scholarly journals Persistent Airflow Obstruction: A Marker of a Severe Asthma Cohort – Inflammatory, Functional and Pathological Features

Author(s):  
Regina Maria Carvalho-Pinto ◽  
Rodrigo Abensur Athanazio ◽  
Diogenes Seraphin Ferreira ◽  
Thais Mauad ◽  
Marisa Dolhnikoff ◽  
...  

Abstract In our previous severe asthma cohort, 82% had fixed obstruction. Although they had greater airway smooth muscle area with decreased periostin, inflammation and remodeling weren’t associated with symptom control. High-resolution computed tomography (HRCT) and measures of small airways could be important tools for exploring asthma severity. Our aim was to describe characteristics associated to airflow obstruction in our non-controlled severe asthmatics according to obstruction profile. Persistent obstruction subgroups were also evaluated comparing disease severity. Methods: Patients were evaluated using asthma control questionnaire, induced sputum, spirometry, plethysmography, and Single Breath N2 washout test, at baseline, after oral corticosteroid (OC) and at the end of the treatment. They also underwent thorax HRCT and bronchoscopy with endobronchial biopsy.Results: Sixty-two were included and 77.4% classified as having persistent obstruction; 75% and 25% with moderate and severe obstruction, respectively. Pulmonary function values (FEV1) improved in both subgroups, except in severe. Patients with bronchial thickening, according to RB1 WA% and pi10, had significantly higher airway smooth muscle area.Conclusion: Patients with severe obstruction had greater lung function impairment, no response to OC or bronchodilator. This could be explained by airway remodeling characterized by higher airway smooth muscle area and bronchial thickness assessed by thorax HRCT.

2012 ◽  
Vol 302 (8) ◽  
pp. L736-L745 ◽  
Author(s):  
Harry Karmouty-Quintana ◽  
Sana Siddiqui ◽  
Muhannad Hassan ◽  
Kimitake Tsuchiya ◽  
Paul-Andre Risse ◽  
...  

Sphingosine-1-phosphate (S1P) is an immunomodulatory lipid mediator that plays an important role in lymphocyte trafficking. Elevated levels of S1P are found in bronchoalveolar lavage (BAL) fluid of patients with asthma; however, its role in disease is not known. FTY720, a synthetic analog of S1P, has been shown to abrogate allergic inflammation and airway hyperresponsiveness following acute allergen challenge. However, its effects on asthmatic airway remodeling induced by repeated allergen exposure are unknown. Ovalbumin (OVA)-sensitized rats were challenged on days 14, 19, and 24 after sensitization. FTY720 or vehicle (PBS) therapy was administered 1 h prior to each challenge. BAL fluid and quantitative histological analysis were performed 48 h after the last challenge. FTY720 inhibited OVA-induced features of airway remodeling including increased airway smooth muscle mass and bronchial neovascularization, without affecting lymphocyte numbers in secondary lymphoid organs. Furthermore, CD3+ cells adjacent to airway smooth muscle bundles were increased in OVA-challenged rats but the increase was inhibited by FTY720. There was an expansion of bronchus-associated lymphoid tissue following FTY720 treatment of OVA-challenged animals. Real-time quantitative PCR revealed that Th2-associated transcription factors were inhibited following FTY720 therapy. Airway remodeling is a cardinal feature of severe asthma. These results demonstrate that allergen-driven airway remodeling can be inhibited by FTY720, offering potential new therapies for the treatment of severe asthma.


2019 ◽  
Vol 316 (5) ◽  
pp. L843-L868 ◽  
Author(s):  
Jon M. Evasovic ◽  
Cherie A. Singer

Severe asthma develops as a result of heightened, persistent symptoms that generally coincide with pronounced neutrophilic airway inflammation. In individuals with severe asthma, symptoms are poorly controlled by high-dose inhaled glucocorticoids and often lead to elevated morbidity and mortality rates that underscore the necessity for novel drug target identification that overcomes limitations in disease management. Many incidences of severe asthma are mechanistically associated with T helper 17 (TH17) cell-derived cytokines and immune factors that mediate neutrophilic influx to the airways. TH17-secreted interleukin-17A (IL-17A) is an independent risk factor for severe asthma that impacts airway smooth muscle (ASM) remodeling. TH17-derived cytokines and diverse immune mediators further interact with structural cells of the airway to induce pathophysiological processes that impact ASM functionality. Transforming growth factor-β1 (TGF-β1) is a pivotal mediator involved in airway remodeling that correlates with enhanced TH17 activity in individuals with severe asthma and is essential to TH17 differentiation and IL-17A production. IL-17A can also reciprocally enhance activation of TGF-β1 signaling pathways, whereas combined TH1/TH17 or TH2/TH17 immune responses may additively impact asthma severity. This review seeks to provide a comprehensive summary of cytokine-driven T cell fate determination and TH17-mediated airway inflammation. It will further review the evidence demonstrating the extent to which IL-17A interacts with various immune factors, specifically TGF-β1, to contribute to ASM remodeling and altered function in TH17-driven endotypes of severe asthma.


Author(s):  
Elvedin Lukovic ◽  
Jose F Perez-Zoghbi ◽  
Yi Zhang ◽  
Yingdong Zhu ◽  
Shengmin Sang ◽  
...  

Asthma affects millions of people worldwide and its prevalence is increasing. It is characterized by chronic airway inflammation, airway remodeling, and pathologic bronchoconstriction, and it poses a continuous treatment challenge with very few new therapeutics available. Thus, many asthmatics turn to plant-based complementary products, including ginger, for better symptom control, indicating an unmet needed for novel therapies. Previously, we demonstrated that 6-shogaol (6S), the primary bioactive component of ginger, relaxes human airway smooth muscle (hASM) likely by inhibition of phosphodiesterases (PDEs) in the b-adrenergic (cyclic nucleotide PDEs) and muscarinic (phospholipase C, PLC) receptor pathways. However, oral 6S is extensively metabolized and it is unknown if the resulting metabolites remain bioactive. Here we screened all the known human metabolites of 6S and several metabolite-based synthetic derivatives to better understand their mechanism of action and structure-function relationships. We demonstrate that several metabolites and metabolite-based synthetic derivatives are able to prevent Gq-coupled stimulation of intracellular calcium [Ca2+]i and inositol triphosphate (IP3) synthesis by inhibiting PLC, similar to the parent compound 6S. We also show that these compounds prevent re-contraction of ASM after b-agonist relaxation likely by inhibiting PDEs. Furthermore, they potentiate isoproterenol-induced relaxation. Importantly, moving beyond cell-based assays, metabolites also retain the functional ability to relax Gq-coupled-contractions in upper (human) and lower (murine) airways. The current study indicates that, although oral ginger may be metabolized rapidly, it retains physiologic activity through its metabolites. Moreover, we are able to use naturally occurring metabolites as inspiration to develop novel therapeutics for brochoconstrictive diseases.


2021 ◽  
pp. 2100622
Author(s):  
Nicholas Jendzjowsky ◽  
Austin Laing ◽  
Michelle Malig ◽  
John Matyas ◽  
Elaine de Heuvel ◽  
...  

RationaleBronchial thermoplasty is a mechanical therapeutic intervention that has been advocated as an effective treatment option for severe asthma. The mechanism is promoted as being related to the attenuation of airway smooth muscle which has been shown to occur in the short-term. However, long-term studies of the effects of bronchial thermoplasty on airway remodeling are few with only limited assessment of airway remodeling indices.ObjectivesTo evaluate the effect of bronchial thermoplasty on (a) airway epithelial and smooth muscle cells in culture, and (b), airway remodeling in patients with severe asthma who have been prescribed bronchial thermoplasty up to 12-months post-treatment.MethodsThe distribution of heat within the airway by bronchial thermoplasty was assessed in a porcine model. Culture of human airway smooth muscle cells and bronchial epithelial cells evaluated the impact of thermal injury. Histological evaluation and morphometric assessment were performed on bronchial biopsies obtained from severe asthma patients at baseline, 6-weeks, and 12-months following bronchial thermoplasty.ResultsBronchial thermoplasty resulted in heterogenous heating of the airway wall. Airway smooth muscle cell cultures sustained thermal injury, whilst bronchial epithelial cells were relatively resistant to heat. Airway smooth muscle and neural bundles were significantly reduced at 6-weeks and 12-months post-treatment. At 6-weeks post treatment, submucosal collagen was reduced, and vessel density increased, with both indices returning to baseline at 12-months. Goblet cell numbers, submucosal gland area and subbasement membrane thickness, were not significantly altered at any timepoint examined.ConclusionsBronchial thermoplasty primarily affects airway smooth muscle and nerves with the effects still present at 12-months post-treatment.


2011 ◽  
Vol 111 (6) ◽  
pp. 1760-1767 ◽  
Author(s):  
Elizabeth L. Kramer ◽  
William D. Hardie ◽  
Elizabeth M. Mushaben ◽  
Thomas H. Acciani ◽  
Patricia A. Pastura ◽  
...  

Airway hyperreactivity (AHR) and remodeling are cardinal features of asthma and chronic obstructive pulmonary disease. New therapeutic targets are needed as some patients are refractory to current therapies and develop progressive airway remodeling and worsening AHR. The mammalian target of rapamycin (mTOR) is a key regulator of cellular proliferation and survival. Treatment with the mTOR inhibitor rapamycin inhibits inflammation and AHR in allergic asthma models, but it is unclear if rapamycin can directly inhibit airway remodeling and AHR, or whether its therapeutic effects are entirely mediated through immunosuppression. To address this question, we utilized transforming growth factor-α (TGF-α) transgenic mice null for the transcription factor early growth response-1 (Egr-1) (TGF-α Tg/Egr-1ko/ko mice). These mice develop airway smooth muscle thickening and AHR in the absence of altered lung inflammation, as previously reported. In this study, TGF-α Tg/Egr-1ko/ko mice lost body weight and developed severe AHR after 3 wk of lung-specific TGF-α induction. Rapamycin treatment prevented body weight loss, airway wall thickening, abnormal lung mechanics, and increases in airway resistance to methacholine after 3 wk of TGF-α induction. Increases in tissue damping and airway elastance were also attenuated in transgenic mice treated with rapamycin. TGF-α/Egr-1ko/ko mice on doxycycline for 8 wk developed severe airway remodeling. Immunostaining for α-smooth muscle actin and morphometric analysis showed that rapamycin treatment prevented airway smooth muscle thickening around small airways. Pentachrome staining, assessments of lung collagen and fibronectin mRNA levels, indicated that rapamycin also attenuated fibrotic pathways induced by TGF-α expression for 8 wk. Thus rapamycin reduced airway remodeling and AHR, demonstrating an important role for mTOR signaling in TGF-α-induced/EGF receptor-mediated reactive airway disease.


2003 ◽  
Vol 284 (6) ◽  
pp. L1020-L1026 ◽  
Author(s):  
Stephen M. Carlin ◽  
Michael Roth ◽  
Judith L. Black

We investigated the chemotactic action of PDGF and urokinase on human airway smooth muscle (HASM) cells in culture. Cells were put in collagen-coated transwells with 8-μm perforations, incubated for 4 h with test compounds, then fixed, stained, and counted as migrated nuclei by microscopy. Cells from all culture conditions showed some basal migration (migration in the absence of stimuli during the assay), but cells preincubated for 24 h in 10% FBS or 20 ng/ml PDGF showed higher basal migration than cells quiesced in 1% FBS. PDGFBB, PDGFAA, and PDGFABwere all chemotactic when added during the assay. PDGF chemotaxis was blocked by the phosphatidyl 3′-kinase inhibitor LY-294002, the MEK inhibitor U-0126, PGE2, formoterol, pertussis toxin, and the Rho kinase inhibitor Y-27632. Urokinase alone had no stimulatory effect on migration of quiescent cells but caused a dose-dependent potentiation of chemotaxis toward PDGF. Urokinase also potentiated the elevated basal migration of cells pretreated in 10% FBS or PDGF. This potentiating effect of urokinase appears to be novel. We conclude that PDGF and similar cytokines may be important factors in airway remodeling by redistribution of smooth muscle cells during inflammation and that urokinase may be important in potentiating the response.


2007 ◽  
Vol 293 (5) ◽  
pp. L1194-L1207 ◽  
Author(s):  
Sonemany Salinthone ◽  
Mariam Ba ◽  
Lisa Hanson ◽  
Jody L. Martin ◽  
Andrew J. Halayko ◽  
...  

Airway smooth muscle (ASM) hypertrophy and hyperplasia are characteristics of asthma that lead to thickening of the airway wall and obstruction of airflow. Very little is known about mechanisms underlying ASM remodeling, but in vascular smooth muscle, it is known that progression of atherosclerosis depends on the balance of myocyte proliferation and cell death. Small heat shock protein 27 (Hsp27) is antiapoptotic in nonmuscle cells, but its role in ASM cell survival is unknown. Our hypothesis was that phosphorylation of Hsp27 may regulate airway remodeling by modifying proliferation, cell survival, or both. To test this hypothesis, adenoviral vectors were used to overexpress human Hsp27 in ASM cells. Cells were infected with empty vector (Ad5) or wild-type Hsp27 (AdHsp27 WT), and proliferation and death were assessed. Overexpressing Hsp27 WT caused a 50% reduction in serum-induced proliferation and increased cell survival after exposure to 100 μM hydrogen peroxide (H2O2) compared with mock-infected controls. Overexpression studies utilizing an S15A, S78A, and S82A non-phosphorylation mutant (AdHsp27 3A) and an S15D, S78D, and S82D pseudo-phosphorylation mutant (AdHsp27 3D) showed phosphorylation of Hsp27 was necessary for regulation of ASM proliferation, but not survival. Hsp27 provided protection against H2O2-induced cytotoxicity by upregulating cellular glutathione levels and preventing necrotic cell death, but not apoptotic cell death. The results support the notion that ASM cells can be stimulated to undergo proliferation and death and that Hsp27 may regulate these processes, thereby contributing to airway remodeling in asthmatics.


2022 ◽  
Vol 50 (1) ◽  
pp. 92-98
Author(s):  
Zhongxiang Fan ◽  
Dan Tang ◽  
Qiang Wu ◽  
Qun Huang ◽  
Jie Song ◽  
...  

Background: Asthma is a common chronic inflammatory disease of the airway, and airway remodeling and the proliferation mechanism of airway smooth muscle cells (ASMCs) is of great significance to combat this disease.Objective: To assess possible effects of scopoletin on asthma and the potential signaling pathway.Materials and methods: ASMCs were treated PDGF-BB and scopoletin and subjected to cell viability detection by CCK-8 assay. Cell migration of ASMCs was determined by a wound closure assay and transwell assay. The protein level of MMP2, MMP9, calponin and α-SMA were measured using western blot. The levels of NF-κB signaling pathway were detected by Western blotting.Results: Scopoletin inhibited proliferation of PDGF-BB - induced ASMCs. Also it suppressed the migration and invasion of PDGF-BB - induced ASMCs. We further showed that Scopoletin regulated phenotypic transition of ASMCs. Mechanically, Scopoletin inhibited proliferation and invasion of ASMCs by regulating NF-κB signaling pathway.Conclusions: We therefore thought Scopoletin could serve as a promising drug for the treatment of asthma.


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