Role for TAK1 in cigarette smoke-induced proinflammatory signaling and IL-8 release by human airway smooth muscle cells

In-hospital outcome of type A aortic dissection repair in patients with chronic obstructive pulmonary disease: A population study of National Inpatient Sample from 2015 to 2020

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common comorbidity that has been linked to higher mortality and respiratory complications in cardiac surgery. However, the postoperative outcomes for COPD patients undergoing Type A Aortic Dissection (TAAD) repair remain unexplored. Thus, this study aimed to assess the impact of COPD on in-hospital outcomes of TAAD repair in a national registry.

METHODS

Patients undergoing TAAD repair were identified in National Inpatient Sample from the last quarter of 2015-2020. Multivariable logistic regressions were used to compare in-hospital outcomes between patients with and without COPD, where demographics, comorbidities, hospital characteristics, primary payer status, and transfer status were adjusted.

RESULTS

There were 701 (16.37 %) COPD patients and 3581 (83.63 %) non-COPD patients who went under TAAD repair, where the prevalence of COPD was higher than in the general population (6 %). COPD and non-COPD patients have comparable rates of in-hospital mortality (14.69 % vs 15.19 %, aOR 1.016, 95 CI 0.797-1.295, p = 0.9) and there was no indication of delayed surgery. However, COPD patients had a higher risk of mechanical ventilation (37.80 % vs 31.42 %, aOR 1.521, 95 CI 1.267-1.825, p < 0.01) and a higher rate of transferring out to other facilities (38.37 % vs 32.23 %, aOR 1.271, 95 CI 1.054-1.533, p = 0.01). In addition, COPD patients had a longer hospital length of stay (14.28 ± 11.32 vs 13.85 ± 12.78 days, F = 5.61, p = 0.01).

CONCLUSION

The presence of COPD could be a risk factor for the development of aortic dissection. However, outcomes for COPD patients were largely similar to those without COPD. These findings can be valuable for preoperative assessments and tailoring perioperative care for COPD patients undergoing TAAD repair.

The association of chronic obstructive pulmonary disease and 30-day outcomes of infrainguinal bypass surgery: A propensity-score matching study

BACKGROUND

Infrainguinal bypass surgery is an effective treatment for peripheral artery disease (PAD). While chronic obstructive pulmonary disease (COPD) has been linked to heightened risks of mortality and morbidity in major surgery, a thorough investigation into COPD's impact on infrainguinal bypass outcomes remained underexplored. Thus, this study aimed to assess the 30-day outcomes for COPD patients undergoing infrainguinal bypass surgery.

METHODS

COPD and non-COPD patients who underwent infrainguinal bypass were identified in American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2011 to 2022. Patients of age<18 were excluded. A 1:1 propensity-score matching was used to match demographics, baseline characteristics, symptomatology, procedure, conduit, and anesthesia. Thirty postoperative outcomes were compared.

RESULTS

There were 3,183 (12.64%) and 22,004 (87.36%) patients with and without COPD, respectively, who underwent infrainguinal bypass. COPD patients had a higher comorbid burden. After propensity-score matching, COPD patients had higher sepsis (3.55% vs 2.42%, p = 0.01), wound complications (18.94% vs 16.40%, p = 0.01), and 30-day readmission (18.00% vs 14.92%, p < 0.01). However, COPD and non-COPD patients had comparable 30-day mortality (2.54% vs 2.67%, p = 0.81), and organ system complications including cardiac (3.58% vs 3.99%, p = 0.43), pulmonary (3.96% vs 3.20%, p = 0.12), and renal complications (1.70% vs 1.82%, p = 0.78). Limb-specific outcomes including major amputation (2.95% vs 2.50%, p = 0.30), untreated loss of patency (1.85% vs 1.38%, p = 0.16), and patent graft (98.24% vs 98.65%, p = 0.27) were also comparable between the cohorts.

CONCLUSION

While COPD might be associated with the development of PAD due to potentially shared pathophysiology, it may not be an independent risk factor for the major 30-day outcomes in infrainguinal bypass surgery.

Methyl lucidone inhibits airway inflammatory response by reducing TAK1 activity in human bronchial epithelial NCI-H292 cells

Background

Methyl lucidone (ML), a methyl derivative of lucidone, has anti-inflammatory properties. However, the molecular mechanisms that reduce the inflammatory effect of ML in human lung epithelial cells remain unkown. This study aimed to elucidate the molecular mechanisms underlying the anti-inflammatory effect of ML.

Methods

Four compounds (ML, methyl linderone, kanakugiol, and linderone) from Lindera erythrocarpa Makino were evaluated for their ability to reduce MUC5AC secretion levels in phorbol-12-myristate-13-acetate (PMA)-stimulated NCI-H292 cells using ELISA. The expression and secretion levels of inflammatory response-related proteins were analyzed using quantitative reverse transcription-PCR, ELISA, and western blotting. To determine whether ML directly regulates TGF-β-activated kinase 1 (TAK1), we performed an in vitro kinase assay.

Results

ML treatment effectively reduced the levels of inflammatory cytokines, including interleukin-1β and TNF-α, increased by stimulation. Furthermore, ML downregulated the pathway cascade of both IκB kinase (IKK)/NF-κB and p38 mitogen-activated protein (MAP) kinase/CREB by inhibiting the upstream kinase TAK1. An in vitro kinase analysis confirmed that ML treatment significantly reduced the kinase activity of TAK1.

Conclusion

ML pretreatment repressed the PMA-stimulated inflammation reaction by reducing the TAK1-mediated IKK/NF-κB and p38 MAP kinase/CREB signaling. These findings suggest that ML may improve respiratory health and can be used as a dietary supplement or functional food to prevent inflammatory lung diseases.

Black Ginseng Extract Suppresses Airway Inflammation Induced by Cigarette Smoke and Lipopolysaccharides In Vivo

Cigarette smoke (CS) is a risk factor that can induce airway enlargement, airway obstruction, and airway mucus hypersecretion. Although studies have shown that Korean black ginseng extract (BGE) has potent anti-inflammatory and antioxidant activities, the CS-induced inflammatory responses and molecular mechanisms are yet to be examined. The aim of this study was to examine the effect of BGE on the airway inflammatory response and its molecular mechanisms, using CS/lipopolysaccharides (LPS)-exposed animals and PMA-stimulated human airway epithelial NCI-H292 cells. The results show that BGE inhibited the recruitment of immune cells and the release of inflammatory mediators, such as tumor necrosis factor (TNF)-α and interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, elastase, and reactive oxygen species (ROS) in the airways of CS/LPS-exposed animals. BGE inhibited mucus secretion and the expression of Mucin 5AC (MUC5AC). Furthermore, BGE exhibited an anti-inflammatory effect by downregulating a signaling pathway mediated by transforming growth factor-β-activated kinase (TAK) 1, an important protein that accelerates inflammation by cigarette smoke (CS). Overall, the findings show that BGE inhibits lung inflammation and mucus secretion by decreasing the activation of TAK1 both in human epithelial cells and in CS/LPS-exposed animals, and could be a potential adjuvant in the treatment and prevention of airway inflammatory diseases caused by airway irritants such as CS.

Epilobiumpyrricholophum Extract Suppresses Porcine Pancreatic Elastase and Cigarette Smoke Extract-Induced Inflammatory response in a Chronic Obstructive Pulmonary Disease Model

Chronic airway exposure to harmful substances, such as deleterious gases, cigarette smoke (CS), and particulate matter, triggers chronic obstructive pulmonary disease (COPD), characterized by impaired lung function and unbridled immune responses. Emerging epigenomic and genomic evidence suggests that excessive recruitment of alveolar macrophages and neutrophils contributes to COPD pathogenesis by producing various inflammatory mediators, such as reactive oxygen species (ROS), neutrophil elastase, interleukin (IL) 6, and IL8. Recent studies showed that Epilobium species attenuated ROS, myeloperoxidase, and inflammatory cytokine production in murine and human innate immune cells. Although the Epilobium genus exerts anti-inflammatory, antioxidant, and antimicrobial effects, the question of whether the Epilobium species regulate lung inflammation and innate immune response in COPD has not been investigated. In this study, Epilobium pyrricholophum extract (EPE) suppressed inflammatory cell recruitment and clinical symptoms in porcine pancreatic elastase and CS extract-induced COPD mice. In addition, EPE attenuated inflammatory gene expression by suppressing MAPKs and NFκB activity. Furthermore, UPLC-Q-TOF MS analyses revealed the anti-inflammatory effects of the identified phytochemical constituents of EPE. Collectively, our studies revealed that EPE represses the innate immune response and inflammatory gene expression in COPD pathogenesis in mice. These findings provide insights into new therapeutic approaches for treating COPD.

miR-558 Reduces the Damage of HBE Cells Exposed to Cigarette Smoke Extract by Targeting TNFRSF1A and Inactivating TAK1/MAPK/NF-κB Pathway

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic smoking-related lung disease associated with higher mortality and morbidity. Herein, we attempted to investigate the function of miR-558/TNF Receptor Superfamily Member 1A (TNFRSF1A) in the progression of COPD.

METHODS

GEO database was applied to filtrate the differentially expressed mRNAs and miRNAs. KEGG enrichment was used to select the meaningful pathway related to the differentially expressed genes. TargetScan was used to predict the upstream regulator of TNFRSF1A, which was further affirmed by dual luciferase assay. HBE cells were stimulated by 20 μg/mL cigarette smoke extract (CSE) to mimic the COPD in vitro. The activity, apoptosis and inflammatory factors of HBE cells were evaluated by biological experiments. The levels of proteins related to TAK1/MAPK/NF-κB pathway were measured by Western blot.

RESULTS

TNFRSF1A is found to be highly expressed in COPD samples and enriched in TNF signaling pathway through bioinformatics analysis. miR-558 was verified as an upstream regulator of TNFRSF1A and negatively regulated TNFRSF1A expression. Up-regulation of miR-558 alleviated CSE-induced damage on HBE cells. The alleviative effect of miR-558 mimic on CSE-induced damage was suppressed by TNFRSF1A overexpression. The elevated expression of p-TAK1/p-p38 MAPK/p-NF-κB P65 in CSE condition was suppressed by miR-558 up-regulation. However, the results were reversed by TNFRSF1A overexpression. TAK1 inhibitor blocked the activation of TAK1/MAPK/NF-κB pathway, which was consistent with the results from miR-558 up-regulation.

CONCLUSIONS

Up-regulation of miR-558 relieved the damage of HBE cells-triggered by CSE via reducing TNFRSF1A and inactivating TAK1/MAPK/NF-κB pathway, affording novel molecules for COPD treatment.

TLR3/TAK1 signalling regulates rhinovirus-induced interleukin-33 in bronchial smooth muscle cells

Background

Asthma exacerbations are commonly associated with rhinovirus (RV) infection. Interleukin-33 (IL-33) plays an important role during exacerbation by enhancing Type 2 inflammation. Recently we showed that RV infects bronchial smooth muscle cells (BSMCs) triggering production of interferons and IL-33. Here we compared levels of RV-induced IL-33 in BSMCs from healthy and asthmatic subjects, and explored the involvement of pattern-recognition receptors (PRRs) and downstream signalling pathways in IL-33 expression.

Method

BSMCs from healthy and severe and non-severe asthmatic patients were infected with RV1B or stimulated with the PRR agonists poly(I:C) (Toll-like receptor 3 (TLR3)), imiquimod (TLR7) and poly(I:C)/LyoVec (retinoic acid-inducible gene 1 (RIG-I)/melanoma differentiation-associated protein 5 (MDA5)). Knockdown of TLR3, RIG-I and MDA5 was performed, and inhibitors targeting TBK1, nuclear factor-κB (NF-κB) and transforming growth factor (TGF)-β-activated kinase 1 (TAK1) were used. Gene and protein expression were assessed.

Results

RV triggered IL-33 gene and protein expression in BSMCs. BSMCs from patients with non-severe asthma showed higher baseline and RV-induced IL-33 gene expression compared to cells from patients with severe asthma and healthy controls. Furthermore, RV-induced IL-33 expression in BSMCs from healthy and asthmatic individuals was attenuated by knockdown of TLR3. Inhibition of TAK1, but not NF-κB or TBK1, limited RV-induced IL-33. The cytokine secretion profile showed higher production of IL-33 in BSMCs from patients with non-severe asthma compared to healthy controls upon RV infection. In addition, BSMCs from patients with non-severe asthma had higher levels of RV-induced IL-8, TNF-α, IL-1β, IL-17A, IL-5 and IL-13.

Conclusion

RV infection caused higher levels of IL-33 and increased pro-inflammatory and Type 2 cytokine release in BSMCs from patients with non-severe asthma. RV-induced IL-33 expression was mainly regulated by TLR3 and downstream via TAK1. These signalling molecules represent potential therapeutic targets for treating asthma exacerbations.

Rhinovirus-induced IL-33 is overexpressed in bronchial smooth muscle cells from asthmatics, and the production of IL-33 following infection is mediated by activation of TLR3 and downstream TAK1 signallinghttps://bit.ly/3fXH0h3

Extracellular acidification-induced CXCL8 production through a proton-sensing receptor OGR1 in human airway smooth muscle cells: a response inhibited by dexamethasone

Background

Human airway smooth muscle cells (ASMCs) contribute to bronchial contraction and airway hyperresponsiveness in patients with bronchial asthma. They also generate cytokines, chemokines, and matricellular proteins. Ovarian cancer G protein-coupled receptor 1 (OGR1) senses extracellular protons and mediates the production of interleukin-6 (IL-6) and connective tissue growth factor (CTGF) in ASMCs.

Methods

ASMCs were stimulated for the indicated time by pH 6.3 or pH 7.4-adjusted Dulbecco’s Modified Eagle Medium (DMEM) containing 0.1% bovine serum albumin (BSA) (0.1% BSA-DMEM). As a control stimulant, pH 7.4-adjusted 0.1% BSA-DMEM containing 10 ng/mL tumor necrosis factor-α (TNF-α) was used. Interleukin-8/C-X-C motif chemokine ligand 8 (CXCL8) mRNA expression in ASMCs was quantified by RT-PCR using real-time TaqMan technology. CXCL8 secreted from ASMCs was measured by enzyme-linked immunosorbent assay (ELISA). Phosphorylation at serine 536 of NF-κB p65 and binding of p65 to oligonucleotide containing an NF-κB consensus binding site were analyzed by Western blotting and an ELISA-based kit.

Results

Acidic pH induced a significant increase of CXCL8 mRNA expression and CXCL8 protein secretion in ASMCs. ASMCs transfected with small interfering RNA (siRNA) targeted for OGR1 produced less CXCL8 compared with those transfected with non-targeting siRNA. Protein kinase C (PKC) inhibitor, MEK1/2 inhibitor, and the inhibitor of IκB phosphorylation reduced acidic pH-stimulated CXCL8 production in ASMCs. Dexamethasone also inhibited acidic pH-stimulated CXCL8 production of ASMCs in a dose-dependent manner. Dexamethasone did not affect either phosphorylation or binding to the consensus DNA site of NF-κB p65.

Conclusions

CXCL8 released from ASMCs by extracellular acidification may play a pivotal role in airway accumulation of neutrophils. Glucocorticoids inhibit acidic pH-stimulated CXCL8 production independent of serine 536 phosphorylation and the binding to DNA of NF-κB p65, although NF-κB activity is essential for CXCL8 production in ASMCs.

New targets for resolution of airway remodeling in obstructive lung diseases

Airway remodeling (AR) is a progressive pathological feature of the obstructive lung diseases, including asthma and chronic obstructive pulmonary disease (COPD). The pathology manifests itself in the form of significant, progressive, and (to date) seemingly irreversible changes to distinct respiratory structural compartments. Consequently, AR correlates with disease severity and the gradual decline in pulmonary function associated with asthma and COPD. Although current asthma/COPD drugs manage airway contraction and inflammation, none of these effectively prevent or reverse features of AR. In this review, we provide a brief overview of the features and putative mechanisms affecting AR. We further discuss recently proposed strategies with promise for deterring or treating AR.

IL-1β induced IL-8 and uPA expression/production of dental pulp cells: Role of TAK1 and MEK/ERK signaling

BACKGROUND/PURPOSE

Interleukin 1 beta (IL-1β) is a pro-inflammatory cytokine involved in the inflammatory processes of dental pulp. IL-8 and urokinase plasminogen activator (uPA) are two inflammatory mediators. However, the role of transforming growth factor beta-activated kinase-1 (TAK1) and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathways in responsible for the effects of IL-1β on IL-8 and uPA expression/secretion of dental pulp cells are not clear.

METHODS

Human dental pulp cells were exposed to IL-1β with/without pretreatment with 5z-7-oxozeaneaeol (a TAK1 inhibitor) or U0126 (a MEK/ERK inhibitor). TAK1 activation was determined by immunofluorescent staining. The protein expression of IL-8 was tested by western blot. The expression of IL-8 and uPA mRNA was studied by reverse transcriptase-polymerase chain reaction (RT-PCR). The secretion of IL-8 and uPA was measured by enzyme-linked immunosorbent assay.

RESULTS

Exposure of dental pulp cells to IL-1β (0.1-10 ng/ml) stimulated IL-8 and uPA expression. IL-1β also induced IL-8 and uPA secretion of dental pulp cells. IL-1β stimulated p-TAK1 activation of pulp cells. Pretreatment and co-incubation of pulp cells by 5z-7oxozeaenol (1 and 2.5 μM) and U0126 (10 and 20 μM) prevented the IL-1β-induced IL-8 and uPA expression. 5z-7oxozeaenol and U0126 also attenuated the IL-1β-induced IL-8 and uPA secretion.

CONCLUSION

IL-1β is important in the pathogenesis of pulpal inflammatory diseases and repair via stimulation of IL-8 and uPA expression and secretion. These events are associated with TAK1 and MEK/ERK signaling. Blocking of TAK1 and MEK/ERK signaling has potential to control inflammation of dental pulp.

Transcription Elongation Factor P-TEFb Is Involved in IL-17F Signaling in Airway Smooth Muscle Cells

BACKGROUND

IL-17F is involved in the pathogenesis of several inflammatory diseases, including asthma and COPD. However, the effects of steroids on the function of IL-17F signaling mechanisms are largely unknown. One of the transcription elongation factors, positive transcription elongation factor b (P-TEFb) composed of cyclin T1 and cyclin-dependent kinase 9 (CDK9), is known as a novel checkpoint regulator of gene expression via bromodomain-containing protein 4 (Brd4).

METHODS

Human airway smooth muscle cells were stimulated with IL-17F and the expression of IL-8 was evaluated by real-time PCR and ELISA. Next, the phosphorylation of CDK9 was determined by Western blotting. The CDK9 inhibitor and short interfering RNAs (siRNAs) targeting Brd4, cyclin T1, and CDK9 were used to identify the effect on IL-17F-induced IL-8 expression. Finally, the effect of steroids and its signaling were evaluated.

RESULTS

IL-17F markedly induced the transcription of the IL-8 gene and the expression of the protein. Pretreatment of CDK9 inhibitor and transfection of siRNAs targeting CDK9 markedly abrogated IL-17F-induced IL-8 production. Transfection of siRNAs targeting Brd4 and cyclin T1 diminished IL-17F-induced phosphorylation of CDK9 and IL-8 production. Moreover, budesonide decreased CDK9 phosphorylation and markedly inhibited IL-17F-induced IL-8 production.

CONCLUSIONS

This is the first report that P-TEFb is involved in IL-17F-induced IL-8 expression and that steroids diminish it via the inhibition of CDK9 phosphorylation. IL-17F and P-TEFb might be novel therapeutic targets for airway inflammatory diseases.

The interaction of TAK1 and TAB1 enhances LPS-induced cytokine release via modulating NF-κB activation (Larimichthys crocea)

Transforming growth factor-β-activating kinase 1 (TAK1) is triggered by foreign pathogenic infection and involves in proinflammatory response through the activation of nuclear factor-κB (NF-κB), which is specifically regulated by TAK1-binding protein 1 (TAB1). However, the expression and regulatory characterizations of TAK1 and TAB1 in fish immune response remain largely unknown. In the present study, the cDNA sequences of TAK1 (LcTAK1) and TAB1 (LcTAB1) were identified from large yellow croaker, Larimichthys crocea. The open reading frame (ORF) of LcTAK1 was 1725 bp in length, encoding 574 amino acids. The putative LcTAK1 protein contained a protein kinase domain and a C-terminal coiled-coil region. The ORF of LcTAB1 was 1518 bp encoding 505 amino acids. And a typical PP2Cc domain and a conserved sequence motif (PYVDFSQFYLLWGSDH) at C-terminal were identified in the predicted LcTAB1 protein. Multiple alignments showed that LcTAK1 shared 74.0-97.9% and LcTAB1 shared 37.4-95.8% sequence identities with TAK1 and TAB1 proteins from other species, respectively. Quantitative PCR analysis indicated that both LcTAK1 and LcTAB1 were broadly expressed in all examined tissues, with the most predominant expression in brain and the weakest expression in muscle, respectively. Subcellular localization revealed that both LcTAK1 and LcTAB1 expressed in the cytoplasm. In addition, LcTAK1 transcripts increased significantly in LCK cells after flagellin, LPS and poly I:C stimulation while LcTAB1 enhanced greatly after LPS and poly I:C challenge. Furthermore, the roles of them in NF-κB activation were investigated by overexpression of LcTAK1 and LcTAB1 in HEK293T cells. Our results revealed that NF-κB luciferase promoter expression could not be induced by overexpression of LcTAK1 or LcTAB1 alone, however, it could be induced by co-expression of LcTAK1 and LcTAB1 together. Moreover, the roles of LcTAK1 and LcTAB1 in immune response analysis showed that NF-κB activation enhanced significantly in co-overexpressed HEK293T cells following LPS and poly I:C stimulation. However, the expression levels of tumor necrosis factor (TNF)-α, Interleukin-6 (IL-6) and IL-8 were induced only after LPS challenge (p < .05). These findings suggested that the TAK1-TAB1 complex of large yellow croaker might play an important role in pro-inflammatory cytokines and chemokine release after LPS stimulation via inducing NF-κB activation.

High prevalence of COPD in atherosclerosis patients

Atherosclerosis and COPD are both systemic inflammatory diseases that may influence each other. The aim of the present study was to determine the prevalence of COPD in patients with cerebral and/or peripheral artery disease and to assess factors associated with the presence of COPD. Following the diagnosis of cerebral and/or peripheral artery disease by means of duplex sonography, 166 consecutive patients underwent body plethysmography with capillary blood gas analysis. Thereafter, blood tests with determination of different parameters such as lipid profile, inflammatory and coagulation markers were conducted in remaining 136 patients who fulfilled inclusion criteria of the study. Thirty-six out of 136 patients suffered from COPD, mostly in early stages of the disease. Residual volume indicating emphysema was increased (162.9%±55.9% vs 124.5%±37.0%, p<0.05) and diffusion capacity was decreased (55.1%±19.5% vs 75.3%±18.6%, p<0.05) in COPD patients vs non-COPD group. In capillary blood gas analysis, COPD patients had lower partial pressure of oxygen (70.9±11.5 vs 75.2±11.0 mmHg, p<0.05) and higher partial pressure of carbon dioxide (36.8±7.5 vs 34.4±4.4 mmHg, p<0.05) compared with non-COPD individuals. Presence of COPD was associated with predominance of diabetes mellitus, interleukin-8-related systemic neutrophilic inflammation and anemia. In conclusion, COPD is highly prevalent in patients with atherosclerotic artery disease.

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.

Porcine reproductive and respiratory syndrome virus (PRRSV) up-regulates IL-8 expression through TAK-1/JNK/AP-1 pathways

The acute phase of respiratory distress caused by porcine reproductive and respiratory syndrome virus (PRRSV) is likely a consequence of the release of inflammatory cytokines in the lung. IL-8, the main chemokine and activator of neutrophils, might be related to the lung injury upon PRRSV infection. In this study, we showed that PRRSV induced IL-8 expression in vivo and in vitro. Subsequently, we demonstrated that JNK and NF-κB pathways were activated upon PRRSV infection and required for the enhancement of IL-8 expression. We further verified that PRRSV-activated TAK-1 was essential for the activation of JNK and NF-κB pathways and IL-8 expression. Moreover, we revealed an AP-1 binding motif in the cloned porcine IL-8 (pIL-8) promoter, and deletion of this motif abolished the pIL-8 promoter activity. Finally, we found that the JNK-activated AP-1 subunit c-Jun was critical for the up-regulation of IL-8 expression by PRRSV. These data suggest that PRRSV-induced IL-8 production is likely through the TAK-1/JNK/AP-1 pathways.

•

PRRSV infection induces IL-8 expression in vitro and in vivo.

•

PRRSV up-regulates IL-8 expression through TAK-1/JNK/AP-1 pathways.

•

AP-1 element in porcine IL-8 promoter is essential for PRRSV induced IL-8 expression.

IL-17F induces IL-6 via TAK1-NFκB pathway in airway smooth muscle cells

Introduction

Interleukin (IL)‐17F plays a critical role in the pathophysiology of asthma. However, the precise role of IL‐17F in airway smooth muscle cells (ASMCs) and its regulatory mechanisms remain to be defined. Therefore, we sought to investigate the expression of IL‐6 by IL‐17F and the involvement of transforming growth factor β‐activated kinase 1 (TAK1) and nuclear factor (NF)‐κB by in ASMCs.

Methods

ASMCs were cultured in the presence or absence of IL‐17F. The expression of IL‐6 gene and protein was analyzed using real‐time PCR and ELISA, and the activation of TAK1 and NF‐κB was detected by Western blotting. The effect of TAK1 inhibitor 5Z‐7‐oxozeaenol and NF‐κB inhibitor BAY 11‐7082 on the expression of IL‐6 was investigated. Finally, the short interfering RNAs (siRNAs) targeting TAK1 and a subunit of NF‐κB, p65 were transfected into ASMCs.

Results

The expression of IL‐6 gene and protein was significantly induced by IL‐17F. IL‐17F activated TAK1 and NF‐κB in ASMCs. Transfection of siRNAs targeting TAK1 abolished IL‐17F‐induced phosphorylation of p65. Both 5Z‐7‐oxozeaenol and BAY 11‐7082 significantly inhibited IL‐17F‐induced IL‐6 production in a dose‐dependent manner. Similarly, transfection of the cells with siRNAs targeting TAK1 and p65 inhibited the expression of IL‐6.

Conclusions

Collectively, these results provided evidence supporting the potential importance of the Th17‐ASMCs crosstalk via the IL‐17F‐IL‐6 axis in airway inflammation and as a candidate pharmacological target for airway inflammatory diseases such as asthma.

Cigarette smoke extract promotes proliferation of airway smooth muscle cells through suppressing C/EBP-α expression

Cigarette smoke has been considered a major contributor to the pathogenesis of chronic obstructive pulmonary disease (COPD). In COPD patients, the airway smooth muscle layer has been observed to be markedly thickened and the proliferation of airway smooth muscle cells (ASMCs) was therefore used by the present study as a model to assess the impact of cigarette smoke extract (CSE). ASMCs were exposed to various concentrations of CSE and the proliferation of the cells was analyzed by an MTT assay. Furthermore, the expression levels of calreticulin and CCAAT/enhancer-binding protein alpha (C/EBP-α) in CSE-stimulated ASMCs were determined by polymerase chain reaction and western blot analyses. In addition, the effects of RNA interference (RNAi) to knockdown calreticulin and/or C/EBP-α on ASMC proliferation were studied. CSE was found to promote the proliferation of ASMCs, which was associated with increased expression of calreticulin and decreased expression of C/EBP-α. Knockdown of calreticulin resulted in the upregulation of C/EBP-α and inhibition of cell proliferation, while simultaneous knockdown of C/EBP-α promoted cell proliferation. The present study revealed that CSE promoted the proliferation of ASMCs, which was mediated by inhibition of C/EBP-α. These findings shed new light on airway remodeling in COPD and may provide novel approaches for therapies.

Functional Effects of WNT1-Inducible Signaling Pathway Protein-1 on Bronchial Smooth Muscle Cell Migration and Proliferation in OVA-Induced Airway Remodeling

Upregulation of WISP1 has been demonstrated in lung remodeling. Moreover, it has been recently found that some signaling components of WNT pathway can activate GSK3β signaling to mediate remodeling of airway smooth muscle (ASM) in asthma. Therefore, we hypothesized that WISP1, a signaling molecule downstream of the WNT signaling pathway, is involved in PI3K/GSK3β signaling to mediate ASM remodeling in asthma. Our results showed that WISP1 depletion partly suppressed OVA-induced ASM hypertrophy in vivo. In vitro, WISP1 could induce hBSMC hypertrophy and proliferation, accompanied by upregulation of levels of PI3K, p-Akt, p-GSK3β, and its own expression. TGF-β treatment could increase expression of PI3K, p-Akt, p-GSK3β, and WISP1. SH-5 treatment could partly suppress TGF-β-induced hypertrophy and proliferation of hBSMC, and depress expression of p-GSK3β and WISP1. In conclusion, WISP1 may be a potential inducer of ASM proliferation and hypertrophy in asthma. The pro-remodeling effect of WISP1 is likely due to be involved in PI3K-GSK3β-dependent noncanonical TGF-β signaling.

Lung inflammation caused by inhaled toxicants: a review

Exposure of the lungs to airborne toxicants from different sources in the environment may lead to acute and chronic pulmonary or even systemic inflammation. Cigarette smoke is the leading cause of chronic obstructive pulmonary disease, although wood smoke in urban areas of underdeveloped countries is now recognized as a leading cause of respiratory disease. Mycotoxins from fungal spores pose an occupational risk for respiratory illness and also present a health hazard to those living in damp buildings. Microscopic airborne particulates of asbestos and silica (from building materials) and those of heavy metals (from paint) are additional sources of indoor air pollution that contributes to respiratory illness and is known to cause respiratory illness in experimental animals. Ricin in aerosolized form is a potential bioweapon that is extremely toxic yet relatively easy to produce. Although the aforementioned agents belong to different classes of toxic chemicals, their pathogenicity is similar. They induce the recruitment and activation of macrophages, activation of mitogen-activated protein kinases, inhibition of protein synthesis, and production of interleukin-1 beta. Targeting either macrophages (using nanoparticles) or the production of interleukin-1 beta (using inhibitors against protein kinases, NOD-like receptor protein-3, or P2X7) may potentially be employed to treat these types of lung inflammation without affecting the natural immune response to bacterial infections.

The novel compound Sul-121 inhibits airway inflammation and hyperresponsiveness in experimental models of chronic obstructive pulmonary disease

COPD is characterized by persistent airflow limitation, neutrophilia and oxidative stress from endogenous and exogenous insults. Current COPD therapy involving anticholinergics, β2-adrenoceptor agonists and/or corticosteroids, do not specifically target oxidative stress, nor do they reduce chronic pulmonary inflammation and disease progression in all patients. Here, we explore the effects of Sul-121, a novel compound with anti-oxidative capacity, on hyperresponsiveness (AHR) and inflammation in experimental models of COPD. Using a guinea pig model of lipopolysaccharide (LPS)-induced neutrophilia, we demonstrated that Sul-121 inhalation dose-dependently prevented LPS-induced airway neutrophilia (up to ~60%) and AHR (up to ~90%). Non-cartilaginous airways neutrophilia was inversely correlated with blood H2S, and LPS-induced attenuation of blood H2S (~60%) was prevented by Sul-121. Concomitantly, Sul-121 prevented LPS-induced production of the oxidative stress marker, malondialdehyde by ~80%. In immortalized human airway smooth muscle (ASM) cells, Sul-121 dose-dependently prevented cigarette smoke extract-induced IL-8 release parallel with inhibition of nuclear translocation of the NF-κB subunit, p65 (each ~90%). Sul-121 also diminished cellular reactive oxygen species production in ASM cells, and inhibited nuclear translocation of the anti-oxidative response regulator, Nrf2. Our data show that Sul-121 effectively inhibits airway inflammation and AHR in experimental COPD models, prospectively through inhibition of oxidative stress.

Verproside inhibits TNF-α-induced MUC5AC expression through suppression of the TNF-α/NF-κB pathway in human airway epithelial cells

Airway mucus secretion is an essential innate immune response for host protection. However, overproduction and hypersecretion of mucus, mainly composed of MUC5AC, are significant risk factors in asthma and chronic obstructive pulmonary disease (COPD) patients. Previously, we reported that verproside, a catalpol derivative iridoid glycoside isolated from Pseudolysimachion rotundum var. subintegrum, is a potent anti-asthmatic candidate drug in vivo. However, the molecular mechanisms underlying the pharmacological actions of verproside remain unknown. Here, we found that verproside significantly reduces the expression levels of tumor necrosis factor alpha (TNF-α)-induced MUC5AC mRNA and protein by inhibiting both nuclear factor kappa B (NF-κB) transcriptional activity and the phosphorylation of its upstream effectors such as IκB kinase (IKK)β, IκBα, and TGF-β-activated kinase 1 (TAK1) in NCI-H292 cells. Moreover, verproside attenuated TNF-α-induced MUC5AC transcription more effectively when combined with an IKK (BAY11-7082) or a TAK1 (5z-7-oxozeaenol) inhibitor than when administered alone. Importantly, we demonstrated that verproside negatively modulates the formation of the TNF-α-receptor (TNFR) 1 signaling complex [TNF-RSC; TNFR1-recruited TNFR1-associated death domain protein (TRADD), TNFR-associated factor 2 (TRAF2), receptor-interacting protein kinase 1 (RIP1), and TAK1], the most upstream signaling factor of NF-κB signaling. In silico molecular docking studies show that verproside binds between TRADD and TRAF2 subunits. Altogether, these results suggest that verproside could be a good therapeutic candidate for treatment of inflammatory airway diseases such as asthma and COPD by blocking the TNF-α/NF-κB signaling pathway.

Interrelated role of cigarette smoking, oxidative stress, and immune response in COPD and corresponding treatments

Cigarette smoking (CS) can impact the immune system and induce pulmonary disorders such as chronic obstructive pulmonary disease (COPD), which is currently the fourth leading cause of chronic morbidity and mortality worldwide. Accordingly, the most significant risk factor associated with COPD is exposure to cigarette smoke. The purpose of the present study is to provide an updated overview of the literature regarding the effect of CS on the immune system and lungs, the mechanism of CS-induced COPD and oxidative stress, as well as the available and potential treatment options for CS-induced COPD. An extensive literature search was conducted on the PubMed/Medline databases to review current COPD treatment research, available in the English language, dating from 1976 to 2014. Studies have investigated the mechanism by which CS elicits detrimental effects on the immune system and pulmonary function through the use of human and animal subjects. A strong relationship among continued tobacco use, oxidative stress, and exacerbation of COPD symptoms is frequently observed in COPD subjects. In addition, therapeutic approaches emphasizing smoking cessation have been developed, incorporating counseling and nicotine replacement therapy. However, the inability to reverse COPD progression establishes the need for improved preventative and therapeutic strategies, such as a combination of intensive smoking cessation treatment and pharmaceutical therapy, focusing on immune homeostasis and redox balance. CS initiates a complex interplay between oxidative stress and the immune response in COPD. Therefore, multiple approaches such as smoking cessation, counseling, and pharmaceutical therapies targeting inflammation and oxidative stress are recommended for COPD treatment.

TGF-β-activated kinase 1 (TAK1) signaling regulates TGF-β-induced WNT-5A expression in airway smooth muscle cells via Sp1 and β-catenin

WNT-5A, a key player in embryonic development and post-natal homeostasis, has been associated with a myriad of pathological conditions including malignant, fibroproliferative and inflammatory disorders. Previously, we have identified WNT-5A as a transcriptional target of TGF-β in airway smooth muscle cells and demonstrated its function as a mediator of airway remodeling. Here, we investigated the molecular mechanisms underlying TGF-β-induced WNT-5A expression. We show that TGF-β-activated kinase 1 (TAK1) is a critical mediator of WNT-5A expression as its pharmacological inhibition or siRNA-mediated silencing reduced TGF-β induction of WNT-5A. Furthermore, we show that TAK1 engages p38 and c-Jun N-terminal kinase (JNK) signaling which redundantly participates in WNT-5A induction as only simultaneous, but not individual, inhibition of p38 and JNK suppressed TGF-β-induced WNT-5A expression. Remarkably, we demonstrate a central role of β-catenin in TGF-β-induced WNT-5A expression. Regulated by TAK1, β-catenin is required for WNT-5A induction as its silencing repressed WNT-5A expression whereas a constitutively active mutant augmented basal WNT-5A abundance. Furthermore, we identify Sp1 as the transcription factor for WNT-5A and demonstrate its interaction with β-catenin. We discover that Sp1 is recruited to the WNT-5A promoter in a TGF-β-induced and TAK1-regulated manner. Collectively, our findings describe a TAK1-dependent, β-catenin- and Sp1-mediated signaling cascade activated downstream of TGF-β which regulates WNT-5A induction.

An ethyl acetate fraction of Moringa oleifera Lam. Inhibits human macrophage cytokine production induced by cigarette smoke

Moringa oleifera Lam. (MO) has been reported to harbor anti-oxidation and anti-inflammatory activity and useful in the treatment of inflammatory diseases. However, despite these findings there has been little work done on the effects of MO on immune cellular function. Since macrophages, TNF and related cytokines play an important pathophysiologic role in lung damage induced by cigarette smoke, we examined the effects of MO on cigarette smoke extract (CSE)-induced cytokine production by human macrophages. An ethyl acetate fraction of MO (MOEF) was prepared from fresh leaves extract of Moringa and shown to consist of high levels of phenolic and antioxidant activities. Human monocyte derived macrophages (MDM) pre-treated with varying concentrations of MOEF showed decreased production of TNF, IL-6 and IL-8 in response to both LPS and CSE. The decrease was evident at both cytokine protein and mRNA levels. Furthermore, the extract inhibited the expression of RelA, a gene implicated in the NF-κB p65 signaling in inflammation. The findings highlight the ability of MOEF to inhibit cytokines (IL-8) which promote the infiltration of neutrophils into the lungs and others (TNF, IL-6) which mediate tissue disease and damage.