Calcitriol/vitamin D receptor system alleviates PM2.5-induced human bronchial epithelial damage through upregulating mitochondrial bioenergetics in association with regulation of HIF-1α/PGC-1α signaling.

PM2.5 exposure causes lung injury by triggering oxidative stress, mitochondrial dysfunction, and modulating HIF-1α signaling. Calcitriol activates VDR, which regulates cellular homeostasis. This study evaluated the protective role of the calcitriol/VDR system in PM2.5-induced damage to BEAS-2B bronchial epithelial cells by reducing oxidative stress, upregulating mitochondrial bioenergetics, and downregulating HIF-1α. We found that the calcitriol/VDR system decreased ROS formation and restored mitochondrial bioenergetics in PM2.5-treated cells. This improvement correlated with reduced HIF-1α nuclear translocation and increased PGC-1α protein and mitochondrial gene expressions. This study is the first to suggest that targeting the calcitriol/VDR system could be a promising pharmacological strategy for mitigating PM2.5-induced lung epithelial damage by promoting mitochondrial bioenergetics and regulating PGC-1α and HIF-1α signaling.

Exosome-transmitted circ_0004664 suppresses the migration and invasion of cadmium-transformed human bronchial epithelial cells by regulating PTEN expression via miR-942-5p.

Exosomes play a crucial role in regulating extracellular communication between normal and cancer cells within the tumor microenvironment, thereby affecting tumor progression through their cargo molecules. However, the specific impact of exosomal circular RNAs (circRNAs) on the development of cadmium-induced carcinogenesis remains unclear. To address this, we investigated whether exosomes derived from normal human bronchial epithelial BEAS-2B (N-B2B) cells could transmit circRNA to cadmium-transformed BEAS-2B (Cd-B2B) cells and the potential effects on Cd-B2B cells. Our findings demonstrated a significant downregulation of circ_0004664 in Cd-B2B cells compared to N-B2B cells (P < 0.01). Overexpression of circ_0004664 in Cd-B2B cells led to a significant inhibition of cell migration and invasion (P < 0.01 or P < 0.05). Furthermore, N-B2B cells could transfer circ_0004664 into recipient Cd-B2B cells via exosomes, subsequently inhibiting cell migration and invasion (P < 0.05 or P < 0.01). Mechanistic investigations revealed that exosomal circ_0004664 functioned as a competitive endogenous RNA for miR-942-5p, resulting in an upregulation of PTEN (P < 0.05). Our study highlights the involvement of exosomal circ_0004664 in cell-cell communication during cadmium carcinogenesis, providing a novel insight into the role of exosomal circRNA in this process.

Distinct Responses of Cystic Fibrosis Epithelial Cells to SARS-CoV-2 and Influenza A Virus.

The COVID-19 pandemic has underscored the impact of viral infections on individuals with cystic fibrosis (CF). Initial observations suggested lower COVID-19 rates among CF populations; however, subsequent clinical data have presented a more complex scenario. This study aimed to investigate how bronchial epithelial cells from CF and non-CF individuals, including various CF transmembrane conductance regulator (CFTR) mutations, respond to in vitro infection with SARS-CoV-2 variants and SARS-CoV. Comparisons with the Influenza A virus (IAV) were included based on evidence that CF patients experience heightened morbidity from IAV infection. Our findings showed that CF epithelial cells exhibited reduced replication of SARS-CoV-2, regardless of the type of CFTR mutation or SARS-CoV-2 variant, as well as the original 2003 SARS-Cove. In contrast, these cells displayed more efficient IAV replication compared to non-CF cells. Interestingly, the reduced susceptibility to SARS-CoV-2 in CF was not linked to the expression of angiotensin converting enzyme 2 (ACE2) receptor nor to CFTR dysfunction, as pharmacological treatments to restore CFTR function did not normalize the viral response. Both SARS-CoV-2 infection and CFTR function influenced the levels of certain cytokines and chemokines, although these effects were not correlated. Overall, this study reveals a unique viral response in CF epithelial cells, characterized by reduced replication for some viruses like SARS-CoV-2, while showing increased susceptibility to others such as IAV. This research offers a new perspective on CF and viral interactions, emphasizing the need for further investigation into the mechanisms underlying these differences. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Experimental Study on Compatibility of Human Bronchial Epithelial Cells in Collagen-Alginate Bioink for 3D Printing.

This paper reports an experimental study on the compatibility of human bronchial epithelial (HBE) cells in a collagen-alginate bioink. The compatibility was assessed using the culture well method with three bioink compositions prepared from a 10% alginate solution and neutralized TeloCol-10 mg/mL collagen stock solution. Cell viability, quantified by (live cell count-dead cell count)/live cell count within the HBE cell-laden hydrogel, was evaluated using the live/dead assay method from Day 0 to Day 6. Experimental results demonstrated that the collagen-alginate 4:1 bioink composition exhibited the highest cell viability on Day 6 (85%), outperforming the collagen-alginate 1:4 bioink composition and the alginate bioink composition, which showed cell viability of 75% and 45%, respectively. Additionally, the live cell count was highest for the collagen-alginate 4:1 bioink composition on Day 0, a trend that persisted through Days 1 to 6, underscoring its superior performance in maintaining cell viability and promoting cell proliferation. These findings show that the compatibility of HBE cells with the collagen-alginate 4:1 bioink composition was higher compared with the other two bioink compositions.

Targeting CCL2-CCR2 signaling pathway alleviates macrophage dysfunction in COPD via PI3K-AKT axis.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) remains a leading cause of morbidity and mortality worldwide, characterized by persistent respiratory symptoms and airflow limitation. The involvement of C-C motif chemokine ligand 2 (CCL2) in COPD pathogenesis, particularly in macrophage regulation and activation, is poorly understood despite its recognized role in chronic inflammation. Our study aims to elucidate the regulatory role and molecular mechanisms of CCL2 in the pathogenesis of COPD, providing new insights for therapeutic strategies. METHODS: This study focused on the CCL2-CCR2 signaling pathway, exploring its role in COPD pathogenesis using both Ccl2 knockout (KO) mice and pharmacological inhibitors. To dissect the underlying mechanisms, we employed various in vitro and in vivo methods to analyze the secretion patterns and pathogenic effects of CCL2 and its downstream molecular signaling through the CCL2-CCR2 axis. RESULTS: Elevated Ccl2 expression was confirmed in the lungs of COPD mice and was associated with enhanced recruitment and activation of macrophages. Deletion of Ccl2 in knockout mice, as well as treatment with a Ccr2 inhibitor, resulted in protection against CS- and LPS-induced alveolar injury and airway remodeling. Mechanistically, CCL2 was predominantly secreted by bronchial epithelial cells in a process dependent on STAT1 phosphorylation and acted through the CCR2 receptor on macrophages. This interaction activated the PI3K-AKT signaling pathway, which was pivotal for macrophage activation and the secretion of inflammatory cytokines, further influencing the progression of COPD. CONCLUSIONS: The study highlighted the crucial role of CCL2 in mediating inflammatory responses and remodeling in COPD. It enhanced our understanding of COPD's molecular mechanisms, particularly how CCL2's interaction with the CCR2 activates critical signaling pathways. Targeting the CCL2-CCR2 axis emerged as a promising strategy to alleviate COPD pathology.

Modulation of Bronchial Epithelial Barrier Integrity by Low Molecular Weight Components from Birch Pollen.

Pollen, in addition to allergens, comprise low molecular weight components (LMC) smaller than 3 kDa. Emerging evidence indicates the relevance of LMC in allergic immune responses. However, the interaction of birch pollen (BP)-derived LMC and epithelial cells has not been extensively studied. We investigated epithelial barrier modifications induced by exposure to BP LMC, using the human bronchial epithelial cell line 16HBE14o-. Epithelial cell monolayers were apically exposed to the major BP allergen Bet v 1, aqueous BP extract or BP-derived LMC. Barrier integrity after the treatments was monitored by measuring transepithelial electrical resistance at regular intervals and by using the xCELLigence Real-Time Cell Analysis system. The polarized release of cytokines 24 h following treatment was measured using a multiplex immunoassay. Epithelial barrier integrity was significantly enhanced upon exposure to BP LMC. Moreover, BP LMC induced the repair of papain-mediated epithelial barrier damage. The apical release of CCL5 and TNF-α was significantly reduced after exposure to BP LMC, while the basolateral release of IL-6 significantly increased. In conclusion, the results of our study demonstrate that BP-derived LMC modify the physical and immunological properties of bronchial epithelial cells and thus regulate airway epithelial barrier responses.

Expression of ISG60 is induced by TLR3 signaling in BEAS­2B bronchial epithelial cells: Possible involvement in CXCL10 expression.

Viral infections in the respiratory tract are common, and, in recent years, severe acute respiratory syndrome coronavirus 2 outbreaks have highlighted the effect of viral infections on antiviral innate immune and inflammatory reactions. Specific treatments for numerous viral respiratory infections have not yet been established and they are mainly treated symptomatically. Therefore, understanding the details of the innate immune system underlying the airway epithelium is crucial for the development of new therapies. The present study aimed to investigate the function and expression of interferon (IFN)­stimulated gene (ISG)60 in non­cancerous bronchial epithelial BEAS­2B cells exposed to a Toll­like receptor 3 agonist. BEAS­2B cells were treated with a synthetic TLR3 ligand, polyinosinic­polycytidylic acid (poly IC). The mRNA and protein expression levels of ISG60 were analyzed using reverse transcription­quantitative PCR and western blotting, respectively. The levels of C­X­C motif chemokine ligand 10 (CXCL10) were examined using an enzyme­linked immunosorbent assay, and the effects of knockdown of IFN­ß, ISG60 and ISG56 were examined using specific small interfering RNAs. Notably, ISG60 expression was increased in proportion to poly IC concentration, and recombinant human IFN­ß also induced ISG60 expression. By contrast, knockdown of IFN­ß and ISG56 decreased ISG60 expression, and ISG60 knockdown reduced CXCL10 and ISG56 expression. These findings suggested that ISG60 is partly implicated in CXCL10 expression and that ISG60 may serve a role in the innate immune response of bronchial epithelial cells. The present study highlights ISG60 as a potential target for new therapeutic strategies against viral infections in the airway.

The flavonoid quercetin decreases ACE2 and TMPRSS2 expression but not SARS-CoV-2 infection in cultured human lung cells.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to angiotensin-converting enzyme 2 (ACE2) on host cells, via its spike protein, and transmembrane protease, serine 2 (TMPRSS2) cleaves the spike-ACE2 complex to facilitate virus entry. As rate-limiting steps for virus entry, modulation of ACE2 and/or TMPRSS2 may decrease SARS-CoV-2 infectivity and COVID-19 severity. In silico modeling suggested the natural bioactive flavonoid quercetin can bind to ACE2 and a recent randomized clinical trial demonstrated that oral supplementation with quercetin increased COVID-19 recovery. A range of cultured human cells were assessed for co-expression of ACE2 and TMPRSS2. Immortalized Calu-3 lung cells, cultured and matured at an air-liquid interface (Calu-3-ALIs), were established as the most appropriate. Primary bronchial epithelial cells (PBECs) were obtained from healthy adult males (N = 6) and cultured under submerged conditions to corroborate the outcomes. Upon maturation or reaching 80% confluence, respectively, the Calu-3-ALIs and PBECs were treated with quercetin, and mRNA and protein expression were assessed by droplet digital PCR and ELISA, respectively. SARS-CoV-2 infectivity, and the effects of pre- and co-treatment with quercetin, was assessed by median tissue culture infectious dose assay. Quercetin dose-dependently decreased ACE2 and TMPRSS2 mRNA and protein in both Calu-3-ALIs and PBECs after 4 h, while TMPRSS2 remained suppressed in response to prolonged treatment with lower doses (twice daily for 3 days). Quercetin also acutely decreased ADAM17 mRNA, but not ACE, in Calu-3-ALIs, and this warrants further investigation. Calu-3-ALIs, but not PBECs, were successfully infected with SARS-CoV-2; however, quercetin had no antiviral effect, neither directly nor indirectly through downregulation of ACE2 and TMPRSS2. Calu-3-ALIs were reaffirmed to be an optimal cell model for research into the regulation of ACE2 and TMPRSS2, without the need for prior genetic modification, and will prove valuable in future coronavirus and respiratory infectious disease work. However, our data demonstrate that a significant decrease in the expression of ACE2 and TMPRSS2 by a promising prophylactic candidate may not translate to infection prevention.

NPRL2 is required for proliferation of oncogenic Ras-transformed bronchial epithelial cells.

Nitrogen permease regulator-like 2 (NPRL2/TUSC4) is known to exert both tumor-suppressing and oncogenic effects in different types of cancers, suggesting that its actions are context dependent. Here, we delineated the molecular and functional effects of NPRL2 in malignantly transformed bronchial epithelial cells. To do so, we depleted NPRL2 in oncogenic HRas-transduced and malignantly transformed human bronchial epithelial (BEAS2B), Ras-AI-T2 cells. Intriguingly, depletion of NPRL2 in these cells induced activation of mTORC1 downstream signaling, inhibited autophagy, and impaired Ras-AI-T2 cell proliferation both in vitro and in vivo. These results suggest that NPRL2 is required for oncogenic HRas-induced cell transformation. Depletion of NPRL2 increased levels of the DNA damage marker γH2AX, the cell cycle inhibitors p21 and p27, and the apoptosis marker cleaved-PARP. These NPRL2-depleted cells first accumulated at G1 and G2, and later exhibited signs of mitotic catastrophe, which implied that NPRL2 depletion may be detrimental to oncogenic HRas-transformed cells. Additionally, NPRL2 depletion reduced heat shock factor 1/heat shock element- and NRF2/antioxidant response element-directed luciferase reporter activities in Ras-AI-T2 cells, indicating that NPRL2 depletion led to the suppression of two key cytoprotective processes in oncogenic HRas-transformed cells. Overall, our data suggest that oncogenic HRas-transduced and malignantly transformed cells may depend on NPRL2 for survival and proliferation, and depletion of NPRL2 also induces a stressed state in these cells.

N-acetyltransferase metabolism and DNA damage following exposure to 4,4'-oxydianiline in human bronchial epithelial cells.

Waterpipe smoking is increasingly popular and understanding how chemicals found in hookah smoke may be harmful to human bronchial epithelial cells is of great importance. 4,4'-Oxydianiline (ODA), is an aromatic amine which is present at comparatively high levels in hookah smoke. The metabolism and the subsequent toxicity of ODA in human bronchial epithelial cells remains unknown. Given that ODA is an aromatic amine, we hypothesized that ODA is N-acetylated and induces DNA damage following exposure to immortalized human bronchial epithelial cells (BEP2D cells). We measured the N-acetylation of ODA to mono-acetyl-ODA and the N-acetylation of mono-acetyl-ODA to diacetyl-ODA by BEP2D cells following separation and quantitation by high performance liquid chromatography. For ODA, the apparent KM in cells was 12.4 ± 3.7 µM with a Vmax of 0.69 ± 0.03 nmol/min/106 cells, while for mono-acetyl-ODA, the apparent KM was 111.2 ± 48.3 µM with a Vmax of 17.8 ± 5.7 nmol/min/106 cells ODA exposure for 24 h resulted in DNA damage to BEP2D cells following concentrations as low as 0.1 µM as measured by yH2Ax protein expression These results demonstrate that ODA, the most prevalent aromatic amine identified in hookah smoke, is N-acetylated and induces DNA damage in human bronchial epithelial cells.

Scutellarein Suppresses the Production of ROS and Inflammatory Mediators of LPS-Activated Bronchial Epithelial Cells and Attenuates Acute Lung Injury in Mice.

Scutellarein is a key active constituent present in many plants, especially in Scutellaria baicalensis Georgi and Erigeron breviscapus (vant.) Hand-Mazz which possesses both anti-inflammatory and anti-oxidative activities. It also is the metabolite of scutellarin, with the ability to relieve LPS-induced acute lung injury (ALI), strongly suggesting that scutellarein could suppress respiratory inflammation. The present study aimed to investigate the effects of scutellarein on lung inflammation by using LPS-activated BEAS-2B cells (a human bronchial epithelial cell line) and LPS-induced ALI mice. The results showed that scutellarein could reduce intracellular reactive oxygen species (ROS) accumulation through inhibiting the activation of NADPH oxidases, markedly downregulating the transcription and translation of pro-inflammatory cytokines, including interleukin-6 (IL-6), C-C motif chemokine ligand 2 (CCL2), and C-X-C motif chemokine ligand (CXCL) 8 in LPS-activated BEAS-2B cells. The mechanism study revealed that it suppressed the phosphorylation and degradation of IκBα, consequently hindering the translocation of p65 from the cytoplasm to the nucleus and its subsequent binding to DNA, thereby decreasing NF-κB-regulated gene transcription. Notably, scutellarein had no impact on the activation of AP-1 signaling. In LPS-induced ALI mice, scutellarein significantly decreased IL-6, CCL2, and tumor necrosis factor-α (TNF-α) levels in the bronchoalveolar lavage fluid, attenuated lung injury, and inhibited neutrophil infiltration. Our findings suggest that scutellarein may be a beneficial agent for the treatment of infectious pneumonia by virtue of its anti-oxidative and anti-inflammatory activities.

Ezrin Contributes to the Damage of Airway Epithelial Barrier Related to Diabetes Mellitus.

Background: Diabetes mellitus predisposes individuals to respiratory infections. The airway epithelial barrier provides defense against inhaled antigens and pathogens. Ezrin, is a component of the membrane-cytoskeleton that maintains the cellular morphology, intercellular adhesion, and barrier function of epithelial cells. This study aimed to explore the role of ezrin in airway epithelial barrier damage and correlate its expression and activation with diabetes mellitus. Methods: This study was performed in a murine model of diabetes mellitus and with human bronchial epithelial BEAS-2B cells using real-time PCR, Western blotting, immunohistochemical and immunofluorescence staining. Ezrin was knocked down in BEAS-2B cells using siRNA. Ezrin phosphorylation levels were measured to determine activation status. The integrity of the airway epithelial barrier was assessed in vivo by characterizing morphological structure, and in vitro in BEAS-2B cells by measuring tight junction protein expression, transepithelial electrical resistance (TER) and permeability. Results: We demonstrated that ezrin expression levels were lower in the lung tissue and airway epithelium of diabetic mice than those in control mice. The morphological structure of the airway epithelium was altered in diabetic mice. High glucose levels downregulated the expression and distribution of ezrin and connexin 43, reduced the expression of tight junction proteins, and altered the epithelial barrier characteristics of BEAS-2B cells. Ezrin knockdown had effects similar to those of high glucose levels. Moreover, a specific inhibitor of ezrin Thr567 phosphorylation (NSC305787) inhibited epithelial barrier formation. Conclusion: These results demonstrate that ezrin expression and activation are associated with airway epithelial damage in diabetes mellitus. These findings provide new insights into the molecular pathogenesis of pulmonary infections in diabetes mellitus and may lead to novel therapeutic interventions for airway epithelial barrier damage.

Investigate the potential impact of Hemagglutinin from the H1N1 strain on severe pneumonia.

The most prevalent glycoprotein on the influenza virus envelope is called hemagglutinin (HA), yet little is known about its involvement in the pathophysiology and etiology of severe influenza pneumonia. Here, after stimulating human bronchial epithelial cells (16-HBE) and mice with HA of H1N1 for 12 h, we investigated the proliferation, migration, inflammatory cytokines expression, and apoptosis in 16-HBE and the pathological damage in mouse lung tissue. The expression of inflammatory cytokines plasminogen activator inhibitor 1(PAI-1), urokinase-type (uPA) and tissue-type (tPA) plasminogen activators, and apoptosis were all enhanced by HA, which also prevented the proliferation and migration of bronchial epithelial cells. HA enhanced up-regulated PAI-1, uPA, and tPA protein expression within mouse lung tissue and caused lung injury. In conclusion, HA alone, but not the whole H1N1 virus, induces lung tissue injury by inhibiting cell proliferation and migration, while promoting the expression of inflammatory cytokines and apoptosis.

Tyndallized bacteria prime bronchial epithelial cells to mount an effective innate immune response against infections.

Airway epithelium represents a physical barrier against toxic substances and pathogens but also presents pattern recognition receptors on the epithelial cells that detect pathogens leading to molecule release and sending signals that activate both the innate and adaptive immune responses. Thus, impaired airway epithelial function and poor integrity may increase the recurrence of infections. Probiotic use in respiratory diseases as adjuvant of traditional therapy is increasingly widespread. There is growing interest in the use of non-viable heat-killed bacteria, such as tyndallized bacteria (TB), due to safety concerns and to their immunomodulatory properties. This study explores in vitro the effects of a TB blend on the immune activation of airway epithelium. 16HBE bronchial epithelial cells were exposed to different concentrations of TB. Cell viability, TB internalization, TLR2 expression, IL-6, IL-8 and TGF-ßl expression/release, E-cadherin expression and wound healing were assessed. We found that TB were tolerated, internalized, increased TLR2, E-cadherin expression, IL-6 release and wound healing but decreased both IL-8 and TGF-ßl release. In conclusion, TB activate TLR2 pathway without inducing a relevant pro-inflammatory response and improve barrier function, leading to the concept that TB preserve epithelial homeostasis and could be used as strategy to prevent and to manage respiratory infection, exacerbations included.

Investigation of lactotransferrin messenger RNA expression levels as an anti-type 2 asthma biomarker.

BACKGROUND: Lactotransferrin (LTF) has an immunomodulatory function, and its expression levels are associated with asthma susceptibility. OBJECTIVES: We sought to investigate LTF messenger RNA (mRNA) expression levels in human bronchial epithelial cells (BECs) as an anti-type 2 (T2) asthma biomarker. METHODS: Association analyses between LTF mRNA expression levels in BECs and asthma-related phenotypes were performed in the Severe Asthma Research Program (SARP) cross-sectional (n = 155) and longitudinal (n = 156) cohorts using a generalized linear model. Correlation analyses of mRNA expression levels between LTF and all other genes were performed by Spearman correlation. RESULTS: Low LTF mRNA expression levels were associated with asthma susceptibility and severity (P < .025), retrospective and prospective asthma exacerbations, and low lung function (P < 8.3 × 10-3). Low LTF mRNA expression levels were associated with high airway T2 inflammation biomarkers (sputum eosinophils and fractional exhaled nitric oxide; P < 8.3 × 10-3) but were not associated with blood eosinophils or total serum IgE. LTF mRNA expression levels were negatively correlated with expression levels of TH2 or asthma-associated genes (POSTN, NOS2, and MUC5AC) and eosinophil-related genes (IL1RL1, CCL26, and IKZF2) and positively correlated with expression levels of TH1 and inflammation genes (IL12A, MUC5B, and CC16) and TH17-driven cytokines or chemokines for neutrophils (CXCL1, CXCL6, and CSF3) (P < 3.5 × 10-6). CONCLUSIONS: Low LTF mRNA expression levels in BECs are associated with asthma susceptibility, severity, and exacerbations through upregulation of airway T2 inflammation. LTF is a potential anti-T2 biomarker, and its expression levels may help determine the balance of eosinophilic and neutrophilic asthma.

Heat-Induced Secretion of Heat Shock Proteins 70 and 90 Does not Affect the Expression of the Glucocorticoid Receptor in Primary Airway Cells in COPD.

PURPOSE: The response to glucocorticoids is hampered in many COPD patients by a yet unknown mechanism. Earlier we reported that short-term heat exposure of primary human bronchial epithelial cells (BEC) and airway smooth muscle cells (ASMC) of asthma patients increased the expression and secretion of extracellular heat shock proteins (eHSPs) resulting in increased expression of glucocorticoid receptor (GR) in BEC and inhibition of ASMC remodeling. The aim of the present study was to assess if the same mechanism is also present in primary airway wall cells of COPD patients. METHODS: Primary BEC and ASMC were established from endobronchial biopsies obtained from COPD patients (n = 73), who participated in the HISTORIC study, an investigator-initiated and driven clinical trial. Secretion and protein expression of HSPs was assessed by ELISA and Western blotting. Expression of total GR, its isoforms GRα and GRß and toll-like receptor 4 (TLR4) was determined by Western-blotting. RESULTS: Short heat exposure (65 °C, 10 s) of BEC resulted in a significant increase of the secretion of eHSP70 and eHSP90, while the intracellular protein was not altered. Heat treatment or exposure to eHSP70 or eHSP90 had no effect on the expression of GR and GR-isoforms. However, eHSP70 and eHSP90 significantly reduced the expression of TLR4. CONCLUSIONS: The results of this study indicate that primary airway cells from COPD patients respond differently to heat exposure and extracellular HSP70 or HSP90 than cells from asthma patients regarding the expression of GR and this may explain the reduced response to glucocorticoids in patients with COPD. TRIAL REGISTRATION: ISRCTN11017699.

CTNNAL1 promotes the structural integrity of bronchial epithelial cells through the RhoA/ROCK1 pathway.

Adhesion molecules play critical roles in maintaining the structural integrity of the airway epithelium in airways under stress. Previously, we reported that catenin alpha-like 1 (CTNNAL1) is downregulated in an asthma animal model and upregulated at the edge of human bronchial epithelial cells (HBECs) after ozone stress. In this work, we explore the potential role of CTNNAL1 in the structural adhesion of HBECs and its possible mechanism. We construct a CTNNAL1 ‒/‒ mouse model with CTNNAL1-RNAi recombinant adeno-associated virus (AAV) in the lung and a CTNNAL1-silencing cell line stably transfected with CTNNAL1-siRNA recombinant plasmids. Hematoxylin and eosin (HE) staining reveals that CTNNAL1 ‒/‒ mice have denuded epithelial cells and structural damage to the airway. Silencing of CTNNAL1 in HBECs inhibits cell proliferation and weakens extracellular matrix adhesion and intercellular adhesion, possibly through the action of the cytoskeleton. We also find that the expressions of the structural adhesion-related molecules E-cadherin, integrin ß1, and integrin ß4 are significantly decreased in ozone-treated cells than in vector control cells. In addition, our results show that the expression levels of RhoA/ROCK1 are decreased after CTNNAL1 silencing. Treatment with Y27632, a ROCK inhibitor, abolished the expressions of adhesion molecules induced by ozone in CTNNAL1-overexpressing HBECs. Overall, the findings of the present study suggest that CTNNAL1 plays a critical role in maintaining the structural integrity of the airway epithelium under ozone challenge, and is associated with epithelial cytoskeleton dynamics and the expressions of adhesion-related molecules via the RhoA/ROCK1 pathway.

Mitochondria protective and anti-apoptotic effects of peripheral benzodiazepine receptor and its ligands on the treatment of asthma in vitro and vivo.

BACKGROUND: Asthma is a prevalent respiratory inflammatory disease. Abnormal apoptosis of bronchial epithelial cells is one of the major factors in the progression of asthma. Peripheral benzodiazepine receptors are highly expressed in bronchial epithelial cells, which act as a component of the mitochondrial permeability transition pore to regulate its opening and closing and apoptosis of bronchial epithelial cells. We aimed to investigate the mechanisms by which peripheral benzodiazepine receptor and its ligands, agonist 4'-Chlorodiazepam (Ro5-4864) and antagonist 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK 11,195), modulate the mitochondrial function and cell apoptosis in the treatment of asthma. METHODS: In vitro study, Ro5-4864 and PK 11,195 were utilized to pretreat cells prior to the inflammatory injury induced by Lipopolysaccharide. The reactive oxygen species, the apoptosis of cell, the mitochondrial membrane potentials, the ultrastructures of the mitochondria and the expression levels of peripheral benzodiazepine receptors and apoptosis-related proteins and genes were detected. In vivo study, mice were administrated intraperitoneally with Ro5-4864 and PK 11,195 before sensitized and challenged by ovalbumin. Serum IgE and bronchoalveolar lavage fluid cytokines were detected, and lung tissues were underwent the histopathological examination. RESULTS: The ligands of peripheral benzodiazepine receptor counteracted the effects of the increase of reactive oxygen species, the elevated extent of apoptosis, the decrease of mitochondrial membrane potentials and the disruption of mitochondrial ultrastructures induced by Lipopolysaccharide. The ligands also promoted the expression of anti-apoptosis-related proteins and genes and inhibited the expression of pro-apoptosis-related proteins and genes. Besides, the ligands reduced the levels of serum IgE and bronchoalveolar lavage fluid cytokines in asthmatic mice and attenuated the histopathological damage of lungs. CONCLUSION: Peripheral benzodiazepine receptor serves as a potential therapeutic target for the treatment of asthma, with its ligands exerting mitochondrial protective and anti-apoptotic effects on bronchial epithelial cells.

The Roles of Neuropeptide Y in Respiratory Disease Pathogenesis via the Airway Immune Response.

The lungs are very complex organs, and the respiratory system performs the dual roles of repairing tissue while protecting against infection from various environmental stimuli. Persistent external irritation disrupts the immune responses of tissues and cells in the respiratory system, ultimately leading to respiratory disease. Neuropeptide Y (NPY) is a 36-amino-acid polypeptide and a neurotransmitter that regulates homeostasis. The NPY receptor is a seven-transmembrane-domain G-protein-coupled receptor with six subtypes (Y1, Y2, Y3, Y4, Y5, and Y6). Of these receptors, Y1, Y2, Y4, and Y5 are functional in humans, and Y1 plays important roles in the immune responses of many organs, including the respiratory system. NPY and the Y1 receptor have critical roles in the pathogenesis of asthma, chronic obstructive pulmonary disease, and idiopathic pulmonary fibrosis. The effects of NPY on the airway immune response and pathogenesis differ among respiratory diseases. This review focuses on the involvement of NPY in the airway immune response and pathogenesis of various respiratory diseases.