ABSTRACT
The activity of PP2A (protein phosphatase 2A), a serine-threonine phosphatase, is reduced by chronic cigarette smoke (SM) exposure and α-1 antitrypsin (AAT) deficiency, and chemical activation of PP2A reduces the loss of lung function in SM-exposed mice. However, the previously studied PP2A-activator tricyclic sulfonamide compound DBK-1154 has low stability to oxidative metabolism, resulting in fast clearance and low systemic exposure. Here we compare the utility of a new more stable PP2A activator, ATUX-792, versus DBK-1154 for the treatment of SM-induced emphysema. ATUX-792 was also tested in human bronchial epithelial cells and a mouse model of AAT deficiency, Serpina1a-e-knockout mice. Human bronchial epithelial cells were treated with ATUX-792 or DBK-1154, and cell viability, PP2A activity, and MAP (mitogen-activated protein) kinase phosphorylation status were examined. Wild-type mice received vehicle, DBK-1154, or ATUX-792 orally in the last 2 months of 4 months of SM exposure, and 8-month-old Serpina1a-e-knockout mice received ATUX-792 daily for 4 months. Forced oscillation and expiratory measurements and histology analysis were performed. Treatment with ATUX-792 or DBK-1154 resulted in PP2A activation, reduced MAP kinase phosphorylation, immune cell infiltration, reduced airspace enlargements, and preserved lung function. Using protein arrays and multiplex assays, PP2A activation was observed to reduce AAT-deficient and SM-induced release of CXCL5, CCL17, and CXCL16 into the airways, which coincided with reduced neutrophil lung infiltration. Our study indicates that suppression of the PP2A activity in two models of emphysema could be restored by next-generation PP2A activators to impact lung function.
Subject(s)
Emphysema , Pulmonary Emphysema , Humans , Animals , Mice , Infant , Protein Phosphatase 2/metabolism , Pulmonary Emphysema/drug therapy , Pulmonary Emphysema/metabolism , Lung/metabolism , Emphysema/drug therapy , Emphysema/metabolism , Mice, KnockoutABSTRACT
The LDL receptor-related protein 1 (LRP1) partakes in metabolic and signaling events regulated in a tissue-specific manner. The function of LRP1 in airways has not been studied. We aimed to study the function of LRP1 in smoke-induced disease. We found that bronchial epithelium of patients with chronic obstructive pulmonary disease and airway epithelium of mice exposed to smoke had increased LRP1 expression. We then knocked out LRP1 in human bronchial epithelial cells in vitro and in airway epithelial club cells in mice. In vitro, LRP1 knockdown decreased cell migration and increased transforming growth factor ß activation. Tamoxifen-inducible airway-specific LRP1 knockout mice (club Lrp1-/-) induced after complete lung development had increased inflammation in the bronchoalveolar space and lung parenchyma at baseline. After 6 months of smoke exposure, club Lrp1-/- mice showed a combined restrictive and obstructive phenotype, with lower compliance, inspiratory capacity, and forced expiratory volume0.05/forced vital capacity than WT smoke-exposed mice. This was associated with increased values of Ashcroft fibrotic index. Proteomic analysis of room air exposed-club Lrp1-/- mice showed significantly decreased levels of proteins involved in cytoskeleton signaling and xenobiotic detoxification as well as decreased levels of glutathione. The proteome fingerprint created by smoke eclipsed many of the original differences, but club Lrp1-/- mice continued to have decreased lung glutathione levels and increased protein oxidative damage and airway cell proliferation. Therefore, LRP1 deficiency leads to greater lung inflammation and damage and exacerbates smoke-induced lung disease.
Subject(s)
Airway Remodeling , Low Density Lipoprotein Receptor-Related Protein-1 , Oxidative Stress , Smoke , Animals , Epithelium/metabolism , Glutathione/metabolism , Humans , Low Density Lipoprotein Receptor-Related Protein-1/genetics , Low Density Lipoprotein Receptor-Related Protein-1/metabolism , Lung/metabolism , Mice , Proteomics , Smoke/adverse effectsABSTRACT
The well-described Wnt inhibitor Dickkopf-1 (DKK1) plays a role in angiogenesis as well as in regulation of growth factor signaling cascades in pulmonary remodeling associated with chronic lung diseases (CLDs) including emphysema and fibrosis. However, the specific mechanisms by which DKK1 influences mesenchymal vascular progenitor cells (MVPCs), microvascular endothelial cells (MVECs), and smooth muscle cells (SMCs) within the microvascular niche have not been elucidated. In this study, we show that knockdown of DKK1 in Abcg2pos lung mouse adult tissue resident MVPCs alters lung stiffness, parenchymal collagen deposition, microvessel muscularization and density as well as loss of tissue structure in response to hypoxia exposure. To complement the in vivo mouse modeling, we also identified cell- or disease-specific responses to DKK1, in primary lung chronic obstructive pulmonary disease (COPD) MVPCs, COPD MVECs, and SMCs, supporting a paradoxical disease-specific response of cells to well-characterized factors. Cell responses to DKK1 were dose dependent and correlated with varying expressions of the DKK1 receptor, CKAP4. These data demonstrate that DKK1 expression is necessary to maintain the microvascular niche whereas its effects are context specific. They also highlight DKK1 as a regulatory candidate to understand the role of Wnt and DKK1 signaling between cells of the microvascular niche during tissue homeostasis and during the development of chronic lung diseases.
Subject(s)
Endothelial Progenitor Cells/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Lung/blood supply , Mesenchymal Stem Cells/metabolism , Neovascularization, Physiologic , Stem Cell Niche , Wnt Signaling Pathway , beta Catenin/metabolism , ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics , ATP Binding Cassette Transporter, Subfamily G, Member 2/metabolism , Animals , Cell Hypoxia , Cell Lineage , Female , Humans , Intercellular Signaling Peptides and Proteins/genetics , Male , Membrane Proteins/metabolism , Mice, Knockout , Myocytes, Smooth Muscle/metabolism , Phenotype , Pulmonary Disease, Chronic Obstructive/metabolism , Pulmonary Disease, Chronic Obstructive/pathology , Vascular Remodeling , beta Catenin/geneticsABSTRACT
Adaptive angiogenesis is necessary for tissue repair, however, it may also be associated with the exacerbation of injury and development of chronic disease. In these studies, we demonstrate that lung mesenchymal vascular progenitor cells (MVPC) modulate adaptive angiogenesis via lineage trace, depletion of MVPC, and modulation of ß-catenin expression. Single cell sequencing confirmed MVPC as multipotential vascular progenitors, thus, genetic depletion resulted in alveolar simplification with reduced adaptive angiogenesis. Following vascular endothelial injury, Wnt activation in MVPC was sufficient to elicit an emphysema-like phenotype characterized by increased MLI, fibrosis, and MVPC driven adaptive angiogenesis. Lastly, activation of Wnt/ß-catenin signaling skewed the profile of human and murine MVPC toward an adaptive phenotype. These data suggest that lung MVPC drive angiogenesis in response to injury and regulate the microvascular niche as well as subsequent distal lung tissue architecture via Wnt signaling.
Subject(s)
Airway Remodeling/physiology , Endothelium, Vascular/metabolism , Lung/metabolism , Mesenchymal Stem Cells/metabolism , Neovascularization, Pathologic/metabolism , Wnt Proteins/metabolism , Wnt Signaling Pathway/physiology , Adult , Aged , Animals , Cell Line , Endothelium, Vascular/pathology , Female , Humans , Lung/pathology , Male , Mesenchymal Stem Cells/pathology , Mice , Middle Aged , Neovascularization, Pathologic/pathology , Pulmonary Emphysema/metabolism , Pulmonary Emphysema/pathology , Vascular System Injuries/metabolism , Vascular System Injuries/pathology , Young Adult , beta Catenin/metabolismABSTRACT
Enhanced expression of the cellular antioxidant glutathione peroxidase (GPX)-1 prevents cigarette smoke-induced lung inflammation and tissue destruction. Subjects with chronic obstructive pulmonary disease (COPD), however, have decreased airway GPX-1 levels, rendering them more susceptible to disease onset and progression. The mechanisms that downregulate GPX-1 in the airway epithelium in COPD remain unknown. To ascertain these factors, analyses were conducted using human airway epithelial cells isolated from healthy subjects and human subjects with COPD and lung tissue from control and cigarette smoke-exposed A/J mice. Tyrosine phosphorylation modifies GPX-1 expression and cigarette smoke activates the tyrosine kinase c-Src. Therefore, studies were conducted to evaluate the role of c-Src on GPX-1 levels in COPD. These studies identified accelerated GPX-1 mRNA decay in COPD airway epithelial cells. Targeting the tyrosine kinase c-Src with siRNA inhibited GPX-1 mRNA degradation and restored GPX-1 protein levels in human airway epithelial cells. In contrast, silencing the tyrosine kinase c-Abl, or the transcriptional activator Nrf2, had no effect on GPX-1 mRNA stability. The chemical inhibitors for c-Src (saracatinib and dasanitib) restored GPX-1 mRNA levels and GPX-1 activity in COPD airway cells in vitro. Similarly, saracatinib prevented the loss of lung Gpx-1 expression in response to chronic smoke exposure in vivo. Thus, this study establishes that the decreased GPX-1 expression that occurs in COPD lungs is at least partially due to accelerated mRNA decay. Furthermore, these findings show that targeting c-Src represents a potential therapeutic approach to augment GPX-1 responses and counter smoke-induced lung disease.
Subject(s)
Epithelial Cells/metabolism , Glutathione Peroxidase/genetics , Lung/pathology , Proto-Oncogene Proteins pp60(c-src)/metabolism , Pulmonary Disease, Chronic Obstructive/genetics , RNA Stability/genetics , Animals , Benzodioxoles/pharmacology , Enzyme Activation/drug effects , Epithelial Cells/drug effects , Epithelium/drug effects , Epithelium/pathology , Female , Gene Expression Regulation/drug effects , Glutathione Peroxidase/metabolism , Humans , Male , Mice , Quinazolines/pharmacology , Smoking/adverse effects , Glutathione Peroxidase GPX1ABSTRACT
Rationale: CTSS (cathepsin S) is a cysteine protease that is observed at higher concentrations in BAL fluid and plasma of subjects with chronic obstructive pulmonary disease (COPD). Objectives: To investigate whether CTSS is involved in the pathogenesis of cigarette smoke-induced COPD and determine whether targeting upstream signaling could prevent the disease. Methods: CTSS expression was investigated in animal and human tissue and cell models of COPD. Ctss-/- mice were exposed to long-term cigarette smoke and forced oscillation and expiratory measurements were recorded. Animals were administered chemical modulators of PP2A (protein phosphatase 2A) activity. Measurements and Main Results: Here we observed enhanced CTSS expression and activity in mouse lungs after exposure to cigarette smoke. Ctss-/- mice were resistant to cigarette smoke-induced inflammation, airway hyperresponsiveness, airspace enlargements, and loss of lung function. CTSS expression was negatively regulated by PP2A in human bronchial epithelial cells isolated from healthy nonsmokers and COPD donors and in monocyte-derived macrophages. Modulating PP2A expression or activity, with silencer siRNA or a chemical inhibitor or activator, during acute smoke exposure in mice altered inflammatory responses and CTSS expression and activity in the lung. Enhancement of PP2A activity prevented chronic smoke-induced COPD in mice. Conclusions: Our study indicates that the decrease in PP2A activity that occurs in COPD contributes to elevated CTSS expression in the lungs and results in impaired lung function. Enhancing PP2A activity represents a feasible therapeutic approach to reduce CTSS activity and counter smoke-induced lung disease.
Subject(s)
Cathepsins/metabolism , Cigarette Smoking/metabolism , Lung/metabolism , Nicotiana , Protein Phosphatase 2/metabolism , Pulmonary Disease, Chronic Obstructive/metabolism , Smoke/adverse effects , Animals , Bronchi/cytology , Case-Control Studies , Cigarette Smoking/adverse effects , Disease Models, Animal , Enzyme Inhibitors/pharmacology , Gene Silencing , Humans , Lung/drug effects , Macrophages, Alveolar/metabolism , Mice , Mice, Knockout , Okadaic Acid/pharmacology , Protein Phosphatase 2/antagonists & inhibitors , Pulmonary Disease, Chronic Obstructive/etiology , Pulmonary Disease, Chronic Obstructive/physiopathology , Respiratory Mucosa/cytologyABSTRACT
Phosphatase activity of the major serine threonine phosphatase, protein phosphatase 2A (PP2A), is blunted in the airways of individuals with chronic obstructive pulmonary disease (COPD), which results in heightened inflammation and proteolytic responses. The objective of this study was to investigate how PP2A activity is modulated in COPD airways. PP2A activity and endogenous inhibitors of PP2A were investigated in animal and cell models of COPD. In primary human bronchial epithelial (HBE) cells isolated from smokers and donors with COPD, we observed enhanced expression of cancerous inhibitor of PP2A (CIP2A), an oncoprotein encoded by the KIAA1524 gene, compared with cells from nonsmokers. CIP2A expression was induced by chronic cigarette smoke exposure in mice that coincided with a reduction in PP2A activity, airspace enlargements, and loss of lung function, as determined by PP2A phosphatase activity, mean linear intercept analysis, and forced expiratory volume in 0.05 second/forced vital capacity. Modulating CIP2A expression in HBE cells by silencing RNA or chemically with erlotinib enhanced PP2A activity, reduced extracellular-signal-regulated kinase phosphorylation, and reduced the responses of matrix metalloproteinases 1 and 9 in HBE cells isolated from subjects with COPD. Enhanced epithelial growth factor receptor responses in cells from subjects with COPD were observed to modulate CIP2A expression levels. Our study indicates that chronic cigarette smoke induction of epithelial growth factor receptor signaling and CIP2A expression can impair PP2A responses that are associated with loss of lung function and enhancement of proteolytic responses. Augmenting PP2A activity by manipulating CIP2A expression may represent a feasible therapeutic approach to counter smoke-induced lung disease.
Subject(s)
Autoantigens/metabolism , Cigarette Smoking/adverse effects , Environmental Exposure/adverse effects , Gene Expression Regulation, Neoplastic/drug effects , Membrane Proteins/metabolism , Protein Phosphatase 2/metabolism , Pulmonary Disease, Chronic Obstructive/metabolism , Animals , Cells, Cultured , Humans , Intracellular Signaling Peptides and Proteins , Mice , Mice, Inbred C57BL , Oncogene Proteins/metabolism , Proteolysis , Pulmonary Disease, Chronic Obstructive/etiology , Pulmonary Disease, Chronic Obstructive/pathologyABSTRACT
Chronic Obstructive Pulmonary Disease (COPD) is a complex disease. Genetic, epigenetic, and environmental factors are known to contribute to COPD risk and disease progression. Therefore we developed a systematic approach to identify key regulators of COPD that integrates genome-wide DNA methylation, gene expression, and phenotype data in lung tissue from COPD and control samples. Our integrative analysis identified 126 key regulators of COPD. We identified EPAS1 as the only key regulator whose downstream genes significantly overlapped with multiple genes sets associated with COPD disease severity. EPAS1 is distinct in comparison with other key regulators in terms of methylation profile and downstream target genes. Genes predicted to be regulated by EPAS1 were enriched for biological processes including signaling, cell communications, and system development. We confirmed that EPAS1 protein levels are lower in human COPD lung tissue compared to non-disease controls and that Epas1 gene expression is reduced in mice chronically exposed to cigarette smoke. As EPAS1 downstream genes were significantly enriched for hypoxia responsive genes in endothelial cells, we tested EPAS1 function in human endothelial cells. EPAS1 knockdown by siRNA in endothelial cells impacted genes that significantly overlapped with EPAS1 downstream genes in lung tissue including hypoxia responsive genes, and genes associated with emphysema severity. Our first integrative analysis of genome-wide DNA methylation and gene expression profiles illustrates that not only does DNA methylation play a 'causal' role in the molecular pathophysiology of COPD, but it can be leveraged to directly identify novel key mediators of this pathophysiology.
Subject(s)
Basic Helix-Loop-Helix Transcription Factors/biosynthesis , Promoter Regions, Genetic , Pulmonary Disease, Chronic Obstructive/genetics , Pulmonary Emphysema/genetics , Animals , Basic Helix-Loop-Helix Transcription Factors/genetics , DNA Methylation/genetics , Epigenesis, Genetic , Gene Expression Regulation , Humans , Mice , Pulmonary Disease, Chronic Obstructive/pathology , Pulmonary Emphysema/pathology , Signal Transduction , Smoking/adverse effectsABSTRACT
The expression of Toll-like receptor (TLR)-9, a pathogen recognition receptor that recognizes unmethylated CpG sequences in microbial DNA molecules, is linked to the pathogenesis of several lung diseases. TLR9 expression and signaling was investigated in animal and cell models of chronic obstructive pulmonary disease (COPD). We observed enhanced TLR9 expression in mouse lungs following exposure to cigarette smoke. Tlr9(-/-) mice were resistant to cigarette smoke-induced loss of lung function as determined by mean linear intercept, total lung capacity, lung compliance, and tissue elastance analysis. Tlr9 expression also regulated smoke-mediated immune cell recruitment to the lung; apoptosis; expression of granulocyte-colony stimulating factor (G-CSF), the CXCL5 protein, and matrix metalloproteinase-2 (MMP-2); and protein tyrosine phosphatase 1B (PTP1B) activity in the lung. PTP1B, a phosphatase with anti-inflammatory abilities, was identified as binding to TLR9. In vivo delivery of a TLR9 agonist enhanced TLR9 binding to PTP1B, which inactivated PTP1B. Ptp1b(-/-) mice had elevated lung concentrations of G-CSF, CXCL5, and MMP-2, and tissue expression of type-1 interferon following TLR9 agonist administration, compared with wild-type mice. TLR9 responses were further determined in fully differentiated normal human bronchial epithelial (NHBE) cells isolated from nonsmoker, smoker, and COPD donors, and then cultured at air liquid interface. NHBE cells from smokers and patients with COPD expressed more TLR9 and secreted greater levels of G-CSF, IL-6, CXCL5, IL-1ß, and MMP-2 upon TLR9 ligand stimulation compared with cells from nonsmoker donors. Although TLR9 combats infection, our results indicate that TLR9 induction can affect lung function by inactivating PTP1B and upregulating expression of proinflammatory cytokines.
Subject(s)
Lung/metabolism , Pulmonary Emphysema/metabolism , Smoke/adverse effects , Toll-Like Receptor 9/genetics , Adult , Animals , Cells, Cultured , Cytokines/biosynthesis , Cytokines/genetics , Female , Gene Expression , Humans , Lung/pathology , Lung/physiopathology , Male , Mice, Inbred C57BL , Middle Aged , Pneumonia/etiology , Pneumonia/immunology , Pneumonia/metabolism , Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism , Pulmonary Disease, Chronic Obstructive/metabolism , Pulmonary Emphysema/etiology , Pulmonary Emphysema/immunology , Smoking/adverse effects , Toll-Like Receptor 9/biosynthesis , Up-Regulation , Young AdultABSTRACT
Oxidative stress provokes endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) in the lungs of chronic obstructive pulmonary (COPD) subjects. The antioxidant, glutathione peroxidase-1 (GPx-1), counters oxidative stress induced by cigarette smoke exposure. Here, we investigate whether GPx-1 expression deters the UPR following exposure to cigarette smoke. Expression of ER stress markers was investigated in fully differentiated normal human bronchial epithelial (NHBE) cells isolated from nonsmoking, smoking, and COPD donors and redifferentiated at the air liquid interface. NHBE cells from COPD donors expressed heightened ATF4, XBP1, GRP78, GRP94, EDEM1, and CHOP compared to cells from nonsmoking donors. These changes coincided with reduced GPx-1 expression. Reintroduction of GPx-1 into NHBE cells isolated from COPD donors reduced the UPR. To determine whether the loss of GPx-1 expression has a direct impact on these ER stress markers during smoke exposure, Gpx-1-/- mice were exposed to cigarette smoke for 1 year. Loss of Gpx-1 expression enhanced cigarette smoke-induced ER stress and apoptosis. Equally, induction of ER stress with tunicamycin enhanced antioxidant expression in mouse precision-cut lung slices. Smoke inhalation also exacerbated the UPR response during respiratory syncytial virus infection. Therefore, ER stress may be an antioxidant-related pathophysiological event in COPD.
Subject(s)
Gene Expression Regulation , Glutathione Peroxidase/physiology , Smoking , Unfolded Protein Response , Adult , Animals , Antioxidants/chemistry , Apoptosis , Bronchi/cytology , Endoplasmic Reticulum Chaperone BiP , Endoplasmic Reticulum Stress , Epithelial Cells , Female , Glutathione Peroxidase/genetics , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Mice, Transgenic , Middle Aged , Oxidative Stress , Pulmonary Disease, Chronic Obstructive/metabolism , Signal Transduction , Smoke , Tobacco Products , Tunicamycin/chemistry , Young Adult , Glutathione Peroxidase GPX1ABSTRACT
RATIONALE: α1-Antitrypsin (A1AT) was identified as a plasma protease inhibitor; however, it is now recognized as a multifunctional protein that modulates immunity, inflammation, proteostasis, apoptosis, and cellular senescence. Like A1AT, protein phosphatase 2A (PP2A), a major serine-threonine phosphatase, regulates similar biologic processes and plays a key role in chronic obstructive pulmonary disease. OBJECTIVES: Given their common effects, this study investigated whether A1AT acts via PP2A to alter tumor necrosis factor (TNF) signaling, inflammation, and proteolytic responses in this disease. METHODS: PP2A activity was measured in peripheral blood neutrophils from A1AT-deficient (PiZZ) and healthy (PiMM) individuals and in alveolar macrophages from normal (60 mg/kg) and high-dose (120 mg/kg) A1AT-treated PiZZ subjects. PP2A activation was assessed in human neutrophils, airway epithelial cells, and peripheral blood monocytes treated with plasma purified A1AT protein. Similarly, lung PP2A activity was measured in mice administered intranasal A1AT. PP2A was silenced in lung epithelial cells treated with A1AT and matrix metalloproteinase and cytokine production was then measured following TNF-α stimulation. MEASUREMENTS AND MAIN RESULTS: PP2A was significantly lower in neutrophils isolated from PiZZ compared with PiMM subjects. A1AT protein activated PP2A in human alveolar macrophages, monocytes, neutrophils, airway epithelial cells, and in mouse lungs. This activation required functionally active A1AT protein and protein tyrosine phosphatase 1B expression. A1AT treatment acted via PP2A to prevent p38 and IκBα phosphorylation and matrix metalloproteinase and cytokine induction in TNF-α-stimulated epithelial cells. CONCLUSIONS: Together, these data indicate that A1AT modulates PP2A to counter inflammatory and proteolytic responses induced by TNF signaling in the lung.
Subject(s)
Inflammation/drug therapy , Lung/drug effects , Neutrophils/drug effects , Protein Phosphatase 2/drug effects , Serine Proteinase Inhibitors/pharmacology , Tumor Necrosis Factor-alpha/drug effects , alpha 1-Antitrypsin/pharmacology , Adult , Animals , Anti-Inflammatory Agents/metabolism , Anti-Inflammatory Agents/pharmacology , Disease Models, Animal , Female , Humans , Inflammation/immunology , Lung/immunology , Male , Mice , Middle Aged , Protein Phosphatase 2/deficiency , Protein Phosphatase 2/metabolism , Pulmonary Disease, Chronic Obstructive/physiopathology , Serine Proteinase Inhibitors/deficiency , Serine Proteinase Inhibitors/metabolism , Smoking/physiopathology , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolism , alpha 1-Antitrypsin/metabolismABSTRACT
The diagnosis of chronic obstructive pulmonary disease (COPD) confers a 2-fold increased lung cancer risk even after adjusting for cigarette smoking, suggesting that common pathways are operative in both diseases. Although the role of the tyrosine kinase c-Src is established in lung cancer, less is known about its impact in other lung diseases, such as COPD. This study examined whether c-Src activation by cigarette smoke contributes to the pathogenesis of COPD. Cigarette smoke increased c-Src activity in human small airway epithelial (SAE) cells from healthy donors and in the lungs of exposed mice. Similarly, higher c-Src activation was measured in SAE cells from patients with COPD compared with healthy control subjects. In SAE cells, c-Src silencing or chemical inhibition prevented epidermal growth factor (EGF) receptor signaling in response to cigarette smoke but not EGF stimulation. Further studies showed that cigarette smoke acted through protein kinase C α to trigger c-Src to phosphorylate EGF receptor and thereby to induce mitogen-activated protein kinase responses in these cells. To further investigate the role of c-Src, A/J mice were orally administered the specific Src inhibitor AZD-0530 while they were exposed to cigarette smoke for 2 months. AZD-0530 treatment blocked c-Src activation, decreased macrophage influx, and prevented airspace enlargement in the lungs of cigarette smoke-exposed mice. Moreover, inhibiting Src deterred the cigarette smoke-mediated induction of matrix metalloproteinase-9 and -12 in alveolar macrophages and lung expression of cathepsin K, IL-17, TNF-α, MCP-1, and KC, all key factors in the pathogenesis of COPD. These results indicate that activation of the proto-oncogene c-Src by cigarette smoke promotes processes linked to the development of COPD.
Subject(s)
Epithelial Cells/drug effects , Lung/drug effects , Pneumonia/etiology , Proto-Oncogene Proteins pp60(c-src)/metabolism , Pulmonary Disease, Chronic Obstructive/etiology , Smoke/adverse effects , Smoking/adverse effects , Animals , Case-Control Studies , Cells, Cultured , Cytokines/metabolism , Disease Models, Animal , Dose-Response Relationship, Drug , Enzyme Activation , Epithelial Cells/enzymology , Epithelial Cells/pathology , ErbB Receptors/metabolism , Humans , Inflammation Mediators/metabolism , Lung/enzymology , Lung/pathology , Macrophages/drug effects , Macrophages/enzymology , Mice , Mice, Inbred C57BL , Mitogen-Activated Protein Kinases/metabolism , Monocytes/drug effects , Monocytes/enzymology , Neutrophils/drug effects , Neutrophils/enzymology , Phosphorylation , Pneumonia/enzymology , Pneumonia/genetics , Pneumonia/pathology , Pneumonia/prevention & control , Protein Kinase C-alpha/metabolism , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Mas , Proto-Oncogene Proteins c-raf/metabolism , Proto-Oncogene Proteins pp60(c-src)/antagonists & inhibitors , Proto-Oncogene Proteins pp60(c-src)/genetics , Pulmonary Disease, Chronic Obstructive/enzymology , Pulmonary Disease, Chronic Obstructive/genetics , Pulmonary Disease, Chronic Obstructive/pathology , Pulmonary Disease, Chronic Obstructive/prevention & control , RNA Interference , Signal Transduction/drug effects , Time Factors , TransfectionABSTRACT
BACKGROUND: Respiratory syncytial virus (RSV) infects the lung epithelium where it stimulates the production of numerous host cytokines that are associated with disease burden and acute lung injury. Characterizing the host cytokine response to RSV infection, the regulation of host cytokines and the impact of neutralizing an RSV-inducible cytokine during infection were undertaken in this study. METHODS: A549, primary human small airway epithelial (SAE) cells and wild-type, TIR-domain-containing adapter-inducing interferon-ß (Trif) and mitochondrial antiviral-signaling protein (Mavs) knockout (KO) mice were infected with RSV and cytokine responses were investigated by ELISA, multiplex analysis and qPCR. Neutralizing anti-leukemia inhibitory factor (LIF) IgG or control IgG was administered to a group of wild-type animals prior to RSV infection. RESULTS AND DISCUSSION: RSV-infected A549 and SAE cells release a network of cytokines, including newly identified RSV-inducible cytokines LIF, migration inhibitory factor (MIF), stem cell factor (SCF), CCL27, CXCL12 and stem cell growth factor beta (SCGF-ß). These RSV-inducible cytokines were also observed in the airways of mice during an infection. To identify the regulation of RSV inducible cytokines, Mavs and Trif deficient animals were infected with RSV. In vivo induction of airway IL-1ß, IL-4, IL-5, IL-6, IL-12(p40), IFN-γ, CCL2, CCL5, CCL3, CXCL1, IP-10/CXCL10, IL-22, MIG/CXCL9 and MIF were dependent on Mavs expression in mice. Loss of Trif expression in mice altered the RSV induction of IL-1ß, IL-5, CXCL12, MIF, LIF, CXCL12 and IFN-γ. Silencing of retinoic acid-inducible gene-1 (RIG-I) expression in A549 cells had a greater impact on RSV-inducible cytokines than melanoma differentiation-associated protein 5 (MDA5) and laboratory of genetics and physiology 2 (LGP2), and Trif expression. To evaluate the role of LIF in the airways during RSV infection, animals were treated with neutralizing anti-LIF IgG, which enhanced RSV pathology observed with increased airspace protein content, apoptosis and airway hyperresponsiveness compared to control IgG treatment. CONCLUSIONS: RSV infection in the epithelium induces a network of immune factors to counter infection, primarily in a RIG-I dependent manner. Expression of LIF protects the lung from lung injury and enhanced pathology during RSV infection.
Subject(s)
Leukemia Inhibitory Factor/metabolism , Lung/pathology , Lung/virology , Protective Agents/metabolism , Respiratory Syncytial Virus Infections/pathology , Respiratory Syncytial Viruses/physiology , Adaptor Proteins, Signal Transducing/deficiency , Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Vesicular Transport/deficiency , Adaptor Proteins, Vesicular Transport/metabolism , Animals , Cytokines/biosynthesis , Cytokines/metabolism , Epithelial Cells/metabolism , Gene Silencing , Humans , Mice, Knockout , Neutralization Tests , Receptors, Retinoic Acid/metabolism , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus Infections/virology , Toll-Like Receptors/metabolismABSTRACT
Protein phosphatase-2A (PP2A) is a primary serine-threonine phosphatase that modulates inflammatory responses in asthma and chronic obstructive pulmonary disease (COPD). Despite its importance, the mechanisms that regulate lung PP2A activity remain to be determined. The redox-sensitive enzyme protein tyrosine phosphatase-1B (PTP1B) activates PP2A by dephosphorylating the catalytic subunit of the protein at tyrosine 307. This study aimed to identify how the interaction between the intracellular antioxidant glutathione peroxidase-1 (GPx-1) and PTP1B affected lung PP2A activity and airway inflammation. Experiments using gene silencing techniques in mouse lung or human small airway epithelial cells determined that knocking down PTP1B expression blocked GPx-1's activation of PP2A and negated the anti-inflammatory effects of GPx-1 protein in the lung. Similarly, the expression of human GPx-1 in transgenic mice significantly increased PP2A and PTP1B activities and prevented chronic cigarette smoke-induced airway inflammation and alveolar destruction. GPx-1 knockout mice, however, exhibited an exaggerated emphysema phenotype, correlating with a nonresponsive PP2A pathway. Importantly, GPx-1-PTP1B-PP2A signaling becomes inactivated in advanced lung disease. Indeed, PTP1B protein was oxidized in the lungs of subjects with advanced emphysema, and cigarette smoke did not increase GPx-1 or PTP1B activity within epithelial cells isolated from subjects with COPD, unlike samples of healthy lung epithelial cells. In conclusion, these findings establish that the GPx-1-PTP1B-PP2A axis plays a critical role in countering the inflammatory and proteolytic responses that result in lung-tissue destruction in response to cigarette smoke exposure.
Subject(s)
Glutathione Peroxidase/metabolism , Pneumonia/enzymology , Protein Phosphatase 2/metabolism , Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism , Pulmonary Alveoli/enzymology , Respiratory Mucosa/enzymology , Signal Transduction , Animals , Case-Control Studies , Cell Line , Enzyme Activation , Gene Knockdown Techniques , Glutathione Peroxidase/deficiency , Glutathione Peroxidase/genetics , Humans , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Mice, Knockout , Oxidation-Reduction , Oxidative Stress , Phosphorylation , Pneumonia/etiology , Pneumonia/genetics , Pneumonia/pathology , Pneumonia/prevention & control , Protein Binding , Protein Tyrosine Phosphatase, Non-Receptor Type 1/genetics , Pulmonary Alveoli/pathology , Pulmonary Disease, Chronic Obstructive/enzymology , Pulmonary Disease, Chronic Obstructive/pathology , Pulmonary Emphysema/enzymology , Pulmonary Emphysema/pathology , RNA Interference , Respiratory Mucosa/pathology , Smoking/adverse effects , Transfection , Glutathione Peroxidase GPX1ABSTRACT
BACKGROUND: Prior studies have demonstrated that the distal 1.5 kb of the MMP-1 promoter is fundamental in directing the induction of the MMP-1 gene by cigarette smoke. METHODS: To characterize the genetic variants in the MMP-1 cigarette smoke-responsive element, deep re-sequencing of this element was performed on DNA samples from participants in the Lung Health Study. Furthermore, evidence of Sp1 binding to the MMP-1 promoter was assessed using chromatin immunoprecipitation assays and the influence of cigarette smoke exposure on this interaction was evaluated in cultured human small airway epithelial cells. RESULTS: Ten polymorphisms (four novel) were detected in the cigarette smoke-responsive element. Chromatin immunoprecipitation assays to assess the protein-DNA interactions at Sp1 sites in the MMP-1 promoter showed increased binding to the Sp1 sites in the cigarette smoke-responsive element in small airway epithelial cells treated with cigarette smoke extract. In contrast, a Sp1 site outside of the element exhibited the opposite effect. None of the polymorphisms were more prevalent in the fast decliners versus the slow decliners (fast decliners = mean -4.14% decline in FEV1% predicted per year vs. decline in FEV1% predicted per year). CONCLUSIONS: Sequencing analyses identified four novel polymorphisms within the cigarette smoke-responsive element of the MMP-1 promoter. This study identifies functional activity within the cigarette smoke-responsive element that is influenced by cigarette smoke and examines this region of the promoter within a small patient population.
Subject(s)
DNA/genetics , Matrix Metalloproteinase 1/genetics , Polymorphism, Single Nucleotide/genetics , Promoter Regions, Genetic/genetics , Pulmonary Disease, Chronic Obstructive/genetics , Smoking/genetics , Adult , Base Sequence , Female , Genetic Association Studies , Humans , Male , Middle Aged , Molecular Sequence DataABSTRACT
The edible fruits of Myrciaria vexator McVaugh (Myrtaceae), from northern South America, are eaten in certain locales, either fresh or processed into jellies and drinks. Activity-guided fractionation of M. vexator resulted in identification of ellagic acid (1), cyanidin-3-O-glucoside (2), delphinidin-3-O-glucoside (3), 2-O-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxyphenylacetic acid (4), and jaboticabin (5), and latter two compounds are being reported for the first time in this species. Ellagic acid was further examined, and found to inhibit cigarette smoke extract induced MMP-1 expression in vitro, and may be of significance in the treatment of chronic obstructive pulmonary (COPD). Other compounds identified for the first time from M. vexator include cyanidin-3-O-galactoside (6), cyanidin-3-O-arabinoside (7), cyanidin-3-O-rutionoside (8), petunidin (9), peonidin-3-O-galactoside (10) malvidin (11), hyperoside (12), querecetin-3-O-glucoside (13), and guajaverin (14), methyl protocatechuate (15), and protocatechuic acid (16).
Subject(s)
Myrtaceae/chemistry , Phenols/chemistry , Cells, Cultured , Chromatography, High Pressure Liquid , Ellagic Acid/chemistry , Ellagic Acid/pharmacology , Ellagic Acid/therapeutic use , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , Free Radical Scavengers/therapeutic use , Fruit/chemistry , Humans , Mass Spectrometry , Matrix Metalloproteinase 1/metabolism , Phenols/pharmacology , Phenols/therapeutic use , Pulmonary Disease, Chronic Obstructive/drug therapyABSTRACT
Nine anthocyanins (1-9) from the edible fruits of Eugenia brasiliensis were identified by HPLC-PDA and LC-MS, and seven of these are described for the first time in this Brazilian fruit. Two of the major anthocyanins, delphinidin (8) and cyanidin (9), were studied for their inhibitory activity against chemokine interleukin-8 (IL-8) production before and after cigarette smoke extract (CSE) treatment of cells. In non-treated cells the amount of IL-8 was unchanged following treatment with cyanidin and delphinidin in concentrations 0.1-10 µM. Both delphinidin (8) and cyanidin (9) decreased the production of IL-8 in treated cells, at 1 and 10 µM, respectively. Delphinidin (8) demonstrated IL-8 inhibition in the CSE treated cells in a dose-dependent manner.
Subject(s)
Anthocyanins/pharmacology , Eugenia/chemistry , Fruit/chemistry , Interleukin-8/metabolism , Plant Extracts/pharmacology , Pulmonary Disease, Chronic Obstructive/drug therapy , Brazil , Cells, Cultured , Chromatography, High Pressure Liquid , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Humans , Mass Spectrometry , Respiratory System/drug effects , Respiratory System/metabolism , Smoke/adverse effectsABSTRACT
OBJECTIVES: Sepsis is one of the leading causes of morbidity and mortality within the healthcare system and remains a diagnostic and therapeutic challenge. A major issue in the diagnosis of sepsis is understanding the pathophysiologic mechanism, which revolves around host immune system activation and dysregulated responses. African Americans are more likely to experience severe sepsis with higher mortality rates compared to the general population. This pilot study characterized multiple inflammatory markers and proteases in plasma of primarily African American and Afro-Caribbean patients with mild sepsis. METHODS: Plasma was collected from 16 healthy controls and 15 subjects presenting with sepsis, on admission, and again upon resolution of the signs of sepsis, defined as a resolution of sepsis criteria. Plasma samples were analyzed for cytokines, chemokines, and proteases using multiplex bead assays. RESULTS: Elevated levels of granulocyte colony-stimulating factor, interleukin-10, interleukin-15, interleukin-1 receptor antagonist, interleukin-8, interferon gamma-induced protein 10, monocyte chemoattractant protein-1, matrix metallopeptidase 12, and cathepsin S were identified in plasma from sepsis patients on admission compared to control subjects. Interleukin-6, interleukin-8, granulocyte colony-stimulating factor, and cathepsin S were reduced in sepsis patients upon clinical resolution of sepsis. CONCLUSION: These findings profile the circulating inflammatory cytokines, chemokines, and proteases in African Americans and Afro-Caribbean patients during sepsis. The role of these targets in sepsis needs addressing in this patient population.
ABSTRACT
Sinusitis is a common condition associated with inflammation in the sinuses and nasal mucosa. Calpain 14 is highly expressed in the nasal tissues of sinusitis subjects. Calpain 14 is associated with epithelial barrier disruption. https://bit.ly/3fyAwVO.