Human rhinovirus induce specific bronchial smooth muscle migration toward bronchial epithelium in severe asthma through the CXCL10/CXCR3 axis

Activation of adenylyl cyclase (AC), of which there are 10 diversely regulated isoforms, is important in regulating pulmonary vascular tone and remodeling. Immunohistochemistry in rat lungs demonstrated that AC2, AC3, and AC5/6 predominated in vascular and bronchial smooth muscle. Isoforms 1, 4, 7, and 8 localized to the bronchial epithelium. Exposure of animals to hypoxia did not change the pattern of isoform expression. RT-PCR confirmed mRNA expression of AC2, AC3, AC5, and AC6 and demonstrated AC7 and AC8 transcripts in smooth muscle. Western blotting confirmed the presence of AC2, AC3, and AC5/6 proteins. Functional studies provided evidence of cAMP regulation by Ca2+ and protein kinase C-activated but not Gi-inhibited pathways, supporting a role for AC2 and a Ca2+-stimulated isoform, AC8. However, NKH-477, an AC5-selective activator, was more potent than forskolin in elevating cAMP and inhibiting serum-stimulated [3H]thymidine incorporation, supporting the presence of AC5. These studies demonstrate differential expression of AC isoforms in rat lungs and provide evidence that AC2, AC5, and AC8 are functionally important in cAMP regulation and growth pathways in pulmonary artery myocytes.

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

ERJ Open Research ◽

10.1183/23120541.00147-2020 ◽

2020 ◽

Vol 6 (4) ◽

pp. 00147-2020

Author(s):

Sangeetha Ramu ◽

Jenny Calvén ◽

Charalambos Michaeloudes ◽

Mandy Menzel ◽

Hamid Akbarshahi ◽

...

Keyword(s):

Smooth Muscle ◽

Severe Asthma ◽

Poly I:C ◽

Healthy Controls ◽

Bronchial Smooth Muscle ◽

Interleukin 33 ◽

Asthma Exacerbations ◽

Gene And Protein Expression ◽

Bronchial Smooth Muscle Cells

BackgroundAsthma 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.MethodBSMCs 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.ResultsRV 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.ConclusionRV 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.

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Human Bronchial Smooth Muscle Cell Lines Show a Hypertrophic Phenotype Typical of Severe Asthma

American Journal of Respiratory and Critical Care Medicine ◽

10.1164/rccm.200307-964oc ◽

2004 ◽

Vol 169 (6) ◽

pp. 703-711 ◽

Cited By ~ 30

Author(s):

Limei Zhou ◽

Jing Li ◽

Adam M. Goldsmith ◽

Dawn C. Newcomb ◽

Diane M. Giannola ◽

...

Keyword(s):

Smooth Muscle ◽

Smooth Muscle Cell ◽

Cell Lines ◽

Severe Asthma ◽

Muscle Cell ◽

Bronchial Smooth Muscle

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Airway β-adrenoceptor number in cystic fibrosis and asthma

Clinical Science ◽

10.1042/cs0780409 ◽

1990 ◽

Vol 78 (4) ◽

pp. 409-417 ◽

Cited By ~ 41

Author(s):

Rajiev K. Sharma ◽

Peter K. Jeffery

Keyword(s):

Cystic Fibrosis ◽

Smooth Muscle ◽

Binding Capacity ◽

Statistical Significance ◽

Bronchial Carcinoma ◽

Bronchial Epithelium ◽

Alveolar Wall ◽

Primary Defect ◽

Bronchial Smooth Muscle ◽

Level 1

1. Maximal binding capacity (Bmax.) and the dissociation constant (KD) for the β-adrenoceptor antagonist 125I-cyanopindol were estimated in membrane preparations of hilar, lobar/main bronchi (level 1) and peripheral lung (level 11) of grossly normal lungs resected for bronchial carcinoma. The tissue distribution of 125I-cyanopindol-binding sites was assessed by autoradiography of complementary cryostat sections. The data obtained from the resections for carcinoma and bronchiectasis were used as disease controls for comparison with those obtained from patients with cystic fibrosis and asthma. 2. In carcinoma controls, mean Bmax. values (± sem) for airway levels 1 and 11 were 89 ± 4 and 133 ± 6 fmol/mg of protein, respectively (P <0.01). The corresponding KD values at each airway level were similar, i.e. 29 ± 2 and 33 ± 1 pmol/l, respectively. Autoradiography revealed that there was dense labelling of bronchial and bronchiolar epithelium and most strikingly of the alveolar wall. 3. Compared with carcinoma controls, mean Bmax. values in cystic fibrosis were significantly reduced in membrane preparations of both airway levels 1 and 11 (P <0.01). Autoradiography showed the reduction was most apparent in alveolar wall and bronchial epithelium. 4. There was a tendency to reduction of Bmax. in membrane preparations from patients with bronchiectasis at airway level I, but this failed to reach statistical significance. Autoradiography demonstrated that the density of labelling was significantly reduced in bronchial epithelium and bronchial smooth muscle as compared with carcinoma controls (P <0.01). 5. The Bmax. values were not significantly altered in membranes prepared from both airway levels in asthma, albeit there was a tendency towards reduction in Bmax. at level 1. At this level autoradiography demonstrated significantly reduced labelling of bronchial epithelium (P>0.01) and submucosal glands (P>0.05) but not of bronchial smooth muscle. 6. It is most likely that the reduction in β-adrenoceptor number that we have found in cystic fibrosis is secondary to pulmonary infection and airway inflammation. Its relationship to the primary defect remains unclear.

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