Acute Lung Injury Patients Research Articles

Qingfei Huoxue Decoction and Its Active Component Narirutin Alleviate LPS-Induced Acute Lung Injury by Regulating TLR4/NF-κB Pathway Mediated Inflammation.

Acute lung injury (ALI) is a life-threatening clinical syndrome with high mortality. Currently, the safe and effective therapies for ALI patients are still limited. Qingfei Huoxue decoction (QFHXD) is a hospital agreement prescription for treating pulmonary diseases and displays a remarkable efficacy. However, the pharmacological effect of QFHXD on preventing lipopolysaccharide (LPS)-induced ALI has yet to be reported, let alone questions of potential molecular mechanisms and anti-ALI active substances. To answer the above-mentioned questions, histopathological observation and kit detection were performed to estimate the protective effect of QFHXD pretreatment against LPS-induced ALI. Based on comprehensive chemical profiling of QFHXD, a network pharmacology strategy and experimental validation were integrated to elucidate the underlying functional mechanisms. The potential anti-ALI active components were identified by molecular docking. The anti-ALI activity of narirutin and its anti-inflammatory mechanism were further validated using animal and molecular experiments. Pretreatment with different doses of QFHXD effectively mitigated histopathological lesions and systemic inflammation caused by LPS stimulation. A detailed analysis of established compound-target-disease network revealed the strong correlation between anti-ALI action of QFHXD and inflammatory mechanisms. Compared with the model group, QFHXD intervention markedly restrained the abnormally increased transcription and protein levels of pro-inflammatory factors (TLR4, NF-κB, IL-6, IL-1β, and TNF-α) in lung tissues of ALI mice. The results of molecular docking highlighted the anti-ALI potential of narirutin targeting to TLR4 and NF-κB p65. In addition to the protective effect of narirutin on suppressing LPS-induced pathological changes, we found that narirutin pretreatment effectively normalized the disordered protein levels of above pro-inflammatory factors of ALI mice. These interesting findings indicate the beneficial effects of QFHXD and its active component narirutin against ALI partly via regulating TLR4/NF-κB mediated inflammation. This work contributes to the development of novel medications for ALI patients.

METTL14/IGF2BP2-mediated m6A modification of STEAP1 aggravates acute lung injury induced by sepsis.

Acute lung injury (ALI) is a severe complication of sepsis, characterized by inflammation, edema, and injury to alveolar cells, leading to high mortality rates. Septic ALI is a complex disease involving multiple factors and signaling pathways. STEAP family member 1 (STEAP1) has been reported to be upregulated in a sepsis-induced ALI model. However, the role of STEAP1 in the regulation of septic ALI is not yet fully understood. The study stimulated human pulmonary microvascular endothelial cells (HPMECs) using lipopolysaccharides (LPS) to establish an in vitro ALI model. The study used quantitative real-time polymerase chain reaction (qRT-PCR) to measure mRNA expression, and western blotting assay or immunohistochemistry (IHC) assay to analyze protein expression. Cell counting kit-8 (CCK-8) assay was performed to assess cell viability. Flow cytometry was conducted to analyze cell apoptosis. Tube formation assay was used to analyze the tube formation rate of human umbilical vein endothelial cells (HUVECs). Enzyme-linked immunosorbent assays (ELISAs) were used to measure the levels of interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α). The levels of Fe2+ and reactive oxygen species (ROS) were determined using colorimetric and fluorometric assays, respectively. The glutathione (GSH) level was also determined using a colorimetric assay. m6A RNA immunoprecipitation assay, dual-luciferase reporter assay, and RNA immunoprecipitation assay were performed to identify the association of STEAP1 with methyltransferase 14, N6-adenosine-methyltransferase non-catalytic subunit (METTL14) and insulin like growth factor 2 mRNA binding protein 2 (IGF2BP2). The transcript half-life of STEAP1 was analyzed by actinomycin D assay. Finally, a rat model of polymicrobial sepsis was established to analyze the effects of STEAP1 knockdown on lung injury in vivo. We found that the mRNA expression levels of STEAP1 and METTL14 were upregulated in the blood of ALI patients induced by sepsis compared to healthy volunteers. LPS treatment increased the protein levels of STEAP1 and METTL14 in HPMECs. STEAP1 depletion attenuated LPS-induced promoting effects on HPMECs' apoptosis, inflammatory response, and ferroptosis, as well as LPS-induced inhibitory effect on tube formation. We also found that METTL14 and IGF2BP2 stabilized STEAP1 mRNA expression through the m6A methylation modification process. Moreover, METTL14 silencing attenuated LPS-induced effects by decreasing STEAP1 expression in HPMECs, and STEAP1 silencing ameliorated cecal ligation and puncture-induced lung injury of mice. METTL14/IGF2BP2-mediated m6A modification of STEAP1 aggravated ALI induced by sepsis. These findings suggest potential therapeutic targets for the treatment of this disease.

Clinical utility of the neutrophil elastase inhibitor sivelestat for the treatment of ALI/ARDS patients with COVID-19

BackgroundSivelestat, a neutrophil elastase inhibitor, is postulated to mitigate acute lung injury in patients following emergency surgery. However, its efficacy in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) induced by coronavirus disease 2019 (COVID-19) remains uncertain. This study aims to evaluate the pulmonary protective effects of sivelestat in COVID-19 patients with ALI/ARDS. MethodsA retrospective study was conducted involving 2454 COVID-19 patients between October 5, 2022, and February 1, 2023. Of these, 102 patients received sivelestat (0.2 mg/kg/h), while 2352 age- and sex-matched controls were identified. Propensity score matching (PSM) analysis was used to match sivelestat and non-sivelestat subgroups in ratios of 1:1 and 1:3 for sensitivity analysis. The primary outcome was a composite of effective outcomes, including 30-day mortality. Secondary outcomes included changes in partial pressure of arterial oxygen (PaO2), the ratio of PaO2 to the fraction of inspired oxygen (PaO2/FiO2), and various cytokine levels. Safety evaluations included assessments of liver function, kidney function, and leukopenia. ResultsIn the propensity score-matched analysis, the sivelestat group had a higher proportion of severe/critical patients (87.26 % vs. 51.02 %, P < 0.001), more ARDS patients (4.9 % vs. 0.43 %, P < 0.001), and more patients with interstitial lung disease (4.9 % vs. 1.49 %, P = 0.023), but fewer patients with stroke (17.65 % vs. 19.86 %, P < 0.001). Oxygen therapy rates were similar between the groups (79.41 % vs. 80.95 %, P = 0.9). The relative risk reduction in 30-day mortality was 88.45 % (95 % confidence interval [CI] 81.23%–93.21 %) for severe/critical COVID-19 patients treated with sivelestat. Sivelestat significantly decreased cytokine levels of interferon alpha (IFNα), interleukin-1 beta (IL-1β), and interleukin-2 (IL-2).In the sivelestat group, the mortality rate was significantly reduced with standard oxygenation and HFNC therapy(P < 0.05). The treatment with sivelestat did not increase side effects. ConclusionThe administration of the neutrophil elastase inhibitor sivelestat may improve clinical outcomes in COVID-19 patients with ALI/ARDS. These findings suggest that sivelestat could be considered an effective treatment option to alleviate pulmonary inflammatory injury caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Mitigation of acute lung injury by human bronchial epithelial cell-derived extracellular vesicles via ANXA1-mediated FPR signaling

Acute lung injury (ALI) is characterized by respiratory failure resulting from the disruption of the epithelial and endothelial barriers as well as immune system. In this study, we evaluated the therapeutic potential of airway epithelial cell-derived extracellular vesicles (EVs) in maintaining lung homeostasis. We isolated human bronchial epithelial cell-derived EVs (HBEC-EVs), which endogenously express various immune-related surface markers and investigated their immunomodulatory potential in ALI. In ALI cellular models, HBEC-EVs demonstrated immunosuppressive effects by reducing the secretion of proinflammatory cytokines in both THP-1 macrophages and HBECs. Mechanistically, these effects were partially ascribed to nine of the top 10 miRNAs enriched in HBEC-EVs, governing toll-like receptor-NF-κB signaling pathways. Proteomic analysis revealed the presence of proteins in HBEC-EVs involved in WNT and NF-κB signaling pathways, pivotal in inflammation regulation. ANXA1, a constituent of HBEC-EVs, interacts with formyl peptide receptor (FPR)2, eliciting anti-inflammatory responses by suppressing NF-κB signaling in inflamed epithelium, including type II alveolar epithelial cells. In a mouse model of ALI, intratracheal administration of HBEC-EVs reduced lung injury, inflammatory cell infiltration, and cytokine levels. Collectively, these findings suggest the therapeutic potential of HBEC-EVs, through their miRNAs and ANXA1 cargo, in mitigating lung injury and inflammation in ALI patients.

Association between high-flow nasal cannula use and mortality in patients with sepsis-induced acute lung injury: a retrospective propensity score-matched cohort study

BackgroundHigh-flow nasal cannula (HFNC) has emerged as a promising noninvasive method for delivering oxygen to critically ill patients, particularly those with sepsis and acute lung injury. However, uncertainties persist regarding its therapeutic benefits in this specific patient population.MethodsThis retrospective study utilized a propensity score-matched cohort from the Medical Information Mart in Intensive Care-IV (MIMIC-IV) database to explore the correlation between HFNC utilization and mortality in patients with sepsis-induced acute lung injury. The primary outcome was 28-day all-cause mortality.ResultsIn the propensity score-matched cohort, the 28-day all-cause mortality rate was 18.63% (95 out of 510) in the HFNC use group, compared to 31.18% (159 out of 510) in the non-HFNC group. The use of HFNC was associated with a lower 28-day all-cause mortality rate (hazard ratio [HR] = 0.53; 95% confidence interval [CI] = 0.41–0.69; P < 0.001). HFNC use was also associated with lower ICU mortality (odds ratio [OR] = 0.52; 95% CI = 0.38–0.71; P < 0.001) and lower in-hospital mortality (OR = 0.51; 95% CI = 0.38–0.68; P < 0.001). Additionally, HFNC use was found to be associated with a statistically significant increase in both the ICU and overall hospitalization length.ConclusionsThese findings indicate that HFNC may be beneficial for reducing mortality rates among sepsis-induced acute lung injury patients; however, it is also associated with longer hospital stays.

Role of Lipopolysaccharides in the Inflammation and Pyroptosis of Alveolar Epithelial Cells in Acute Lung Injury and Acute Respiratory Distress Syndrome.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a spectrum of common critical respiratory conditions characterized by damage and death of alveolar epithelial cells (AECs). Pyroptosis is a form of programmed cell death with inflammatory characteristics, and activation of pyroptosis markers has been observed in AECs of patients with ALI/ARDS. Lipopolysaccharides (LPS) possess strong pro-inflammatory effects and are a crucial pathological factor leading to ALI in patients and animals. In LPS-induced ALI models, AECs undergo pyroptosis. However, physiologically and pathologically relevant concentrations of LPS lead to minor effects on AEC cell viability and minimal induction of cytokine release in vitro and do not induce classical pyroptosis. Nevertheless, LPS can enter the cytoplasm directly and induce non-classical pyroptosis in AECs when assisted by extracellular vesicles from bacteria, HMGB1, and pathogens. In this review, we have explored the effects of LPS on AECs concerning inflammation, cell viability, and pyroptosis, analyzing key factors that influence LPS actions. Notably, we highlight the intricate response of AECs to LPS within the framework of ALI and ARDS, emphasizing the variable induction of pyroptosis. Despite the minimal effects of LPS on AEC viability and cytokine release in vitro, LPS can induce non-classical pyroptosis under specific conditions, presenting potential pathways for therapeutic intervention. Collectively, understanding these mechanisms is crucial for the development of targeted treatments that mitigate the inflammatory responses in ALI/ARDS, thereby enhancing patient outcomes in these severe respiratory conditions.

MicroRNA-1258 suppresses oxidative stress and inflammation in septic acute lung injury through the Pknox1-regulated TGF-β1/SMAD3 cascade

AimThe study was to clarify the mechanism of miR-1258 targeting Prep1 (pKnox1) to control Transforming Growth Factor β1 (TGF-β1)/SMAD3 pathway in septic Acute Lung Injury (ALI)-induced oxidative stress and inflammation. MethodsBEAS-2B cells and C57BL/6 mice were used to make in vitro and in vivo septic ALI models, respectively. miR-1258 expression was checked by RT-qPCR. After transfection in the in vitro experimental model, inflammation, oxidative stress, viability, and apoptosis were observed through ELISA, MTT, and flow cytometry. ResultsIn the in vivo model after miR-1258 overexpression treatment, inflammation, oxidative stress, and lung injury were further investigated. The targeting relationship between miR-1258 and Pknox1 was tested. Low miR-1258 was expressed in septic ALI patients, LPS-treated BEAS-2B cells, and mice. Upregulated miR-1258 prevented inflammation, oxidative stress, and apoptosis but enhanced the viability of LPS-treated BEAS-2B cells. The impact of upregulated miR-1258 on LPS-treated BEAS-2B cells was mitigated by inhibiting Pknox1 expression. MiR-1258 overexpression had the alleviating effects on inflammation, oxidative stress, and lung injury of LPS-injured mice through suppressing Pknox1 expression and TGF-β1/SMAD3 cascade activation. ConclusionsThe study concludes that miR-1258 suppresses oxidative stress and inflammation in septic ALI through the Pknox1-regulated TGF-β1/SMAD3 cascade.

Predicting acute lung injury in infants with congenital heart disease after cardiopulmonary bypass by gut microbiota.

Acute lung injury (ALI) is a serious and common complication that occurs in children with congenital heart disease after cardiopulmonary bypass (CPB) surgery, leading to higher mortality rates and poorer prognosis. Currently, there is no reliable predictive strategy for CPB-associated lung injury (CPB-ALI) in infants. Certain characteristics of the gut microbiota could potentially serve as biomarkers for predicting the development of CPB-ALI. We conducted 16S rRNA sequencing to analyze the characteristics of the intestinal microbiota in healthy controls and infants with CHD admitted to the hospital. The CHD infants were divided into CPB-ALI and non-ALI (CPB-NALI) groups based on postoperative outcomes. Bacterial functional pathway prediction analysis was performed using PIRCUSt2, and the gut microbiota composition associated with immune status was determined with heatmap. Random forest regression models and ROC curves were utilized to predict the occurrence of CPB-ALI. Our study revealed significantly different microbiota compositions among three groups (CON, CPB-ALI, and CPB-NALI). The microbiota diversity was low in the CPB-ALI group with high pathogen abundance and significant decrease in Bacteroides, while the opposite was observed in the CPB-NALI group. The microbiota dysbiosis index was high in the CPB-ALI group, with its dominant microbiota significantly associated with multiple metabolic pathways. Additionally, CPB-ALI patients showed high levels of inflammatory cytokines IL-8 and HMGB1 in their serum, with high expression of IL-8 being associated with Enterobacteriaceae. Further correlation analysis showed that the differences in gut bacterial taxonomy were related to the occurrence of ALI, length of stay in the cardiac care unit, and ventilation time. It is noteworthy that Escherichia Shigella performed best in distinguishing CPB-ALI patients from non-ALI patients. Our study suggests that postoperative ALI patients have distinct gut microbiota upon admission compared to non-ALI patients after surgery. Dysbiosis of the gut microbiota may potentially impact the progression of ALI through metabolic pathways, quorum sensing, and the levels of inflammatory factors expressed in the serum. Escherichia Shigella represents a potential predictive factor for the occurrence of ALI in CHD infants after surgery. Acute lung injury, congenital heart disease, cardiopulmonary bypass surgery, gut microbiota, biomarker.

MiRNA transcriptomics analysis shows miR-483-5p and miR-503-5p targeted miRNA in extracellular vesicles from severe acute pancreatitis-associated lung injury patients

AimThis study sought to identify potential biomarkers and miRNA-mRNA networks within extracellular vesicles (EVs) for detecting severe acute pancreatitis-associated lung injury (SAPALI). MethodsBlood-derived EVs were isolated, and their miRNA transcriptomic profiles were comprehensively analyzed using miRBase v.21 database along with miRDeep2 tool to predict novel miRNAs. DEGseq R package was deployed for the identification of differentially expressed miRNAs (DEMs). Protein-protein interaction (PPI) networks were assembled using STRING and Cytoscape. A lung injury model was established using Lipopolysaccharide (LPS)-induced BEAS-2B cells, chosen for their respiratory epithelial origin and pertinent association with lung injury. The expression levels of targeted miRNA and associated proteins, TLR4, NF-κB mRNA were quantified via RT-PCR and Western Blot. Levels of IL-6, IL-1β, TNF-α, and ROS were measured using designated kits. Dual-luciferase reporter assay was conducted to examine the interaction between miRNA and proteins. ResultsThe comparisons between the SAPALI and the control group revealed 10 DEM, including miR-503-5p and miR-483-5p. The cytoHubba plugin in Cytoscape identified three principal miRNA-mRNA interactions: miR-483-5p with PTK2 and HDAC2; miR-28-5p with MAPK1, TP53BP1, SEMA3A; and miR-503-5p with PPP1CB, SEMA6D, EPHB2, UNC5B. The SAPALI model exhibited elevated miR-503-5p, HDAC2 and inflammatory markers, with a decline UNC5B, miR-483-5p and miR-28-5p. Transfection with miR-503-5p and miR-483-5p inhibitors increased the levels of their supposed binding proteins but not miR-28-5p inhibitor. The Dual-luciferase reporter gene assay identified the interaction of miR-503-5p with UNC5B, and miR-483-5p with HDAC2, but not miR-28-5p with TP53BP1. ConclusionsOur study maps miRNA-mRNA interactions in SAPALI, identifying miR-503-5p and miR-483-5p as critical regulatory miRNAs.

Metabolomic characterization benefits the identification of acute lung injury in patients with type A acute aortic dissection.

Introduction: Acute aortic dissection (AAD) often leads to the development of acute lung injury (ALI). However, the early detection and diagnosis of AAD in patients with ALI pose significant challenges. The objective of this study is to investigate distinct metabolic alterations in the plasma samples of AAD patients with ALI, AAD patients without ALI, and healthy individuals. Method: Between September 2019 and September 2022, we retrospectively collected data from 228 AAD patients who were diagnosed with ALI through post-surgery chest X-ray and PaO2/FiO2 assessments. Univariate analysis was employed to identify pre-surgery risk factors for ALI. Additionally, we conducted high-throughput target metabolic analysis on 90 plasma samples, comprising 30 samples from AAD patients with ALI, 30 from patients with AAD only, and 30 from healthy controls. After LC-MS spectral processing and metabolite quantification, the recursive feature elimination with cross-validation (RFECV) analysis based on the random forest was used to select the optimal metabolites as a diagnostic panel for the detection of AAD patients with ALI. The support vector machines (SVM) machine learning model was further applied to validate the diagnostic accuracy of the established biomarker panel. Results: In the univariate analysis, preoperative β-HB and TNF-α exhibited a significant association with lung injury (OR = 0.906, 95% CI 0.852-0.965, p = 0.002; OR = 1.007, 95% CI 1.003-1.011, p < 0.0001). The multiple-reaction monitoring analysis of 417 common metabolites identified significant changes in 145 metabolites (fold change >1.2 or <0.833, p < 0.05) across the three groups. Multivariate statistical analysis revealed notable differences between AAD patients and healthy controls. When compared with the non-ALI group, AAD patients with ALI displayed remarkable upregulation in 19 metabolites and downregulation in 4 metabolites. Particularly, combining citric acid and glucuronic acid as a biomarker panel improved the classification performance for distinguishing between the ALI and non-ALI groups. Discussion: Differentially expressed metabolites in the ALI group were primarily involved in amino acids biosynthesis, carbohydrate metabolism (TCA cycle), arginine and proline metabolism, and glucagon signaling pathway. These findings demonstrate a great potential of the targeted metabolomic approach for screening, routine surveillance, and diagnosis of pulmonary injury in patients with AAD.

Secretion of related factors and AMPK/PGC-1 α signal pathway by alveolar macrophages in viral acute lung injury.

This study was to investigate the secretion of related factors by alveolar macrophages and AMPK/PGC-1 α signal pathway in viral acute lung injury (VALI) patients. 30 SD rats were randomly divided into blank control group (BCG) and VALI group (VALIG) with 15 rats in each group. The model of VALIG was induced by polyI: C and the BCG was given the same amount of normal saline. The IL-6, IL-8 and TNF-α levels in bronchoalveolar lavage fluid (BALF) were detected by ELISA. The protein, surface markers of alveolar macrophages, and related mRNA expression were detected by Western blot, ELISA, and qRT-PCR. IL-8, IL-6, TNF-α, MUC5AC and TLR4 levels in VALIG were raised than those in BCG (P<0.05), while the AQP5 level was reduced than that in the BCG (P<0.05). The Bcl-2 protein level in the VALIG was reduced than that in the BCG (P<0.05), while the Caspase3 protein level was raised than that in the BCG (P<0.05). The AMPK and PGC-1 α mRNA and protein expression level in the VALIG rat lung tissue was lower than that of the BCG (P<0.05) VALIG is related to inflammatory damage, activation of alveolar macrophages, and secretion of related factors by alveolar macrophages. This may be related to AMPK/PGC-1 α signal pathways.

The mitochondrial-derived peptide MOTS-c suppresses ferroptosis and alleviates acute lung injury induced by myocardial ischemia reperfusion via PPARγ signaling pathway

Acute lung injury (ALI) is a life-threatening complication of cardiac surgery that has a high rate of morbidity and mortality. Epithelial ferroptosis is believed to be involved in the pathogenesis of ALI. MOTS-c has been reported to play a role in regulating inflammation and sepsis-associated ALI. The purpose of this study is to observe the effect of MOTS-c on myocardial ischemia reperfusion (MIR)-induced ALI and ferroptosis. In humans, we used ELISA kits to investigate MOTS-c and malondialdehyde (MDA) levels in patients undergoing off-pump coronary artery bypass grafting (CABG). In vivo, we pretreated Sprague-Dawley rats with MOTS-c, Ferrostatin-1 and Fe-citrate(Ⅲ). We conducted Hematoxylin and Eosin (H&E) staining and detection of ferroptosis-related genes in MIR-induced ALI rats. In vitro, we evaluated the effect of MOTS-c on hypoxia regeneration (HR)-induced mouse lung epithelial-12 (MLE-12) ferroptosis and analyzed the expression of PPARγ through western blotting. We found that circulating MOTS-c levels were decreased in postoperative ALI patients after off-pump CABG, and that ferroptosis contributed to ALI induced by MIR in rats. MOTS-c suppressed ferroptosis and alleviated ALI induced by MIR, and the protective effect of MOTS-c- was dependent on PPARγ signaling pathway. Additionally, HR promoted ferroptosis in MLE-12 cells, and MOTS-c inhibited ferroptosis against HR through the PPARγ signaling pathway. These findings highlight the therapeutic potential of MOTS-c for improving postoperative ALI induced by cardiac surgery.

CircSLCO3A1 depletion ameliorates lipopolysaccharide-induced inflammation and apoptosis of human pulmonary alveolar epithelial cells through the miR-424-5p/HMGB3 pathway.

Recent studies have shown the pathogenesis of acute lung injury (ALI) involves circular RNA (circRNA). However, there are no data on the role of circSLCO3A1 in ALI and the underlying mechanism. ALI-like cell injury was induced by stimulating human pulmonary alveolar epithelial cells (HPAEpiCs) using lipopolysaccharide (LPS). The expression of circSLCO3A1, miR-424-5p and high mobility group box 3 (HMGB3) was detected by quantitative real-time polymerase chain reaction. Cell viability and cell apoptosis were assessed by cell counting kit-8 (CCK-8) assay and flow cytometry analysis, respectively. Enzyme-linked immunosorbent assay was performed to determine the production of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α) and monocyte chemotactic protein 1 (MCP-1). Caspase-3 activity was detected by caspase-3 activity assay. Protein expression of inducible NOS (iNOS), cyclooxygenase-2 (COX2), p-p65 and p65 was analyzed by Western blot. The interactions among circSLCO3A1, miR-424-5p and HMGB3 were identified by dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay. CircSLCO3A1 and HMGB3 expression were significantly increased, while miR-424-5p was decreased in LPS-treated HPAEpiCs and the serum of septic ALI patients in comparison with controls. CircSLCO3A1 knockdown assuaged LPS-induced HPAEpiC inflammation and apoptosis. Besides, circSLCO3A1 targeted miR-424-5p and regulated LPS-triggered HPAEpiC inflammation and apoptosis by binding to miR-424-5p. Under the treatment of LPS, miR-424-5p mediated HPAEpiC disorders by targeting HMGB3. Importantly, circSLCO3A1 modulated HMGB3 production by interacting with miR-424-5p. CircSLCO3A1 absence assuaged LPS-induced HPAEpiC inflammation and apoptosis through the miR-424-5p/HMGB3 axis. CircSLCO3A1 expression was upregulated in LPS-induced HPAEpiCs and sepsis-induced ALI patients.CircSLCO3A1 depletion protected against LPS-induced HPAEpiC disorders.CircSLCO3A1 bound to miR-424-5p in HPAEpiCs.MiR-424-5p targeted HMGB3 in HPAEpiCs.CircSLCO3A1 regulated HMGB3 expression through miR-424-5p. The online version contains supplementary material available at 10.1007/s13273-023-00341-6.

Activation of Endothelial Large Conductance Potassium Channels Protects against TNF-α-Induced Inflammation.

Elevated TNF-α levels in serum and broncho-alveolar lavage fluid of acute lung injury patients correlate with mortality rates. We hypothesized that pharmacological plasma membrane potential (Em) hyperpolarization protects against TNF-α-induced CCL-2 and IL-6 secretion from human pulmonary endothelial cells through inhibition of inflammatory Ca2+-dependent MAPK pathways. Since the role of Ca2+ influx in TNF-α-mediated inflammation remains poorly understood, we explored the role of L-type voltage-gated Ca2+ (CaV) channels in TNF-α-induced CCL-2 and IL-6 secretion from human pulmonary endothelial cells. The CaV channel blocker, Nifedipine, decreased both CCL-2 and IL-6 secretion, suggesting that a fraction of CaV channels is open at the significantly depolarized resting Em of human microvascular pulmonary endothelial cells (-6 ± 1.9 mV), as shown by whole-cell patch-clamp measurements. To further explore the role of CaV channels in cytokine secretion, we demonstrated that the beneficial effects of Nifedipine could also be achieved by Em hyperpolarization via the pharmacological activation of large conductance K+ (BK) channels with NS1619, which elicited a similar decrease in CCL-2 but not IL-6 secretion. Using functional gene enrichment analysis tools, we predicted and validated that known Ca2+-dependent kinases, JNK-1/2 and p38, are the most likely pathways to mediate the decrease in CCL-2 secretion.

Mechanism of CAV and CAVIN Family Genes in Acute Lung Injury based on DeepGENE.

The fatality rate of acute lung injury (ALI) is as high as 40% to 60%. Although various factors, such as sepsis, trauma, pneumonia, burns, blood transfusion, cardiopulmonary bypass, and pancreatitis, can induce ALI, patients with these risk factors will eventually develop ALI. The rate of developing ALI is not high, and the outcomes of ALI patients vary, indicating that it is related to genetic differences between individuals. In a previous study, we found multiple functions of cavin-2 in lung function. In addition, many other studies have revealed that CAV1 is a critical regulator of lung injury. Due to the strong relationship between cavin-2 and CAV1, we suspect that cavin-2 is also associated with ALI. Furthermore, we are curious about the role of the CAV family and cavin family genes in ALI. To reveal the mechanism of CAV and CAVIN family genes in ALI, we propose DeepGENE to predict whether CAV and CAVIN family genes are associated with ALI. This method constructs a gene interaction network and extracts gene expression in 84 tissues. We divided these features into two groups and used two network encoders to encode and learn the features. Compared with DNN, GBDT, RF and KNN, the AUC of DeepGENE increased by 7.89%, 16.84%, 20.19% and 32.01%, respectively. The AUPR scores increased by 8.05%, 15.58%, 22.56% and 23.34%. DeepGENE shows that CAVIN-1, CAVIN-2, CAVIN-3 and CAV2 are related to ALI. DeepGENE is a reliable method for identifying acute lung injury-related genes. Multiple CAV and CAVIN family genes are associated with acute lung injury-related genes through multiple pathways and gene functions.

The neutrophil elastase inhibitor, sivelestat, attenuates acute lung injury in patients with cardiopulmonary bypass.

The sivelestat is a neutrophil elastase inhibitor thought to have an effect against acute lung injury (ALI) in patients after scheduled cardiac surgery. However, the beneficial effect of sivelestat in patients undergoing emergent cardiovascular surgery remains unclear. We aim to evaluate the effect of sivelestat on pulmonary protection in patients with ALI after emergent cardiovascular surgery. Firstly, a case-control study in 665 patients undergoing emergent cardiovascular surgery from January 1st, 2020 to October 26th, 2022 was performed. 52 patients who received sivelestat (0.2mg/kg/h for 3 days) and 613 age- and sex-matched controls. Secondly, a propensity-score matched cohort (sivelestat vs control: 50 vs 50) was performed in these 665 patients. The primary outcome was a composite of adverse outcomes, including 30-day mortality, ECMO, continuous renal replacement therapy (CRRT) and IABP, etc. The secondary outcome included pneumonia, ventricular arrhythmias and mechanical ventilation time, etc. In propensity-matched patients, the 30-day mortality (16% vs 24%, P=0.32), stroke (2% vs 8%, P=0.17), ECMO(6% vs 10%, P=0.46), IABP(4% vs 8%, P=0.40) and CRRT(8% vs 20%, P=0.08) had no differences between sivelestat and control group; sivelestat could significantly decrease pneumonia (40% vs 62%, P=0.03), mechanical ventilation time (median: 96hours, IQR:72-120hours vs median:148hours, IQR:110-186hours, P<0.01), bilateral pulmonary infiltrates (P<0.01), oxygen index (P<0.01), interleukin-6(P=0.02), procalcitonin(P<0.01) and C-reactive protein(P<0.01). Administration of sivelestat might improve postoperative outcomes in patients with ALI after emergent cardiovascular surgery. Our results show that sivelestat may be considered to protect pulmonary function against inflammatory injury by CPB. http://www.chictr.org.cn/showproj.aspx?proj=166643, identifier ChiCTR2200059102.

Peptide-guided delivery improves the therapeutic efficacy and safety of glucocorticoid drugs for treating acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening conditions with excessive inflammation in the lung. Glucocorticoids had been widely used for ALI/ARDS, but their clinical benefit remains unclear. Here, we tackled the problem by conjugating prednisolone (PSL) with a targeting peptide termed CRV. Systemically administered CRV selectively homes to the inflamed lung of a murine ALI model, but not healthy organs or the lung of healthy mice. The expression of the CRV receptor, retinoid X receptor β, was elevated in the lung of ALI mice and patients with interstitial lung diseases, which may be the basis of CRV targeting. We then covalently conjugated PSL and CRV with a reactive oxygen species (ROS)-responsive linker in the middle. While being intact in blood, the ROS linker was cleaved intracellularly to release PSL for action. Invitro, CRV-PSL showed an anti-inflammatory effect similar to that of PSL. Invivo, CRV conjugation increased the amount of PSL in the inflamed lung but reduced its accumulation in healthy organs. Accordingly, CRV-PSL significantly reduced lung injury and immune-related side effects elsewhere. Taken together, our peptide-based strategy for targeted delivery of glucocorticoids for ALI may have great potential for clinical translation.

Circ_0001498 contributes to lipopolysaccharide-induced lung cell apoptosis and inflammation in sepsis-related acute lung injury via upregulating SOX6 by interacting with miR-574-5p.

Circular RNAs (circRNAs) have important regulation in in sepsis-related acute lung injury (ALI). Circ_0001498 was significantly overexpressed in sepsis-induced acute respiratory distress syndrome. The aims of this study were to explore role and mechanism of circ_0001498 in lipopolysaccharide (LPS)-treated WI-38 cells. Human samples were collected from 56 sepsis patients and 46 healthy volunteers at Liyang People's Hospital. Circ_0001498, microRNA-574-5p (miR-574-5p) or sex-determining region Y-related high-mobility-group box 6 (SOX6) levels were detected via reverse transcription-quantitative polymerase chain reaction assay. Cell viability was determined through Cell Counting Kit-8 assay. Apoptosis rate was examined by flow cytometry. Western blot was used for measurement of proteins. Inflammatory cytokines were detected via enzyme-linked immunosorbent assay. Target relation was analyzed via dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Circ_0001498 was overexpressed in sepsisrelated ALI patients and LPS-treated WI-38 cells. Silencing circ_0001498 reduced LPS-induced cell apoptosis and inflammation. Circ_0001498 interacted with miR-574-5p. The regulation of circ_0001498 knockdown was abolished by miR-574-5p inhibitor. Furthermore, miR-574-5p directly targeted SOX6 and circ_0001498 upregulated SOX6 via targeting miR-574-5p. Overexpression of miR-574-5p alleviated LPS-induced cell injury by downregulating SOX6. This research identified that circ_0001498 facilitated sepsis-related ALI progression by targeting miR-574-5p to upregulate SOX6.

MicroRNA-9-5p Is Involved in Lipopolysaccharide-Induced Acute Lung Injury Via the Regulation of Macrophage Polarization.

MicroRNA (miR)-9-5p has been shown to affect lung cancer progression and lung fibrosis, but the efficacy of miR-9-5p in acute lung injury (ALI) remained indefinite. The study was performed to probe the modulating mechanism of miR-9-5p in ALI via regulating macrophage polarization. The ALI mouse model was established and blood samples of ALI patients were obtained. MiR-9-5p levels in ALI mice and ALI patients were detected. Mouse pulmonary macrophages were extracted from bronchoalveolar lavage fluid and polarized into M1 and M2 macrophages. Intervention of miR-9-5p expression was performed to observe the effects on M1 polarization and M2 polarization in lung macrophages, inflammatory factors in BALF, wet/dry weight ratio (W/D) in lung tissues, myeloperoxidase (MPO) activity in lung tissues, and lung tissue lesion condition. MiR-9-5p levels were elevated in the lung tissues of ALI mice and ALI patients. MiR-9-5p silencing could repress lung macrophages in ALI mice polarized toward the M1 phenotype and promoted the polarization toward the M2 phenotype, reduced the lung lesions, the lung water content, and the secretion levels of the pro-inflammatory factors TNF-α, IL-6, and IL-1β in BALF, increased the secretion of the anti-inflammatory factor IL-10, as well as impeded the MPO activity in the lung tissues of ALI mice. MiR-9-5p deletion ameliorates LPS-induced inflammatory infiltration in lung tissues via inhibiting the polarization of mouse lung macrophages to the M1 phenotype and promoting the polarization to the M2 phenotype.

Investigating the immunomodulatory activities of omadacycline.

Apart from their antimicrobial activities, some antibiotics have immunomodulatory effects on host cells, particularly monocytes. Because hyperactivation of the pro-inflammatory cytokine response contributes to acute lung injury in patients with bacterial pneumonia and other lung diseases, antimicrobial agents with immunomodulatory activity can reduce cytokine-mediated tissue injury and improve outcomes. Omadacycline has been recently FDA-approved for community-acquired bacterial pneumonia and acute bacterial skin and skin-structure infections. The present study investigated omadacycline's ability to modulate LPS-induced production of pro-inflammatory cytokines (TNF-α, IL-1β), acute-phase reactants (IL-6) and anti-inflammatory cytokines (IL-4, IL-10) by human monocytes in vitro. Isolated human monocytes from healthy consenting adults were cultured in RPMI with 1% pooled human serum. Cells were pre-exposed to omadacycline (0.5-64 μg/mL), minocycline (25, 50 or 25 μg/mL) or azithromycin (20, 40 or 80 μg/mL) for 2 h, followed by stimulation with Escherichia coli LPS for 24 h. Cytokines elaborated in the culture supernatant were quantitated by multiplex immunoassay. Omadacycline dose-dependently suppressed LPS-induced production of all cytokines tested. Only high-dose minocycline (100 μg/mL) modestly suppressed TNF-α whereas minocycline significantly increased LPS-induced IL-1β production. Lower concentrations of minocycline were also stimulatory for IFN-γ, IL-6 and IL-4. Except for suppression of IL-6, azithromycin was largely without effect. Omadacycline has unique and broad immunomodulatory properties. Such activity supports its use in settings where hyperactivation of the immune response contributes to tissue injury and poor outcomes, especially at sites where pro-inflammatory M-type 1 macrophages dominate the cellular immune response.