Lung Tissue Research Articles

FAS gene expression, prognostic significance and molecular interactions in lung cancer.

FAS has been implicated in the development of various cancers, but its involvement in lung cancer has not been systematically characterized. In this study, we performed data mining in online tumor databases to investigate the expression, methylation, alterations, protein interactions, co-expression and prognostic significance of FAS in lung cancer. The expression, prognostic significance and molecular interactions of FAS in lung cancer was mined and analyzed using GENT2, GEPIA2, UALCAN, cBioPortal, STRING, GeneMANIA, UCSC Xena, Enrichr, and OSluca databases. FAS expression was subsequently investigated at the protein level in samples from 578 lung cancer patients to understand its protein-level expression. In vitro validation of FAS gene expression was performed on H1299, H1993, A549 and HBE cell lines. We found that the expression of FAS was significantly downregulated in both lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) compared to normal lung tissue. In addition, we observed a higher level of FAS promoter methylation in LUSC tissue than in normal tissue. FAS alterations were rare (1.9%) in lung cancer samples, with deep deletions being more common than missense mutations, which occurred mainly in the TNFR-like cysteine-rich domain and the death domain. We also identified a list of proteins interacting with FAS and genes co-expressed with FAS, with LUAD having 11 co-expressed genes and LUSC having 90 co-expressed genes. Our results also showed that FAS expression has limited prognostic significance (HR=1.302, 95% CI=0.935-1.139, P=0.530). Protein level investigation revealed that FAS expression varied among individuals, with nTPM values ranging from 5.2 to 67.2. This study provides valuable insights into the involvements and characteristics of FAS in lung cancer. Further studies are needed to investigate the clinical significance of FAS alterations in lung cancer and to explore the potential of targeting FAS for therapeutic intervention.

Advances on physiology and pathology of subpopulations of macrophages in the lung tissue

Macrophages are vital in maintaining tissue homeostasis in the lungs by modulating and regulating immune responses. Based on different origins and anatomical locations, macrophages in the lungs are categorized into alveolar macrophages, interstitial macrophages, perivascular macrophages, and inflammatory macrophages. Alveolar macrophages are located in the alveolar spaces and are primarily responsible for maintaining alveolar surfactant homeostasis, defending against pathogens and regulating immune responses. Interstitial macrophages can maintain homeostasis, regulate immunity and anti-inflammation in the lung tissue. Perivascular macrophages play a crucial role in inhibiting lung inflammation, improving pulmonary fibrosis, and regulating lung tumor progression due to antigen-presenting and immunomodulatory effects. Inflammatory macrophages, which are differentiated from monocytes during inflammation, regulate the inflammatory process. This article reviews the origins of various subpopulations of macro-phages in the lung tissue and their physiological and pathological functions as well as discusses the underlying mechanisms and potential therapeutic targets.

Curcumin Alleviates Airway Inflammation in Cough-Variant Asthmatic Rats by Modulating M1/M2 Macrophage Polarization.

With the increase of environmental pollution and atypical pathogen infections, the incidence of cough variant asthma (CVA) has been increasing annually, making it a pressing issue of the medical community. This study aims to observe the ameliorative effect of curcumin on a rat model of cough variant asthma. A rat model of cough variant asthma was induced by sensitization with ovalbumin combined with aluminum hydroxide (Al(OH)3), followed by repeated excitations. The drug was administered on the day of the initial nebulized attack, and gavage was administered for 14 d. Pathological changes in the lung tissues were observed, along with the assessment of cough susceptibility and airway resistance. The number of inflammatory cell eosinophils and leukocytes were determined in alveolar lavage fluid. Additionally, serum inflammatory factors and lung tissues Matrix Metalloproteinase-9 (MMP-9) protein were assessed. The level of M1/M2 macrophages was also detected. Following the administration of curcumin, there was reduced inflammatory infiltration, less disordered arrangement of the lung tissue, and decreased abnormal proliferation of lung tissues in cough variant asthma rats compared to the model group. Curcumin treatment led toa notable reduction in cough frequency, a significant decrease in pro-inflammatory factor concentration levels in serum and inflammatory cell counts in the alveolar lavage fluid, and a marked increase in anti-inflammatory factor levels (p < 0.05). Additionally, curcumin administration led to a significant increase in M2-type macrophage levels, while simultaneously decreasing the levels of M1-type macrophages (p < 0.05). The administration of curcumin effectively ameliorates ovalbumin-induced airway inflammation in cough-variant asthma rats. This effect is attributed to modulating macrophage polarization towards the anti-inflammatory M2 phenotype, thereby reducing airway inflammation, airway hyperresponsiveness, and lung tissue injury.

Suppression of miR-17 Alleviates Acute Respiratory Distress-associated Lung Fibrosis by Regulating Mfn2.

Acute respiratory distress syndrome (ARDS) patients currently have relatively high mortality, which is associated with early lung fibrosis. This study aimed to investigate whether miR-17 suppression could alleviate ARDS-associated lung fibrosis by regulating Mfn2. A mouse model of ARDS-related lung fibrosis was constructed via intratracheal instillation of bleomycin. The expression level of miR-17 in lung tissues was detected via quantitative real time polymerase chain reaction (qRT-PCR). In the ARDS mouse model of lung fibrosis, the mitigating effects of miR-17 interference were evaluated via tail vein injection of the miR negative control or the miR-17 antagomir. The pathological changes in the lung tissue were examined via HE staining and Masson's trichrome staining, and the underlying molecular mechanism was investigated via ELISA, qRT-PCR and Western blotting. Bleomycin-induced pulmonary fibrosis significantly increased collagen deposition and the levels of hydroxyproline (HYP) and miR-17. Interfering with miR-17 significantly reduced the levels of HYP and miR-17 and upregulated the expression of Mfn2. The intravenous injection of the miR-17 antagomir alleviated lung inflammation and reduced collagen deposition. In addition, interference with miR-17 could upregulate LC3B expression, downregulate p62 expression, and improve mitochondrial structure. Interfering with miR-17 can improve pulmonary fibrosis in mice by promoting mitochondrial autophagy via Mfn2.

SULF1 expression is increased and promotes fibrosis through the TGF-β1/SMAD pathway in idiopathic pulmonary fibrosis

BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic and progressive interstitial lung disease of unknown etiology. Despite the increasing global incidence and poor prognosis, the exact pathogenic mechanisms remain elusive. Currently, effective therapeutic targets and treatment methods for this disease are still lacking. This study tried to explore the pathogenic mechanisms of IPF. We found elevated expression of SULF1 in lung tissues of IPF patients compared to normal control lung tissues. SULF1 is an enzyme that modifies heparan sulfate chains of heparan sulfate proteoglycans, playing a critical role in biological regulation. However, the effect of SULF1 in pulmonary fibrosis remains incompletely understood. Our study aimed to investigate the impact and mechanisms of SULF1 in fibrosis.MethodsWe collected lung specimens from IPF patients for transcriptome sequencing. Validation of SULF1 expression in IPF patients was performed using Western blotting and RT-qPCR on lung tissues. ELISA experiments were employed to detect SULF1 concentrations in IPF patient plasma and TGF-β1 levels in cell culture supernatants. We used lentiviral delivery of SULF1 shRNA to knock down SULF1 in HFL1 cells, evaluating its effects on fibroblast secretion, activation, proliferation, migration, and invasion capabilities. Furthermore, we employed Co-Immunoprecipitation (Co-IP) to investigate the regulatory mechanisms involved.ResultsThrough bioinformatic analysis of IPF transcriptomic sequencing data (HTIPF) and datasets GSE24206, and GSE53845, we identified SULF1 may potentially play a crucial role in IPF. Subsequently, we verified that SULF1 was upregulated in IPF and predominantly increased in fibroblasts. Furthermore, SULF1 expression was induced in HFL1 cells following exposure to TGF-β1. Knockdown of SULF1 suppressed fibroblast secretion, activation, proliferation, migration, and invasion under both TGF-β1-driven and non-TGF-β1-driven conditions. We found that SULF1 catalyzes the release of TGF-β1 bound to TGFβRIII, thereby activating the TGF-β1/SMAD pathway to promote fibrosis. Additionally, TGF-β1 induces SULF1 expression through the TGF-β1/SMAD pathway, suggesting a potential positive feedback loop between SULF1 and the TGF-β1/SMAD pathway.ConclusionsOur findings reveal that SULF1 promotes fibrosis through the TGF-β1/SMAD pathway in pulmonary fibrosis. Targeting SULF1 may offer a promising therapeutic strategy against IPF.

Human Umbilical Cord Mesenchymal Stem Cell Exosome-derived miR-335-5p Alleviated Lipopolysaccharide-induced Acute Lung Injury by Regulating the m6A Level of ITGβ4 Gene.

Acute lung injury (ALI) is a serious complication that may accompany severe pneumonia in children. Derived from human umbilical cord mesenchymal stem cell exosome (HucMSC-Exo) can contribute to the regeneration of damaged lung tissue. This study aims to investigate the impact of HucMSC-Exo on ALI and its potential mechanisms. Firstly, RT-qPCR was performed to assess the expression of miR-335-5p. Subsequently, Pearson correlation analysis was performed to examine the correlation between METTL14 and miR-335-5p, as well as the correlation between METTL14 and ITGβ4, while RNA immunoprecipitation (RIP) was used to determine the m6A modification level of ITGβ4. Additionally, molecular biology techniques were employed to evaluate the expression of glycolysis-related factors. Definitively, an LPS-induced ALI model was established to investigate the effect of miR-335-5p on mice lung tissue. miR-335-5p was found to be highly expressed in HucMSC-Exo. Transfection with miR-335-5p mimics resulted in increased glucose uptake. Pearson correlation analysis revealed a negative correlation between METTL14 and miR-335-5p, as well as between METTL14 and ITGβ4. The m6A level of ITGβ4 was elevated in ALI. Overexpression of METTL14 was found to reduce the expression of ITGβ4 and glucose levels, while overexpression of ITGβ4 reversed the effects of METTL14 overexpression. In vivo, results demonstrated that miR-335-5p could improve the extent of lung tissue lesions and reduce glycolytic levels. This study revealed the mechanism by which miR-335-5p derived from HucMSC-Exo could alleviate LPS-induced ALI by regulating the m6A modification of ITGβ4, providing a new direction for the treatment of ALI.

Arbutin alleviates Mycoplasma gallinarum-induced damage caused by pulmonary fibrosis via the JAK2/STAT3 pathway

Mycoplasma gallinarum (MG) can cause infectious respiratory diseases in poultry that are chronic. Arbutin (AR) possesses anti-inflammatory, bacteriostatic, antitussive, and expectorant pharmacological effects, but whether it exerts regulatory effects on MG-induced pneumonia and fibrosis remains unclear. The study results unveiled that pulmonary connective tissue hyperplasia, pulmonary capillary congestion, and inflammatory cell infiltration, as well as serum levels of cytokines (i.e., TNF-α, IL-1β, IL-6, and IL-10), were elevated after MG infection. Collagen fibers were significantly deposited in the lung tissue from MG-infected chicks. Furthermore, the expression levels of key factors in the JAK2/STAT3 and TGF-β/Smad pathways markedly increased. AR intervention significantly alleviated MG-induced pneumonic injury, and reduced collagen deposition and the expression of fibrosis markers in the lung tissue. AR reduced the degree of pulmonary fibrosis by regulating key factors of the JAK2/STAT3 signaling pathway in the MG-infected HD11 cells. Thus, AR effectively reduced the expression of inflammatory factors by regulating the JAK2/STAT3 signaling pathway, thereby improving lung inflammation and fibrosis.

Functional evaluation of TMEM176B and its predictive role for severe respiratory viral infection through integrated analysis of single-cell and bulk RNA-sequencing.

Transmembrane protein 176B (TMEM176B), localized mainly on the endosomal membrane, has been reported as an immune regulatory factor in malignant diseases. However, the biological function of this molecule remains undetermined during respiratory viral infections. To investigate the functions and prognostic value of this gene, six gene sets were selected from the Gene Expression Omnibus database for research. First, the function of TMEM176B and its co-expressed genes were evaluated at different levels (cell, peripheral blood, lung tissue). Afterwards, a machine learning algorithm was utilized to analyze the relationship between TMEM176B and its interacting genes with prognosis. After importance evaluation and variable screening, a prognostic model was established. Finally, the reliability of the model was further verified through external data sets. In vitro experiments were conducted to validate the function of TMEM176B. TMEM176B and its co-expressed genes are involved in multiple processes such as inflammasome activation, myeloid immune cell development, and immune cell infiltration. Machine learning further screened 27 interacting gene modules including TMEM176B as prognostic models for severe respiratory viral infections, with the area under the ROC curve (AUCs) of 0.986 and 0.905 in derivation and external validation sets, respectively. We further confirmed that viral load as well as NLRP3 activation and cell death were significantly enhanced in TMEM176B-/- THP-1-differentiated macrophages via in vitro experiments. Our study revealed that TMEM176B is involved in a wide range of biological functions in respiratory viral infections and has potential prognostic value, which is expected to bring new insights into the clinical management of severe respiratory viral infection hosts.

Exploring the Antioxidant and Anti-Inflammatory Effects of Rhoifolin Isolated from Teucrium Polium on Rats' Lungs Exposed to Tobacco Smoke.

Cigarette smoking exacerbates respiratory diseases, while plant-derived polyphenols offer antioxidant and anti-inflammatory benefits. This study exploresd the effects of Rhoifolin (ROF), a polyphenol from Jordanian Teucrium polium, on lung health in rats exposed to tobacco smoke. Male rats were divided into two groups: one exposed to cigarette smoke (CS), and the other to ROF treatment alongside smoke exposure (CS/ROF). ROF was administered orally for 21 days before smoke exposure. Results showed smoke-induced lung inflammation and oxidative stress, mitigated by ROF treatment. Histological examination revealed smoke-related morphological changes in lung tissue. ROF treatment reduced oxidative stress and inflammation, as evidenced by decreased proinflammatory cytokines. In silico docking demonstrated ROF's potential as an inhibitor of proinflammatory cytokines. This study demonstrates the therapeutic potential of ROF and similar polyphenols in mitigating the harmful effects of cigarette smoke on lung health.

Imaging the immune sequelae of infection with SARS-CoV-2 in nonhuman primates by using two nanobody PET-tracers.

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacts multiple anatomical sites. Whether this is due to the virus itself or is a secondary effect caused by the influx and activation of immune cells is not known. Positron emission tomography (PET) with immunoglobulins can provide insights into which sites and cells are activated in a living animal. Our aim is to use two nanobodies as tools to monitor (1) the distribution of antigen presenting cells (APC) by virtue of their Mafa-DR expression profile, (2) virus-infected cells and viral particles using a nanobody against the SARS-CoV-2 spike protein. Two [89Zr]-labeled nanobodies that target the SARS-CoV-2 spike protein and major histocompatability complex (MHC) class II antigens (Mafa-DR), respectively, are used to monitor their distribution during an experimental SARS-CoV-2 infection in a nonhuman primate model. Scans are obtained before infection and on Day 3 and 10 post infection (pi) in two macaques each. The [89Zr]anti-SARS-CoV-2 spike nanobody localized to SARS-CoV-2-associated lung lesions and the nasal mucosa, while the [89Zr]anti-human leukocyte antigen (HLA)-DR nanobody was predominantly found in non-affected lung tissue after infection. We also detected, pi, upregulation of the Mafa-DR signal, indicative of recruitment of professional APCs, in the superior sagittal sinus. [89Zr]-labeled nanobodies show recruitment of macrophages/monocytes in non-lesional lung tissue in cynomolgus macaques after experimental infection with SARS-CoV-2, as well as accumulation of the spike protein in both lung lesions and the nasal mucosa during infection. These results show the possibility of in vivo monitoring the quality and quantity of immune responses during the initial stages of an infection.

Scutellaria baicalensis ameliorates allergic airway inflammation through agonism and transcriptional regulation of TAS2Rs

Ethnopharmacological relevanceScutellaria baicalensis Georgi (SCB, Huangqin) is a traditional medicinal plant used to treat fever and respiratory diseases. SCB has a good therapeutic effect on asthma and anti-inflammation in traditional clinic use. However, the molecular mechanism and targets of SCB in treating asthma are still unclear. Aim of the studyCombining transcriptomic analysis and in vitro experimental validation, this study aimed to reveal the molecular mechanism and targets of SCB in treating asthma. Materials and methodsThe anti-asthmatic effects of SCB and its active components, scutellarin and oroxylin A, were evaluated in ovalbumin (OVA)-induced rats by analysis of pulmonary function and pathology. The signaling pathways in rat pulmonary tissue were analyzed using transcriptomics and protein interaction network analysis. Calcium mobilization assay and molecular docking were utilized to discover the active compounds from SCB with agonism activity of type 2 taste receptors (TAS2Rs). The anti-asthmatic effect and transcriptional regulation of TAS2Rs regulated by SCB and its active components were analyzed in vitro. ResultsExtracts of SCB (ESB), scutellarin, and oroxylin A ameliorated airway function and inflammation in OVA-induced rats. The anti-asthma mechanism of ESB, scutellarin and oroxylin A was highly related to immune and taste transduction pathways based on transcriptomic analysis, especially the TAS2Rs signaling pathway. ESB was the direct agonist of TAS2R4 and TAS2R14 with EC50 of 209.1 and 217.2 μg/mL based on calcium mobilization assay, respectively. Baicalein was the main active component for TAS2R4 agonism activity, and scutellarin and oroxylin A had weak agonism activity of TAS2R4 and TAS2R14 through calcium mobilization assay and molecular docking. However, scutellarin and oroxylin A significantly upregulated the gene expression of Tas2r108 (the mouse ortholog of the TAS2R4) in lung tissue. ESB, scutellarin, and oroxylin A inhibited LPS-induced lactate dehydrogenase release and gene expression of TNF through transcriptional regulation of TAS2R4 and TAS2R14 on bronchial epithelial cells. ESB and oroxylin A ameliorated IgE-induced β-hexosaminidase release and gene expression of Il4 and Tnf and upregulated gene expression of Tas2r108. ConclusionThese results provided new insight into the anti-asthmatic mechanism of SCB and active components, scutellarin and oroxylin A, through agonism and transcriptional regulation of TAS2Rs to ameliorate allergic airway inflammation.

The role of ischaemia-modified albumin in the prognosis of acute pancreatitis and its correlation with the NF-κB-mediated inflammatory response.

To investigate the correlation between the serum levels of ischaemia-modified albumin (IMA) and disease severity in rats with acute pancreatitis (AP). A rat AP model was established and blood samples from each group were analysed at different time points. After the experiment, the pancreatic tissues of the rats were collected for pathological examination and the measurement of protein levels of NF-κB and NF-κB p65. Serum levels of amylase (α-AMY), tumour necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-8 were also compared between groups of rats. The serum IMA concentration in the severe acute pancreatitis (SAP) group was greater than that in the mild acute pancreatitis (MAP) group. The levels of the NF-κB and NF-κB p65 proteins were increased in the MAP and SAP groups in a time-dependent manner. α-AMY, TNF-α and IL-6 were increased at all time points in the MAP and SAP groups. The increases were greatest at 24 h in the SAP group. In terms of pathological changes in the pancreas, renal and lung tissues, the damage in the SAP group was more obvious than that in the MAP group. Serum IMA level was associated with inflammatory markers and NF-κB p65 in rats with AP.

Total alkaloids in Fritillaria cirrhosa D. Don alleviate OVA-induced allergic asthma by inhibiting M2 macrophage polarization

Fritillaria cirrhosa D. Don (FCD) is a traditional Chinese medicine used to treat respiratory disorders, known for its effects in clearing heat, moistening the lungs, resolving phlegm, and relieving cough. Additionally, the total alkaloids extracted from FCD can alleviate asthma symptoms and reduce airway inflammation. However, no studies have investigated the effects of total alkaloids on lung macrophages. This study explored whether the total alkaloids of FCD (TAs-FCD) reduce M2 macrophage polarization and, consequently, attenuate airway remodeling in asthmatic mice. This study further elucidated its mechanism of action in treating allergic asthma. The extracted TAs-FCD was analyzed for its composition using UPLC-Q-TOF/MS. Network pharmacology was employed to identify the active ingredients and potential mechanisms of TAs-FCD in the treatment of allergic asthma. A mouse model of ovalbumin-induced allergic asthma was established, adopted, and validated through in vivo experiments. Hematoxylin-eosin staining (H&E), immunohistochemistry (IHC), immunofluorescence staining (IF), enzyme-linked immunosorbent assay (ELISA), Western blotting (WB), and real-time fluorescence quantitative polymerase chain reaction (q-PCR) were used to investigate the role of TAs-FCD in inhibiting M2 macrophage polarization in the context of allergic asthma. A total of 66 active ingredients were screened from 116 compounds using SWISSADME. The targets of these 66 compounds were predicted by SwissTargetPrediction, resulting in 808 unique drug targets after excluding duplicates. Additionally, 1,756 targets related to allergic asthma were identified from the DisGeNET, Genecard, and OMIM databases. This led to 267 cross-targets between the active ingredient targets and allergic asthma targets, including interleukin (IL)-1β, tumor necrosis factor (TNF), and STAT3. Animal experiments demonstrated that TAs-FCD improved histopathological injury in mouse lungs, reduced peri-airway collagen fiber accumulation, airway mucus secretion, and airway smooth muscle proliferation. TAs-FCD also lowered IL-1β, TNF-α and IL-4 levels in lung tissues and alleviated airway inflammation. Furthermore, TAs-FCD significantly reduced levels of Arg1 and CD206, which are closely associated with M2 macrophages, and downregulated the expression of p-STAT3 and p-JAK2. TAs-FCD may inhibit M2 macrophage polarization by regulating the JAK2/STAT3 pathway, thereby alleviating airway remodeling and inflammation in allergic asthmatic mice.

Isoliquiritigenin: A natural compound with a promising role in inhibiting breast cancer lung metastasis

Background and aimIsoliquiritigenin (ISL) is a dietary bioactive compound that is derived from the roots of licorice and various other plants. Accumulating evidence suggests that ISL has noteworthy anticancer activity in a variety of cancer cells, but it is currently unknown how ISL affects the invasion and migration of breast cancer (BC) cells. Hence, the purpose of this study to determine the inhibitory effect of ISL on cell invasion, migration, and metastasis of BC cells in 4T1-treated lung metastatic animal models. Experimental ProcedureISL was found to inhibit BC lung metastasis, as confirmed by MTT assay, clonogenic assay, wound healing assay, transwell assay, histological analysis, western blot and bioluminescence assay in the xenograft model. Results and conclusionThe in vitro studies revealed that ISL treatment significantly prevented BC cell invasion and migration for 24 h. ISL decreased the protein expressions of PI3K, Akt, p-Akt, mTOR, p-mTOR, matrix metalloproteinase (MMP)-2, MMP-9, and N-cadherin , thereby inhibiting BC cell invasion. In addition, ISL decreased MMP-2/9 and N-cadherin expression in lung tissues and reduced mouse 4T1 BC cell lung metastasis. Based on these findings, it suggests that ISL inhibits cell migration and invasion in BC cells by inhibiting the PI3K/Akt signaling pathway and decreasing the activation of MMP-2 and MMP-9 expression. Therefore, ISL may be useful in managing BC invasion and metastasis.

Tangeretin inhibits airway inflammatory responses by reducing early growth response 1 (EGR1) expression in mice exposed to cigarette smoke and lipopolysaccharide

BackgroundTangeretin, a natural polymethoxyflavone compound, possesses potent anti-inflammatory activity that improves respiratory inflammation in chronic obstructive pulmonary disease (COPD). However, the molecular mechanisms underlying the anti-COPD effects of tangeretin remain unclear. In this study, we aimed to investigate the key molecular mechanisms by which tangeretin suppresses COPD-related inflammatory responses. MethodsWe conducted the investigation in phorbol-12-myristate-13-acetate (PMA)-stimulated human airway epithelial cells (in vitro) and cigarette smoke (CS)/lipopolysaccharide (LPS)-exposed mice (in vivo). ResultsTangeretin decreased the release of inflammatory mediators, including tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and mucin 5AC (MUC5AC), by suppressing early growth response 1 (EGR1) expression in vitro. Tangeretin and EGR1 small interfering ribonucleic acid (siRNA) combination showed a synergistic reduction in MUC5AC and TNF-α secretion. Tangeretin administration significantly inhibited the levels of reactive oxygen species (ROS) production, elastase activity, TNF-α, IL-6, and monocyte chemoattractant protein-1 (MCP-1) secretion, and macrophage and neutrophil numbers in the bronchoalveolar lavage fluid of CS/LPS-exposed mice. Tangeretin also prevented CS/LPS-induced abnormal pathological changes and excessive MUC5AC and EGR1 expression in lung tissue. ConclusionComprehensively, tangeretin inhibits the lung inflammatory response associated with COPD by reducing EGR1 expression in PMA-induced human epithelial cells and in a CS/LPS-stimulated mouse model. This study shows that tangeretin has anti-COPD properties and can be a promising alternative (or complementary) treatment for inflammatory lung disease.

NLRP3 inflammasome-mediated disruption of mitochondrial homeostasis in alveolar macrophages contributes to ozone-induced acute lung inflammatory injury.

Ozone (O 3), a prevalent atmospheric pollutant, can induce lung injury. However, the molecular mechanisms of O 3-induced acute lung inflammatory injury remain unclear. In this study, we investigate the abnormal changes in and molecular mechanism of mitochondrial homeostasis in alveolar macrophages (AMs) in O 3-induced acute lung inflammatory injury mice. Mitochondria and mitochondrial reactive oxygen species (mtROS) are labeled with Mito-Tracker® Deep Red and MitoSOX Red, respectively. Mitochondrial DNA (mtDNA) in AMs from the bronchoalveolar lavage fluid (BALF) is detected via real-time PCR, and the expressions of mitochondrial fusion/fission-related and biogenesis-related proteins in AMs are determined via immunofluorescence staining. Our data show that in O 3-induced acute lung inflammatory injury mice, the number of AMs and the protein expression of the NLRP3 inflammasome complex in the lung tissue are increased. In AMs from O 3-exposed mice, the number of mitochondria, mtROS, and fission-related protein DRP1 are increased, but the levels of Na +-K +-ATPase, fusion-related protein OPA1, biogenesis-related protein NRF1 and mtDNA are significantly decreased. Compared with that in O 3-exposed WT mice, lung inflammation is attenuated, especially the indicators of mitochondrial homeostatic imbalance in AMs, which are alleviated in NLRP3 ‒/‒ and Caspase-1 ‒/‒ mice after O 3 exposure. These findings indicate that the NLRP3 inflammasome-mediated imbalance in mitochondrial homeostasis in AMs contributes to O 3-induced acute lung inflammatory injury. This study may provide a new target for the prevention of lung inflammation induced by O 3.

Reproducible lung protective effects of a TGFβR1/ALK5 inhibitor in a bleomycin-induced and spirometry-confirmed model of IPF in male mice.

This study comprehensively validated the bleomycin (BLEO) induced mouse model of IPF for utility in preclinical drug discovery. To this end, the model was rigorously evaluated for reproducible phenotype and TGFβ-directed treatment outcomes. Lung disease was profiled longitudinally in male C57BL6/JRJ mice receiving a single intratracheal instillation of BLEO (n = 10-12 per group). A TGFβR1/ALK5 inhibitor (ALK5i) was profiled in six independent studies in BLEO-IPF mice, randomized/stratified to treatment according to baseline body weight and non-invasive whole-body plethysmography. ALK5i (60 mg/kg/day) or vehicle (n = 10-16 per study) was administered orally for 21 days, starting 7 days after intratracheal BLEO installation. BLEO-IPF mice recapitulated functional, histological and biochemical hallmarks of IPF, including declining expiratory/inspiratory capacity and inflammatory and fibrotic lung injury accompanied by markedly elevated TGFβ levels in bronchoalveolar lavage fluid and lung tissue. Pulmonary transcriptome signatures of inflammation and fibrosis in BLEO-IPF mice were comparable to reported data in IPF patients. ALK5i promoted reproducible and robust therapeutic outcomes on lung functional, biochemical and histological endpoints in BLEO-IPF mice. The robust lung fibrotic disease phenotype, along with the consistent and reproducible lung protective effects of ALK5i treatment, makes the spirometry-confirmed BLEO-IPF mouse model highly applicable for profiling novel drug candidates for IPF.

Phillyrin prevents sepsis-induced acute lung injury through inhibiting the NLRP3/caspase-1/GSDMD-dependent pyroptosis signaling pathway.

Acute lung injury (ALI) is a severe pulmonary disorder of sepsis with high clinical incidence and mortality. Nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3)-cysteinyl aspartate specific proteinase 1-gasdermin D (GSDMD)-dependent pyroptosis of alveolar epithelial cells (AECs) has emerged as a crucial contributor to ALI during sepsis. Phillyrin (PHI), a natural lignan isolated from the traditional Chinese herbal medicine Forsythia suspensa, has been shown to have anti-inflammatory, antioxidant and antiviral properties. However, little is known about the protective role and potential mechanism of PHI in sepsis-induced ALI, and it is uncertain whether the protective effect of PHI in sepsis-induced ALI is connected to pyroptosis. This study aims to examine the preventive effects of PHI on sepsis-induced ALI via the inhibition of NLRP3/caspase-1/GSDMD-mediated pyroptosis in AECs. Our findings demonstrate that preadministration of PHI successfully reduces sepsis-induced pulmonary edema, systemic/pulmonary inflammation, and pulmonary histological damage in lung tissues, bronchoalveolar lavage fluid, and the serum of septic mice. Intriguingly, PHI preadministration suppresses sepsis-induced protein expressions of pyroptosis-specific markers, especially their active forms. In vitro assays show that PHI pretreatment also protects type II AECs (MLE-12) from lipopolysaccharide-induced pyroptosis by preventing the activation of the pyroptosis signaling pathway. The results from molecular docking and surface plasmon resonance reveal that PHI has a significant affinity for direct binding to the GSDMD protein, suggesting that GSDMD is a potential pharmacological target for PHI. In conclusion, PHI can prevent sepsis-triggered ALI by effectively suppressing the activation of the canonical pyroptosis signaling pathway and pyroptosis of AECs.

MiR-149-3p targeting TMPRSS4 regulates the sensitivity to cisplatin to inhibit the progression of lung cancer.

Lung cancer cells tend to develop resistance to cisplatin (DDP) during continuous chemotherapy, making it crucial to improve DDP sensitivity to enhance therapeutic outcomes. The levels of miR-149-3p in lung tissues and cells, as well as the biological behaviors of lung cancer cells, were analyzed. H446/DDP and A549/DDP cell lines were established to investigate how miR-149-3p affects lung cancer cells' sensitivity to DDP. Bioinformatics analysis predicted transmembrane serine protease 4 (TMPRSS4) as a downstream target of miR-149-3p, which was subsequently confirmed. Western blot analysis was used to examine proteins related to migration, invasion, apoptosis, and TMPRSS4 expression. Additionally, a subcutaneous graft tumor model in nude mice was created to assess the impact of miR-149-3p on tumor growth. In lung cancer tissues and cells, miR-149-3p expression was reduced, while TMPRSS4 expression was elevated. Overexpression of miR-149-3p inhibited cancer progression, promoted apoptosis, and enhanced the chemosensitivity of lung cancer cells to DDP. Moreover, miR-149-3p negatively regulated TMPRSS4, reducing malignancy-associated characteristics of lung cancer cells and further improving their DDP sensitivity. In vivo, high miR-149-3p expression increased the chemosensitivity of cancer cells. In conclusion, miR-149-3p suppresses the aggressive progression of lung cancer by directly downregulating TMPRSS4 and enhances the responsiveness of lung cancer cells to DDP.

Endothelial PHD2 deficiency induces apoptosis resistance and inflammation via AKT activation and AIP1 loss independent of HIF2α.

In hypoxic and pseudohypoxic rodent models of pulmonary hypertension (PH), hypoxia-inducible factor (HIF) inhibition attenuates disease initiation. However, HIF activation alone, due to genetic alterations or use of inhibitors of prolyl hydroxylase domain (PHD) enzymes, has not been definitively shown to cause PH in humans, indicating the involvement of other mechanisms. Given the association between endothelial cell dysfunction and PH, the effects of pseudohypoxia and its underlying pathways were investigated in primary human lung endothelial cells. PHD2 silencing or inhibition, while activating HIF2α, induced apoptosis-resistance and IFN/STAT activation in endothelial cells, independent of HIF signaling. Mechanistically, PHD2 deficiency activated AKT and ERK, inhibited JNK, and reduced AIP1 (ASK1-interacting protein 1), all independent of HIF2α. Like PHD2, AIP1 silencing affected these same kinase pathways and produced a similar dysfunctional endothelial cell phenotype, which was partially reversed by AKT inhibition. Consistent with these in vitro findings, AIP1 protein levels in lung endothelial cells were decreased in Tie2-Cre/Phd2 knockout mice compared with wild-type controls. Lung vascular endothelial cells from patients with pulmonary arterial hypertension (PAH) showed IFN/STAT activation. Lung tissue from both SU5416/hypoxia PAH rats and patients with PAH all showed AKT activation and dysregulated AIP1 expression. In conclusion, PHD2 deficiency in lung vascular endothelial cells drives an apoptosis-resistant and inflammatory phenotype, mediated by AKT activation and AIP1 loss independent of HIF signaling. Targeting these pathways, including PHD2, AKT, and AIP1, holds the potential for developing new treatments for endothelial dysfunction in PH.NEW & NOTEWORTHY HIF activation alone does not conclusively lead to human PH, suggesting that HIF-independent signaling may also contribute to hypoxia-induced PH. This study demonstrated that PHD2 silencing-induced pseudohypoxia in human lung endothelial cells suppresses apoptosis and activates STAT, effects that persist despite HIF2α inhibition or knockdown and are attributed to AKT and ERK activation, JNK inhibition, and AIP1 loss. These findings align with observations in lung endothelial cells and tissues from PAH rodent models and patients.