Severe Lung Injury Research Articles

Immunomodulatory activity of omadacycline in vitro and in a murine model of acute lung injury.

Cystic fibrosis (CF) is characterized by chronic airway obstruction, infection, and inflammation leading to progressive loss of lung function and eventual respiratory failure. Omadacycline, a tetracycline antibiotic, demonstrates in vitro activity against key CF pathogens, substantial lung penetration, and increasing clinical evidence for the treatment of lung infections in people with CF (PwCF). Preliminary in vitro data demonstrate that omadacycline exhibits anti-inflammatory activity. This study aims to determine the anti-inflammatory effects of omadacycline in vitro and in a murine model of lipopolysaccharide (LPS)-induced lung neutrophilia. In vitro, THP-1-derived macrophages were treated with omadacycline (20-100 µg/mL) 30 minutes prior to LPS stimulation. Pro-inflammatory cytokine (TNF-α, IL-1β/6), chemokine (CXCL-1/2), and MMP-9 levels were analyzed after 24 hours by ELISA. Omadacycline's effects on IL-8-induced human neutrophil chemotaxis were also investigated. In vivo, omadacycline (2.5-30 mg/kg), comparators dexamethasone (1 mg/kg), and azithromycin (30 mg/kg) were administered 1 hour before and 6 hours after intranasal LPS challenge, respectively. Leukocyte counts and differentials in bronchoalveolar lavage fluid (BALF), inflammatory mediator levels in BALF and lung homogenates, pulmonary edema markers, and the severity of lung injury were evaluated 24 hours or 48 hours post-challenge. Treatment with omadacycline in vitro resulted in significant, dose-dependent reductions in IL-6, CXCL-1, and MMP-9 expression and inhibition of IL-8-induced neutrophil chemotaxis. In vivo, omadacycline yielded protective and therapeutic effects by reducing the production of proinflammatory cytokines and chemokines and neutrophil infiltration into the lungs, along with modestly improving lung injury severity. These preclinical results suggest that omadacycline may provide dual anti-bacterial and anti-inflammatory activities relevant to chronic lung infection treatment in PwCF.IMPORTANCENontuberculous mycobacteria, particularly Mycobacterium abscessus complex (MABSC), are a major concern for people with cystic fibrosis (PwCF) due to their association with deteriorating lung function. A substantial barrier to effective treatment is the limited number of safe and effective antibiotics. Omadacycline offers a potential advancement in managing MABSC infections in cystic fibrosis due to its activity, effective penetration into pulmonary secretions, improved tolerability, and good oral bioavailability as shown in healthy volunteers. Our study is the first to explore omadacycline's effects in a model of sterile lung inflammation and acute lung injury. We found that omadacycline not only has potent anti-bacterial properties but also exhibits anti-inflammatory effects, reducing lung inflammation and injury in our preclinical models. These findings underscore omadacycline's potential as a dual-action therapy for lung infections in PwCF, indicating significant potential to improve patient outcomes and guide more effective antimicrobial therapy decisions.

Heme Oxygenase-1 Protected Against Severe Acute Pancreatitis by Inhibiting Inflammatory Response

Abstract Background Activation of NLPR3 inflammasome promotes the maturation and secretion of IL-1β and IL-18, leading to a series of inflammatory reactions, while inhibition of NLRP3 inflammasome alleviates the severity of Severe Acute Pancreatitis (SAP). An inducible enzyme responsible for heme decomposition, heme oxygenase-1 (HO-1), has anti-inflammatory, antioxidant, and anti-proliferative effects. HO-1 activity profoundly affects the host ability to forbear infection by reducing tissue damage or affecting resistance and increasing the capacity to pathogen load. We postulated that hemin, a strong HO-1 inducer, could decrease NLRP3 inflammasome activation, which would alleviate the severity of SAP and acute lung injury caused by pancreatitis. Methods By administering intraperitoneal injections of caerulein (Cae) and lipopolysaccharide (LPS), the SAP rat model was created. Then, the SAP rats were pretreated with Hemin or zinc protoporphyrin IX (Znpp, a HO-1 inhibitor) to stimulate or inhibit the HO-1 enzyme respectively, and the effects and mechanisms were investigated. Results The pancreas and lung tissue of the SAP rats suffered considerable pathological damage after Cae and LPS injection, with significant increases of amylase, lipase, IL-1β and IL-18 levels in the serum. Hemin pretreatment decreased IL-1β and IL-18 release in the serum and prevented pancreatic and pulmonary damage. Hemin dramatically reduced oxidative stress, downregulated the expression of NLRP3, ASC, and Caspase-1, and elevated HO-1 expression. On the contrary, there were no discernible changes between the SAP control and Znpp treated groups. Conclusion These results showed that hemin prevented Cae and LPS-induced lung and pancreatic injury through suppression of the inflammatory response. The impact of hemin on the activity of the NLRP3 inflammasome was depending critically on HO-1 activity. The protective role and mechanism HO-1 against the acute and severe inflammatory responses may provide a novel and effective therapeutic approach for SAP treatment.

Priming Mesenchymal Stem Cells with Lipopolysaccharide Boosts the Immunomodulatory and Regenerative Activity of Secreted Extracellular Vesicles

Background: Mesenchymal stem cells (MSCs)-derived extracellular vesicles (EVs) have been proposed as an alternative to live-cell administration for Acute Respiratory Distress Syndrome (ARDS). MSC-EVs can be chiefly influenced by the environment to which the MSCs are exposed. Here, lipopolysaccharide (LPS) priming of MSCs was used as a strategy to boost the natural therapeutic potential of the EVs in acute lung injury (ALI). Methods: The regenerative and immunemodulatory effect of LPS-primed MSC-EVs (LPS-EVs) and non-primed MSC-EVs (C-EVs) were evaluated in vitro on alveolar epithelial cells and macrophage-like THP-1 cells. In vivo, ALI was induced in adult male rats by the intrapulmonary instillation of HCl and LPS. Rats (n = 8 to 22/group) were randomized to receive a single bolus (1 × 108 particles) of LPS-EVs, C-EVs, or saline. Lung injury severity was assessed at 72 h in lung tissue and bronchoalveolar lavage. Results: In vitro, LPS-EVs improved wound regeneration and attenuated the inflammatory response triggered by the P. aeruginosa infection, enhancing the M2 macrophage phenotype. In in vivo studies, LPS-EVs, but not C-EVs, significantly decreased the neutrophilic infiltration and myeloperoxidase (MPO) activity in lung tissue. Alveolar macrophages from LPS-EVs-treated animals exhibited a reduced expression of CXCL-1, a key neutrophil chemoattractant. However, both C-EVs and LPS-EVs reduced alveolar epithelial and endothelial permeability, mitigating lung damage. Conclusions: EVs from LPS-primed MSCs resulted in a better resolution of ALI, achieving a greater balance in neutrophil infiltration and activation, while avoiding the complete disruption of the alveolar barrier. This opens new avenues, paving the way for the clinical implementation of cell-based therapies.

“CAMPANHA DE ALERTA AOS RISCOS DO CIGARRO ELETRÔNICO.”

The DEF’S (electronic devices for smoking) were created under the pretext of helping smokers to quit the conventional cigarette, eventually attracting a new audience: young people. Through different flavors, flashy colors, practical formats, small and that fit in any pocket. In Brazil, it is forbidden to commercialize this product as a precaution against diseases that may arise. But it’s not hard to find them for sale. Severe lung injuries lead to addiction to nicotine. In addition, they can cause damage to the oral mucosa, irritation of the throat and eyes, rhinitis, pneumonia and other conditions. Serious problems that many young people and teens lack a knowledge that these e-cigarettes can cause. Accompanied by sharing among themselves that can lead to communicable diseases. The objective of this project is to disseminate predominant information on the use of electronic devices to young people and adolescents. It is expected that through this project we will be able to show the negative impacts of DEF’S (electronic devices for smoking).

Single-cell transcriptome analysis of the mouse lungs during the injury and recovery periods after lipopolysaccharide administration.

This study sought to investigate the cellular and molecular alterations during the injury and recovery periods of ALI and develop effective treatments for ALI. Pulmonary histology at 1, 3, 6, and 9 days after lipopolysaccharide administration mice were assessed. An unbiased single-cell RNA sequencing was performed in alveoli tissues from injury (day 3) and recovery (day 6) mice after lipopolysaccharide administration. The roles of Fpr2 and Dpp4 in ALI were assessed. The most severe lung injury occurred on day 3, followed by recovery entirely on day 9 after lipopolysaccharide administration. The numbers of Il1a+ neutrophils, monocytes/macrophages, and Cd4+ and Cd8+ T cells significantly increased at day 3 after LPS administration; subsequently, the number of Il1a+ neutrophils greatly decreased, the numbers of monocytes/macrophages and Cd4+ and Cd8+ T cells continuously increased, and the number of resident alveolar macrophages significantly increased at day 6. The interactions between monocytes/macrophages and pneumocytes during the injury period were enhanced by the Cxcl10/Dpp4 pair, and inhibiting Dpp4 improved ALI significantly, while inhibiting Fpr2 did not. Our results offer valuable insights into the cellular and molecular mechanisms underlying its progression and identify Dpp4 as an effective therapeutic target for ALI.

Improved Discriminability of Severe Lung Injury and Atelectasis in Thoracic Trauma at Low keV Virtual Monoenergetic Images from Photon-Counting Detector CT

Objectives: To evaluate the value of virtual monoenergetic images (VMI) from photon-counting detector CT (PCD-CT) for discriminability of severe lung injury and atelectasis in polytraumatized patients. Materials & Methods: Contrast-enhanced PCD-CT examinations of 20 polytraumatized patients with severe thoracic trauma were included in this retrospective study. Spectral PCD-CT data were reconstructed using a noise-optimized virtual monoenergetic imaging (VMI) algorithm with calculated VMIs ranging from 40 to 120 keV at 10 keV increments. Injury-to-atelectasis contrast-to-noise ratio (CNR) was calculated and compared at each energy level based on CT number measurements in severely injured as well as atelectatic lung areas. Three radiologists assessed subjective discriminability, noise perception, and overall image quality. Results: CT values for atelectasis decreased as photon energy increased from 40 keV to 120 keV (mean Hounsfield units (HU): 69 at 40 keV; 342 at 120 keV), whereas CT values for severe lung injury remained near-constant from 40 keV to 120 keV (mean HU: 42 at 40 keV; 44 at 120 keV) with significant differences at each keV level (p < 0.001). The optimal injury-to-atelectasis CNR was observed at 40 keV in comparison with the remaining energy levels (p < 0.001) except for 50 keV (p > 0.05). In line with this, VMIs at 40 keV were rated best regarding subjective discriminability. VMIs at 60–70 keV, however, provided the highest subjective observer parameters regarding subjective image noise as well as image quality. Conclusions: Discriminability between severely injured and atelectatic lung areas after thoracic trauma can be substantially improved by virtual monoenergetic imaging from PCD-CT with superior contrast and visual discriminability at 40–50 keV.

Predictive Factors for Onset of Moderate-to-Severe Disability Following Hospital Discharge Due to Rib Fractures.

According to previous studies, a prolonged hospital stay, along with the patient's clinical features, can lead to the onset of disability. This study aimed to identify predictive factors of moderate-to-severe disability following hospital discharge in rib fracture patients. We conducted a retrospective study with hospitalized adult patients with rib fractures who received conservative treatment. Patients' clinical profiles and characteristics were collected from their clinical histories and healthcare professional records. Overall, patients exhibited a 44% rate of moderate-to-severe disability after a six-day hospital stay. The incidence of patients with a prolonged hospital stay who showed disabilities was associated with male sex (HR 0.73, p < 0.001), presence of first rib fracture (HR 1.78, p = 0.047), presence of flail chest (HR 1.29, p = 0.046), severity of lung injury (HR 1.65, p < 0.001), and functional status (HR 1.37, p < 0.001). Moderate-to-severe disability in patients with rib fractures may depend on factors such as sex, functionality, severity of lung injury, and presence of first rib fracture and flail chest during a prolonged hospital stay.

The surfactant protein B polymorphisms (rs7316 and rs1130866) and their correlation with disease progression of COVID-19

BackgroundIt is critical to examine the pathogenic pathways in coronavirus disease 2019 (COVID-19) that resulted in the development of severe lung injury. Surfactant protein B (SFTPB) is a vital component for sustaining life and serves pivotal functions in the host’s defensive mechanisms and alveolar surface tension reduction. Our study aimed to determine the effect of SFTPB rs7316 and rs1130866 variants on the course of disease in COVID-19 patients. MethodsThe study cohort comprised 3,184 individuals diagnosed with COVID-19. We employed the RFLP approach to determine the variations of the SFTPB genes. ResultsSFTPB rs7316 did not exhibit a statistically significant correlation with COVID-19 mortality across different inheritance models. But, after making more changes for SARS-CoV-2 variants, it was found that there was a strong link between the TT and TC genotypes of SFTPB rs7316 and death rates, especially for the Delta variant. Furthermore, our study’s findings indicate a significant association between the SFTPB rs1130866 G allele and an elevated risk of mortality in COVID-19 across all variants of SARS-CoV-2. ConclusionsThe use of the SFTPB rs1130866 marker has the potential to facilitate the prediction of COVID-19 severity. On the other hand, for SFTPB rs7316, this kind of prediction seems to depend on the particular SARS-CoV-2 variants.

Omicron XBB.1.5 subvariant causes severe pulmonary disease in K18-hACE-2 mice.

Owing to their continuous evolution, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) display disparate pathogenicity in mouse models. Omicron and its sublineages have been dominant worldwide. Compared to pre-Omicron VOCs, early Omicron subvariants reportedly cause attenuated disease in human ACE-2-expressing mice (K18-hACE-2). In late 2022, the frequency of Omicron subvariant XBB.1.5 rapidly increased and it progressively replaced other circulating strains. The emergence of new strains requires current SARS-CoV-2 clinical animal model re-evaluation. In this study, we aim to characterize XBB.1.5 pathogenesis in K18-hACE-2. Herein, we demonstrated that XBB.1.5 infection is associated with significant weight loss, severe lung pathology, and substantial mortality. Intranasal XBB.1.5 infection resulted in 100% mortality in K18-hACE2 mice. High virus titers were detected in the lungs on days 3 and 5 after infection. Moreover, XBB.1.5 productively infected the cells within the nasal turbinate, olfactory bulb, intestines, and kidneys. In addition, in a subset of infected mice, we detected high virus titers in the brain. Consistently, we detected high viral antigen expression in the lungs. Furthermore, we observed severe lung injury hallmarks (e.g., immune cell infiltration, perivascular cuffing, and alveolar consolidation). Using immunofluorescence labeling and cytometric analysis, we revealed that XBB.1.5 infection leads to CD45+ cell influx into the lung parenchyma. We further demonstrated that most immune infiltrates are CD11b+ CD11c+ dendritic cells. Additionally, we detected significant induction of proinflammatory cytokines and chemokines in infected lungs. Taken together, our data show that Omicron subvariant XBB.1.5 is highly pathogenic in K18-hACE2 mice.

Comparative pathogenicity of influenza virus-induced pneumonia mouse model following intranasal and aerosolized intratracheal inoculation

BackgroundInfection of mice with mouse-adapted strains of influenza virus has been widely used to establish mouse pneumonia models. Intranasal inoculation is the traditional route for constructing an influenza virus-induced pneumonia mouse model, while intratracheal inoculation has been gradually applied in recent years. In this article, the pathogenicity of influenza virus-induced pneumonia mouse models following intranasal and aerosolized intratracheal inoculation were compared.MethodsBy comparing the two ways of influenza inoculation, intranasal and intratracheal, a variety of indices such as survival rate, body weight change, viral titer and load, pathological change, lung wet/dry ratio, and inflammatory factors were investigated. Meanwhile, the transcriptome was applied for the initial exploration of the mechanism underlying the variations in the results between the two inoculation methods.ResultsThe findings suggest that aerosolized intratracheal infection leads to more severe lung injury and higher viral loads in the lungs compared to intranasal infection, which may be influenced by the initial site of infection, sialic acid receptor distribution, and host innate immunity.ConclusionIntratracheal inoculation is a better method for modelling severe pneumonia in mice than intranasal infection.

Exploring the intersection of disasters and science education with preservice science teachers through a disaster case study

AbstractModern society is under increasing threats of natural and technological disasters, which involve complex interactions among science, technology and social structures. Although a scientific understanding of disasters is an immediate global issue, there is limited discussion about how disasters can relate to science education. To address this gap, we report findings from a research study to support preservice science teachers’ learning about disasters and its relevance to science education. Fifteen preservice science teachers participated in a six-hour workshop focused on the scientific and sociotechnical aspects of the humidifier disinfectant disaster, which caused severe lung injuries to half a million people in South Korea. The study aim was to identify preservice science teachers’ perceptions about how disasters can be incorporated into science teaching. The participants were engaged in a series of group activities using the official investigation report, followed by a discussion on the aspects of science, technology, and society that unfolded in the disaster. Our analysis suggested that the participants were able to discover important aspects of the mutual relationship between science and disasters, and propose various cognitive, attitudinal, and functional aims that could be pursued by embedding disasters in science lessons. The lesson plans showed that the participants were able to suggest how to use disasters in science lessons and leverage diverse teaching methods to achieve their lesson goals. However, the shift in their perceptions before and after the workshop was limited. We argue that support is necessary for preservice science teachers to incorporate disasters into the science classroom, by providing more time and resources and lowering the barriers related to the political and traumatic aspects of disasters.

Curcumin-mediated enhancement of lung barrier function in rats with high-altitude-associated acute lung injury via inhibition of inflammatory response

BackgroundExposure to a hypobaric hypoxic environment at high altitudes can lead to lung injury. In this study, we aimed to determine whether curcumin (Cur) could improve lung barrier function and protect against high-altitude-associated acute lung injury.MethodsTwo hundred healthy rats were randomly divided into standard control, high-altitude control (HC), salidroside (40 mg/kg, positive control), and Cur (200 mg/kg) groups. Each group was further divided into five subgroups. Basic vital signs, lung injury histopathology, routine blood parameters, plasma lactate level, and arterial blood gas indicators were evaluated. Protein and inflammatory factor (tumor necrosis factor α (TNF-α), interleukin [IL]-1β, IL-6, and IL-10) concentrations in bronchoalveolar lavage fluid (BALF) were determined using the bicinchoninic acid method and enzyme-linked immunosorbent assay, respectively. Inflammation-related and lung barrier function-related proteins were analyzed using immunoblotting.ResultsCur improved blood routine indicators such as hemoglobin and hematocrit and reduced the BALF protein content and TNF-α, IL-1β, and IL-6 levels compared with those in the HC group. It increased IL-10 levels and reduced pulmonary capillary congestion, alveolar hemorrhage, and the degree of pulmonary interstitial edema. It increased oxygen partial pressure, oxygen saturation, carbonic acid hydrogen radical, and base excess levels, and the expression of zonula occludens 1, occludin, claudin-4, and reduced carbon dioxide partial pressure, plasma lactic acid, and the expression of phospho-nuclear factor kappa.ConclusionsExposure to a high-altitude environment for 48 h resulted in severe lung injury in rats. Cur improved lung barrier function and alleviated acute lung injury in rats at high altitudes.

Impact of the transpulmonary pressure on right ventricle impairment incidence during acute respiratory distress syndrome: a pilot study in adults and children

BackgroundRight ventricle impairment (RVI) is common during acute respiratory distress syndrome (ARDS) in adults and children, possibly mediated by the level of transpulmonary pressure (PL). We sought to investigate the impact of the level of PL on ARDS-associated right ventricle impairment (RVI).MethodsAdults and children (> 72 h of life) were included in this two centers prospective study if they were ventilated for a new-onset ARDS or pediatric ARDS, without spontaneous breathing and contra-indication to esophageal catheter. Serial measures of static lung, chest wall, and respiratory mechanics were coupled to critical care echocardiography (CCE) for 3 days. Mixed-effect logistic regression models tested the impact of lung stress (ΔPL) along with age, lung injury severity, and carbon dioxide partial pressure, on RVI using two definitions: acute cor pulmonale (ACP), and RV dysfunction (RVD). ACP was defined as a dilated RV with septal dyskinesia; RVD was defined as a composite criterion using tricuspid annular plane systolic excursion, S wave velocity, and fractional area change.Results46 patients were included (16 children, 30 adults) with 106 CCE (median of 2 CCE/patient). At day one, 19% of adults and 4/7 children > 1 year exhibited ACP, while 59% of adults and 44% of children exhibited RVD. In the entire population, ACP was present on 17/75 (23%) CCE. ACP was associated with an increased lung stress (mean ΔPL of 16.2 ± 6.6 cmH2O in ACP vs 11.3 ± 3.6 cmH2O, adjusted OR of 1.33, CI95% [1.11–1.59], p = 0.002) and being a child. RVD was present in 59/102 (58%) CCE and associated with lung stress. In children > 1 year, PEEP was significantly lower in case of ACP (9.3 [8.6; 10.0] cmH2O in ACP vs 15.0 [11.9; 16.3] cmH2O, p = 0.03).ConclusionLung stress was associated with RVI in adults and children with ARDS, children being particularly susceptible to RVI.Trial registration Clinical trials identifier: NCT0418467.

COVID-19-Induced Changes in the Fibrin Network of Pulmonary and Renal Microthrombi

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection often causes coagulation disorders that affect highly vascularized organs, such as the lungs and kidneys. Objective The objective of this study was to report the histopathological findings of variations in the fibrin pattern of pulmonary and renal microthrombi in patients who died from SARS-CoV-2 infection. Methods Minimally invasive autopsies were performed on 40 patients to collect lung (n=40) and kidney (n=16) tissue samples. Histochemical and immunohistochemical staining techniques were used for histopathological analyses. Premortem laboratory data were obtained from the patients' electronic medical records. Results The lung tissue showed a patchy pattern, characterized by areas of both minimal and severe damage. The most significant histopathological finding was the detection of thrombi with fibrin structures organized into discrete star-shaped units, which were more frequently observed in areas with severe lung injury than in those with minimal lung injury (p = 0.012). Star-shaped fibrin structures were also observed in the renal glomerular capillaries. Immunohistochemical staining revealed the presence of platelets and the procoagulant proteins von Willebrand factor (VWF) and Factor VIII within the star-shaped fibrin thrombi. Patients with star-shaped fibrin thrombi had higher levels of the systemic inflammatory indicators C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio (NLR). Conclusion Our observations suggest that the inflammatory microenvironment resulting from SARS-CoV-2 infection may contribute to the formation of star-shaped fibrin units in the pulmonary and renal microthrombi.

Nebulized Lipopolysaccharide Causes Delayed Cortical Neuroinflammation in a Murine Model of Acute Lung Injury.

Lung injury caused by respiratory infection is a major cause of hospitalization and mortality and a leading origin of sepsis. Sepsis-associated encephalopathy and delirium are frequent complications in patients with severe lung injury, yet the pathogenetic mechanisms remain unclear. Here, 70 female C57BL/6 mice were subjected to a single full-body-exposure with nebulized lipopolysaccharide (LPS). Neuromotor impairment was assessed repeatedly and brain, blood, and lung samples were analyzed at survival points of 24 h, 48 h, 72 h, and 96 h after exposure. qRT-PCR revealed increased mRNA-expression of TNFα and IL-1β 24 h and 48 h after LPS-exposure in the lung, concomitantly with increased amounts of proteins in bronchoalveolar lavage and interstitial lung edema. In the cerebral cortex, at 72 h and/or 96 h after LPS exposure, the inflammation- and activity-associated markers TLR4, GFAP, Gadd45b, c-Fos, and Arc were increased. Therefore, single exposure to nebulized LPS not only triggers an early inflammatory reaction in the lung but also induces a delayed neuroinflammatory response. The identified mechanisms provide new insights into the pathogenesis of sepsis-associated encephalopathy and might serve as targets for future therapeutic approaches.

Differential Immunoregulation by Human Surfactant Protein A Variants Determines Severity of SARS-CoV-2-induced Lung Disease.

COVID-19 remains a significant threat to public health globally. Infection in some susceptible individuals causes life-threatening acute lung injury (ALI/ARDS) and/or death. Human surfactant protein A (SP-A) is a C-type lectin expressed in the lung and other mucosal tissues, and it plays a critical role in host defense against various pathogens. The human SP-A genes ( SFTPA1 and SFTPA2 ) are highly polymorphic and comprise several common genetic variants, i.e., SP-A1 (variants 6A 2 , 6A 4 ) and SP-A2 (variants 1A 0 , 1A 3 ). Here, we elucidated the differential antiviral and immunoregulatory roles of SP-A variants in response to SARS-CoV-2 infection in vivo . Six genetically-modified mouse lines, expressing both hACE2 (SARS-CoV-2 receptor) and individual SP-A variants: (hACE2/6A 2 (6A 2 ), hACE2/6A 4 (6A 4 ), hACE2/1A 0 (1A 0 ), and hACE2/1A 3 (1A 3 ), one SP-A knockout (hACE2/SP-A KO (KO) and one hACE2/mouse SP-A (K18) mice, were challenged intranasally with 10 3 PFU SARS-CoV-2 or saline (Sham). Infected KO and 1A 0 mice had more weight loss and mortality compared to other mouse lines. Relative to other infected mouse lines, a more severe ALI was observed in KO, 1A 0 , and 6A 2 mice. Reduced viral titers were generally observed in the lungs of infected SP-A mice relative to KO mice. Transcriptomic analysis revealed an upregulation in genes that play central roles in immune responses such as MyD88 , Stat3 , IL-18 , and Jak2 in the lungs of KO and 1A 0 mice. However, Mapk1 was significantly downregulated in 6A 2 versus 1A 0 mice. Analysis of biological pathways identified those involved in lung host defense and innate immunity, including pathogen-induced cytokine, NOD1/2, and Trem1 signaling pathways. Consistent with the transcriptomic data, levels of cytokines and chemokines such as G-CSF, IL-6 and IL-1β were comparatively higher in the lungs and sera of KO and 1A 0 mice with the highest mortality rate. These findings demonstrate that human SP-A variants differentially modulate SARS-CoV-2-induced lung injury and disease severity by differentially inhibiting viral infectivity and regulating immune-related gene expressions.

Preconditioning with β-hydroxybutyrate attenuates lung ischemia-reperfusion injury by suppressing alveolar macrophage pyroptosis through the SIRT1-FOXO3 signaling pathway.

The complex pathogenesis of lung ischemia-reperfusion injury (LIRI) was examined in a murine model, focusing on the role of pyroptosis and its exacerbation of lung injury. We specifically examined the levels and cellular localization of pyroptosis within the lung, which revealed alveolar macrophages as the primary site. The inhibition of pyroptosis by VX-765 reduced the severity of lung injury, underscoring its significant role in LIRI. Furthermore, the therapeutic potential of β-hydroxybutyrate (β-OHB) in ameliorating LIRI was examined. Modulation of β-OHB levels was evaluated by ketone ester supplementation and 3-hydroxybutyrate dehydrogenase 1 (BDH-1) gene knockout, along with the manipulation of the SIRT1-FOXO3 signaling pathway using EX-527 and pCMV-SIRT1 plasmid transfection. This revealed that β-OHB exerts lung-protective and anti-pyroptotic effects, which were mediated through the upregulation of SIRT1 and the enhancement of FOXO3 deacetylation, leading to decreased pyroptosis markers and lung injury. In addition, β-OHB treatment of MH-S cells invitro showed a concentration-dependent improvement in pyroptosis, linking its therapeutic benefits to specific cell mechanisms. Overall, this study highlights the significance of alveolar macrophage pyroptosis in the exacerbation of LIRI and indicates the potential of β-OHB in mitigating injury by modulating the SIRT1-FOXO3 signaling pathway.

Protection of Parkin over-expression on lung in rats with exertional heat stroke by activating mitophagy

ObjectiveTo investigate the role of Parkin overexpression-induecd mitophagy in alleviating acute lung injury of exertional heat stroke(EHS) rats.MethodsEighty SD rats were divided into four groups: Control group (CON group), Control Parkin overexpression group (CON + Parkin group), exertional heat stroke group (EHS group), and exertional heat stroke Parkin overexpression group (EHS + Parkin group). Adeno-associated virus carrying the Parkin gene was intravenously injected into the rats to overexpress Parkin in the lung tissue. An exertional heat stroke rat model was established, and survival curves were plotted. Lung Micro-CT was performed, and lung coefficient and pulmonary microvascular permeability were measured. Enzyme-linked immunosorbent assays(ELISA) were used to determine the levels of interleukin-6(IL-6), interleukin-1β(IL-1β), Tumor necrosis factor-α(TNF-α), and reactive oxygen species(ROS). The morphology of mitochondria in type II epithelial cells of lung tissue was observed using transmission electron microscopy. The apoptosis of lung tissue, the level of mitophagy, and the co-localization of Pink1 and Parkin were determined using immunofluorescence. The expression of Pink1, Parkin, MFN2, PTEN-L, PTEN, p62, and microtubule associated protein 1 light chain 3 (LC3) in rat lung tissue was measured by western blot.ResultsCompared with the CON group, there were more severe lung injury and more higher levels of IL-6, IL-1β, TNF-α in EHS rats. Both of the LC3-II/LC3-I ratio and the co-localization of LC3 and Tom20 in the lung tissue of EHS rats decreased. Compared with the EHS group, the survival rate of rats in the EHS + Parkin overexpression group was significantly increased, lung coefficient and pulmonary microvascular permeability were reduced, and pathological changes such as exudation and consolidation were significantly alleviated. The levels of IL-6, IL-1β, TNF-α, and ROS were significantly decreased; the degree of mitochondrial swelling in type II alveolar epithelial cells was reduced, and no vacuolization was observed. Lung tissue apoptosis was reduced, and the colocalization fluorescence of Pink1 and Parkin, as well as LC3 and Tom20, were increased. The expression of Parkin and LC3-II/LC3-I ratio in lung tissue were both increased, while the expression of P62, Pink1, MFN2, and PTEN-L was decreased.ConclusionPink1/Parkin-mediated mitophagy dysfunction is one of the mechanisms underlying acute lung injury in rats with EHS, and activation of Parkin overexpression induced-mitophagy can alleviate acute lung injury caused by EHS.

Exploring antiviral effect and mechanism of Jinye Baidu granules（JYBD）against influenza A virus through network pharmacology and in vitro and invivo experiments

Ethnopharmacological relevanceJinye Baidu granules (JYBD) have been used to treat acute respiratory tract infections and demonstrated clinical efficacy for the treatment of emerging or epidemic respiratory viruses such as SARS-CoV-2 and influenza virus. Aim of the studyThis study is to investigate the antiviral effect of JYBD against influenza A viruses (IAV) in vitro and in vivo and elucidate its underlying mechanism. Materials and methodsUltra-high-performance liquid chromatography connected with Orbitrap mass spectrometer (UHPLC-Orbitrap MS) was employed to describe the chemical profile of JYBD. The potential pathways and targets involved in JYBD against IAV infection were predicted by network pharmacology. The efficacy and mechanism of JYBD were validated through both in vivo and in vitro experiments. Moreover, combination therapy with JYBD and the classic anti-influenza drugs was also investigated. ResultsA total of 126 compounds were identified by UHPLC-Orbitrap MS, of which 9 compounds were unambiguously confirmed with reference standards. JYBD could significantly inhibit the replication of multiple strains of IAV, especially oseltamivir-resistant strains. The results of qRT-PCR and WB demonstrated that JYBD could inhibit the excessive induction of pro-inflammatory cytokines induced by IAV infection and regulate inflammatory response through inhibiting JAK/STAT, NF-κB and MAPK pathways. Moreover, both JYBD monotherapy or in combination with oseltamivir could alleviate IAV-induced severe lung injury in mice. ConclusionsJYBD could inhibit IAV replication and mitigate virus-induced excessive inflammatory response. Combinations of JYBD and neuraminidase inhibitors conferred synergistic suppression of IAV both in vitro and in vivo. It might provide a scientific basis for clinical applications of JYBD against influenza virus infected diseases.

Neutrophil activation, acute lung injury and disease severity in Plasmodium knowlesi malaria.

The risk of severe malaria from the zoonotic parasite Plasmodium knowlesi approximates that from P. falciparum. In severe falciparum malaria, neutrophil activation contributes to inflammatory pathogenesis, including acute lung injury. The role of neutrophil activation in the pathogenesis of severe knowlesi malaria has not been examined. We evaluated 213 patients with P. knowlesi mono-infection (138 non-severe, 75 severe) and 49 Plasmodium-negative controls from Malaysia. Markers of neutrophil activation (soluble neutrophil elastase [NE], citrullinated histone [CitH3] and circulating neutrophil extracellular traps [NETs]) were quantified in peripheral blood by microscopy and immunoassays. Findings were correlated with malaria severity, ALI clinical criteria, biomarkers of parasite biomass, haemolysis, and endothelial activation. Neutrophil activation increased with disease severity, with median levels higher in severe than non-severe malaria and controls for NE (380[IQR:210-930]ng/mL, 236[139-448]ng/mL, 218[134-307]ng/mL, respectively) and CitH3 (8.72[IQR:3.0-23.1]ng/mL, 4.29[1.46-9.49]ng/mL, 1.53[0.6-2.59]ng/mL, respectively)[all p<0.01]. NETs were higher in severe malaria compared to controls (126/μL[IQR:49-323] vs 51[20-75]/μL, p<0.001). In non-severe malaria, neutrophil activation fell significantly upon discharge from hospital (p<0.03). In severe disease, NETs, NE, and CitH3 were correlated with parasitaemia, cell-free haemoglobin and angiopoietin-2 (all Pearson's r>0.24, p<0.05). Plasma NE and angiopoietin-2 were higher in knowlesi patients with ALI than those without (p<0.008); neutrophilia was associated with an increased risk of ALI (aOR 3.27, p<0.01). In conclusion, neutrophil activation is increased in ALI and in proportion to disease severity in knowlesi malaria, is associated with endothelial activation, and may contribute to disease pathogenesis. Trials of adjunctive therapies to regulate neutrophil activation are warranted in severe knowlesi malaria.