S1PR3 inhibition protects against LPS-induced ARDS by inhibiting NF-κB and improving mitochondrial oxidative phosphorylation.

BACKGROUND: Inflammation and endothelial barrier dysfunction are the major pathophysiological changes in acute respiratory distress syndrome (ARDS). Sphingosine-1-phosphate receptor 3 (S1PR3), a G protein-coupled receptor, has been found to mediate inflammation and endothelial cell (EC) integrity. However, the function of S1PR3 in ARDS has not been fully elucidated. METHODS: We used a murine lipopolysaccharide (LPS)-induced ARDS model and an LPS- stimulated ECs model to investigate the role of S1PR3 in anti-inflammatory effects and endothelial barrier protection during ARDS. RESULTS: We found that S1PR3 expression was increased in the lung tissues of mice with LPS-induced ARDS. TY-52156, a selective S1PR3 inhibitor, effectively attenuated LPS-induced inflammation by suppressing the expression of proinflammatory cytokines and restored the endothelial barrier by repairing adherens junctions and reducing vascular leakage. S1PR3 inhibition was achieved by an adeno-associated virus in vivo and a small interfering RNA in vitro. Both the in vivo and in vitro studies demonstrated that pharmacological or genetic inhibition of S1PR3 protected against ARDS by inhibiting the NF-κB pathway and improving mitochondrial oxidative phosphorylation. CONCLUSIONS: S1PR3 inhibition protects against LPS-induced ARDS via suppression of pulmonary inflammation and promotion of the endothelial barrier by inhibiting NF-κB and improving mitochondrial oxidative phosphorylation, indicating that S1PR3 is a potential therapeutic target for ARDS.

Omentin-1 ameliorates pulmonary arterial hypertension by inhibiting endoplasmic reticulum stress through AMPKα signaling.

BACKGROUND: Endothelial dysfunction of the pulmonary artery contributes to hypoxia-induced pulmonary arterial hypertension (PAH). Omentin-1, as a novel adipocytokine, plays an important protective role against cardiovascular diseases. However, the effect and underlying mechanisms of omentin-1 against PAH remain unclear. METHODS: PAH was induced in SD (Sprague & Dawley) rats via a low-oxygen chamber for 4 weeks. Hemodynamic evaluation was undertaken using a PowerLab data acquisition system, and histopathological analysis was stained with hematoxylin and eosin (H&E). Endothelial function of pulmonary artery was assessed using wire myography. RESULTS: We found that omentin-1 significantly improved pulmonary endothelial function in rats exposed to hypoxia and attenuated PAH. Mechanistically, we found that omentin-1 increased phosphorylated 5'­adenosine monophosphate­activated protein kinase (p­AMPK) level and reduced endoplasmic reticulum (ER) stress and increased NO production in pulmonary artery from rats exposed to hypoxia. However, the effect of omentin-1 was abolished by treatment with AMPK inhibitor (Compound C). CONCLUSIONS: Our results reveal a protective effect of omentin-1 in PAH via inhibiting ER stress through AMPKα signaling and provide an agent with translational potential for the treatment of PAH.

Circulating microvesicles miR139-3p from bronchopulmonary dysplasia aggravates pulmonary vascular simplification by targeting 4E binding protein 1.

BACKGROUND: Microvesicles (MVs) play a crucial role in bronchopulmonary dysplasia (BPD). There are many MVs in circulating plasma, and they are in direct contact with lung endothelial cells. However, the molecular mechanism and causative effect of circulating MVs on BPD remain unclear. METHODS: Clinical plasma samples were collected, circulating MVs were isolated, and microRNA (miRNA) sequencing was performed. The BPD model was established, and different MVs were administered. Alveoli and pulmonary vessels were examined by hematoxylin-eosin staining, and body weight and length were measured. In vitro, gene expression was disrupted by miRNA mimics, miRNA inhibitors or plasmid transfection. Cell proliferation and protein expression were detected by cell scratch assay, accurate 5-ethynyl-2-deoxyuridine test, western blotting, or immunofluorescence assay. RESULTS: BPD-derived MVs further aggravated pulmonary vascular simplification, while circulating MVs from control mice mitigated pulmonary vascular simplification. Micro-RNA sequencing and independent sample verification revealed that miR139-3p, but not miR6125 or miR193b-3p, was the most critical effector molecule in MVs. Mechanism studies showed that eukaryotic translation initiation factor 4E binding protein 1 was the target gene for miR139-3p. In addition, we found that supplementation of miR139-3p inhibitor partially alleviated pulmonary vascular simplification. CONCLUSIONS: These results indicate that circulating MVs are involved in forming BPD by carrying miR139-3p molecules and support miR139-3p inhibitors as a potential therapeutic strategy for alleviating pulmonary vascular simplification in BPD.

Interferon regulatory factor 1 (IRF1) inhibits lung endothelial regeneration following inflammation-induced acute lung injury.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a respiratory condition caused by severe endothelial barrier dysfunction within the lung. In ARDS, excessive inflammation, tissue edema, and immune cell influx prevents endothelial cell regeneration that is crucial in repairing the endothelial barrier. However, little is known about the molecular mechanism that underpin endothelial cell regeneration in ARDS. METHODS: R-based bioinformatics tools were used to analyze microarray-derived transcription profiles in human lung microvascular endothelial cells (HLMVECs) subjected to non-treatment or lipopolysaccharide (LPS) exposure. We generated endothelial cell-specific interferon regulatory factor 1 (Irf1) knockout (Irf1EC-/-) and Irf1fl/fl control mice for use in an endotoxemic murine model of acute lung injury (ALI). In vitro studies (qPCR, immunoblotting, and ChIP-qPCR) were conducted in mouse lung endothelial cells (MLECs) and HLMVECs. Dual-luciferase promoter reporter assays were performed in HLMVECs. RESULTS: Bioinformatics analyses identified IRF1 as a key up-regulated gene in HLMVECs post-LPS exposure. Endothelial-specific knockout of Irf1 in ALI mice resulted in enhanced regeneration of lung endothelium, while liposomal delivery of endothelial-specific Irf1 to wild-type ALI mice inhibited lung endothelial regeneration in a leukemia inhibitory factor (Lif)-dependent manner. Mechanistically, we demonstrated that LPS-induced Stat1Ser727 phosphorylation promotes Irf1 transactivation, resulting in downstream up-regulation of Lif that inhibits endothelial cell proliferation. CONCLUSIONS: These results demonstrate the existence of a p-Stat1Ser727-Irf1-Lif axis that inhibits lung endothelial cell regeneration post-LPS injury. Thus, direct inhibition of IRF1 or LIF may be a promising strategy for enhancing endothelial cell regeneration and improving clinical outcomes in ARDS patients.

Successful treatment with osimertinib for nonmucinous bronchioloalveolar carcinoma with massive bronchorrhea and respiratory failure: a case report and literature review.

Background: Correct diagnosis of bronchioloalveolar carcinoma (BAC) is often delayed due to the lack of familiarity with the condition among clinicians as its sporadic nature and its symptoms are similar to other respiratory issues. Among these, acute respiratory failure (ARF) caused by massive bronchorrhea is rarely associated with BAC. Here we first reported osimertinib in the treatment of BAC with bronchorrhea and ARF. Case Description: A 38-year-old woman presented with massive bronchorrhea and progressive dyspnea. A chest computed tomography (CT) scan showed consolidation with air bronchograms and multiple nodules in both lungs. The patient had no history of chronic pulmonary disease, diabetes mellitus, hypertension or smoke. The patient was initially diagnosed with pneumonia, but ARF developed despite the antibiotic therapy provided. Lung biopsy results revealed nonmucinous BAC. Osimertinib (80 mg daily) was prescribed and proved effective for the first time with an improved ARF and a decreased multiple nodules or consolidation in the lungs during the follow-up period. Conclusions: It is important for physicians to recognize the typical symptoms and radiological manifestations of BAC to avoid misdiagnosis or late diagnosis. This is especially important since early diagnosis allows for immediate epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy, which is a potentially beneficial treatment for patients with BAC.

APELIN-13 AMELIORATES LPS-INDUCED ENDOTHELIAL-TO-MESENCHYMAL TRANSITION AND POST-ACUTE LUNG INJURY PULMONARY FIBROSIS BY SUPPRESSING TRANSFORMING GROWTH FACTOR-Β1 SIGNALING.

ABSTRACT: The pathophysiology of acute respiratory distress syndrome (ARDS) involves cytokine storms, alveolar-capillary barrier destruction, and fibrotic progression. Pulmonary interstitial fibrosis is an important factor affecting the prognosis of ARDS patients. Endothelial-to-mesenchymal transition (EndMT) plays an important role in the development of fibrotic diseases, and the occurrence of EndMT has been observed in experimental models of LPS-induced acute lung injury (ALI). Apelin is an endogenous active polypeptide that plays an important role in maintaining endothelial cell homeostasis and inhibiting fibrotic progression in various diseases. However, whether apelin attenuates EndMT in ALI and post-ALI pulmonary fibrosis remains unclear. We analyzed the serum levels of apelin-13 in patients with sepsis-associated ARDS to examine its possible clinical value. A murine model of LPS-induced pulmonary fibrosis and an LPS-challenged endothelial cell injury model were used to analyze the protective effect and underlying mechanism of apelin-13. Mice were treated with apelin-13 by i.p. injection, and human pulmonary microvascular endothelial cells were incubated with apelin-13 in vitro . We found that the circulating apelin-13 levels were significantly elevated in sepsis-associated ARDS patients compared with healthy controls. Our study also confirmed that LPS induced EndMT progression and pulmonary fibrosis, which were characterized by decreased CD31 expression and increased α-smooth muscle actin expression and collagen deposition. LPS also stimulated the production of transforming growth factor ß1 and activated the Smad signaling pathway. However, apelin-13 treatment significantly attenuated these changes. Our findings suggest that apelin-13 may be a novel biomarker in patients with sepsis-associated ARDS. These results demonstrate that apelin-13 ameliorates LPS-induced EndMT and post-ALI pulmonary fibrosis by suppressing transforming growth factor ß1 signaling.

The Establishment of China Bronchiectasis Registry and Research Collaboration (BE-China): Protocol of a prospective multicenter observational study.

BACKGROUND: Bronchiectasis is a highly heterogeneous chronic airway disease with marked geographic and ethnic variations. Most influential cohort studies to date have been performed in Europe and USA, which serve as the examples for developing a cohort study in China where there is a high burden of bronchiectasis. The Establishment of China Bronchiectasis Registry and Research Collaboration (BE-China) is designed to: (1) describe the clinical characteristics and natural history of bronchiectasis in China and identify the differences of bronchiectasis between the western countries and China; (2) identify the risk factors associated with disease progression in Chinese population; (3) elucidate the phenotype and endotype of bronchiectasis by integrating the genome, microbiome, proteome, and transcriptome with detailed clinical data; (4) facilitate large randomized controlled trials in China. METHODS: The BE-China is an ongoing prospective, longitudinal, multi-center, observational cohort study aiming to recruit a minimum of 10,000 patients, which was initiated in January 2020 in China. Comprehensive data, including medical history, aetiological testing, lung function, microbiological profiles, radiological scores, comorbidities, mental status, and quality of life (QoL), will be collected at baseline. Patients will be followed up annually for up to 10 years to record longitudinal data on outcomes, treatment patterns and QoL. Biospecimens, if possible, will be collected and stored at - 80 °C for further research. Up to October 2021, the BE-China has enrolled 3758 patients, and collected 666 blood samples and 196 sputum samples from 91 medical centers. The study protocol has been approved by the Shanghai Pulmonary Hospital ethics committee, and all collaborating centers have received approvals from their local ethics committee. All patients will be required to provide written informed consent to their participation. CONCLUSIONS: Findings of the BE-China will be crucial to reveal the clinical characteristics and natural history of bronchiectasis and facilitate evidence-based clinical practice in China. Trial registration Registration Number in ClinicalTrials.gov: NCT03643653.

CNTN-1 Upregulation Induced by Low-Dose Cisplatin Promotes Malignant Progression of Lung Adenocarcinoma Cells via Activation of Epithelial-Mesenchymal Transition.

Tumor metastasis and invasion are the main impediments to lung adenocarcinoma successful treatment. Previous studies demonstrate that chemotherapeutic agents can elevate the malignancy of cancer cells other than their therapeutic effects. In this study, the effects of transient low-dose cisplatin treatment on the malignant development of lung adenocarcinoma cells (A549) were detected, and the underlying epigenetic mechanisms were investigated. The findings showed that A549 cells exhibited epithelial-mesenchymal transition (EMT)-like phenotype along with malignant progression under the transient low-dose cisplatin treatment. Meanwhile, low-dose cisplatin was found to induce contactin-1 (CNTN-1) upregulation in A549 cells. Subsequently, we found that further overexpressing CNTN-1 in A549 cells obviously activated the EMT process in vitro and in vivo, and caused malignant development of A549 cells in vitro. Taken together, we conclude that low-dose cisplatin can activate the EMT process and resulting malignant progression through upregulating CNTN-1 in A549 cells. The findings provided new evidence that a low concentration of chemotherapeutic agents could facilitate the malignancy of carcinoma cells via activating the EMT process other than their therapeutic effects.

Gene Expression and Mutational Landscape in a PMEC Patient With Low to Intermediate-High Grade Transition.

Primary pulmonary mucoepidermoid carcinoma (PMEC) is a very rare form of lung carcinoma. Due to the low incidence, little is known about its inherent genetic variation characteristics. The uniform treatment for PMEC has not been determined. In this case, we present a 45-year-old male with stage IA PMEC. The surgical specimens contained changes from low- to intermediate-to-high grade. We performed integrative analysis of whole-exome sequencing (WES-seq) and messenger ribonucleic acid sequencing (RNA-seq) to compare the molecular changes in the different lesions. Molecular testing exhibits the specimens harboring CRTC3-MAML2 fusion. The copy number gain of PDPK1 is only present in high-grade regional specimens. We also explored the level of immune infiltration by CIBERSORT. To our knowledge, this is the first report to describe a case of PMEC in the low- to intermediate-high-grade transition with multiomics analysis.

Antineutrophil cytoplasmic antibody-associated vasculitis with alveolar hemorrhage and ruptured renal aneurysm: A case report and literature review.

RATIONALE: Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is characterized by necrotizing damage to small-vessel vasculitis and mainly occurs in the kidney or lung. We report a rare case of AAV manifesting as alveolar hemorrhage and a renal aneurysm. PATIENT CONCERNS: A 50-year-old Chinese man presented with repeated coughing, expectoration, fever, hypoxemia, and respiratory failure. The patient suffered from rupture of the renal aneurysm during immunosuppressive therapy. DIAGNOSIS: Considering the clinical picture (fever, progressive hypoxemia, renal insufficiency, hemorrhagic bronchoalveolar lavage fluid, and left retroperitoneal hematoma) along with cANCA-PR3 positivity, and lung biopsy findings, the patient was finally diagnosed with granulomatosis with polyangiitis complicated by alveolar hemorrhage and renal aneurysm. INTERVENTIONS: The patient was initially treated with immunosuppressive therapy combined with plasma exchange and subsequently with renal arterial embolization due to rupture of the renal aneurysm. OUTCOMES: The general condition and inflammatory reaction improved with immunosuppressive therapy combined with plasma exchange. Unfortunately, the patient did not respond to treatment and eventually died of respiratory failure and acute kidney injury after the rupture of the renal aneurysm. LESSONS: We encountered unprecedented difficulties and challenges with renal aneurysm rupture. The possibility of aneurysmal rupture should be carefully considered and frequently checked for immunosuppressive therapy for AAV.

Alcohol inhibits alveolar fluid clearance through the epithelial sodium channel via the A2 adenosine receptor in acute lung injury.

Chronic alcohol abuse increases the risk of mortality and poor outcomes in patients with acute respiratory distress syndrome. However, the underlying mechanisms remain to be elucidated. The present study aimed to investigate the effects of chronic alcohol consumption on lung injury and clarify the signaling pathways involved in the inhibition of alveolar fluid clearance (AFC). In order to produce rodent models with chronic alcohol consumption, wild­type C57BL/6 mice were treated with alcohol. A2a adenosine receptor (AR) small interfering (si)RNA or A2bAR siRNA were transfected into the lung tissue of mice and primary rat alveolar type II (ATII) cells. The rate of AFC in lung tissue was measured during exposure to lipopolysaccharide (LPS). Epithelial sodium channel (ENaC) expression was determined to investigate the mechanisms underlying alcohol­induced regulation of AFC. In the present study, exposure to alcohol reduced AFC, exacerbated pulmonary edema and worsened LPS­induced lung injury. Alcohol caused a decrease in cyclic adenosine monophosphate (cAMP) levels and inhibited α­ENaC, ß­ENaC and γ­ENaC expression levels in the lung tissue of mice and ATII cells. Furthermore, alcohol decreased α­ENaC, ß­ENaC and γ­ENaC expression levels via the A2aAR or A2bAR­cAMP signaling pathways in vitro. In conclusion, the results of the present study demonstrated that chronic alcohol consumption worsened lung injury by aggravating pulmonary edema and impairing AFC. An alcohol­induced decrease of α­ENaC, ß­ENaC and γ­ENaC expression levels by the A2AR­mediated cAMP pathway may be responsible for the exacerbated effects of chronic alcohol consumption in lung injury.

Serum MCP-1 and NGAL Play an Important Role in the Acute Inflammatory Event of Chronic Obstructive Pulmonary Disease.

NGAL is mainly secreted by neutrophils which play the core role in AECOPD. MCP-1 is secreted specifically by monocytes and macrophages. Both biomarkers are involved in the core process of acute inflammatory reaction in COPD. So We analyzed serum NGAL and MCP-1levels to explore their potential clinical values in the chronic obstructive pulmonary disease (COPD) .This study enrolled 97 COPD patients and 50 healthy controls. All participants received blood collection and lung function test and arterial blood gas measurements. The expression levels of serum NGAL and MCP-1 were measured by ELISA. The serum NGAL and MCP-1 levels of COPD with community-acquired pneumonia (COPD-CAP) patients were significantly higher than those of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients and healthy adults. The NGAL levels of the GOLD III and IV groups were significantly higher than those of the GOLD II group. Spearman correlation analysis showed a negative correlation between NGAL and FEV1%pred, FVC% pred. ROC curves indicated that NGAL has a high diagnostic value for both AECOPD and COPD-CAP. NGAL has the value of distinguishing GOLD I and II from GOLD III and IV. MCP-1 have moderate diagnostic value for COPD-CAP and can differentiate COPD-CAP from AECOPD. This study shows NGAL has certain diagnostic value for AECOPD and COPD-CAP, but can not distinguish the two. NGAL is closely related to airway remodeling and can be used as a potential indicator to distinguish the higher GOLD degree. MCP-1 can be used as potential indicator for the diagnosis of COPD-CAP.

Intermedin alleviates the inflammatory response and stabilizes the endothelial barrier in LPS-induced ARDS through the PI3K/Akt/eNOS signaling pathway.

Inflammatory storms and endothelial barrier dysfunction are the central pathophysiological features of acute respiratory distress syndrome (ARDS). Intermedin (IMD), a member of the calcitonin gene-related peptide (CGRP) family, has been reported to alleviate inflammation and protect endothelial cell (EC) integrity. However, the effects of IMD on ARDS have not been clearly elucidated. In the present study, clinical ARDS data were used to explore the relationship between serum IMD levels and disease severity and prognosis, and we then established a model to predict the possibility of hospital survival. Mouse models of ARDS and LPS-challenged endothelial cells were used to analyze the protective effect and underlying mechanism of IMD. We found that in patients with ARDS, increased serum IMD levels were associated with reduced disease severity and increased rates of hospital survival. IMD alleviated the LPS-induced inflammatory response by decreasing proinflammatory cytokines, NF-κB p65 expression and NF-κB p65 nuclear translocation. In addition, IMD stabilized the endothelial barrier by repairing adherens junctions (AJs), cytoskeleton and capillary leakage. IMD exerted protective effects against ARDS on pulmonary endothelial cells, at least partly, through PI3K/Akt/eNOS signaling, while IMD's anti-inflammation effect was mediated through an eNOS-independent mechanism. Our study may provide new therapeutic insight for ARDS treatment.

An increase in alveolar fluid clearance induced by hyperinsulinemia in obese rats with LPS-induced acute lung injury.

A lower mortality rate is observed in obese patients with acute lung injury (ALI), which is referred to as the obesity paradox, in several studies and recent meta-analyses. Hyperinsulinemia is characterized as the primary effect of obesity, and exogenous insulin attenuates LPS-induced pulmonary edema. The detailed mechanism responsible for the effect of hyperinsulinemia on pulmonary edema and alveolar filling needs to be elucidated. SD rats were fed with a high-fat diet (HFD) for a total of 14 weeks. SD rats were anesthetized and intraperitoneally injected with 10 mg/kg lipopolysaccharide (LPS), while control rats received only saline vehicle. Insulin receptor antagonist S961 (20 nmol/kg) was given by the tail vein and serum, and glucocorticoid-induced protein kinase-1 (SGK-1) inhibitor EMD638683 (20 mg/kg) was administrated intragastrically prior to LPS exposure. The lungs were isolated for the measurement of alveolar fluid clearance. The protein expression of epithelial sodium channel (ENaC) was detected by Western blot. Insulin level in serum was significantly higher in HFD rats compared with normal diet rats in the presence or absence of LPS pretreatment. Hyperinsulinemia induced by high fat feeding increased alveolar fluid clearance and the abundance of α-ENaC, ß-ENaC, and γ-ENaC in both normal rats and ALI rats. Moreover, these effects were reversed in response to S961. EMD638683 prevented the simulation of alveolar fluid clearance and protein expression of ENaC in HFD rats with ALI. These findings suggest that hyperinsulinemia induced by obesity results in the stimulation of alveolar fluid clearance via the upregulation of the abundance of ENaC in clinical acute lung injury, whereas theses effects are prevented by an SGK-1 inhibitor.

Circulating Exosomes From Lipopolysaccharide-Induced Ards Mice Trigger Endoplasmic Reticulum Stress in Lung Tissue.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a critical clinical syndrome with high mortality rate, and few effective therapies have been found in the past 50 years, indicating that the pathogenesis of ARDS remains unclear. Exosomes, a novel cross-communication mechanism, are involved in critical diseases. However, the role of circulating exosomes in the development of ARDS remains poorly understood. METHODS: In the present study, naive mice were treated with circulating exosomes from lipopolysaccharide (LPS)-induced ARDS mice or exosome-depleted serum. Histological lung damage, bronchoalveolar lavage fluid (BALF), and endoplasmic reticulum (ER) stress were measured. RESULTS: Increased tumor necrosis factor (TNF)-α, interleukin (IL)-6, total cell counts, polymorphonuclear (PMN) leukocyte proportions and myeloperoxidase (MPO) activity in BALF, and increased wet/dry weight ratios and protein concentrations in BALF were found in mice after exosome injection but not in mice treated with exosome-depleted serum. Furthermore, western blot analysis showed that circulating exosomes from ARDS mice upregulated glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) expression and downregulated ß-Catenin and VE-cadherin expression in lung tissues. CONCLUSIONS: Collectively, these data demonstrate that circulating exosomes from LPS-induced ARDS mice trigger ER stress in lung tissue, facilitating the development of ARDS, at least partly by promoting endothelial dysfunction.

A Peptide-Based Magnetic Chemiluminescence Enzyme Immunoassay for Serological Diagnosis of Coronavirus Disease 2019.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel ß-coronavirus, causes severe pneumonia and has spread throughout the globe rapidly. The disease associated with SARS-CoV-2 infection is named coronavirus disease 2019 (COVID-19). To date, real-time reverse-transcription polymerase chain reaction (RT-PCR) is the only test able to confirm this infection. However, the accuracy of RT-PCR depends on several factors; variations in these factors might significantly lower the sensitivity of detection. METHODS: In this study, we developed a peptide-based luminescent immunoassay that detected immunoglobulin (Ig)G and IgM. The assay cutoff value was determined by evaluating the sera from healthy and infected patients for pathogens other than SARS-CoV-2. RESULTS: To evaluate assay performance, we detected IgG and IgM in the sera from confirmed patients. The positive rate of IgG and IgM was 71.4% and 57.2%, respectively. CONCLUSIONS: Therefore, combining our immunoassay with real-time RT-PCR might enhance the diagnostic accuracy of COVID-19.

Increased p300/CBP expression in acute respiratory distress syndrome is associated with interleukin-17 and prognosis.

PURPOSE: Transcription co-activator p300/CBP, a histone acetyltransferase, has a central role in tumours, inflammation and neurodegenerative diseases. We investigated the effect of p300/CBP and its association with various IL-17-related indicators and prognosis in patients with acute respiratory distress syndrome (ARDS). MATERIALS AND METHODS: We enrolled 45 adult ARDS patients who were followed for 28 days and 22 healthy controls. The mRNA expression of p300, CBP, RORγt and Foxp3 and the plasma levels of several cytokines were measured. RESULT: The mRNA levels of p300, CBP and RORγt, and plasma concentration of IL-17, IL-6, were higher in acute ARDS patients (P < 0.05) compared with controls, and the mean levels of p300, CBP and IL-6 in non-survivors were higher than in survivors (P < 0.05). The expression of p300 was associated with the level of RORγt, IL-17 and disease prognosis. CONCLUSION: The levels of p300, RORγt mRNA and plasma concentration of IL-6 and IL-17 in acute ARDS patients were increased compared with controls. Increased p300/CBP expression may be an independent risk factor for 28-day mortality in ARDS.

Tangeretin attenuates lipopolysaccharide-induced acute lung injury through Notch signaling pathway via suppressing Th17 cell response in mice.

Tangeretin, a polymethoxylated flavonoid is abundant in citrus fruits, which has been reported to inhibit inflammation by inhibiting NF-κB activation and proinflammatory cytokines. Notch blockage inhibits Th17 cells response that are involved in the development of acute lung injury (ALI). This study investigated the protective effects of tangeretin on LPS-induced ALI in mice. Male C57BL/6 mice were treated with phosphate-buffered saline (PBS), lipopolysaccharide (LPS), LPS and tangeretin, or LPS and N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT, a Notch signaling inhibitor), which were harvested at 48 h after challenged by LPS. CD4+ T cells were treated with tangeretin or DAPT and harvested after 72 h. Tangeretin notably attenuated pathological changes and decreased the wet to dry weight ratio of the mouse lungs. The total cell and neutrophil counts, tumor necrosis factor (TNF)-α in bronchoalveolar lavage fluid (BALF), myeloperoxidase activity of lung tissue were markedly reduced by tangeretin. The percentage of CD4+IL-17 + T cells in the lungs and the concentration of interleukin (IL)-17 and IL-22 in BALF were significantly down-regulated by tangeretin. As with the positive control (DAPT), tangeretin inhibited the activity of the Notch signaling pathway accompanied with the down-regulation of acid-related orphan receptor gamma t and IL-23 receptor expression. This study demonstrated that tangeretin protects against LPS-induced ALI by suppressing Th17 response at least partially, through a Notch-dependent mechanism.

Protein Kinase C Theta Inhibition Attenuates Lipopolysaccharide-Induced Acute Lung Injury through Notch Signaling Pathway via Suppressing Th17 Cell Response in Mice.

Acute lung injury (ALI)/acute respiratory distress syndrome is characterized by increased pulmonary inflammation, where T helper 17 (Th17) cells play an important regulatory role. Notch signaling critically regulates Th17 differentiation and is known to be linked with proximal T cell by protein kinase C theta (PKCθ). We hypothesized that PKCθ inhibition could attenuate ALI by suppressing Th17 response via the Notch signaling pathway. Male C57BL/6 mice were treated with phosphate-buffered saline (PBS), lipopolysaccharide (LPS), LPS and N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT, a Notch signaling inhibitor), or LPS and PKCθ inhibitor (PI), and the bronchoalveolar lavage fluid (BALF), blood, and lung tissues were harvested at 48 h after the LPS challenge. CD4+ T cells were treated with DAPT or PI and harvested after 72 h. PKCθ inhibition markedly attenuated pathological changes and decreased the wet to dry weight ratio of the mouse lungs. The total cell and neutrophil counts, tumor necrosis factor-α (TNF- α) in BALF, myeloperoxidase activity in lung tissue, and the leukocyte count in whole blood were markedly reduced by PKCθ inhibition. The concentration of interleukin (IL)-17 and IL-22 in BALF, and the percentage of CD4+IL-17A+ T cells in the lungs were significantly downregulated by PKCθ inhibition. A similar trend was observed for the expression of retinoic acid-related orphan receptor gamma t and IL-23 receptor after PKCθ inhibition accompanied with inactivation of the Notch signaling pathway in vivo and in vitro. Collectively, these data demonstrated that PKCθ inhibition protects against LPS-induced ALI by suppressing the differentiation and pathogenicity of Th17, at least partially, through a Notch-dependent mechanism.