TLR2 ligand engagement upregulates airway smooth muscle TNFα-induced cytokine production

2012 ◽  
Vol 302 (9) ◽  
pp. L838-L845 ◽  
Author(s):  
Melanie Manetsch ◽  
Petra Seidel ◽  
Udo Heintz ◽  
Wenchi Che ◽  
J. Margaret Hughes ◽  
...  

Airway inflammation and respiratory infections are important factors contributing to disease exacerbation in chronic airway diseases such as asthma and chronic obstructive pulmonary disease. Airway smooth muscle (ASM) cells express Toll-like receptors (TLRs) and may be involved in the amplification of airway inflammatory responses during infectious exacerbations. We determined whether infectious stimuli (mimicked using Pam3CSK4, a synthetic bacterial lipopeptide that binds to TLR2/TLR1) further enhance ASM cell inflammatory responses to TNFα in vitro and the signaling pathways involved. Human ASM cells were pretreated for 1 h with Pam3CSK4 (1 μg/ml) in the absence or presence of TNFα (10 ng/ml), and IL-6 and IL-8 release was measured after 24 h. As expected, stimulation with Pam3CSK4 or TNFα alone induced significant IL-6 and IL-8 release. Furthermore, Pam3CSK4 significantly increased TNFα-induced IL-6 and IL-8 mRNA expression and protein release and neutrophil chemotactic activity. The potentiating effect of Pam3CSK4 on TNFα-induced inflammatory responses was not due to enhanced TLR2 expression nor did it involve augmentation of NF-κB or MAPK signaling pathways. Rather, Pam3CSK4 induced cAMP response element (CRE) binding protein phosphorylation and induced CRE-mediated transcriptional regulation, suggesting that Pam3CSK4 and TNFα are acting in concert to enhance ASM cytokine secretion via parallel transcriptional pathways. Our findings suggest that ASM cells may be involved in the amplification of airway inflammatory responses during infectious exacerbations in chronic airway disease.

2016 ◽  
Vol 311 (5) ◽  
pp. L893-L902 ◽  
Author(s):  
Yidi Wu ◽  
Youliang Huang ◽  
Susan J. Gunst

The effects of mechanical forces and focal adhesion kinase (FAK) in regulating the inflammatory responses of airway smooth muscle (ASM) tissues to stimulation with interleukin (IL)-13 were investigated. Canine tracheal tissues were subjected to different mechanical loads in vitro, and the effects of mechanical load on eotaxin secretion and inflammatory signaling pathways in response to IL-13 were determined. Eotaxin secretion by tissues in response to IL-13 was significantly inhibited in muscles maintained at a higher (+) load compared with those at a lower (−) load as assessed by ELISA, and Akt activation was also reduced in the higher (+) loaded tissues. Conversely the (+) mechanical load increased activation of the focal adhesion proteins FAK and paxillin in the tissues. The role of FAK in regulating the mechanosensitive responses was assessed by overexpressing FAK-related nonkinase in the tissues, by expressing the FAK kinase-dead mutant FAK Y397F, or by treating tissues with the FAK inhibitor PF-573228. FAK inactivation potentiated Akt activity and increased eotaxin secretion in response to IL-13. FAK inhibition also suppressed the mechanosensitivity of Akt activation and eotaxin secretion. In addition, FAK inactivation suppressed smooth muscle myosin heavy chain expression induced by the higher (+) mechanical load. The results demonstrate that the imposition of a higher mechanical load on airway smooth muscle stimulates FAK activation, which promotes the expression of the differentiated contractile phenotype and suppresses the synthetic phenotype and the inflammatory responses of the muscle tissue.


Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1193 ◽  
Author(s):  
Liang Chen ◽  
Chun Hu ◽  
Molly Hood ◽  
Xue Zhang ◽  
Lu Zhang ◽  
...  

Novel coronaviruses (CoV) have emerged periodically around the world in recent years. The recurrent spreading of CoVs imposes an ongoing threat to global health and the economy. Since no specific therapy for these CoVs is available, any beneficial approach (including nutritional and dietary approach) is worth investigation. Based on recent advances in nutrients and phytonutrients research, a novel combination of vitamin C, curcumin and glycyrrhizic acid (VCG Plus) was developed that has potential against CoV infection. System biology tools were applied to explore the potential of VCG Plus in modulating targets and pathways relevant to immune and inflammation responses. Gene target acquisition, gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment were conducted consecutively along with network analysis. The results show that VCG Plus can act on 88 hub targets which are closely connected and associated with immune and inflammatory responses. Specifically, VCG Plus has the potential to regulate innate immune response by acting on NOD-like and Toll-like signaling pathways to promote interferons production, activate and balance T-cells, and regulate the inflammatory response by inhibiting PI3K/AKT, NF-κB and MAPK signaling pathways. All these biological processes and pathways have been well documented in CoV infections studies. Therefore, our findings suggest that VCG Plus may be helpful in regulating immune response to combat CoV infections and inhibit excessive inflammatory responses to prevent the onset of cytokine storm. However, further in vitro and in vivo experiments are warranted to validate the current findings with system biology tools. Our current approach provides a new strategy in predicting formulation rationale when developing new dietary supplements.


2011 ◽  
Vol 300 (2) ◽  
pp. L295-L304 ◽  
Author(s):  
Charalambos Michaeloudes ◽  
Maria B. Sukkar ◽  
Nadia M. Khorasani ◽  
Pankaj K. Bhavsar ◽  
Kian Fan Chung

Reactive oxygen species (ROS) are generated as a result of normal cellular metabolism, mainly through the mitochondria and peroxisomes, but their release is enhanced by the activation of oxidant enzymes such as NADPH oxidases or downregulation of endogenous antioxidant enzymes such as manganese-superoxide dismutase (MnSOD) and catalase. Transforming growth factor-β (TGF-β), found to be overexpressed in airway smooth muscle (ASM) from asthmatic and chronic obstructive pulmonary disease patients, may be a pivotal regulator of abnormal ASM cell (ASMC) function in these diseases. An important effect of TGF-β on ASMC inflammatory responses is the induction of IL-6 release. TGF-β also triggers intracellular ROS release in ASMCs by upregulation of NADPH oxidase 4 (Nox4). However, the effect of TGF-β on the expression of key antioxidant enzymes and subsequently on oxidant/antioxidant balance is unknown. Moreover, the role of redox-dependent pathways in the mediation of the proinflammatory effects of TGF-β in ASMCs is unclear. In this study, we show that TGF-β induced the expression of Nox4 while at the same time inhibiting the expression of MnSOD and catalase. This change in oxidant/antioxidant enzymes was accompanied by elevated ROS levels and IL-6 release. Further studies revealed a role for Smad3 and phosphatidyl-inositol kinase-mediated pathways in the induction of oxidant/antioxidant imbalance and IL-6 release. The changes in oxidant/antioxidant enzymes and IL-6 release were reversed by the antioxidants N-acetyl-cysteine (NAC) and ebselen through inhibition of Smad3 phosphorylation, indicating redox-dependent activation of Smad3 by TGF-β. Moreover, these findings suggest a potential role for NAC in preventing TGF-β-mediated pro-oxidant and proinflammatory responses in ASMCs. Knockdown of Nox4 using small interfering RNA partially prevented the inhibition of MnSOD but had no effect on catalase and IL-6 expression. These findings provide novel insights into redox regulation of ASM function by TGF-β.


Author(s):  
Hua Luo ◽  
Chi Teng Vong ◽  
Dechao Tan ◽  
Jinming Zhang ◽  
Hua Yu ◽  
...  

Panax notoginseng saponins (PNS) are the main active ingredients of Panax notoginseng (Burk) F. H. Chen, which are used as traditional Chinese medicine for thousands of years and have various clinical effects, including anti-inflammation, anti-oxidation, and cardiovascular protection. Inflammatory bowel disease (IBD) is a complex gastrointestinal inflammatory disease that cannot be cured completely nowadays. The anti-inflammatory and protective effects of PNS were analyzed in vitro and in dextran sulfate sodium (DSS)-induced colitis mouse model. PNS inhibited the release of nitric oxide (NO), tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text], interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) in Pam3CSK4-induced RAW 264.7 macrophages. In the animal study, compared with DSS-induced mice, PNS reduced the expression of pro-inflammatory cytokines (TNF-[Formula: see text], IL-6, and MCP-1) in the colon tissues. Furthermore, PNS treatment led to a remarkable reduction in the activation of the inhibitor of nuclear factor kappa-B kinase [Formula: see text]/[Formula: see text] (IKK[Formula: see text]/[Formula: see text], I[Formula: see text]B[Formula: see text] and p65 induced by DSS. On the other hand, PNS inhibited the phosphorylation of c-Jun N-terminal kinase (JNK), p38, and extracellular regulated protein kinase 1/2 (ERK1/2). Taken together, our results suggested that PNS conferred profound protection for colitis mice through the downregulation of mitogen-activated protein kinase (MAPK) and NF-[Formula: see text]B signaling pathways, which were associated with reducing inflammatory responses, alleviating tissue damage, and maintaining of intestinal integrity and functionality.


2012 ◽  
Vol 302 (3) ◽  
pp. L325-L333 ◽  
Author(s):  
Yukikazu Ichimaru ◽  
David I. Krimmer ◽  
Janette K. Burgess ◽  
Judith L. Black ◽  
Brian G. G. Oliver

Chronic obstructive pulmonary disease (COPD) and asthma are characterized by irreversible remodeling of the airway walls, including thickening of the airway smooth muscle layer. Perlecan is a large, multidomain, proteoglycan that is expressed in the lungs, and in other organ systems, and has been described to have a role in cell adhesion, angiogenesis, and proliferation. This study aimed to investigate functional properties of the different perlecan domains in relation to airway smooth muscle cells (ASMC). Primary human ASMC obtained from donors with asthma ( n = 13), COPD ( n = 12), or other lung disease ( n = 20) were stimulated in vitro with 1 ng/ml transforming growth factor-β1 (TGF-β1) before perlecan deposition and cytokine release were analyzed. In some experiments, inhibitors of signaling molecules were added. Perlecan domains I–V were seeded on tissue culture plates at 10 μg/ml with 1 μg/ml collagen I as a control. ASM was incubated on top of the peptides before being analyzed for attachment, proliferation, and wound healing. TGF-β1 upregulated deposition of perlecan by ASMC from COPD subjects only. TGF-β1 upregulated release of IL-6 into the supernatant of ASMC from all subjects. Inhibitors of SMAD and JNK signaling molecules decreased TGF-β1-induced perlecan deposition by COPD ASMC. Attachment of COPD ASMC was upregulated by collagen I and perlecan domains IV and V, while perlecan domain II upregulated attachment only of asthmatic ASMC. Seeding on perlecan domains did not increase proliferation of any ASMC type. TGF-β1-induced perlecan deposition may enhance attachment of migrating ASMC in vivo and thus may be a mechanism for ASMC layer hypertrophy in COPD.


2018 ◽  
Vol 132 (14) ◽  
pp. 1615-1627 ◽  
Author(s):  
Mathew S. Eapen ◽  
Anudeep Kota ◽  
Howard Vindin ◽  
Kielan D. McAlinden ◽  
Dia Xenaki ◽  
...  

Increased airway smooth muscle (ASM) mass is observed in chronic obstructive pulmonary disease (COPD), which is correlated with disease severity and negatively affects lung function in these patients. Thus, there is clear unmet clinical need for finding new therapies which can target airway remodeling and disease progression in COPD. Apoptosis signal-regulating kinase 1 (ASK1) is a ubiquitously expressed mitogen-activated protein kinase (MAPK) kinase kinase (MAP3K) activated by various stress stimuli, including reactive oxygen species (ROS), tumor necrosis factor (TNF)-α, and lipopolysaccharide (LPS) and is known to regulate cell proliferation. ASM cells from COPD patients are hyperproliferative to mitogens in vitro. However, the role of ASK1 in ASM growth is not established. Here, we aim to determine the effects of ASK1 inhibition on ASM growth and pro-mitogenic signaling using ASM cells from COPD patients. We found greater expression of ASK1 in ASM bundles of COPD lung when compared with non-COPD. Pre-treatment of ASM cells with highly selective ASK1 inhibitor, TC ASK 10 resulted in a dose-dependent reduction in mitogen (FBS, PDGF, and EGF; 72 h)-induced ASM growth as measured by CyQUANT assay. Further, molecular targetting of ASK1 using siRNA in ASM cells prevented mitogen-induced cell growth. In addition, to anti-mitogenic potential, ASK1 inhibitor also prevented TGFβ1-induced migration of ASM cells in vitro. Immunoblotting revealed that anti-mitogenic effects are mediated by C-Jun N-terminal kinase (JNK) and p38MAP kinase-signaling pathways as evident by reduced phosphorylation of downstream effectors JNK1/2 and p38MAP kinases, respectively, with no effect on extracellular signal-regulated kinase (ERK) 1/2 (ERK1/2). Collectively, these findings establish the anti-mitogenic effect of ASK1 inhibition and identify a novel pathway that can be targetted to reduce or prevent excessive ASM mass in COPD.


2015 ◽  
Vol 308 (8) ◽  
pp. L766-L775 ◽  
Author(s):  
Wilfred J. Poppinga ◽  
Irene H. Heijink ◽  
Laura J. Holtzer ◽  
Philipp Skroblin ◽  
Enno Klussmann ◽  
...  

β2-Agonist inhibitors can relieve chronic obstructive pulmonary disease (COPD) symptoms by stimulating cyclic AMP (cAMP) signaling. A-kinase-anchoring proteins (AKAPs) compartmentalize cAMP signaling by establishing protein complexes. We previously reported that the β2-agonist fenoterol, direct activation of protein kinase A (PKA), and exchange factor directly activated by cAMP decrease cigarette smoke extract (CSE)-induced release of neutrophil attractant interleukin-8 (IL-8) from human airway smooth muscle (ASM) cells. In the present study, we tested the role of AKAPs in CSE-induced IL-8 release from ASM cells and assessed the effect of CSE on the expression levels of different AKAPs. We also studied mRNA and protein expression of AKAPs in lung tissue from patients with COPD. Our data show that CSE exposure of ASM cells decreases AKAP5 and AKAP12, both capable of interacting with β2-adrenoceptors. In lung tissue of patients with COPD, mRNA levels of AKAP5 and AKAP12 were decreased compared with lung tissue from controls. Using immunohistochemistry, we detected less AKAP5 protein in ASM of patients with COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II compared with control subjects. St-Ht31, which disrupts AKAP-PKA interactions, augmented CSE-induced IL-8 release from ASM cells and diminished its suppression by fenoterol, an effect mediated by disturbed ERK signaling. The modulatory role of AKAP-PKA interactions in the anti-inflammatory effects of fenoterol in ASM cells and the decrease in expression of AKAP5 and AKAP12 in response to cigarette smoke and in lungs of patients with COPD suggest that cigarette smoke-induced changes in AKAP5 and AKAP12 in patients with COPD may affect efficacy of pharmacotherapy.


2016 ◽  
Vol 310 (2) ◽  
pp. L202-L211 ◽  
Author(s):  
Arij Faksh ◽  
Rodney D. Britt ◽  
Elizabeth R. Vogel ◽  
Michael A. Thompson ◽  
Hitesh C. Pandya ◽  
...  

Viral infections, such as respiratory syncytial virus and rhinovirus, adversely affect neonatal and pediatric populations, resulting in significant lung morbidity, including acute asthma exacerbation. Studies in adults have demonstrated that human airway smooth muscle (ASM) cells modulate inflammation through their ability to secrete inflammatory cytokines and chemokines. The role of ASM in the developing airway during infection remains undefined. In our study, we used human fetal ASM cells as an in vitro model to examine the effect of Toll-like receptor (TLR) agonists on chemokine secretion. We found that fetal ASM express multiple TLRs, including TLR3 and TLR4, which are implicated in the pathogenesis of respiratory syncytial virus and rhinovirus infection. Cells were treated with TLR agonists, polyinosinic-polycytidylic acid [poly(I:C)] (TLR3 agonist), lipopolysaccharide (TLR4 agonist), or R848 (TLR7/8 agonist), and IL-8 and chemokine (C-C motif) ligand 5 (CCL5) secretion were evaluated. Interestingly, poly(I:C), but neither lipopolysaccharide nor R848, increased IL-8 and chemokine (C-C motif) ligand 5 secretion. Examination of signaling pathways suggested that the poly(I:C) effects in fetal ASM involve TLR and ERK signaling, in addition to another major inflammatory pathway, NF-κB. Moreover, there are variations between fetal and adult ASM with respect to poly(I:C) effects on signaling pathways. Pharmacological inhibition suggested that ERK pathways mediate poly(I:C) effects. Overall, our data show that poly(I:C) initiates activation of proinflammatory pathways in developing ASM, which may contribute to immune responses to infection and exacerbation of asthma.


2013 ◽  
Vol 305 (5) ◽  
pp. L396-L403 ◽  
Author(s):  
Elizabeth A. Townsend ◽  
Charles W. Emala

Asthma is a disease of the airways with symptoms including exaggerated airway narrowing and airway inflammation. Early asthma therapies used methylxanthines to relieve symptoms, in part, by inhibiting cyclic nucleotide phosphodiesterases (PDEs), the enzyme responsible for degrading cAMP. The classification of tissue-specific PDE subtypes and the clinical introduction of PDE-selective inhibitors for chronic obstructive pulmonary disease (i.e., roflumilast) have reopened the possibility of using PDE inhibition in the treatment of asthma. Quercetin is a naturally derived PDE4-selective inhibitor found in fruits, vegetables, and tea. We hypothesized that quercetin relaxes airway smooth muscle via cAMP-mediated pathways and augments β-agonist relaxation. Tracheal rings from male A/J mice were mounted in myographs and contracted with acetylcholine (ACh). Addition of quercetin (100 nM-1 mM) acutely and concentration-dependently relaxed airway rings precontracted with ACh. In separate studies, pretreatment with quercetin (100 μM) prevented force generation upon exposure to ACh. In additional studies, quercetin (50 μM) significantly potentiated isoproterenol-induced relaxations. In in vitro assays, quercetin directly attenuated phospholipase C activity, decreased inositol phosphate synthesis, and decreased intracellular calcium responses to Gq-coupled agonists (histamine or bradykinin). Finally, nebulization of quercetin (100 μM) in an in vivo model of airway responsiveness significantly attenuated methacholine-induced increases in airway resistance. These novel data show that the natural PDE4-selective inhibitor quercetin may provide therapeutic relief of asthma symptoms and decrease reliance on short-acting β-agonists.


Sign in / Sign up

Export Citation Format

Share Document