Increased expression of nuclear factor-kappaB in bronchial biopsies from smokers and patients with COPD

Casticin Improves Respiratory Dysfunction and Attenuates Oxidative Stress and Inflammation via Inhibition of NF-ĸB in a Chronic Obstructive Pulmonary Disease Model of Chronic Cigarette Smoke-Exposed Rats

Objective

The present study was conducted to elucidate the protective effect of Casticin against chronic obstructive pulmonary disease (COPD) in rats.

Methods

The COPD in rats was induced by the controlled cigarette smoke, and CST (10, 20, and 30 mg/kg) was injected into the cigarette-smoke exposed rats. Blood was taken from the abdominal vein and centrifuged (1500×g, 4°C, 15min); plasma was collected and used for the determination of various biochemical parameters.

Results

The results of the study suggested that CST significantly improved the lung functions of the rats in a dose-dependent manner. It also causes a reduction of white blood cells, neutrophils, and macrophages in BALF of rats. The plasma level of leptin and C-reactive protein together with pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) were also significantly restored to near to normal in CST-treated group. In Western blot analysis, CST causes significant inhibition of the NF-ĸB and iNOS pathway.

Conclusion

Our study demonstrated that the CST protects lungs against COPD via improving lung functions and inhibition of oxidative stress and inflammation.

Protective effect of selegiline on cigarette smoke-induced oxidative stress and inflammation in rat lungs in vivo

Background

Cigarette smoke (CS)-induced build-up of oxidative stress is the leading cause of chronic obstructive pulmonary disease (COPD). Monoamine oxidases (MAOs) are novel sources of reactive oxygen species (ROS) due to the production of hydrogen peroxide (H₂O₂). However, it remains unclear whether MAO signaling is involved in CS-induced oxidative stress in vivo. This study aimed at investigating the impact of selegiline, a selective MAO-B inhibitor, on CS-induced lung oxidative stress and inflammation in vivo and its underlying mechanism.

Methods

Sprague Dawley rats were randomly divided into four groups: saline plus sham air (Saline/air), saline plus cigarette smoke (Saline/CS), selegiline plus sham air (Slg/air) and selegiline plus cigarette smoke (Slg/CS). Rats from Saline/air and Saline/CS groups were intraperitoneally injected with saline (2 mL/kg body weight) while rats from Slg/air and Slg/CS groups were injected with selegiline (2 mg/kg body weight) about 30 min prior to exposure daily. The Saline/air and Slg/air groups were exposed to atmospheric air while the Saline/CS and Slg/CS groups were exposed to mainstream CS generated from the whole body inExpose smoking system (SCIREQ, Canada) for twice daily (each for 1 hour with 20 cigarettes). After 7 days, rats were sacrificed to collect bronchoalveolar lavage (BAL) and lung tissues for the measurement of oxidative/anti-oxidative and inflammatory/anti-inflammatory makers respectively.

Results

CS caused significant elevation of MAO-B activity, reduction of total antioxidant capacity (T-AOC) and rGSH/GSSG ratio, and enhancement of superoxide dismutase (SOD) activity in rat lung. Selegiline significantly only reversed CS-induced elevation of MAO-B activity and reduction of rGSH/GSSG ratio. The CS-induced elevation of heme oxygenase-1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1) expression via nuclear factor erythroid 2-related factor 2 (Nrf2) was also reversed by selegiline. Despite of CS-induced increase in total cell counts, especially the number of macrophages, selegiline had no effect. Selegiline attenuated CS-induced elevation of pro-inflammatory mediators (CINC-1, MCP-1 and IL-6) and restored CS-induced reduction of anti-inflammatory mediator IL-10 in BAL, which was driven through MAPK and NF-κB.

Conclusions

Inhibition of MAO-B may provide a promising therapeutic strategy for CS-mediated oxidative stress and inflammation in acute CS-exposed rat lungs.

Epigallocatechin gallate diminishes cigarette smoke-induced oxidative stress, lipid peroxidation, and inflammation in human bronchial epithelial cells

Cigarette smoke (CS), the major risk factor of chronic obstructive pulmonary disease (COPD), contains numerous free radicals that can cause oxidative stress and exaggerated inflammatory responses in the respiratory system. Lipid peroxidation which is oxidative degradation of polyunsaturated fatty acids and results in cell damage has also been associated with COPD pathogenesis. Increased levels of lipid peroxidation as well as its end product 4-hydroxynonenal have indeed been detected in COPD patients. Additionally, reactive oxygen species such as those contained in CS can activate nuclear factor-κB signaling pathway, initiating cascades of proinflammatory mediator expression. As emerging evidence attests to the antioxidative and anti-inflammatory properties of tea catechins, we sought to determine whether epigallocatechin gallate, the most abundant tea catechin, can provide protection against oxidative stress, lipid peroxidation, and inflammatory responses caused by CS. We found that EGCG treatment blocked cigarette smoke extract (CSE)-induced oxidative stress as indicated by decreased production and accumulation of reactive oxygen species in airway epithelial cells (AECs). Likewise, lipid peroxidation in CSE-stimulated AECs was suppressed by EGCG. Our findings further suggest that EGCG sequestered 4-hydroxynonenal and interfered with its protein adduct formation. Lastly, we show that EGCG inhibited nuclear factor-κB activation and the downstream expression of proinflammatory mediators. In summary, our study describing the antioxidative and anti-inflammatory effects of EGCG in CSE-exposed AECs provide valuable information about the therapeutic potential of this tea catechin for COPD.

Inhibition of metalloproteinases in therapy for severe lung injury due to COVID-19

Since its first appearance in December 2019 in the Chinese province of Wuhan, COVID-19 has spread rapidly throughout the world and poses a serious threat to public health. Acute respiratory failure due to widespread lung inflammation progress to acute respiratory distress syndrome (ARDS) with an altered pulmonary and alveolar function that can lead to disability, prolong hospitalizations, and adverse outcomes.

While there is no specific treatment for severe acute lung injury (ALI) and ARDS due to the COVID-19 and the management is mostly supportive, it is very important to better understand the pathophysiological processes activated by the inflammatory mediators such as cytokines and metalloproteinases with the aim of their subsequent inhibition in the course of the complex treatment.

Herein, we will discuss the pathophysiological mechanisms of ALI/ARDS, with a focus on the pivotal role played by matrix metalloproteinases (MMP) and the kinin-kallikrein system (KKS), and the effects of the possible pharmacological interventions.

Aprotinin is a nonspecific protease inhibitor especially of trypsin, chymotrypsin, plasmin, and kallikrein, and it is many years in clinical use. Aprotinin inhibits the release of pro-inflammatory cytokines and involved in the process of glycoprotein homeostasis. Experimental data support that the use of aprotinin to inhibit MMPs and KKS may be a new potential approach to the treatment of ALI / ARDS.

Trans-4,4'-dihydroxystilbene ameliorates cigarette smoke-induced progression of chronic obstructive pulmonary disease via inhibiting oxidative stress and inflammatory response

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease resulted from airflow obstructions, and there is a driving requirement for novel and effective preventive and therapeutic agents of COPD. Nuclear factor-erythroid 2-related factor 2 (Nrf2) has been regarded to be a promising therapeutic target for COPD. Resveratrol is a natural Nrf2 activator with antioxidant and anti-inflammatory properties, however, its application is limited by its relative low efficiency and poor bioavailability. Herein, based on the skeleton of resveratrol, trans-4,4'-dihydroxystilbene (DHS) has been firstly identified to be an Nrf2 activator, which is more potent than the well-known sulforaphane (SF) and resveratrol. Our results indicate that DHS blocks Nrf2 ubiquitylation through specifically reacting with Cys151 cysteine in Keap1 protein to activate Nrf2-regulated defensive response, and thus enhances intracellular antioxidant capability. Furthermore, DHS relieves lipopolysaccharide (LPS)-stimulated inflammatory response via inhibition of NF-κB. Importantly, DHS significantly ameliorates pathological alterations (e.g. infiltration of leukocytes and fibrosis), downregulates the levels of oxidant biomarkers malondialdehyde (MDA) and 8-oxo-7,8-dihydro-2'-deoxyguanosin (8-oxo-dG), and inhibits the overproductions of inflammatory mediators [e.g. tumor necrosis factor α (TNF-α), cyclooxygenase-2 (COX-2), and matrix metalloproteinase-9 (MMP-9)] in a cigarette smoke (CS)-induced pulmonary impairment mice model. Taken together, this study demonstrates that DHS attenuates the CS-induced pulmonary impairments through inhibitions of oxidative stress and inflammatory response targeting Nrf2 and NF-κB in vitro and in vivo, and could be developed into a preventive agent against pulmonary impairments induced by CS.

Necroptosis Mediates Cigarette Smoke-Induced Inflammatory Responses in Macrophages

Introduction

Cigarette smoke (CS)-induced inflammation in macrophages is involved in the pathological process of chronic obstructive pulmonary disease (COPD). Necroptosis, which is a form of programmed necrosis, has a close relationship with robust inflammation, while its roles in COPD are unclear.

Materials and Methods

Necroptosis markers were measured in mouse alveolar macrophages and cultured bone marrow-derived macrophages (BMDMs). Necroptosis inhibitors were used to block necroptosis in BMDMs, and inflammatory cytokines were detected. We further explored the related signaling pathways.

Results

In this study, we demonstrated the way in which necroptosis, in addition to its upstream and downstream signals, regulates CS-induced inflammatory responses in macrophages. We observed that CS exposure caused a significant increase in the levels of necroptosis markers (receptor interacting kinases [RIPK] 1 and 3) in mouse alveolar macrophages and BMDMs. Pharmacological inhibition of RIPK1 or 3 caused a significant suppression in CS extract (CSE)-induced inflammatory cytokines, chemokine ligands (CXCL) 1 and 2, and interleukin (IL)-6 in BMDMs. CSE-induced necroptosis was regulated by mitochondrial reactive oxygen species (mitoROS), which also promoted inflammation in BMDMs. Furthermore, necroptosis regulated CSE-induced inflammatory responses in BMDMs, most likely through activation of the nuclear factor-κB pathway.

Conclusion

Taken together, our results demonstrate that mitoROS-dependent necroptosis is essential for CS-induced inflammation in BMDMs and suggest that inhibition of necroptosis in macrophages may represent effective therapeutic approaches for COPD patients.

Regional differences in airway susceptibility to cigarette smoke: An investigational case study of epithelial function and gene alterations inin vitroairway epithelial three-dimensional cultures

Cigarette smoke (CS) is a risk factor contributing to lung remodeling in chronic obstructive pulmonary disease (COPD). COPD is a heterogeneous disease because many factors contribute in varying degrees to the resulting airflow limitations in different regions of the respiratory tract. This heterogeneity makes it difficult to understand mechanisms behind COPD development. In the current study, we investigate the regional heterogeneity of the acute response to CS exposure between large and small airways using in vitro three-dimensional (3D) cultures. We used two in vitro 3D human airway epithelial tissues from large and small airway epithelial cells, namely, MucilAir™ and SmallAir™, respectively, which were derived from the same single healthy donor to eliminate donor differences. Impaired epithelial functions and altered gene expression were observed in SmallAir™ exposed to CS at the lower dose and earlier period following the last exposure compared with MucilAir™. In addition, severe damage in SmallAir™ was retained for a longer duration than MucilAir™. Transcriptomic analysis showed that although well-known CS-inducible biological processes (i.e. inflammation, cell fate, and metabolism) were disturbed with consistent activity in both tissues exposed to CS, we elucidated distinctively regulated genes in only MucilAir™ and SmallAir™, which were mostly related to catalytic and transporter activities. Our findings suggest that CS exposure elicited epithelial dysfunction through almost the same perturbed pathways in both airways; however, they expressed different genes related to metabolic and transporter activities in response to CS exposure which may contribute to cytotoxic heterogeneity to the response to CS in the respiratory tract.

Cigarette smoke downregulates Nur77 to exacerbate inflammation in chronic obstructive pulmonary disease (COPD)

Cigarette smoke (CS) contains multiple gaseous and particulate materials that can cause lung inflammation, and smoking is the major cause of chronic obstructive pulmonary disease (COPD). We sought to determine the mechanisms of how CS triggers lung inflammation. Nur77, a nuclear hormone receptor belonging to the immediate-early response gene family, controls inflammatory responses, mainly by suppressing the NF-κB signaling pathway. Because it is unknown if Nur77's anti-inflammatory role modulates COPD, we assessed if and how Nur77 expression and activity are altered in CS-induced airway inflammation. In lung tissues and bronchial epithelial cells from COPD patients, we found Nur77 was downregulated. In a murine model of CS-induced airway inflammation, CS promoted lung inflammation and also reduced Nur77 activity in wild type (WT) mice, whereas lungs of Nur77-deficient mice showed exaggerated CS-induced inflammatory responses. Our findings in in vitro studies of human airway epithelial cells complemented those in vivo data in mice, together showing that CS induced threonine-phosphorylation of Nur77, which is known to interfere with its anti-inflammatory functions. In summary, our findings point to Nur77 as an important regulator of CS-induced inflammatory responses and support the potential benefits of Nur77 activation for COPD treatment.

Crocin ameliorates chronic obstructive pulmonary disease-induced depression via PI3K/Akt mediated suppression of inflammation

Clinical studies have indicated the co-occurrence of chronic obstructive pulmonary disease (COPD) and psychiatric disorders, for example, comorbid depression. However, the underlying mechanism is rarely addressed. The present study aimed to investigate the mechanism of COPD-induced depression and the psychological and physiological effects of crocin, an active constituent of Crocus sativus L. C57BL/6 mice were randomly exposed to cigarette smoke for 7 weeks to establish COPD animal model. Crocin (50 mg/kg), Dexamethasone (2 mg/kg) and IGF-1 (2 mg/kg) were respectively injected to mice once a day. The FEV1/FVC ratio and the mean alveolus area of lung tissue demonstrated the COPD model was successfully established by cigarette smoke. Crocin administration significantly reversed markers of depression [loss of body weight, sucrose preference, and elevation of immobile time in tail-suspension tests (TST) and in forced swimming tests (FST)]. Besides, crocin treatment significantly inhibited the numbers of inflammatory cells (macrophages, neutrophils, and lymphocytes), suppressed the infiltration of peribronchial inflammatory cells, and reduced the concentration of proinflammatory cytokines in bronchoalveolar lavage (BAL) fluid and lung tissue. Crocin also reduced proinflammatory cytokines in the hippocampus. In exploring associated mechanisms, we discovered that crocin blunted cigarette smoke-induced IκB phosphorylation and degradation, and NF-κBp65 nuclear translocation. IGF-1, an activator of PI3K, abrogated the effect of crocin against cigarette smoke-induced activation of the NF-κB pathway. Together, these results showed that an inflammatory mechanism might be involved in the pathogenesis of COPD with comorbid depression. Crocin exhibited significant effects through the regulation of PI3K/Akt-mediated inflammatory pathways.

Chronic obstructive pulmonary disease (COPD) and lung cancer: common pathways for pathogenesis

Chronic obstructive pulmonary disease (COPD) and lung cancer comprise the leading causes of lung disease-related mortality worldwide. Exposure to tobacco smoke is a mutual aetiology underlying the two diseases, accounting for almost 90% of cases. There is accumulating evidence supporting the role of immune dysfunction, the lung microbiome, extracellular vesicles and underlying genetic susceptibility in the development of COPD and lung cancer. Further, epigenetic factors, involving DNA methylation and microRNA expression, have been implicated in both diseases. Chronic inflammation is a key feature of COPD and could be a potential driver of lung cancer development. Using next generation technologies, further studies investigating the genomics, epigenetics and gene-environment interaction in key molecular pathways will continue to elucidate the pathogenic mechanisms underlying the development of COPD and lung cancer, and contribute to the development of novel diagnostic and prognostic tools for early intervention and personalised therapeutic strategies.

Does chronic obstructive pulmonary disease increase the risk of prostate cancer? A nationwide population-based study

Purpose

Chronic obstructive pulmonary disease (COPD) is a major pulmonary disease. However, few studies have investigated the relationship between COPD and prostate cancer (PCa). This study aimed to investigate the association between COPD severity and PCa risk.

Patients and methods

We conducted a nationwide population-based cohort study utilizing data from 2001 to 2013 from the National Health Insurance Research Database of Taiwan. Cox proportional hazards models with 1:1 propensity score-matched analysis were used to investigate the association between COPD and PCa risk. We further divided the COPD group according to severe complications (including acute respiratory failure, cardiopulmonary arrest, pneumonia, and acute exacerbation) to test for the relationship between COPD severity and PCa risk.

Results

This study included 47,634 patients (23,817 COPD patients and 23,817 matched non-COPD controls). Among them, 756 (1.59%) were diagnosed with PCa during a mean follow-up period of 7.05±4.13 years; 387 (1.62%) were from the COPD group and 369 (1.55%) were from the control group. Compared with the patients without COPD, the adjusted hazard ratio (HR) for PCa in the COPD patients was 1.10 (95% confidence interval [CI] 0.95–1.27), while that in the COPD patients with complications was 2.46 (95% CI 1.96–3.61).

Conclusions

An increased risk for PCa was found among the COPD patients with complications. COPD complications included acute respiratory failure, cardiopulmonary arrest, pneumonia, and acute exacerbation. These findings may help physicians in treating COPD with complications and in remaining alert to the potential development of PCa.

Effect of short-term oral prednisone therapy on blood gene expression: a randomised controlled clinical trial

BACKGROUND

Effects of systemic corticosteroids on blood gene expression are largely unknown. This study determined gene expression signature associated with short-term oral prednisone therapy in patients with chronic obstructive pulmonary disease (COPD) and its relationship to 1-year mortality following an acute exacerbation of COPD (AECOPD).

METHODS

Gene expression in whole blood was profiled using the Affymetrix Human Gene 1.1 ST microarray chips from two cohorts: 1) a prednisone cohort with 37 stable COPD patients randomly assigned to prednisone 30 mg/d + standard therapy for 4 days or standard therapy alone and 2) the Rapid Transition Program (RTP) cohort with 218 COPD patients who experienced AECOPD and were treated with systemic corticosteroids. All gene expression data were adjusted for the total number of white blood cells and their differential cell counts.

RESULTS

In the prednisone cohort, 51 genes were differentially expressed between prednisone and standard therapy group at a false discovery rate of < 0.05. The top 3 genes with the largest fold-changes were KLRF1, GZMH and ADGRG1; and 21 genes were significantly enriched in immune system pathways including the natural killer cell mediated cytotoxicity. In the RTP cohort, 27 patients (12.4%) died within 1 year after hospitalisation of AECOPD; 32 of 51 genes differentially expressed in the prednisone cohort significantly changed from AECOPD to the convalescent state and were enriched in similar cellular immune pathways to that in the prednisone cohort. Of these, 10 genes including CX3CR1, KLRD1, S1PR5 and PRF1 were significantly associated with 1-year mortality.

CONCLUSIONS

Short-term daily prednisone therapy produces a distinct blood gene signature that may be used to determine and monitor treatment responses to prednisone in COPD patients during AECOPD.

TRIAL REGISTRATION

The prednisone cohort was registered at clinicalTrials.gov ( NCT02534402 ) and the RTP cohort was registered at ClinicalTrials.gov ( NCT02050022 ).

Chemical modification-mediated optimisation of bronchodilatory activity of mepenzolate, a muscarinic receptor antagonist with anti-inflammatory activity

The treatment for patients with chronic obstructive pulmonary disease (COPD) usually involves a combination of anti-inflammatory and bronchodilatory drugs. We recently found that mepenzolate bromide (1) and its derivative, 3-(2-hydroxy-2, 2-diphenylacetoxy)-1-(3-phenoxypropyl)-1-azoniabicyclo[2.2.2]octane bromide (5), have both anti-inflammatory and bronchodilatory activities. We chemically modified 5 with a view to obtain derivatives with both anti-inflammatory and longer-lasting bronchodilatory activities. Among the synthesized compounds, (R)-(-)-12 ((R)-3-(2-hydroxy-2,2-diphenylacetoxy)-1-(3-phenylpropyl)-1-azoniabicyclo[2.2.2]octane bromide) showed the highest affinity in vitro for the human muscarinic M3 receptor (hM₃R). Compared to 1 and 5, (R)-(-)-12 exhibited longer-lasting bronchodilatory activity and equivalent anti-inflammatory effect in mice. The long-term intratracheal administration of (R)-(-)-12 suppressed porcine pancreatic elastase-induced pulmonary emphysema in mice, whereas the same procedure with a long-acting muscarinic antagonist used clinically (tiotropium bromide) did not. These results suggest that (R)-(-)-12 might be therapeutically beneficial for use with COPD patients given the improved effects seen against both inflammatory pulmonary emphysema and airflow limitation in this animal model.

Role of Diet in Chronic Obstructive Pulmonary Disease Prevention and Treatment

Chronic obstructive pulmonary disease is one of the leading causes of morbidity and mortality worldwide and a growing healthcare problem. Identification of modifiable risk factors for prevention and treatment of COPD is urgent, and the scientific community has begun to pay close attention to diet as an integral part of COPD management, from prevention to treatment. This review summarizes the evidence from observational and clinical studies regarding the impact of nutrients and dietary patterns on lung function and COPD development, progression, and outcomes, with highlights on potential mechanisms of action. Several dietary options can be considered in terms of COPD prevention and/or progression. Although definitive data are lacking, the available scientific evidence indicates that some foods and nutrients, especially those nutraceuticals endowed with antioxidant and anti-inflammatory properties and when consumed in combinations in the form of balanced dietary patterns, are associated with better pulmonary function, less lung function decline, and reduced risk of COPD. Knowledge of dietary influences on COPD may provide health professionals with an evidence-based lifestyle approach to better counsel patients toward improved pulmonary health.

The Possible Pathogenesis of Idiopathic Pulmonary Fibrosis considering MUC5B

Background

Overexpression of the MUC5B protein is associated with idiopathic pulmonary fibrosis (IPF), but little information is available regarding the pathogenic effects and regulatory mechanisms of overexpressed MUC5B in IPF.

Main Body

The overexpression of MUC5B in terminal bronchi and honeycomb cysts produces mucosal host defensive dysfunction in the distal airway which may play an important role in the development of IPF. This review addresses the possible association of overexpression of MUC5B, with MUC5B promoter polymorphism, MUC5B gene epigenetic changes, effects of some transcriptional factors, and inflammatory mediators in IPF. In addition, the associated signaling pathways which may influence the expression of MUC5B are also discussed.

Conclusion

This work has important implications for further exploration of the mechanisms of overexpression of MUC5B in IPF, and future personalized treatment.

The Antioxidant MitoQ Protects Against CSE-Induced Endothelial Barrier Injury and Inflammation by Inhibiting ROS and Autophagy in Human Umbilical Vein Endothelial Cells

Chronic obstructive pulmonary disease (COPD) is a common disease characterized by persistent airflow limitation. Pulmonary vascular endothelial barrier injury and inflammation are increasingly considered to be important pathophysiological processes in cigarette smoke extract (CSE)-induced COPD, but the mechanism remains unclear. To identify the cellular mechanism of endothelial barrier injury and inflammation in CSE-treated human umbilical vein endothelial cells (HUVECs), we investigated the effect of the mitochondrion-targeting antioxidant mitoquinone (MitoQ) on endothelial barrier injury and inflammation. We demonstrated that MitoQ restored endothelial barrier integrity by preventing VE-cadherin disassembly and actin cytoskeleton remodeling, as well as decreased inflammation by the NF-κB and NLRP3 inflammasome pathways in endothelial cells. In addition, MitoQ also maintained mitochondrial function by reducing the production of ROS and excess autophagy. Inhibition of autophagy by 3-MA protected against cytotoxicity that was induced by CSE in HUVECs. Overall, our study indicated that mitochondrial damage is a key promoter in the induction of endothelial barrier dysfunction and inflammation by CSE. The protective effect of MitoQ is related to the inhibition of ROS and excess autophagy in CSE-induced HUVEC injury.

Effect of Bufei Yishen Granules Combined with Electroacupuncture in Rats with Chronic Obstructive Pulmonary Disease via the Regulation of TLR-4/NF-κB Signaling

BACKGROUND

The combined therapy of Bufei Yishen granules (BY) and electroacupuncture (EA) has shown good effects clinically in treating chronic obstructive pulmonary disease (COPD). The present study aimed to observe the effects of the BY + EA combination in a COPD rat model and dissect the potential mechanisms via Toll-like receptor (TLR) 4/nuclear factor kappa B (NF-κB) signaling.

METHODS

The COPD rats were treated with normal saline, aminophylline, Bufei Yishen granules, electroacupuncture, or Bufei Yishen granules combined with electroacupuncture. The pulmonary function; lung tissue histology; levels of inflammatory factors; expression levels of TLR-4, inhibitor of nuclear factor kappa B (IκB), and NF-κB; and activation of NF-κB in the lung tissues were evaluated.

RESULTS

Pulmonary function was markedly decreased in the COPD rats, and the lung tissue histology of the COPD rats showed severe pathological changes. The pulmonary function and lung tissue morphology in the treatment groups (APL, BY, EA, and BY + EA) were improved. The increased levels of the inflammatory cytokines interleukin (IL)-1β and IL-6 indicated a chronic inflammatory state in the COPD rats. In the BY, EA, and BY + EA groups, the levels of IL-1β and IL-6 were decreased, especially in the BY + EA group. In addition, the mRNA and protein expression levels of TLR-4, IκB, and NF-κB were obviously downregulated in the BY and BY + EA groups; and the NF-κB p65 activation was significantly decreased in the BY, EA, and BY + EA groups.

CONCLUSIONS

Bufei Yishen granules and electroacupuncture have curative effects in COPD rats, and the combination therapy of Bufei Yishen granules and electroacupuncture is superior. The TLR-4/NF-κB pathway may be involved in the potential mechanisms by which Bufei Yishen granules and electroacupuncture reduce inflammation.

Regulation of NRF2, AP-1 and NF-κB by cigarette smoke exposure in three-dimensional human bronchial epithelial cells

Cigarette smoke (CS) is a complex mixture of chemicals and interacts with various physiological processes. We previously reported that nuclear factor erythroid 2-related factor 2 (NRF2) was the most sensitive transcription factor to aqueous CS extract (AqCSE) exposure in monolayer cultured human bronchial epithelial cell lines. Recently, in vitro three-dimensional (3D) culture models have been used to supplement pharmacological and toxicological assessments. Bronchial epithelium models in particular are useful for the evaluation of substances that directly contact the respiratory tract, such as CS. In the present study, we used 3D-cultured human bronchial epithelial cells (HBECs) to assess activation of transcription factors and relevant gene expression in response to AqCSE, primarily focusing on NRF2 and nuclear factor-kappa B (NF-κB) pathways. The 3D-cultured HBECs exposed to AqCSE showed expression of NRF2 and its nuclear translocation in addition to upregulation of genes related to oxidative stress. Our results suggest that the NRF2 pathway was the dominant pathway when 3D-cultured HBECs were exposed to AqCSE at a low dose, supporting our previous findings that NRF2 was the most sensitive transcription factor in response to AqCSE. Expression and nuclear translocation of NF-κB were not increased, although proinflammatory genes were upregulated. However, another inflammation-related transcription factor, activation protein 1, was induced by AqCSE. Gene classification analysis suggested that induction of the inflammatory response by AqCSE was dependent on NRF2 and activation protein 1 rather than NF-κB.

In vitro exposure of a 3D-tetraculture representative for the alveolar barrier at the air-liquid interface to silver particles and nanowires

BACKGROUND

The present study aimed to evaluate the potential differences in the biological effects of two types of spherical silver particles of 20 and 200 nm (Ag20 and Ag200), and of PVP-coated silver nanowires (AgNWs) with a diameter of 50 nm and length up to 50 μm, using a complex 3D model representative for the alveolar barrier cultured at air-liquid interface (ALI). The alveolar model was exposed to 0.05, 0.5 and 5 μg/cm2 of test compounds at ALI using a state-of-the-art exposure system (Vitrocell™Cloud System). Endpoints related to the oxidative stress induction, anti-oxidant defence mechanisms, pro-inflammatory responses and cellular death were selected to evaluate the biocompatibility of silver particles and nanowires (AgNMs) and to further ascribe particular biological effects to the different morphologic properties between the three types of AgNMs evaluated.

RESULTS

Significant cytotoxic effect was observed for all three types of AgNMs at the highest tested doses. The increased mRNA levels of the pro-apoptotic gene CASP7 suggests that apoptosis may occur after exposure to AgNWs. All three types of AgNMs increased the mRNA level of the anti-oxidant enzyme HMOX-1 and of the metal-binding anti-oxidant metallothioneins (MTs), with AgNWs being the most potent inducer. Even though all types of AgNMs induced the nuclear translocation of NF-kB, only AgNWs increased the mRNA level of pro-inflammatory mediators. The pro-inflammatory response elicited by AgNWs was further confirmed by the increased secretion of the 10 evaluated interleukins.

CONCLUSION

In the current study, we demonstrated that the direct exposure of a complex tetra-culture alveolar model to different types of AgNMs at ALI induces shape- and size-specific biological responses. From the three AgNMs tested, AgNWs were the most potent in inducing biological alterations. Starting from 50 ng/cm2, a dose representative for an acute exposure in a high exposure occupational setting, AgNWs induced prominent changes indicative for a pro-inflammatory response. Even though the acute responses towards a dose representative for a full-lifetime exposure were also evaluated, chronic exposure scenarios at low dose are still unquestionably needed to reveal the human health impact of AgNMs during realistic conditions.

NRF2 and NF-қB interplay in cerebrovascular and neurodegenerative disorders: Molecular mechanisms and possible therapeutic approaches

Electrophiles and reactive oxygen species (ROS) play a major role in modulating cellular defense mechanisms as well as physiological functions, and intracellular signaling. However, excessive ROS generation (endogenous and exogenous) can create a state of redox imbalance leading to cellular and tissue damage (Ma and He, 2012) [1]. A growing body of research data strongly suggests that imbalanced ROS and electrophile overproduction are among the major prodromal factors in the onset and progression of several cerebrovascular and neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS), stroke, Alzheimer's disease (AD), Parkinson's disease (PD), and aging (Ma and He, 2012; Ramsey et al., 2017; Salminen et al., 2012; Sandberg et al., 2014; Sarlette et al., 2008; Tanji et al., 2013) [1-6]. Cells offset oxidative stress by the action of housekeeping antioxidative enzymes (such as superoxide dismutase, catalase, glutathione peroxidase) as well direct and indirect antioxidants (Dinkova-Kostova and Talalay, 2010) [7]. The DNA sequence responsible for modulating the antioxidative and cytoprotective responses of the cells has been identified as the antioxidant response element (ARE), while the nuclear factor erythroid 2-related factor (NRF2) is the major regulator of the xenobiotic-activated receptor (XAR) responsible for activating the ARE-pathway, thus defined as the NRF2-ARE system (Ma and He, 2012) [1]. In addition, the interplay between the NRF2-ARE system and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB, a protein complex that controls cytokine production and cell survival), has been further investigated in relation to neurodegenerative and neuroinflammatory disorders. On these premises, we provide a review analysis of current understanding of the NRF2-NF-ĸB interplay, their specific role in major CNS disorders, and consequent therapeutic implication for the treatment of neurodegenerative and cerebrovascular diseases.

Evaluation of plasma antimicrobial peptide LL-37 and nuclear factor-kappaB levels in stable chronic obstructive pulmonary disease

Background

Antimicrobial peptides are effectors of host defence against infection and inflammation and can encourage wound repair.

Objectives

The objectives of this study were to investigate the plasma antimicrobial peptide LL-37 and nuclear factor-kappaB (NF-κB) levels in patients with stable COPD compared with a control group and to highlight their importance in immune inflammation.

Methods

One hundred and thirty-eight stable COPD patients and 33 control subjects were enrolled in the study. The COPD patients were classified into four groups based on FEV₁ (groups I-IV) and also divided into "low-risk and high-risk" groups (groups A-B [low risk], C-D [high risk]).

Results

Plasma LL-37 levels were significantly lower while plasma NF-κB levels of the COPD patients were significantly higher than those of the control subjects (P<0.001, both). LL-37 levels were significantly lower in group IV than in groups I, II, and III (P<0.01, all). NF-κB levels were significantly higher in groups III and IV than in groups I and II (P<0.05, both). There was a positive correlation between FEV₁ and FEV₁/FVC in all COPD patients (r=0.742, P<0.001) and in group D (r=0.741, P<0.001). Furthermore, there was an inverse correlation between LL-37 and NF-κB in both the groups C (r=-0.566, P<0.001) and D (r=-0.694, P<0.001) and group C+D combined (r=-0.593, P<0.001). Furthermore, in group C, LL-37 and FEV₁ were positively correlated (r=0.633, P<0.001).

Conclusion

Our study indicated that plasma LL-37 and NF-κB may play an important role in chronic immune inflammation. Decreased LL-37 levels may be particularly high risk for patients in stage IV disease. The role of LL-37 as a target for treatment of the immune system and COPD must be widely evaluated.

Gene silencing of receptor-interacting protein 2 protects against cigarette smoke-induced acute lung injury

BACKGROUND AND PURPOSE

Chronic obstructive pulmonary disease (COPD) is characterized by progressive alveolar damage and generally irreversible airflow limitation. Nuclear factor-κB (NF-κB) plays a critical role in COPD pathogenesis. Receptor-interacting protein 2 (Rip2), a 60 kDa adaptor protein, is a positive regulator of NF-κB pathway and also an inducible transcriptional product of NF-κB activation. We sought to investigate if Rip2 gene silencing could protect against cigarette smoke (CS)-induced acute lung injury.

EXPERIMENTAL APPROACH

Gene silencing efficacy of Rip2 siRNA was characterized in mouse macrophage and mouse lung epithelial cell lines, and in a CS-induced acute lung injury mouse model. Bronchoalveolar lavage (BAL) fluid cell counts, levels of pro-inflammatory and oxidative damage markers, lung section inflammatory and epithelium thickness scorings, and nuclear NF-κB translocation were measured.

KEY RESULTS

CS was found to upregulate Rip2 level in mouse lungs. Rip2 siRNA was able to suppress Rip2 levels in both macrophage and lung epithelial cell lines and in mouse lungs, block CS extract (CSE)-induced mediator release by the cultured cells, and abate neutrophil counts in BAL fluid from CS-challenged mice. Rip2 siRNA suppressed CS-induced inflammatory and oxidative damage markers, and nuclear p65 accumulation and transcriptional activation in lung tissues. Besides, Rip2 siRNA was able to disrupt CSE-induced NF-κB activation in a NF-κB reporter gene assay.

CONCLUSIONS AND IMPLICATIONS

Taken together, we report for the first time that Rip2 gene silencing ameliorated CS-induced acute lung injury probably via disruption of the NF-κB activity, postulating that Rip2 may be a novel therapeutic target for COPD.

Inhaled calcium salts inhibit tobacco smoke-induced inflammation by modulating expression of chemokines and cytokines

Tobacco smoke-induced lung inflammation in patients with chronic obstructive pulmonary disease (COPD) worsens with disease progression and acute exacerbations caused by respiratory infections. Chronic therapies to manage COPD center on bronchodilators to improve lung function and inhaled corticosteroids (ICS) to help reduce the risk of exacerbations. Novel therapies are needed that reduce the underlying inflammation associated with COPD and the inflammation resulting from respiratory infections that worsen disease. The lung is lined with airway surface liquid (ASL), a rheologically active material that provides an innate defense for the airway against inhaled particulate and is continuously cleared from the airways by mucociliary clearance. The rheological properties of the ASL can be altered by changes in airway hydration and by cations, such as calcium, that interact with electronegative glycoproteins. The effect of inhaled salts on inflammation resulting from tobacco smoke exposure was studied to determine if cations could be used to alter the properties of the ASL and reduce inflammation. Inhaled calcium salts, but not sodium or magnesium salts, reduced cellular inflammation and key chemokines and cytokines that were induced by tobacco smoke exposure. Similar anti-inflammatory effects of calcium salts were observed using in vitro cultures of human monocyte derived macrophages and human bronchial epithelial cells. The data suggest that inhaled calcium salts may act broadly on both biophysical and biological pathways to reduce pulmonary inflammation.

Differential expression of RNA-binding proteins in bronchial epithelium of stable COPD patients

Purpose

Inflammatory gene expression is modulated by posttranscriptional regulation via RNA-binding proteins (RBPs), which regulate mRNA turnover and translation by binding to conserved mRNA sequences. Their role in COPD is only partially defined. This study evaluated RBPs tristetraprolin (TTP), human antigen R (HuR), and AU-rich element-binding factor 1 (AUF-1) expression using lung tissue from COPD patients and control subjects and probed their function in epithelial responses in vitro.

Patients and methods

RBPs were detected by immunohistochemistry in bronchial and peripheral lung samples from mild-to-moderate stable COPD patients and age/smoking history-matched controls; RBPs and RBP-regulated genes were evaluated by Western blot, ELISA, protein array, and real-time PCR in human airway epithelial BEAS-2B cell line stimulated with hydrogen peroxide, cytokine combination (cytomix), cigarette smoke extract (CSE), and following siRNA-mediated silencing. Results were verified in a microarray database from bronchial brushings of COPD patients and controls. RBP transcripts were measured in peripheral blood mononuclear cell samples from additional stable COPD patients and controls.

Results

Specific, primarily nuclear immunostaining for the RBPs was detected in structural and inflammatory cells in bronchial and lung tissues. Immunostaining for AUF-1, but not TTP or HuR, was significantly decreased in bronchial epithelium of COPD samples vs controls. In BEAS-2B cells, cytomix and CSE stimulation reproduced the RBP pattern while increasing expression of AUF-1-regulated genes, interleukin-6, CCL2, CXCL1, and CXCL8. Silencing expression of AUF-1 reproduced, but not enhanced, target upregulation induced by cytomix compared to controls. Analysis of bronchial brushing-derived transcriptomic confirmed the selective decrease of AUF-1 in COPD vs controls and revealed significant changes in AUF-1-regulated genes by genome ontology.

Conclusion

Downregulated AUF-1 may be pathogenic in stable COPD by altering posttranscriptional control of epithelial gene expression.

Role of GPx3 in PPARγ-induced protection against COPD-associated oxidative stress

Cigarette smoke, a source of numerous oxidants, produces oxidative stress and exaggerated inflammatory responses that lead to irreversible lung tissue damage. It is the single, most significant risk factor for chronic obstructive pulmonary disease (COPD). Although an intrinsic defense system that includes both enzymatic and non-enzymatic modulators exists to protect lung tissues against oxidative stress, impairment of these protective mechanisms has been demonstrated in smokers and COPD patients. The antioxidant enzyme GSH peroxidase (GPx) is an important part of this intrinsic defense system. Although cigarette smoke has been shown to downregulate its expression and activity, the underlying mechanism is not known. Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear hormone receptor with antioxidant effects. PPARγ activation has demonstrated protective effects against cigarette smoke-induced oxidative stress and inflammation. Molecular mechanisms for PPARγ's antioxidant function likewise remain to be elucidated. This study explored the link between PPARγ and GPx3 and found a positive association in cigarette smoke extract (CSE)-exposed human bronchial epithelial cells. Moreover, we provide evidence that identifies GPx3 as a PPARγ transcriptional target. Attenuation of antioxidant effects in the absence of GPx3 highlights the antioxidant's prominent role in mediating PPARγ's function. We also demonstrate that ligand-mediated PPARγ activation blocks CSE-induced reactive oxygen species and hydrogen peroxide production via upregulation of GPx3. In summary, our findings describing the molecular mechanisms involving GPx3 and PPARγ in CSE-induced oxidative stress and inflammation may provide valuable information for the development of more effective therapeutics for COPD.

Ribosomal Protein S3 Gene Silencing Protects Against Cigarette Smoke-Induced Acute Lung Injury

Chronic obstructive pulmonary disease (COPD) is estimated to be the third leading cause of death by 2030. Transcription factor NF-κB may play a critical role in COPD pathogenesis. Ribosomal protein S3 (RPS3), a 40S ribosomal protein essential for executing protein translation, has recently been found to interact with the NF-κB p65 subunit and promote p65 DNA-binding activity. We sought to study whether RPS3 gene silencing could protect against cigarette-smoke (CS)-induced acute lung injury in a mouse model. Effects of an intratracheal RPS3 siRNA in CS-induced lung injury were determined by measuring bronchoalveolar lavage (BAL) fluid cell counts, levels of inflammatory and oxidative damage markers, and NF-κB translocation. Lung RPS3 level was found to be upregulated for the first time with CS exposure, and RPS3 siRNA blocked CS-induced neutrophil counts in BAL fluid. RPS3 siRNA suppressed CS-induced lung inflammatory mediator and oxidative damage marker levels, as well as nuclear p65 accumulation and transcriptional activation. RPS3 siRNA was able to disrupt CS extract (CSE)-induced NF-κB activation in an NF-κB reporter gene assay. We report for the first time that RPS3 gene silencing ameliorated CS-induced acute lung injury, probably via interruption of the NF-κB activity, postulating that RPS3 is a novel therapeutic target for COPD.

Responsiveness assessment of a 3D tetra-culture alveolar model exposed to diesel exhaust particulate matter

The aim of the current study was to evaluate the responses of a 3D tetra-culture alveolar model cultivated at the air-liquid-interface (ALI) after apical exposure to diesel exhaust particulate matter (DEPM) based on the three-tiered oxidative stress concept. The alveolar model exposed to increasing doses of DEPM (1.75-5 μg/cm²) responded with increasing activity of the anti-oxidant defense mechanisms (Nrf2 translocation, increased gene expression for anti-oxidant proteins and increased HMOX-1 synthesis) (tier 1). Higher exposure generated a proinflammatory response (NF-kB translocation, increased gene expression of pro-inflammatory cytokines and adhesion molecules, and increased IL-6 and IL-8 synthesis) (tier 2) and, finally, the highest doses applied resulted in a decrease of cell viability due to necrosis (extra-cellular release of LDH) or apoptosis (increased expression of the pro-apoptotic genes CASP7 and FAS) (tier 3). Overall, the results of our study demonstrate that the 3D tetra-culture model when directly exposed to DEPM potently generates a realistic response according to the three-tiered oxidative stress concept. Further evaluation and benchmarking against currently used in vivo rodent models is needed to show its suitability, and to serve in the future as an alternative for in vivo studies in the hazard evaluation of inhalable irritants.

Recombinant club cell protein 16 (CC16) ameliorates cigarette smoke‑induced lung inflammation in a murine disease model of COPD

Club cell protein (CC16) is expressed primarily by club cells possesses anti-inflammatory properties and is located in the bronchiolar epithelium. Previous studies have demonstrated that CC16 deficiency is associated with the progression of chronic obstructive pulmonary disease (COPD). In the present study, the therapeutic effects of recombinant rat CC16 protein in mice with COPD were examined and the underlying mechanisms investigated. A total of 30 adult male C57/BL6 mice were randomly divided into three groups (10 mice/group). A mouse COPD model was generated by exposing 20 mice to cigarette smoke (CS) for 24 weeks. A total of 10 mice were treated intranasally with rCC16 (2.5 µg/g body weight) and control mice were exposed to normal room air. Results indicated that rCC16 treatment ameliorated pathological damage in the lungs and reduced the production of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-8, which were induced by CS exposure. After rCC16 administration, endogenous CC16 was upregulated and the body weight of COPD mice was increased, whereas the opposite was observed in CS-exposed mice. Additionally, rCC16 treatment inhibited the DNA binding of NF-κB/p65 in lung tissues and reduced nuclear translocation of NF-κB/p65 in BALF and epithelial cells. Moreover, rCC16 treatment lead to a decrease in the total number of BALF cells, including macrophages, which was elevated in COPD mice. In conclusion, the present results demonstrate that rCC16 has therapeutic effects on COPD by downregulating pro-inflammatory factors via the NF-κB pathway.

Neutrophils induce macrophage anti-inflammatory reprogramming by suppressing NF-κB activation

Apoptotic cells modulate the function of macrophages to control and resolve inflammation. Here, we show that neutrophils induce a rapid and sustained suppression of NF-κB signalling in the macrophage through a unique regulatory relationship which is independent of apoptosis. The reduction of macrophage NF-κB activation occurs through a blockade in transforming growth factor β-activated kinase 1 (TAK1) and IKKβ activation. As a consequence, NF-κB (p65) phosphorylation is reduced, its translocation to the nucleus is inhibited and NF-κB-mediated inflammatory cytokine transcription is suppressed. Gene Set Enrichment Analysis reveals that this suppression of NF-κB activation is not restricted to post-translational modifications of the canonical NF-κB pathway, but is also imprinted at the transcriptional level. Thus neutrophils exert a sustained anti-inflammatory phenotypic reprogramming of the macrophage, which is reflected by the sustained reduction in the release of pro- but not anti- inflammatory cytokines from the macrophage. Together, our findings identify a novel apoptosis-independent mechanism by which neutrophils regulate the mediator profile and reprogramming of monocytes/macrophages, representing an important nodal point for inflammatory control.

IκB Kinase α Is Required for Development and Progression of KRAS-Mutant Lung Adenocarcinoma

Although oncogenic activation of NFκB has been identified in various tumors, the NFκB-activating kinases (inhibitor of NFκB kinases, IKK) responsible for this are elusive. In this study, we determined the role of IKKα and IKKβ in KRAS-mutant lung adenocarcinomas induced by the carcinogen urethane and by respiratory epithelial expression of oncogenic KRASG12D Using NFκB reporter mice and conditional deletions of IKKα and IKKβ, we identified two distinct early and late activation phases of NFκB during chemical and genetic lung adenocarcinoma development, which were characterized by nuclear translocation of RelB, IκBβ, and IKKα in tumor-initiated cells. IKKα was a cardinal tumor promoter in chemical and genetic KRAS-mutant lung adenocarcinoma, and respiratory epithelial IKKα-deficient mice were markedly protected from the disease. IKKα specifically cooperated with mutant KRAS for tumor induction in a cell-autonomous fashion, providing mutant cells with a survival advantage in vitro and in vivo IKKα was highly expressed in human lung adenocarcinoma, and a heat shock protein 90 inhibitor that blocks IKK function delivered superior effects against KRAS-mutant lung adenocarcinoma compared with a specific IKKβ inhibitor. These results demonstrate an actionable requirement for IKKα in KRAS-mutant lung adenocarcinoma, marking the kinase as a therapeutic target against this disease.Significance: These findings report a novel requirement for IKKα in mutant KRAS lung tumor formation, with potential therapeutic applications. Cancer Res; 78(11); 2939-51. ©2018 AACR.

MTOR Suppresses Cigarette Smoke-Induced Epithelial Cell Death and Airway Inflammation in Chronic Obstructive Pulmonary Disease

Airway epithelial cell death and inflammation are pathological features of chronic obstructive pulmonary disease (COPD). Mechanistic target of rapamycin (MTOR) is involved in inflammation and multiple cellular processes, e.g., autophagy and apoptosis, but little is known about its function in COPD pathogenesis. In this article, we illustrate how MTOR regulates cigarette smoke (CS)-induced cell death, airway inflammation, and emphysema. Expression of MTOR was significantly decreased and its suppressive signaling protein, tuberous sclerosis 2 (TSC2), was increased in the airway epithelium of human COPD and in mouse lungs with chronic CS exposure. In human bronchial epithelial cells, CS extract (CSE) activated TSC2, inhibited MTOR, and induced autophagy. The TSC2-MTOR axis orchestrated CSE-induced autophagy, apoptosis, and necroptosis in human bronchial epithelial cells; all of which cooperatively regulated CSE-induced inflammatory cytokines IL-6 and IL-8 through the NF-κB pathway. Mice with a specific knockdown of Mtor in bronchial or alveolar epithelial cells exhibited significantly augmented airway inflammation and airspace enlargement in response to CS exposure, accompanied with enhanced levels of autophagy, apoptosis, and necroptosis in the lungs. Taken together, these data demonstrate that MTOR suppresses CS-induced inflammation and emphysema-likely through modulation of autophagy, apoptosis, and necroptosis-and thus suggest that activation of MTOR may represent a novel therapeutic strategy for COPD.

Endoplasmic reticulum chaperone GRP78 mediates cigarette smoke-induced necroptosis and injury in bronchial epithelium

Introduction

Bronchial epithelial cell death and airway inflammation induced by cigarette smoke (CS) have been involved in the pathogenesis of COPD. GRP78, belonging to heat shock protein 70 family, has been implicated in cell death and inflammation, while little is known about its roles in COPD. Here, we demonstrate that GRP78 regulates CS-induced necroptosis and injury in bronchial epithelial cells.

Materials and methods

GRP78 and necroptosis markers were examined in human bronchial epithelial (HBE) cell line, primary mouse tracheal epithelial cells, and mouse lungs. siRNA targeting GRP78 gene and necroptosis inhibitor were used. Expression of inflammatory cytokines, mucin MUC5AC, and related signaling pathways were detected.

Results

Exposure to CS significantly increased the expression of GRP78 and necroptosis markers in HBE cell line, primary mouse tracheal epithelial cells, and mouse lungs. Inhibition of GRP78 significantly suppressed CS extract (CSE)-induced necroptosis. Furthermore, GRP78–necroptosis cooperatively regulated CSE-induced inflammatory cytokines such as interleukin 6 (IL6), IL8, and mucin MUC5AC in HBE cells, likely through the activation of nuclear factor (NF-κB) and activator protein 1 (AP-1) pathways, respectively.

Conclusion

Taken together, our results demonstrate that GRP78 promotes CSE-induced inflammatory response and mucus hyperproduction in airway epithelial cells, likely through upregulation of necroptosis and subsequent activation of NF-κB and AP-1 pathways. Thus, inhibition of GRP78 and/or inhibition of necroptosis could be the effective therapeutic approaches for the treatment of COPD.

Pathogenesis of COPD and Asthma

Asthma and COPD remain two diseases of the respiratory tract with unmet medical needs. This review considers the current state of play with respect to what is known about the underlying pathogenesis of these two chronic inflammatory diseases of the lung. The review highlights why they are different conditions requiring different approaches to treatment and provides a backdrop for the subsequent chapters in this volume discussing recent advances in the pharmacology and treatment of asthma and COPD.

Inhibition of endoplasmic reticulum stress alleviates cigarette smoke-induced airway inflammation and emphysema

Chronic bronchitis and emphysema are pathologic features of chronic obstructive pulmonary disease (COPD). Cigarette smoke (CS)-induced endoplasmic reticulum (ER) stress has been implicated in the COPD development, but the molecular mechanism by which it contributes to COPD etiology and the specific role it plays in COPD pathogenesis remain poorly understood. Here, we aimed to determine the role of ER stress in the pathogenesis of CS-induced airway inflammation and emphysema. Exposure to CS significantly increased the expression of ER stress markers in Beas-2B cells and in mouse lungs, possibly through the production of oxidative stress. Further, inhibition of ER stress by 4-phenylbutyric acid (4-PBA) reduced CS extract-induced inflammation in Beas-2B cells through the modulation of NF-κB signaling. 4-PBA also protected against CS-induced airway inflammation and the development of emphysema in mice, which was associated with a reduction in NF-κB activation and alveolar cell apoptosis in the lungs. Taken together, our results suggest that ER stress is crucial for CS-induced inflammation and emphysema, and that targeting ER stress may represent a novel approach to the treatment of COPD.

Vitamin E isoform γ-tocotrienol protects against emphysema in cigarette smoke-induced COPD

Inflammation and oxidative stress contribute to emphysema in COPD. Although corticosteroids are the standard of care for COPD, they do not reduce oxidative stress, and a subset of patients is steroid-resistant. Vitamin E isoform γ-tocotrienol possesses both anti-inflammatory and anti-oxidative properties that may protect against emphysema. We aimed to establish the therapeutic potential of γ-tocotrienol in cigarette smoke-induced COPD models in comparison with prednisolone. BALB/c mice were exposed to cigarette smoke for 2 weeks or 2 months. γ-Tocotrienol and prednisolone were given orally. Bronchoalveolar lavage (BAL) fluid and lung tissues were assessed for inflammation, oxidative damage, and regulation of transcription factor activities. Emphysema and lung function were also evaluated. γ-Tocotrienol dose-dependently reduced cigarette smoke-induced BAL fluid neutrophil counts and levels of cytokines, chemokines and oxidative damage biomarkers, and pulmonary pro-inflammatory and pro-oxidant gene expression, but restored lung endogenous antioxidant activities. γ-Tocotrienol acted by inhibiting nuclear translocation of STAT3 and NF-κB, and up-regulating Nrf2 activation in the lungs. In mice exposed to 2-month cigarette smoke, γ-tocotrienol ameliorated bronchial epithelium thickening and destruction of alveolar sacs in lungs, and improved lung functions. In comparison with prednisolone, γ-tocotrienol demonstrated better anti-oxidative efficacy, and protection against emphysema and lung function in COPD. We revealed for the first time the anti-inflammatory and antioxidant efficacies of γ-tocotrienol in cigarette smoke-induced COPD models. In addition, γ-tocotrienol was able to attenuate emphysematous lesions and improve lung function in COPD. γ-Tocotrienol may have therapeutic potential for the treatment of COPD.

Chronic Cigarette Smoke Mediated Global Changes in Lung Mucoepidermoid Cells: A Phosphoproteomic Analysis

Proteomics analysis of chronic cigarette smoke exposure is a rapidly emerging postgenomics research field. While smoking is a major cause of lung cancer, functional studies using proteomics approaches could enrich our mechanistic understanding of the elusive lung cancer global molecular signaling and cigarette smoke relationship. We report in this study on a stable isotope labeling by amino acids in cell culture-based quantitative phosphoproteomic analysis of a human lung mucoepidermoid carcinoma cell line, H292 cells, chronically exposed to cigarette smoke. Using high resolution Orbitrap Velos mass spectrometer, we identified the hyperphosphorylation of 493 sites, which corresponds to 341 proteins and 195 hypophosphorylated sites, mapping to 142 proteins upon smoke exposure (2.0-fold change). We report differential phosphorylation of multiple kinases, including PAK6, EPHA4, LYN, mitogen-activated protein kinase, and phosphatases, including TMEM55B, PTPN14, TIGAR, among others, in response to chronic cigarette smoke exposure. Bioinformatics analysis revealed that the molecules differentially phosphorylated upon chronic exposure of cigarette smoke are associated with PI3K/AKT/mTOR and CDC42-PAK signaling pathways. These signaling networks are involved in multiple cellular processes, including cell polarity, cytoskeletal remodeling, cellular migration, protein synthesis, autophagy, and apoptosis. The present study contributes to emerging proteomics insights on cigarette smoke mediated global signaling in lung cells, which in turn may aid in development of precision medicine therapeutics and postgenomics biomarkers.

Genome-Wide Association Study of the Genetic Determinants of Emphysema Distribution

RATIONALE

Emphysema has considerable variability in the severity and distribution of parenchymal destruction throughout the lungs. Upper lobe-predominant emphysema has emerged as an important predictor of response to lung volume reduction surgery. Yet, aside from alpha-1 antitrypsin deficiency, the genetic determinants of emphysema distribution remain largely unknown.

OBJECTIVES

To identify the genetic influences of emphysema distribution in non-alpha-1 antitrypsin-deficient smokers.

METHODS

A total of 11,532 subjects with complete genotype and computed tomography densitometry data in the COPDGene (Genetic Epidemiology of Chronic Obstructive Pulmonary Disease [COPD]; non-Hispanic white and African American), ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints), and GenKOLS (Genetics of Chronic Obstructive Lung Disease) studies were analyzed. Two computed tomography scan emphysema distribution measures (difference between upper-third and lower-third emphysema; ratio of upper-third to lower-third emphysema) were tested for genetic associations in all study subjects. Separate analyses in each study population were followed by a fixed effect metaanalysis. Single-nucleotide polymorphism-, gene-, and pathway-based approaches were used. In silico functional evaluation was also performed.

MEASUREMENTS AND MAIN RESULTS

We identified five loci associated with emphysema distribution at genome-wide significance. These loci included two previously reported associations with COPD susceptibility (4q31 near HHIP and 15q25 near CHRNA5) and three new associations near SOWAHB, TRAPPC9, and KIAA1462. Gene set analysis and in silico functional evaluation revealed pathways and cell types that may potentially contribute to the pathogenesis of emphysema distribution.

CONCLUSIONS

This multicohort genome-wide association study identified new genomic loci associated with differential emphysematous destruction throughout the lungs. These findings may point to new biologic pathways on which to expand diagnostic and therapeutic approaches in chronic obstructive pulmonary disease. Clinical trial registered with www.clinicaltrials.gov (NCT 00608764).

Impaired Antiviral Stress Granule and IFN-β Enhanceosome Formation Enhances Susceptibility to Influenza Infection in Chronic Obstructive Pulmonary Disease Epithelium

Chronic obstructive pulmonary disease (COPD) is a serious lung disease that progressively worsens lung function. Those affected are highly susceptible to influenza virus infections that result in exacerbations with exaggerated symptoms with increased mortality. The mechanisms underpinning this increased susceptibility to infection in COPD are unclear. In this study, we show that primary bronchial epithelial cells (pBECs) from subjects with COPD have impaired induction of type I IFN (IFN-β) and lead to heightened viral replication after influenza viral infection. COPD pBECs have reduced protein levels of protein kinase (PK) R and decreased formation of PKR-mediated antiviral stress granules, which are critical in initiating type I IFN inductions. In addition, reduced protein expression of p300 resulted in decreased activation of IFN regulatory factor 3 and subsequent formation of IFN-β enhanceosome in COPD pBECs. The decreased p300 induction was the result of enhanced levels of microRNA (miR)-132. Ectopic expression of PKR or miR-132 antagomiR alone failed to restore IFN-β induction, whereas cotreatment increased antiviral stress granule formation, induction of p300, and IFN-β in COPD pBECs. This study reveals that decreased induction of both PKR and p300 proteins contribute to impaired induction of IFN-β in COPD pBECs upon influenza infection.

Kinases as Novel Therapeutic Targets in Asthma and Chronic Obstructive Pulmonary Disease

Multiple kinases play a critical role in orchestrating the chronic inflammation and structural changes in the respiratory tract of patients with asthma and chronic obstructive pulmonary disease (COPD). Kinases activate signaling pathways that lead to contraction of airway smooth muscle and release of inflammatory mediators (such as cytokines, chemokines, growth factors) as well as cell migration, activation, and proliferation. For this reason there has been great interest in the development of kinase inhibitors as anti-inflammatory therapies, particular where corticosteroids are less effective, as in severe asthma and COPD. However, it has proven difficult to develop selective kinase inhibitors that are both effective and safe after oral administration and this has led to a search for inhaled kinase inhibitors, which would reduce systemic exposure. Although many kinases have been implicated in inflammation and remodeling of airway disease, very few classes of drug have reached the stage of clinical studies in these diseases. The most promising drugs are p38 MAP kinases, isoenzyme-selective PI3-kinases, Janus-activated kinases, and Syk-kinases, and inhaled formulations of these drugs are now in development. There has also been interest in developing inhibitors that block more than one kinase, because these drugs may be more effective and with less risk of losing efficacy with time. No kinase inhibitors are yet on the market for the treatment of airway diseases, but as kinase inhibitors are improved from other therapeutic areas there is hope that these drugs may eventually prove useful in treating refractory asthma and COPD.

MicroRNA-125a and -b inhibit A20 and MAVS to promote inflammation and impair antiviral response in COPD

Influenza A virus (IAV) infections lead to severe inflammation in the airways. Patients with chronic obstructive pulmonary disease (COPD) characteristically have exaggerated airway inflammation and are more susceptible to infections with severe symptoms and increased mortality. The mechanisms that control inflammation during IAV infection and the mechanisms of immune dysregulation in COPD are unclear. We found that IAV infections lead to increased inflammatory and antiviral responses in primary bronchial epithelial cells (pBECs) from healthy nonsmoking and smoking subjects. In pBECs from COPD patients, infections resulted in exaggerated inflammatory but deficient antiviral responses. A20 is an important negative regulator of NF-κB-mediated inflammatory but not antiviral responses, and A20 expression was reduced in COPD. IAV infection increased the expression of miR-125a or -b, which directly reduced the expression of A20 and mitochondrial antiviral signaling (MAVS), and caused exaggerated inflammation and impaired antiviral responses. These events were replicated in vivo in a mouse model of experimental COPD. Thus, miR-125a or -b and A20 may be targeted therapeutically to inhibit excessive inflammatory responses and enhance antiviral immunity in IAV infections and in COPD.

HDAC1-3 inhibitor MS-275 enhances IL10 expression in RAW264.7 macrophages and reduces cigarette smoke-induced airway inflammation in mice

Chronic obstructive pulmonary disease (COPD) constitutes a major health burden. Studying underlying molecular mechanisms could lead to new therapeutic targets. Macrophages are orchestrators of COPD, by releasing pro-inflammatory cytokines. This process relies on transcription factors such as NF-κB, among others. NF-κB is regulated by lysine acetylation; a post-translational modification installed by histone acetyltransferases and removed by histone deacetylases (HDACs). We hypothesized that small molecule HDAC inhibitors (HDACi) targeting class I HDACs members that can regulate NF-κB could attenuate inflammatory responses in COPD via modulation of the NF-κB signaling output. MS-275 is an isoform-selective inhibitor of HDAC1-3. In precision-cut lung slices and RAW264.7 macrophages, MS-275 upregulated the expression of both pro- and anti-inflammatory genes, implying mixed effects. Interestingly, anti-inflammatory IL10 expression was upregulated in these model systems. In the macrophages, this was associated with increased NF-κB activity, acetylation, nuclear translocation, and binding to the IL10 promoter. Importantly, in an in vivo model of cigarette smoke-exposed C57Bl/6 mice, MS-275 robustly attenuated inflammatory expression of KC and neutrophil influx in the lungs. This study highlights for the first time the potential of isoform-selective HDACi for the treatment of inflammatory lung diseases like COPD.

Antibacterial Defense of Human Airway Epithelial Cells from Chronic Obstructive Pulmonary Disease Patients Induced by Acute Exposure to Nontypeable Haemophilus influenzae: Modulation by Cigarette Smoke

Antimicrobial proteins and peptides (AMPs) are a central component of the antibacterial activity of airway epithelial cells. It has been proposed that a decrease in antibacterial lung defense contributes to an increased susceptibility to microbial infection in smokers and patients with chronic obstructive pulmonary disease (COPD). However, whether reduced AMP expression in the epithelium contributes to this lower defense is largely unknown. We investigated the bacterial killing activity and expression of AMPs by air-liquid interface-cultured primary bronchial epithelial cells from COPD patients and non-COPD (ex-)smokers that were stimulated with nontypeable Haemophilus influenzae (NTHi). In addition, the effect of cigarette smoke on AMP expression and the activation of signaling pathways was determined. COPD cell cultures displayed reduced antibacterial activity, whereas smoke exposure suppressed the NTHi-induced expression of AMPs and further increased IL-8 expression in COPD and non-COPD cultures. Moreover, smoke exposure impaired NTHi-induced activation of NF-κB, but not MAP-kinase signaling. Our findings demonstrate that the antibacterial activity of cultured airway epithelial cells induced by acute bacterial exposure was reduced in COPD and suppressed by cigarette smoke, whereas inflammatory responses persisted. These findings help to explain the imbalance between protective antibacterial and destructive inflammatory innate immune responses in COPD.

Anti-asthmatic activity of osthole in an ovalbumin-induced asthma murine model

Osthole, an active coumarin extracted from the dried fruits of Cnidium monnieri (L.) Cusson, is known to possess a variety of pharmacological activities. In the present study, we investigated and illuminated the mechanisms underlying the protective effects of osthole in an experimental model of allergic asthma. Our results show that osthole treatment significantly reduced the OVA-induced increase in serum IgE and inflammatory cytokines (IL-4, IL-5, IL-13) in bronchoalveolar lavage fluid (BALF), and decreased the recruitment of inflammatory cells in BALF and the lung. It also effectively attenuated goblet cell hyperplasia and mucus overproduction in lung tissue. In addition, western blot analysis demonstrated that osthole blocked NF-κB activation, which may be associated with a reduction in inflammatory cytokine production. These data suggest that osthole attenuated OVA-induced allergic asthma inflammation by inhibiting NF-κB activation. The present study identified the molecular mechanisms of action of osthole, which support the potential pharmaceutical application of osthole treatment for asthma and other airway inflammation disorders.