Verbenalin alleviates acute lung injury induced by sepsis and IgG immune complex through GPR18 receptor.

Acute lung injury is significantly associated with the aberrant activation and pyroptosis of alveolar macrophages. Targeting the GPR18 receptor presents a potential therapeutic approach to mitigate inflammation. Verbenalin, a prominent component of Verbena in Xuanfeibaidu (XFBD) granules, is recommended for treating COVID-19. In this study, we demonstrate the therapeutic effect of verbenalin on lung injury through direct binding to the GPR18 receptor. Verbenalin inhibits the activation of inflammatory signaling pathways induced by lipopolysaccharide (LPS) and IgG immune complex (IgG IC) via GPR18 receptor activation. The structural basis for verbenalin's effect on GPR18 activation is elucidated through molecular docking and molecular dynamics simulations. Furthermore, we establish that IgG IC induces macrophage pyroptosis by upregulating the expression of GSDME and GSDMD through CEBP-δ activation, while verbenalin inhibits this process. Additionally, we provide the first evidence that IgG IC promotes the formation of neutrophil extracellular traps (NETs), and verbenalin suppresses NETs formation. Collectively, our findings indicate that verbenalin functions as a "phytoresolvin" to promote inflammation regression and suggests that targeting the C/EBP-δ/GSDMD/GSDME axis to inhibit macrophage pyroptosis may represent a novel strategy for treating acute lung injury and sepsis.

Cannabinoids receptors in Covid-19: Perpetrators and victims.

COVID-19 is caused by SARS-CoV-2 and leads to acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and extrapulmonary manifestations in severely affected cases. However, most of the affected cases are mild or asymptomatic. Cannabinoids (CBs) such as tetrahydrocannabinol (THC) and cannabidiol (CBD), which act on G-protein-coupled receptors called CB1 and CB2, have anti-inflammatory effects. Many published studies show that CBs are effective in various inflammatory disorders, viral infections, and attenuation of ALI and ARDS. Therefore, the aim of the present narrative review was to summarize the possible immunological role of CBs in COVID-19. The effects of CBs are controversial, although they have beneficial effects via CB2 receptors and adverse effects via CB1 receptors against ALI, ARDS, and hyperinflammation, which are hallmarks of COVID-19. The present narrative review has shown that CBs effectively manage ALI and ARDS by suppressing pro-inflammatory cytokines, which are common in COVID-19. Therefore, CBs may be used to manage COVID-19 because of their potent anti-inflammatory effects with suppression of pro-inflammatory cytokines and inhibition of inflammatory signaling pathways.

Cepharanthine Dry Powder Inhaler for the Treatment of Acute Lung Injury.

Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) induces a severe cytokine storm that may cause acute lung injury/acute respiratory distress syndrome (ALI/ARDS) with high clinical morbidity and mortality in infected individuals. Cepharanthine (CEP) is a bisbenzylisoquinoline alkaloid isolated and extracted from Stephania cepharantha Hayata. It exhibits various pharmacological effects, including antioxidant, anti-inflammatory, immunomodulatory, anti-tumor, and antiviral activities. The low oral bioavailability of CEP can be attributed to its poor water solubility. In this study, we utilized the freeze-drying method to prepare dry powder inhalers (DPI) for the treatment of acute lung injury (ALI) in rats via pulmonary administration. According to the powder properties study, the aerodynamic median diameter (Da) of the DPIs was 3.2 µm, and the in vitro lung deposition rate was 30.26; thus, meeting the Chinese Pharmacopoeia standard for pulmonary inhalation administration. We established an ALI rat model by intratracheal injection of hydrochloric acid (1.2 mL/kg, pH = 1.25). At 1 h after the model's establishment, CEP dry powder inhalers (CEP DPIs) (30 mg/kg) were sprayed into the lungs of rats with ALI via the trachea. Compared with the model group, the treatment group exhibited a reduced pulmonary edema and hemorrhage, and significantly reduced content of inflammatory factors (TNF-α, IL-6 and total protein) in their lungs (p < 0.01), indicating that the main mechanism of CEP underlying the treatment of ALI is anti-inflammation. Overall, the dry powder inhaler can deliver the drug directly to the site of the disease, increasing the intrapulmonary utilization of CEP and improving its efficacy, making it a promising inhalable formulation for the treatment of ALI.

Basement membrane product, endostatin, as a link between inflammation, coagulation and vascular permeability in COVID-19 and non-COVID-19 acute respiratory distress syndrome.

Background: Immune cell recruitment, endothelial cell barrier disruption, and platelet activation are hallmarks of lung injuries caused by COVID-19 or other insults which can result in acute respiratory distress syndrome (ARDS). Basement membrane (BM) disruption is commonly observed in ARDS, however, the role of newly generated bioactive BM fragments is mostly unknown. Here, we investigate the role of endostatin, a fragment of the BM protein collagen XVIIIα1, on ARDS associated cellular functions such as neutrophil recruitment, endothelial cell barrier integrity, and platelet aggregation in vitro. Methods: In our study we analyzed endostatin in plasma and post-mortem lung specimens of patients with COVID-19 and non-COVID-19 ARDS. Functionally, we investigated the effect of endostatin on neutrophil activation and migration, platelet aggregation, and endothelial barrier function in vitro. Additionally, we performed correlation analysis for endostatin and other critical plasma parameters. Results: We observed increased plasma levels of endostatin in our COVID-19 and non-COVID-19 ARDS cohort. Immunohistochemical staining of ARDS lung sections depicted BM disruption, alongside immunoreactivity for endostatin in proximity to immune cells, endothelial cells, and fibrinous clots. Functionally, endostatin enhanced the activity of neutrophils, and platelets, and the thrombin-induced microvascular barrier disruption. Finally, we showed a positive correlation of endostatin with soluble disease markers VE-Cadherin, c-reactive protein (CRP), fibrinogen, and interleukin (IL)-6 in our COVID-19 cohort. Conclusion: The cumulative effects of endostatin on propagating neutrophil chemotaxis, platelet aggregation, and endothelial cell barrier disruption may suggest endostatin as a link between those cellular events in ARDS pathology.

2022 CAS Virtual Annual Meeting

The proceedings contain 63 papers. The topics discussed include: a retrospective study to optimize post-anesthetic recovery time after ambulatory lower limb orthopedic procedures at a tertiary care hospital in Canada;a virtual airway evaluation as good as the real thing?;airway management during in hospital cardiac arrest by a consultant led airway management team during the COVID-19 pandemic: a prospective and retrospective quality assurance project;prevention of cautery induced airway fire using saline filled endotracheal tube cuffs: a study in a trachea airway fire model;smart phone assisted retrograde illumination versus conventional laryngoscope illumination for orotracheal intubation: a prospective comparative trial;time to single lung isolation in massive pulmonary hemorrhage simulation using a novel bronchial blocker and traditional techniques;cannabinoid type 2 receptor activation ameliorates acute lung injury induced systemic inflammation;bleeding in patients with end-stage liver disease undergoing liver transplantation and fibrinogen level: a cohort study;endovascular Vena Cavae occlusion in right anterior mini-thoracoscopic approach for tricuspid valve in patients with previous cardiac surgery;and mesenchymal stem cell extracellular vesicles as a novel, regenerative nanotherapeutic for myocardial infarction: a preclinical systematic review.

Acute Fibrinous Organizing Pneumonia in a COVID-19 Patient: A Case Report

Background: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has varied clinical and radiographic manifestations. Severe initial viral infection, cytokine release, opportunistic infection and post-viral inflammation may all contribute to progressive symptoms and severe lung injury. Acute fibrinous and organizing pneumonitis (AFOP), a rare pattern of acute lung injury characterized by intra-alveolar fibrin ball, has so far been reported associated with infections, connective tissue diseases, drugs and toxins, hematologic malignancy, altered immune status and inhalation injury. Case Report: The authors report a case of 26-year-old man with severe COVID-19 pneumonia that clinical and radiographic imaging worsened after episode of cytokine storm. The diagnosis of AFOP was confirmed by transbronchial biopsy, and the patient was successfully treated with high-dose corticosteroids. Conclusion(s): AFOP can be found in severe COVID-19 patients especially when clinical deterioration occurs later in disease course. Clinical suspicion is needed for prompt diagnosis and treatment. High-dose corticosteroid is an effective medication.Copyright © 2023 JOURNAL OF THE MEDICAL ASSOCIATION OF THAILAND.

Integrative proteomic profiling of lung tissues and blood in acute respiratory distress syndrome.

Introduction: Acute respiratory distress syndrome and acute lung injury (ARDS/ALI) still lack a recognized diagnostic test and pharmacologic treatments that target the underlying pathology. Methods: To explore the sensitive non-invasive biomarkers associated with pathological changes in the lung of direct ARDS/ALI, we performed an integrative proteomic analysis of lung and blood samples from lipopolysaccharide (LPS)-induced ARDS mice and COVID-19-related ARDS patients. The common differentially expressed proteins (DEPs) were identified based on combined proteomic analysis of serum and lung samples in direct ARDS mice model. The clinical value of the common DEPs was validated in lung and plasma proteomics in cases of COVID-19-related ARDS. Results: We identified 368 DEPs in serum and 504 in lung samples from LPS-induced ARDS mice. Gene ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that these DEPs in lung tissues were primarily enriched in pathways, including IL-17 and B cell receptor signaling pathways, and the response to stimuli. In contrast, DEPs in the serum were mostly involved in metabolic pathways and cellular processes. Through network analysis of protein-protein interactions (PPI), we identified diverse clusters of DEPs in the lung and serum samples. We further identified 50 commonly upregulated and 10 commonly downregulated DEPs in the lung and serum samples. Internal validation with a parallel-reacted monitor (PRM) and external validation in the Gene Expression Omnibus (GEO) datasets further showed these confirmed DEPs. We then validated these proteins in the proteomics of patients with ARDS and identified six proteins (HP, LTA4H, S100A9, SAA1, SAA2, and SERPINA3) with good clinical diagnostic and prognostic value. Discussion: These proteins can be viewed as sensitive and non-invasive biomarkers associated with lung pathological changes in the blood and could potentially serve as targets for the early detection and treatment of direct ARDS especially in hyperinflammatory subphenotype.

PIMT is a novel and potent suppressor of endothelial activation.

Proinflammatory agonists provoke the expression of cell surface adhesion molecules on endothelium in order to facilitate leukocyte infiltration into tissues. Rigorous control over this process is important to prevent unwanted inflammation and organ damage. Protein L-isoaspartyl O-methyltransferase (PIMT) converts isoaspartyl residues to conventional methylated forms in cells undergoing stress-induced protein damage. The purpose of this study was to determine the role of PIMT in vascular homeostasis. PIMT is abundantly expressed in mouse lung endothelium and PIMT deficiency in mice exacerbated pulmonary inflammation and vascular leakage to LPS(lipopolysaccharide). Furthermore, we found that PIMT inhibited LPS-induced toll-like receptor signaling through its interaction with TNF receptor-associated factor 6 (TRAF6) and its ability to methylate asparagine residues in the coiled-coil domain. This interaction was found to inhibit TRAF6 oligomerization and autoubiquitination, which prevented NF-κB transactivation and subsequent expression of endothelial adhesion molecules. Separately, PIMT also suppressed ICAM-1 expression by inhibiting its N-glycosylation, causing effects on protein stability that ultimately translated into reduced EC(endothelial cell)-leukocyte interactions. Our study has identified PIMT as a novel and potent suppressor of endothelial activation. Taken together, these findings suggest that therapeutic targeting of PIMT may be effective in limiting organ injury in inflammatory vascular diseases.

Hyperglycemia and Hypoglycemia Contributions to Acute Respiratory Distress Syndrome

Purpose of Study Non-diabetic COVID-19 patients with elevated admission fasting blood glucose levels ('hyperglycemia') inexplicably have an increased 28 day mortality and higher inhospital complications including the Acute Respiratory Distress Syndrome (ARDS) but potentially contributing blood glucose changes during ARDS development were not reported (Wang S et al: Diabetologia 2020). Our goal was to determine blood glucose alterations before and during acute lung injury development in a rat model used to study ARDS. Methods Used We sequentially evaluated blood glucose levels for 24 hours and lung lavage protein levels (lung permeability) and lung lavage neutrophil numbers (lung inflammation) at 24 hours to assess acute lung injury ('ARDS') in young (~3 month) and old (~12 month) control and a novel strain of hyperoxia surviving 'resistant' rats before and after administering high and low insulin doses and before and after interleukin- 1/lipopolysaccharide (IL-1/LPS) insufflation. Summary of Results Glucose levels increase rapidly and sequentially in young control, but not young resistant, rats peaking ~2 hours after insufflation. Glucose levels also increase in old control and old resistant rats after insufflation compared to young control and young resistant rats after insufflation. The pattern of glucose levels at 2 hours after insufflation resembles lung lavage proteins and neutrophils at 24 h after insufflation (table 1). Administering high insulin (High In) doses decreases glucose levels ('hypoglycemia') and worsens ARDS while administering low insulin (Low In) doses correct glucose levels and improve ARDS. Conclusions Hyperglycemia develops in both young and old rats developing ARDS and high or low glucose levels parallel worse acute lung inflammation and acute lung injury ('ARDS'). Controlling glucose judiciously with insulin may be beneficial in combatting ARDS caused by SARS-CoV-2 infection and other insults.

Combined Therapy of Lung and Intestine in Treatment of Lung Diseases: A Review.

The theoretical origin of the combined therapy of lung and intestine can be traced back to the Inner Canon of Huangdi, which explains the physiological and pathological interaction between the lung and the large intestine. In recent years, researchers have investigated the scientific essence of the "lung- intestine axis" theory from many aspects, which enriches the relevant theoretical basis, and applied it to the treatment of COVID-19, acute lung injury, and other lung diseases. The close relation between lung and intestine in many aspects embodies the holistic conception of traditional Chinese medicine and explains the holistic theory of interrelation between organs, which correlate to each other physiologically and pathologically. Intestinal microecological disorders can affect lung immune function and cause respiratory diseases, and respiratory diseases are usually accompanied by gastrointestinal symptoms. Lung diseases can be prevented and treated by regulating intestinal flora. According to histoembryology, the epithelial tissue of the lung and intestine comes from primitive foregut. In immunology, both lung and intestine contain mucosa-associated lymphoid tissue, and the pathological changes of the respiratory tract are also closely related to intestinal microorganisms. The tissue origin of lung and large intestine, the correlation of mucosal immunity, and the synchronization of ecological changes provide a scientific basis for the combined therapy of lung and intestine. Therefore, this paper summarizes the theoretical origin, modern research mechanism, and clinical application of combined therapy of lung and intestine, in order to provide a new direction for its application in clinical and scientific research.Copyright © 2022, China Academy of Chinese Medical Sciences Institute of Chinese Materia Medica. All rights reserved.

The Role of Histone Deacetylases in Acute Lung Injury-Friend or Foe.

Acute lung injury (ALI), caused by intrapulmonary or extrapulmonary factors such as pneumonia, shock, and sepsis, eventually disrupts the alveolar-capillary barrier, resulting in diffuse pulmonary oedema and microatasis, manifested by refractory hypoxemia, and respiratory distress. Not only is ALI highly lethal, but even if a patient survives, there are also multiple sequelae. Currently, there is no better treatment than supportive care, and we urgently need to find new targets to improve ALI. Histone deacetylases (HDACs) are epigenetically important enzymes that, together with histone acetylases (HATs), regulate the acetylation levels of histones and non-histones. While HDAC inhibitors (HDACis) play a therapeutic role in cancer, inflammatory, and neurodegenerative diseases, there is also a large body of evidence suggesting the potential of HDACs as therapeutic targets in ALI. This review explores the unique mechanisms of HDACs in different cell types of ALI, including macrophages, pulmonary vascular endothelial cells (VECs), alveolar epithelial cells (AECs), and neutrophils.

SARS-CoV-2 N Protein Triggers Acute Lung Injury via Modulating Macrophage Activation and Infiltration in in vitro and in vivo.

Background: SARS-CoV-2-induced acute lung injury but its nucleocapsid (N) and/or Spike (S) protein involvements in the disease pathology remain elusive. Methods: In vitro, the cultured THP-1 macrophages were stimulated with alive SARS-CoV-2 virus at different loading dose, N protein or S protein with/without TICAM2-siRNA, TIRAP-siRNA or MyD88-siRNA. The TICAM2, TIRAP and MyD88 expression in the THP-1 cells after N protein stimulation were determined. In vivo, naïve mice or mice with depletion macrophages were injected with N protein or dead SARS-CoV-2. The macrophages in the lung were analyzed with flow cytometry, and lung sections were stained with H&E or immunohistochemistry. Culture supernatants and serum were harvested for cytokines measurements with cytometric bead array. Results: Alive SARS-CoV-2 virus or N protein but not S protein induced high cytokine releases from macrophages in a time or virus loading dependent manner. MyD88 and TIRAP but not TICAM2 were highly involved in macrophage activation triggered by N protein whilst both inhibited with siRNA decreased inflammatory responses. Moreover, N protein and dead SARS-CoV-2 caused systemic inflammation, macrophage accumulation and acute lung injury in mice. Macrophage depletion in mice decreased cytokines in response to N protein. Conclusion: SARS-CoV-2 and its N protein but not S protein induced acute lung injury and systemic inflammation, which was closely related to macrophage activation, infiltration and release cytokines.

The Effectiveness of Bevacizumab in COVID-19 Pneumonia Among Critically Ill Patients

Background:Bevacizumab, an antiangiogenic drug, is being evaluated for the management of novel coronavirus disease (COVID-19) pneumonia among critically ill patients. The objective of this study was to assess the effectiveness of bevacizumab in severe COVID-19 pneumonia. Methods:This was a retrospective, observational study performed in 111 patients diagnosed with COVID-19 pneumonia. Bevacizumab was administered intravenously at 7.5 mg/kg along with standard care in a non-randomly selected subset of patients (n = 29) with evidence of acute respiratory distress syndrome (ARDS) within 72 hours of worsening of oxygenation. The primary outcome measure was intensive care unit (ICU)-related mortality. Results:Bevacizumab was administered for a median of 9.4 (4-24) days from the onset of symptoms and 2.2 (1-3) days from the day of ICU admission. Bevacizumab-treated patients showed a statistically significant improvement in PF ratio and reduction in radiological severity score. In the bevacizumab group, 13 (44.8%) of 29 patients died in ICU, and in the standard-of-care group, 37 (45.1%) of 82 patients died. The difference in clinical status assessed using the World Health Organization 7-category Ordinary Scale at 28 days between the bevacizumab group and the standard-of-care group was not statistically significant (odds ratio 1.02, 95% confidence interval 0.44-2.4, P = .94). Conclusion:Bevacizumab plus standard care was not superior to standard care alone in reducing mortality and improving clinical outcomes at day 28.

COVID-19 convalescent plasma: Mechanisms of action and rationale for use: A narrative review

The use of convalescent plasma (CP) transfusions for patients with coronavirus disease 2019 (COVID-19) has gained great interest during the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic. This review aims at summarizing the literature on the potential mechanisms of action of COVID-19 CP (CCP) and the rationale for use. A narrative review of the literature was conducted using PubMed, Google Scholar, and the Cochrane Database through October 2020. The rationale of CCP deployment was based on historical use in other outbreaks and pandemics and the emergent need at the time of lack of proven therapies and vaccines. There are many proposed mechanisms of action including direct neutralization and suppression of viremia, antibody-dependent cellular cytotoxicity, modification of the inflammatory response, restoration of the coagulation factors, immunomodulation of the hypercoagulable state and the potential role of ABO naturally occurring iso-agglutinins. Many donor, product, and patient factors can impact the response to CCP, such as antibody titer in the CCP product, CCP dose, frequency of administration, the severity of underlying illness, and the timing of administration from time of disease onset. Based on current evidence, CCP appears to be safe. However, it remains unknown whether it impacts the improvement of clinical symptoms, time to death, and all-cause mortality. In conclusion, the use of CCP offers quick access as an empirical therapy when specific therapies are not available or under development. Ongoing clinical trials are expected to add to the breadth of knowledge on the safety and efficacy of CCP use in patients with COVID-19.Copyright © 2021 AME Publishing Company.

Stereoselective and regioselective Heck arylation at C-17 exocyclic double bond of andrographolide to generate labdane-based lead molecule against acute lung injury

Andrographolide (AG-1) is identified as an attractive scaffold based on in silico/in vitro/in vivo (preclinical and clinical) studies against COVID-19 infection, for which hardly any effective drug is available to date. Due to complexity of its chemical structure, stereoselective and regioselective Heck arylation reactions at C-17 exocyclic double bond of AG-1 is a major challenge and we stepped forward to generate a small focused library of compounds. Among all the molecules, AG-12 and AG-13 were predicted to have better pharmacokinetic profiles than AG-1. Upon evaluation of in vivo efficacy of AG-12 and AG-13 in comparison to AG-1 using an LPS-induced acute lung injury model, AG-13 showed promising action towards reduction of the neutrophil count, minimization of oxidative stress, and inhibition of inflammatory cytokines. Further, lead optimization should be carried out towards developing potential natural product-driven therapeutics to combat acute respiratory distress syndrome (ARDS) situations during COVID-19. © 2023 Elsevier B.V.

Esculin alleviates LPS-induced acute lung injury via inhibiting neutrophil recruitment and migration.

OBJECTIVES: Acute lung injury (ALI) poses a serious threat to human health globally, particularly with the Coronavirus 2019 (COVID-19) pandemic. Excessive recruitment and infiltration of neutrophils is the major etiopathogenesis of ALI. Esculin, also known as 6,7-dihydroxycoumarin, is a remarkable compound derived from traditional Chinese medicine Cortex fraxini. Accumulated evidence indicates that esculin has potent anti-inflammatory effects, but its pharmaceutical effect against ALI and potential mechanisms are still unclear. METHODS: This study evaluated the protective effect of esculin against ALI by histopathological observation and biochemical analysis of lung tissues and bronchoalveolar lavage fluid (BALF) in lipopolysaccharide (LPS)-challenged ALI mice in vivo. The effects of esculin on N-formyl-met-leu-phe (fMLP)-induced neutrophil migration and chemotaxis were quantitatively assessed using a Transwell assay and an automated cell imaging system equipped with a Zigmond chamber, respectively. The drug affinity responsive target stability (DARTS) assay, in vitro protein binding assay and molecular docking were performed to identify the potential therapeutic target of esculin and the potential binding sites and pattern. RESULTS: Esculin significantly attenuated LPS-induced lung pathological injury, reduced the levels of pro-inflammatory cytokines in both BALF and lung, and suppressed the activation of NF-κB signaling. Esculin also significantly reduced the number of total cells and neutrophils as well as myeloperoxidase (MPO) activity in the BALF. Esculin impaired neutrophil migration and chemotaxis as evidenced by the reduced migration distance and velocity. Furthermore, esculin remarkably inhibited Vav1 phosphorylation, suppressed Rac1 activation and the PAK1/LIMK1/cofilin signaling axis. Mechanistically, esculin could interact with ß2 integrin and then diminish its ligand affinity with intercellular adhesion molecule-1 (ICAM-1). CONCLUSIONS: Esculin inhibits ß2 integrin-dependent neutrophil migration and chemotaxis, blocks the cytoskeletal remodeling process required for neutrophil recruitment, thereby contributing to its protective effect against ALI. This study demonstrates the new therapeutic potential of esculin as a novel lead compound.

Acute Lung Injury in aortic dissection : new insights in anesthetic management strategies.

Acute aortic dissection (AAD) is a severe cardiovascular disease characterized by rapid progress and a high mortality rate. The incidence of acute aortic dissection is approximately 5 to 30 per 1 million people worldwide. In clinical practice, about 35% of AAD patients are complicated with acute lung injury (ALI). AAD complicated with ALI can seriously affect patients' prognosis and even increase mortality. However, the pathogenesis of AAD combined with ALI remains largely unknown. Given the public health burden of AAD combined with ALI, we reviewed the anesthetic management advances and highlighted potential areas for clinical practice.

Diosmetin alleviates acute lung injury caused by lipopolysaccharide by targeting barrier function.

Acute lung injury (ALI) is an acute and devastating disease caused by systemic inflammation e.g. patients infected with bacteria and viruses such as SARS-CoV-2 have an unacceptably high mortality rate. It has been well documented that endothelial cell damage and repair play a central role in the pathogenesis of ALI because of its barrier function. Nevertheless, the leading compounds that effectively accelerate endothelial cell repair and improve barrier dysfunction in ALI are largely unknown. In the present study, we found that diosmetin had promising characteristics to inhibit the inflammatory response and accelerate the repair of endothelial cells. Our results indicated that diosmetin accelerated wound healing and barrier repair by improving the expression of the barrier-related proteins, including zonula occludens-l (ZO-1) and occludin, in human umbilical vein endothelial cells (HUVECs) treated with lipopolysaccharide (LPS). Meanwhile, diosmetin administration significantly inhibited inflammatory response by decreasing the content of TNFα and IL-6 in the serum, alleviated lung injury by reducing lung wet/dry (W/D) ratio and histologic score, improved endothelial hyperpermeability by decreasing protein levels and neutrophil infiltration in the bronchoalveolar lavage fluid (BALF) and increasing ZO-1 and occludin expression in the lung tissues of LPS-treated mice. Mechanistically, diosmetin also mediated the expression of Rho A and ROCK1/2 in HUVECs treated with LPS, and fasudil, a Rho A inhibitor remarkably inhibited the role of diosmetin in ZO-1 and occludin proteins. All these findings of this study revealed that diosmetin can be an effective protector of lung injury and the Rho A/ROCK1/2 signal pathway plays a pivotal role in diosmetin accelerating barrier repair in ALI.

Choice of respiratory therapy for COVID-19 patients with acute hypoxemic respiratory failure: a retrospective case series study.

Background: In the treatment of acute hypoxemic respiratory failure (AHRF) due to coronavirus 2019 (COVID-19), physicians choose respiratory management ranging from low-flow oxygen therapy to more invasive methods, depending on the severity of the patient's symptoms. Recently, the ratio of oxygen saturation (ROX) index has been proposed as a clinical indicator to support the decision for either high-flow nasal cannulation (HFNC) or mechanical ventilation (MV). However, the reported cut-off value of the ROX index ranges widely from 2.7 to 5.9. The objective of this study was to identify indices to achieve empirical physician decisions for MV initiation, providing insights to shorten the delay from HFNC to MV. We retrospectively analyzed the ROX index 6 hours after initiating HFNC and lung infiltration volume (LIV) calculated from chest computed tomography (CT) images in COVID-19 patients with AHRF. Methods: We retrospectively analyzed the data for 59 COVID-19 patients with AHRF in our facility to determine the cut-off value of the ROX index for respiratory therapeutic decisions and the significance of radiological evaluation of pneumonia severity. The physicians chose either HFNC or MV, and the outcomes were retrospectively analyzed using the ROX index for initiating HFNC. LIV was calculated using chest CT images at admission. Results: Among the 59 patients who required high-flow oxygen therapy with HFNC at admission, 24 were later transitioned to MV; the remaining 35 patients recovered. Four of the 24 patients in the MV group died, and the ROX index values of these patients were 9.8, 7.3, 5.4, and 3.0, respectively. These index values indicated that the ROX index of half of the patients who died was higher than the reported cut-off values of the ROX index, which range from 2.7-5.99. The cut-off value of the ROX index 6 hours after the start of HFNC, which was used to classify the management of HFNC or MV as a physician's clinical decision, was approximately 6.1. The LIV cut-off value on chest CT between HFNC and MV was 35.5%. Using both the ROX index and LIV, the cut-off classifying HFNC or MV was obtained using the equation, LIV = 4.26 × (ROX index) + 7.89. The area under the receiver operating characteristic curve, as an evaluation metric of the classification, improved to 0.94 with a sensitivity of 0.79 and specificity of 0.91 using both the ROX index and LIV. Conclusion: Physicians' empirical decisions associated with the choice of respiratory therapy for HFNC oxygen therapy or MV can be supported by the combination of the ROX index and the LIV index calculated from chest CT images.

Exploring m6A-RNA methylation as a potential therapeutic strategy for acute lung injury and acute respiratory distress syndrome.

N6-methyladenosine (m6A) is the most common methylation modification in mammalian messenger RNA (mRNA) and noncoding RNAs. m6A modification plays a role in the regulation of gene expression and deregulation of m6A methylation has been implicated in many human diseases. Recent publications suggest that exploitation of this methylation process may possess utility against acute lung injury (ALI). ALI and its more severe form, acute respiratory distress syndrome (ARDS) are acute, inflammatory clinical syndromes characterized by poor oxygenation and diffuse pulmonary infiltrates. This syndrome is associated with microvascular endothelial dysfunction, subsequent pulmonary hypertension and may ultimately lead to mortality without rigorous and acute clinical intervention. Over the years, many attempts have been made to detect novel therapeutic avenues for research without much success. The urgency for the discovery of novel therapeutic agents has become more pronounced recently given the current pandemic infection of coronavirus disease 2019 (COVID-2019), still ongoing at the time that this review is being written. We review the current landscape of literature regarding ALI and ARDS etiology, pathophysiology, and therapeutics and present a potential role of m6A methylation. Additionally, we will establish the axiomatic principles of m6A methylation to provide a framework. In conclusion, METTL3, or methyltransferase-like 3, the selective RNA methyltransferase for m6A, is a hub of proinflammatory gene expression regulation in ALI, and using a modern drug discovery strategy will identify new and effective ALI drug candidates targeting METTTL3.