual-luciferase reporter assay.

RESULTS

MP greatly improved pulmonary function in vivo, reduced inflammation, and promoted the proliferation of the alveolar type II epithelial cells (AECII) in vitro. By comparing the alterations of microRNAs in lung tissues between MP treatment and control groups, we found that miR-151-5p exhibited a significant increase after LPS-treated AECII, but decreased after MP treatment. Confirmed by a luciferase reporter assay, USP38, identified as a downstream target of miR-151-5p, was found to increase after MP administration. Inhibition of miR-151-5p or overexpression of USP38 in AECII significantly improved the anti-inflammatory, anti-apoptotic, and proliferation-promotive effects of MP.

CONCLUSION

In summary, our data demonstrated that MP alleviates the inflammation and apoptosis of AECII induced by LPS, and promotes the proliferation of AECII partially via miR-151-5p suppression and subsequent USP38 activation.

Add-on hemoperfusion in SARS-CoV-2-infected pregnant patients: a case series

BACKGROUND

Pregnant women are more likely to have a higher severity of illness after being infected with coronavirus disease 2019 compared with the general population, particularly in the hyperinflammatory phase. However, immunomodulatory drugs are contraindicated and have been associated with an increased risk of fetal abnormalities. Therefore, we are reporting our experience with the use of HA330 hemoperfusion in combination with standard therapy in severe to critical coronavirus disease 2019 cases among pregnant patients.

CASE PRESENTATION

From January 2020 to December 2021, four pregnant Thai women were treated with hemoperfusion using a cytokine adsorptive technique. The patients' ages ranged from 21 to 36 years old, and their gestational ages at the time of admission ranged from 18 to 38 weeks. Two patients required intubation. Extracorporeal blood purification with an adsorptive cartridge (HA330®, Jafron, China) was applied as an adjunctive strategy to standard therapy approximately one week after the onset of symptoms, and most patients received three sessions of hemoperfusion. The baseline C-reactive protein level was greater than 80 mg/dL. The results showed that hemoperfusion could decrease the C-reactive protein level by approximately 80% and improve oxygenation. The newborns were delivered by Cesarean section without complications. Neither mortality nor serious adverse events related to hemoperfusion occurred.

CONCLUSION

This report may help ensure the use of the hemoperfusion strategy in pregnant patients during a cytokine storm. However, a larger cohort is needed to confirm its safety and efficacy.

Efficacy and safety of early prone position in postoperative cardiac surgery adults with acute respiratory distress syndrome: a single-center retrospective cohort study

Background

Acute respiratory distress syndrome (ARDS) is a leading cause of postoperative respiratory failure after cardiac surgery, and the mortality rate is extremely high. Although prone positioning (PP) may be safe and effective for ARDS, it is still not widely adopted in cardiac surgery patients. We aimed to assess the efficacy and safety of early PP in ARDS after cardiac surgery.

Methods

This is a single-center retrospective cohort study. We included adult intensive care unit (ICU) patients who developed ARDS with arterial pressure of oxygen to fraction of oxygen ratio (P/F) ≤200 mmHg within 72 hours after cardiac surgery between 1 January 2019 and 1 August 2023. The outcomes were P/F after 1 session of PP, duration of mechanical ventilation (MV) and ICU stay, and adverse events.

Results

In total, 79 patients who underwent PP and 87 patients who underwent supine position (SP) were included. The mean time to perform PP after ICU admission was 38.0 hours. The P/F improved significantly after 1 session of PP treatment [160.0 (127.8-184.3) vs. 275.0 (220.0-325.0) mmHg, P<0.001], the duration of MV and ICU stay in the PP group were significantly shorter than those in the SP group [84.0 (64.0-122.0) vs. 120.0 (97.0-182.0) h, P<0.001; 6.0 (5.0-8.0) vs. 8.0 (6.0-12.0) days, P<0.001, respectively]. No adverse events were observed during the PP even in patients with intra-aortic balloon pump (IABP).

Conclusions

Early PP treatment is effective and safe for patients with moderate to severe ARDS after cardiac surgery and it is even safe in a subgroup placed with IABP.

Budesonide and N-acetylcysteine inhibit activation of the NLRP3 inflammasome by regulating miR-381 to alleviate acute lung injury caused by the pyroptosis-mediated inflammatory response

Background

The anti-inflammatory effects of budesonide (BUN) and N-acetylcysteine (NAC) attenuate acute lung injury (ALI). The aim of this study was to investigate the effects of combination therapy consisting of BUN and NAC on ALI and the underlying mechanisms.

Methods

In vitro and in vivo models of ALI were generated by LPS induction. Western blotting was used to detect the expression levels of pyroptosis-related proteins and inflammation-related factors, and RT-qPCR was used to detect the expression of miR-381. Cell proliferation and apoptosis were detected by CCK-8 and flow cytometry, respectively. ELISA was used to detect the levels of inflammation-related factors. HE staining was used to detect lung injury.

Results

The results showed that LPS effectively induced pyroptosis in cells and promoted the expression of pyroptosis-related proteins (Caspase1, Gasdermin D and NLRP3) and inflammatory cytokines (TNF-α, IL-6 and IL-1β). The combination of BUN and NAC significantly alleviated LPS-induced pyroptosis and inflammation. In addition, the combination of BUN and NAC effectively promoted miR-381 expression. Transfection of miR-381 mimics effectively alleviated LPS-induced pyroptosis and inflammation, while transfection of miR-381 inhibitors had the opposite effect. miR-381 negatively regulates NLRP3 expression. Treatment with a miR-381 inhibitor or pc-NLRP3 reversed the effects of the combination of BUN and NAC. In a mouse model of ALI, the combination of BUN and NAC effectively improved lung injury, while treatment with a miR-381 inhibitor or pc-NLRP3 effectively reversed this effect.

Conclusion

Overall, this study revealed that BUN + NAC inhibits the activation of NLRP3 by regulating miR-381, thereby alleviating ALI caused by pyroptosis-mediated inflammation.

Diterpene Coronarin Attenuates Lipopolysaccharide-Induced Acute Lung Injury in Both In Vivo and In Vitro Models

Acute lung injury (ALI) is a clinical condition occurs due to severe systemic inflammatory response for clinical stimulus like pneumonia, sepsis, trauma, aspiration, inhalation of toxic gases, and pancreatitis. Disruption of alveolar barriers, activation of macrophages, infiltration of neutrophils, and proinflammatory cytokines are the vital events occurs during ALI. The drugs which inhibit these inflammatory response can protect lungs from inflammatory insults. In this study, we examined the potency of phytochemical coronarin, a diterpene which have been proven to possess anti-inflammatory, antioxidant, antiangiogenic, and antitumor activities. Healthy BALB/c mice were induced to acute lung injury with intra-tracheal administration of LPS and then treated with 5 and 10 mg/kg concentration of coronarin. The wet/dry lung weight of mice were estimated to assess the induction of pulmonary edema. BALF fluid was analyzed for protein concentrations and immune cells count. Myeloperoxidase activity and levels of chemokines MCP-2 and MIP-2, iNOS, COX-2, and PGE-2 were quantified to assess the immunomodulatory effect of coronarin against LPS-induced ALI. The levels of proinflammatory cytokines was measured to examine the anti-inflammatory property of coronarin, and it was confirmed with histopathological analysis of the lung tissue. Murine RAW 264.7 cells were utilized for the in vitro analysis. Cell cytoxicity and cytoprotective property of coronarin was assessed with MTT assay in LPS-treated Murine RAW 264.7. The anti-inflammatory property of coronarin was further confirmed in in vitro condition by estimating the levels of pro-inflammatory cytokines in coronarin-treated and untreated LPS-induced cells. Overall, our in vivo and in vitro results confirm coronarin significantly inhibited the infiltration of neutrophils prevented immunodulatory activity and synthesis of proinflammatory cytokines and alleviated the acute lung injury induced by LPS. Coronarin is a potent anti-inflammatory drug which can be subjected to further research to be prescribed as drug for ALI.

Hibifolin protected pro-inflammatory response and oxidative stress in LPS-induced acute lung injury through antioxidative enzymes and the AMPK2/Nrf-2 pathway

ALI is a grave medical ailment that manifests as abrupt inflammation of the lungs and diminished oxygen levels. It poses a considerable challenge to the medical fraternity, with elevated rates of morbidity and mortality. Our research endeavors to investigate the potential of hibifolin, a flavonoid glucuronide, imbued with potent antioxidant properties, and its molecular mechanism to combat LPS-induced ALI in mice. The study utilized ICR mice to create an ALI model induced by LPS. Prior to LPS administration, hibifolin was given at 10, 30, or 50 mg/kg, or dexamethasone was given at 1 mg/kg to assess its preventative impact. Changes in lung tissue, pulmonary edema, and lipid peroxidation were analyzed using H&E stain assay, lung wet/dry ratio assay, and MDA formation assay, respectively. Activity assay kits were used to measure MPO activity and antioxidative enzymes (SOD, CAT, GPx) activity in the lungs. Western blot assay was used to determine the phosphorylation of Nrf-2 and AMPK2 in the lungs. Hibifolin demonstrated a concentration-dependent improvement in LPS-induced histopathologic pulmonary changes. This treatment notably mitigated pulmonary edema, lipid peroxidation, and MPO activity in ALI mice. Additionally, hibifolin successfully restored antioxidative enzyme activity in the lungs of ALI mice. Moreover, hibifolin effectively promoted Nrf-2 phosphorylation and reinstated AMPK2 phosphorylation in the lungs of ALI mice. The results indicate that hibifolin could effectively alleviate the pathophysiological impact of LPS-induced ALI. This is likely due to its antioxidative properties, which help to restore antioxidative enzyme activity and activate the AMPK2/Nrf2 pathway. These findings are valuable in terms of enhancing our knowledge of ALI treatment and pave the way for further investigation into hibifolin as a potential therapeutic option for lung injuries.

FAK regulates tension transmission to the nucleus and endothelial transcriptome independent of kinase activity

The mechanical environment generated through the adhesive interaction of endothelial cells (ECs) with the matrix controls nuclear tension, preventing aberrant gene synthesis and the transition from restrictive to leaky endothelium, a hallmark of acute lung injury (ALI). However, the mechanisms controlling tension transmission to the nucleus and EC-restrictive fate remain elusive. Here, we demonstrate that, in a kinase-independent manner, focal adhesion kinase (FAK) safeguards tension transmission to the nucleus to maintain EC-restrictive fate. In FAK-depleted ECs, robust activation of the RhoA-Rho-kinase pathway increased EC tension and phosphorylation of the nuclear envelope protein, emerin, activating DNMT3a. Activated DNMT3a methylates the KLF2 promoter, impairing the synthesis of KLF2 and its target S1PR1 to induce the leaky EC transcriptome. Repleting FAK (wild type or kinase dead) or inhibiting RhoA-emerin-DNMT3a activities in damaged lung ECs restored KLF2 transcription of the restrictive EC transcriptome. Thus, FAK sensing and control of tension transmission to the nucleus govern restrictive endothelium to maintain lung homeostasis.

The Synthetic Surfactant CHF5633 Restores Lung Function and Lung Architecture in Severe Acute Respiratory Distress Syndrome in Adult Rabbits

PURPOSE

Acute respiratory distress syndrome (ARDS) is a major cause of hypoxemic respiratory failure in adults. In ARDS extensive inflammation and leakage of fluid into the alveoli lead to dysregulation of pulmonary surfactant metabolism and function. Altered surfactant synthesis, secretion, and breakdown contribute to the clinical features of decreased lung compliance and alveolar collapse. Lung function in ARDS could potentially be restored with surfactant replacement therapy, and synthetic surfactants with modified peptide analogues may better withstand inactivation in ARDS alveoli than natural surfactants.

METHODS

This study aimed to investigate the activity in vitro and the bolus effect (200 mg phospholipids/kg) of synthetic surfactant CHF5633 with analogues of SP-B and SP-C, or natural surfactant Poractant alfa (Curosurf®, both preparations Chiesi Farmaceutici S.p.A.) in a severe ARDS model (the ratio of partial pressure arterial oxygen and fraction of inspired oxygen, P/F ratio ≤ 13.3 kPa) induced by hydrochloric acid instillation followed by injurious ventilation in adult New Zealand rabbits. The animals were ventilated for 4 h after surfactant treatment and the respiratory parameters, histological appearance of lung parenchyma and levels of inflammation, oxidative stress, surfactant dysfunction, and endothelial damage were evaluated.

RESULTS

Both surfactant preparations yielded comparable improvements in lung function parameters, reductions in lung injury score, pro-inflammatory cytokines levels, and lung edema formation compared to untreated controls.

CONCLUSIONS

This study indicates that surfactant replacement therapy with CHF5633 improves lung function and lung architecture, and attenuates inflammation in severe ARDS in adult rabbits similarly to Poractant alfa. Clinical trials have so far not yielded conclusive results, but exogenous surfactant may be a valid supportive treatment for patients with ARDS given its anti-inflammatory and lung-protective effects.

S100A9 exacerbates sepsis-induced acute lung injury via the IL17-NFκB-caspase-3 signaling pathway

BACKGROUND

Sepsis-induced acute lung injury (ALI) is associated with considerable morbidity and mortality in critically ill patients. S100A9, a key endothelial injury factor, is markedly upregulated in sepsis-induced ALI; however, its specific mechanism of action has not been fully elucidated.

METHODS

The Gene Expression Omnibus database transcriptome data for sepsis-induced ALI were used to screen for key differentially expressed genes (DEGs). Using bioinformatics analysis methods such as Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and protein-protein interaction network analyses, the pathogenesis of sepsis-induced ALI was revealed. Intratracheal infusion of lipopolysaccharide (LPS, 10 mg/kg) induced ALI in wild-type (WT) and S100A9 knockout mice. Multiomics analyses (transcriptomics and proteomics) were performed to investigate the potential mechanisms by which S100A9 exacerbates acute lung damage. Hematoxylin-eosin, Giemsa, and TUNEL staining were used to evaluate lung injury and cell apoptosis. LPS (10 μg/mL)-induced murine lung epithelial MLE-12 cells were utilized to mimic ALI and were modulated by S100A9 lentiviral transfection. The impact of S100A9 on cell apoptosis and inflammatory responses were identified using flow cytometry and PCR. The expression of interleukin (IL)-17-nuclear factor kappa B (NFκB)-caspase-3 signaling components was identified using western blotting.

RESULTS

Six common DEGs (S100A9, S100A8, IFITM6, SAA3, CD177, and MMP9) were identified in the six datasets related to ALI in sepsis. Compared to WT sepsis mice, S100A9 knockout significantly alleviated LPS-induced ALI in mice, with reduced lung structural damage and inflammatory exudation, decreased exfoliated cell and protein content in the lung lavage fluid, and reduced apoptosis and necrosis of pulmonary epithelial cells. Transcriptomic analysis revealed that knocking out S100A9 significantly affected 123 DEGs, which were enriched in immune responses, defense responses against bacteria or lipopolysaccharides, cytokine-cytokine receptor interactions, and the IL-17 signaling pathway. Proteomic analysis revealed that S100A9 knockout alleviated muscle contraction dysfunction and structural remodeling in sepsis-induced ALI. Multiomics analysis revealed that S100A9 may be closely related to interferon-induced proteins with tetratricopeptide repeats and oligoadenylate synthase-like proteins. LPS decreased MLE12 cell activity, accompanied by high expression of S100A9. The expression of IL-17RA, pNFκB, and cleaved-caspase-3 were increased by S100A9 overexpression and reduced by S100A9 knockdown in LPS-stimulated MLE12 cells. S100A9 knockdown decreases transcription of apoptosis-related markers Bax, Bcl and caspase-3, alleviating LPS-induced apoptosis.

CONCLUSIONS

S100A9 as a key biomarker of sepsis-induced acute lung injury, and exacerbates lung damage and epithelial cell apoptosis induced by LPS via the IL-17-NFκB-caspase-3 signaling pathway.

Endothelial cell-derived extracellular vesicles modulate the therapeutic efficacy of mesenchymal stem cells through IDH2/TET pathway in ARDS

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe and fatal disease. Although mesenchymal stem cell (MSC)-based therapy has shown remarkable efficacy in treating ARDS in animal experiments, clinical outcomes have been unsatisfactory, which may be attributed to the influence of the lung microenvironment during MSC administration. Extracellular vesicles (EVs) derived from endothelial cells (EC-EVs) are important components of the lung microenvironment and play a crucial role in ARDS. However, the effect of EC-EVs on MSC therapy is still unclear. In this study, we established lipopolysaccharide (LPS) - induced acute lung injury model to evaluate the impact of EC-EVs on the reparative effects of bone marrow-derived MSC (BM-MSC) transplantation on lung injury and to unravel the underlying mechanisms.

METHODS

EVs were isolated from bronchoalveolar lavage fluid of mice with LPS - induced acute lung injury and patients with ARDS using ultracentrifugation. and the changes of EC-EVs were analysed using nanoflow cytometry analysis. In vitro assays were performed to establish the impact of EC-EVs on MSC functions, including cell viability and migration, while in vivo studies were performed to validate the therapeutic effect of EC-EVs on MSCs. RNA-Seq analysis, small interfering RNA (siRNA), and a recombinant lentivirus were used to investigate the underlying mechanisms.

RESULTS

Compared with that in non-ARDS patients, the quantity of EC-EVs in the lung microenvironment was significantly greater in patients with ARDS. EVs derived from lipopolysaccharide-stimulated endothelial cells (LPS-EVs) significantly decreased the viability and migration of BM-MSCs. Furthermore, engrafting BM-MSCs pretreated with LPS-EVs promoted the release of inflammatory cytokines and increased pulmonary microvascular permeability, aggravating lung injury. Mechanistically, LPS-EVs reduced the expression level of isocitrate dehydrogenase 2 (IDH2), which catalyses the formation of α-ketoglutarate (α-KG), an intermediate product of the tricarboxylic acid (TCA) cycle, in BM-MSCs. α-KG is a cofactor for ten-eleven translocation (TET) enzymes, which catalyse DNA hydroxymethylation in BM-MSCs.

CONCLUSIONS

This study revealed that EC-EVs in the lung microenvironment during ARDS can affect the therapeutic efficacy of BM-MSCs through the IDH2/TET pathway, providing potential strategies for improving the therapeutic efficacy of MSC-based therapy in the clinic.

An overview of the efficacy of inhaled curcumin: a new mode of administration for an old molecule

INTRODUCTION

Curcumin is a polyphenol with a variety of pharmacological actions. Despite its therapeutic effects and well-known safety profile, the utility of curcumin has been limited due to its deprived physical, chemical, and pharmacokinetic profile resulting from limited solubility, durability, prompt deterioration and pitiable systemic availability. Employment of an amalgamated framework integrating the potential advantages of a nanoscaffold alongside the beneficial traits of inhalational drug delivery system beautifully bringing down the restricting attributes of intended curative interventions and further assures its clinical success.

AREAS COVERED

Current review discussed different application of inhalable nanocurcumin in different medical conditions. Lung diseases have been the prime field in which inhalable nanocurcumin had resulted in significant beneficial effects. Apart from this several lung protective potentials of the inhaled nanocurcumin have been discussed against severe pulmonary disorders such as pulmonary fibrosis, radiation pneumonitis and IUGR induced bronchopulmonary dysplasia. Also, application of the disclosed intervention in the clinical management of COVID-19 and Alzheimer's Disease has been discussed.

EXPERT OPINION

In this portion, the potential of inhalable nanocurcumin in addressing various medical conditions along with ongoing advancements in nanoencapsulation techniques and the existing challenges in transitioning from pre-clinical models to clinical practice has been summarized.

Hussein S, Abdalhabib EK, Nabi SU. The critical impacts of cytokine storms in respiratory disorders

Cytokine storm (CS) refers to the spontaneous dysregulated and hyper-activated inflammatory reaction occurring in various clinical conditions, ranging from microbial infection to end-stage organ failure. Recently the novel coronavirus involved in COVID-19 (Coronavirus disease-19) caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) has been associated with the pathological phenomenon of CS in critically ill patients. Furthermore, critically ill patients suffering from CS are likely to have a grave prognosis and a higher case fatality rate. Pathologically CS is manifested as hyper-immune activation and is clinically manifested as multiple organ failure. An in-depth understanding of the etiology of CS will enable the discovery of not just disease risk factors of CS but also therapeutic approaches to modulate the immune response and improve outcomes in patients with respiratory diseases having CS in the pathogenic pathway. Owing to the grave consequences of CS in various diseases, this phenomenon has attracted the attention of researchers and clinicians throughout the globe. So in the present manuscript, we have attempted to discuss CS and its ramifications in COVID-19 and other respiratory diseases, as well as prospective treatment approaches and biomarkers of the cytokine storm. Furthermore, we have attempted to provide in-depth insight into CS from both a prophylactic and therapeutic point of view. In addition, we have included recent findings of CS in respiratory diseases reported from different parts of the world, which are based on expert opinion, clinical case-control research, experimental research, and a case-controlled cohort approach.

Heparin-Binding Protein Promotes Acute Lung Injury in Sepsis Mice by Blocking the Aryl Hydrocarbon Receptor Signaling Pathway

Purpose

This study aimed to explore the therapeutic effect and potential mechanism of heparin-binding protein (HBP) reduction on sepsis-related acute lung injury.

Methods

We utilized a murine model of sepsis-induced by intraperitoneal injection of lipopolysaccharides (LPS) in C57BL/6J mice divided into four groups: Control, LPS, Anti-HBP, and ceftriaxone (CEF). Following sepsis induction, Anti-HBP or CEF treatments were administered, and survival rates were monitored for 48 h. We then used reverse-transcription quantitative PCR to analyze the expression levels of HBP in lung tissues, immunohistochemistry for protein localization, and Western blotting for protein quantification. Pulmonary inflammation was assessed using enzyme-linked immunosorbent assays of proinflammatory cytokines (tumor necrosis factor-α, interleukin [IL]-1β, IL-6, and interferon-γ). The activation state of the aryl hydrocarbon receptor (AhR) signaling pathway was determined via Western blotting, evaluating both cytoplasmic and nuclear localization of AhR and the expression of cytochrome P450 1A1 protein by its target gene.

Results

Anti-HBP specifically reduced HBP levels. The survival rate of mice in the Anti-HBP and CEF groups was much higher than that in the LPS group. The severity of lung injury and pulmonary inflammatory response in the Anti-HBP and CEF groups was significantly lower than that in the LPS group. AhR signaling pathway activation was observed in the Anti-HBP and CEF groups. Additionally, there was no significant difference in the above indices between the Anti-HBP and CEF groups.

Conclusion

HBP downregulation in lung tissues significantly improved LPS-induced lung injury and the pulmonary inflammatory response, thereby prolonging the survival of sepsis mice, suggesting activation of the AhR signaling pathway. Moreover, the effect of lowering the HBP level was equivalent to that of the classical antibiotic CEF.

Trial Registration

Not applicable.

Therapeutic potential of proteases in acute lung injury and respiratory distress syndrome via TLR4/Nrf2/NF-kB signaling modulation

The COVID-19 pandemic has drawn attention to acute lung injury and respiratory distress syndrome as major causes of death, underscoring the urgent need for effective treatments. Protease enzymes possess a wide range of beneficial effects, including antioxidant, anti-inflammatory, antifibrotic, and fibrinolytic effects. This study aimed to evaluate the potential therapeutic effects of bacterial protease and chymotrypsin in rats in mitigating acute lung injury induced by lipopolysaccharide. Molecular docking was employed to investigate the inhibitory effect of bacterial protease and chymotrypsin on TLR-4, the receptor for lipopolysaccharide. Bacterial protease restored TLR-4, Nrf2, p38 MAPK, NF-kB, and IKK-β levels to normal levels, while chymotrypsin normalized TLR-4, IKK-β, IL-6, and IL-17 levels. The expression of TGF-β, caspase-3, and VEGF in the bacterial protease- and chymotrypsin-treated groups was markedly reduced. Our results suggest that both therapies ameliorate LPS-induced acute lung injury and modulate the TLR4/Nrf2/NF-k signaling pathway. Each protease exhibited distinct mechanisms, with bacterial protease showing a better response to oxidative stress, edema, and fibrosis, whereas chymotrypsin provided a better response in the acute phase and innate immunity. These findings highlight the potential of each protease as a promising therapeutic option for acute lung injury and respiratory distress syndrome.

Chronic inhalation of H2S in low concentration induces immunotoxicity and inflammatory effects in lung tissue of rats

Hydrogen sulfide (H2S) is a typical odour compound mainly causing respiratory and central nervous system symptoms. However, the immunotoxicity of inhaled H2S and the underlying mechanisms remain largely unknown. In this study, a low-dose inhalation exposure to H2S was arranged to observe inflammatory response and immunotoxicity in lung tissue of rats. Low concentrations of H2S exposure affected the immune level of pulmonary tissue and peripheral blood. Significant pathological changes in lung tissue in the exposure group were observed. At low concentration, H2S not only induced the upregulation of AQP-4 and MMP-9 expression but also stimulated immune responses, initiating various anti-inflammatory and inflammatory factors, altering tissue homeostatic environments. The TNF and chemokine signaling pathway played an important role which can promote the deterioration of pulmonary inflammatory processes and lead to lung injury and fibrosis. Excessive immune response causes an inflammatory effect and blood-gas barrier damage. These data will be of value in evaluating future occupational health risks and providing technical support for the further development of reliable, sensitive, and easy-to-use screening indicators of exposure injury.

A Narrative Review on the Administration of Inhaled Prostaglandins in Critically Ill Adult Patients With Acute Respiratory Distress Syndrome

OBJECTIVE

To describe the effect of inhaled prostaglandins on both oxygenation and mortality in critically ill patients with acute respiratory distress syndrome (ARDS), with a focus on safety and efficacy in coronavirus disease 2019 (COVID-19)-associated ARDS and non-COVID-19 ARDS.

DATA SOURCES

A literature search of MEDLINE was performed using the following search terms: inhaled prostaglandins, inhaled epoprostenol, inhaled nitric oxide, ARDS, critically ill. All abstracts were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language reports and studies conducted in humans between 1980 and June 2023 were considered.

DATA SYNTHESIS

Data regarding inhaled prostaglandins and their effect on oxygenation are limited but show a benefit in patients who respond to therapy, and data pertaining to their effect on mortality is scarce. Concerns exist regarding the formulation of inhaled epoprostenol (iEPO) utilized in addition to modes of medication delivery; however, the limited data surrounding their use have shown a reasonable safety profile. Other avenues and beneficial effects may exist with inhaled prostaglandins, such as use in COVID-19-associated ARDS or non-COVID-19 ARDS patients undergoing noninvasive mechanical ventilation or during patient transport.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

The use of inhaled prostaglandins can be considered in critically ill patients with COVID-19-associated ARDS or non-COVID-19 ARDS who are experiencing difficulties with oxygenation refractory to nonpharmacologic strategies.

CONCLUSIONS

The use of iEPO and other inhaled prostaglandins requires further investigation to fully elucidate their effects on clinical outcomes, but it appears these medications may have a potential benefit in COVID-19-associated ARDS and non-COVID-19 ARDS patients with refractory hypoxemia but with little effect on mortality.

Corilagin Inhibits Neutrophil Extracellular Trap Formation and Protects against Hydrochloric Acid/Lipopolysaccharide-Induced Acute Lung Injury in Mice by Suppressing the STAT3 and NOX2 Signaling Pathways

Acute lung injury (ALI) and its severe manifestation, acute respiratory distress syndrome (ARDS), are characterized by uncontrolled inflammatory responses, neutrophil activation and infiltration, damage to the alveolar capillary membrane, and diffuse alveolar injury. Neutrophil extracellular traps (NETs), formed by activated neutrophils, contribute significantly to various inflammatory disorders and can lead to tissue damage and organ dysfunction. Corilagin, a compound found in Phyllanthus urinaria, possesses antioxidative and anti-inflammatory properties. In this study, we investigated the protective effects and underlying mechanisms of corilagin in hydrochloric acid (HCl)/lipopolysaccharide (LPS)-induced lung injury. Mice received intraperitoneal administration of corilagin (2.5, 5, or 10 mg/kg) or an equal volume of saline 30 min after intratracheal HCl/LPS administration. After 20 h, lung tissues were collected for analysis. Corilagin treatment significantly mitigated lung injury, as evidenced by reduced inflammatory cell infiltration, decreased production of proinflammatory cytokines, and alleviated oxidative stress. Furthermore, corilagin treatment suppressed neutrophil elastase expression, reduced NET formation, and inhibited the expression of ERK, p38, AKT, STAT3, and NOX2. Our findings suggest that corilagin inhibits NET formation and protects against HCl/LPS-induced ALI in mice by modulating the STAT3 and NOX2 signaling pathways.