Airway Smooth Muscle (ASM) from Caveolin-1 Knockout (Cav-1 KO) Mice Exhibits Gs-Coupled β2-Receptor Hyperresponsiveness In Vitro.

2009 ◽  
Author(s):  
RW Mitchell ◽  
Y Bai ◽  
T Hynes ◽  
S Basu ◽  
MJ Sanderson ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Caveolin 1

Inhibition of dihydropyridine-sensitive calcium entry in hypoxic relaxation of airway smooth muscle

1995 ◽  
Vol 268 (2) ◽  
pp. L201-L206 ◽  
Author(s):  
C. Vannier ◽  
T. L. Croxton ◽  
L. S. Farley ◽  
C. A. Hirshman
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Muscle Tone ◽  
Bay K 8644 ◽  
O2 Concentration ◽  
Voltage Dependent ◽  
Progressive Hypoxia ◽  
Carbamyl Choline

Hypoxia dilates airways in vivo and reduces active tension of airway smooth muscle in vitro. To determine whether hypoxia impairs Ca2+ entry through voltage-dependent channels (VDC), we tested the ability of dihydropyridines to modulate hypoxia-induced relaxation of KCl- and carbamyl choline (carbachol)-contracted porcine bronchi. Carbachol- or KCl-contracted bronchial rings were exposed to progressive hypoxia in the presence or absence of 1 microM BAY K 8644 (an L-type-channel agonist). In separate experiments, rings were contracted with carbachol or KCl, treated with nifedipine (a VDC antagonist), and finally exposed to hypoxia. BAY K 8644 prevented hypoxia-induced relaxation in KCl-contracted bronchi. Nifedipine (10(-5) M) totally relaxed KCl- contracted bronchi. Carbachol-contracted bronchi were only partially relaxed by nifedipine but were completely relaxed when the O2 concentration of the gas was reduced from 95 to 0%. These data indicate that hypoxia can reduce airway smooth muscle tone by limiting entry of Ca2+ through a dihydropyridine-sensitive pathway, but that other mechanisms also contribute to hypoxia-induced relaxation of carbachol-contracted bronchi.

scholarly journals Focal adhesion kinase (FAK) and mechanical stimulation negatively regulate the transition of airway smooth muscle tissues to a synthetic phenotype

2016 ◽  
Vol 311 (5) ◽  
pp. L893-L902 ◽  
Author(s):  
Yidi Wu ◽  
Youliang Huang ◽  
Susan J. Gunst
Keyword(s):  
Smooth Muscle ◽  
Focal Adhesion Kinase ◽  
Airway Smooth Muscle ◽  
Focal Adhesion ◽  
Inflammatory Responses ◽  
Mechanical Load ◽  
Akt Activation ◽  
Lower Load ◽  
Synthetic Phenotype

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.

Evaluation of Airway Smooth Muscle Contractions in Vitro by High-Frequency Ultrasonic Imaging

CHEST Journal ◽  
1992 ◽  
Vol 102 (4) ◽  
pp. 1251-1257 ◽  
Author(s):  
Kunihiko Iizuka ◽  
Kunio Dobashi ◽  
Shinobu Houjou ◽  
Hiromi Sakai ◽  
Kouichi Itoh ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
High Frequency ◽  
Ultrasonic Imaging ◽  
Muscle Contractions ◽  
Smooth Muscle Contractions

scholarly journals MiR-365-3p is Involved in IL17-Mediated Asthma in Mouse Model

2020 ◽  
Author(s):  
Weijia Wang ◽  
Ying Li ◽  
Xiaoyan Qu ◽  
Dong Shang ◽  
Qiaohong Qin ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Target Gene ◽  
Alveolar Epithelial Cells ◽  
Mouse Lung ◽  
Collagen Deposition ◽  
Wild Type ◽  
Sterile Saline ◽  
The Relationship

Abstract BACKGROUND The IL-17 superfamily, which mediates cross-talk between the adaptive and innate immune systems, has been associated with severity of asthma. The role of miRNAs in the disease has been paid much attention. To explore the roles of IL-17 in asthma and the relationship between IL-17 and miRNAs, we used a model of severe asthma driven by chronic respiratory exposure to house dust mite (HDM) exposure in wild type and IL-17KO mice, followed with miRNA profiling assays and analysis.METHODS Male and female C57BL/6 mice (6-8 weeks old) and IL-17KO mice (C57BL/6 background) were exposed to purified HDM extract intranasally for 5 days/week for 5 consecutive weeks. Sterile saline was used as the control. The parameters including airway responsiveness, inflammatory cells in bronchoalveolar lavage fluid (BALF), airway smooth muscle bundle, collagen deposition, and cytokine levels in BALF were examined. The miRNA profile of mouse lung tissue was analyzed by microarray assays. The dysregulation of miRNA related to IL-17 and asthma was validated by qRT-PCR. The in vitro cell culture experiment was performed to confirm the relationship between IL-17 and selected miRNA. The regulation of miRNA on predicted target gene was validated by administration of miRNA mimics. RESULTS The expression of IL-17A significantly increased in wild type (WT) mice with HDM exposure compared to the control mice. IL-17 deficiency did not reduce airway hyper responsiveness (AHR) induced by HDM exposure. In comparison to HDM-exposed WT mice, BALF neutrophils in IL-17KO mice were significantly decreased. In WT mice, HDM exposure led to increased expression of IL-4 and KC, which was significantly decreased in IL-17KO mice. Furthermore, under HDM exposure, significantly less airway smooth muscle mass and collagen deposition was found in IL-17KO mice compared to WT mice. In the dysregulated miRNAs, the decreased expression of miR-365-3p in HDM-exposed WT mice was validated, and its expression recovered in IL-17KO mice. Furthermore, miR-365-3p was decreased in mouse alveolar epithelial cells by IL-17 treatment. The transfection of miR-365-3p mimics decreased the expression of predicted target gene ARRB2.

scholarly journals In vitro, in silico and in vivo study challenges the impact of bronchial thermoplasty on acute airway smooth muscle mass loss

2018 ◽  
Vol 51 (5) ◽  
pp. 1701680 ◽  
Author(s):  
Igor L. Chernyavsky ◽  
Richard J. Russell ◽  
Ruth M. Saunders ◽  
Gavin E. Morris ◽  
Rachid Berair ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Asthma Control ◽  
Muscle Mass ◽  
Airway Smooth Muscle ◽  
In Silico ◽  
Heat Distribution ◽  
Airway Wall ◽  
Epithelial Integrity

Bronchial thermoplasty is a treatment for asthma. It is currently unclear whether its histopathological impact is sufficiently explained by the proportion of airway wall that is exposed to temperatures necessary to affect cell survival.Airway smooth muscle and bronchial epithelial cells were exposed to media (37–70°C) for 10 s to mimic thermoplasty. In silico we developed a mathematical model of airway heat distribution post-thermoplasty. In vivo we determined airway smooth muscle mass and epithelial integrity pre- and post-thermoplasty in 14 patients with severe asthma.In vitro airway smooth muscle and epithelial cell number decreased significantly following the addition of media heated to ≥65°C. In silico simulations showed a heterogeneous heat distribution that was amplified in larger airways, with <10% of the airway wall heated to >60°C in airways with an inner radius of ∼4 mm. In vivo at 6 weeks post-thermoplasty, there was an improvement in asthma control (measured via Asthma Control Questionnaire-6; mean difference 0.7, 95% CI 0.1–1.3; p=0.03), airway smooth muscle mass decreased (absolute median reduction 5%, interquartile range (IQR) 0–10; p=0.03) and epithelial integrity increased (14%, IQR 6–29; p=0.007). Neither of the latter two outcomes was related to improved asthma control.Integrated in vitro and in silico modelling suggest that the reduction in airway smooth muscle post-thermoplasty cannot be fully explained by acute heating, and nor did this reduction confer a greater improvement in asthma control.

scholarly journals The Strain on Airway Smooth Muscle During a Deep Inspiration to Total Lung Capacity

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Ynuk Bossé
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Total Lung Capacity ◽  
In Vitro Studies ◽  
Deep Inspiration ◽  
Bronchodilator Effect ◽  
Lung Capacity ◽  
Residual Capacity

The deep inspiration (DI) maneuver entices a great deal of interest because of its ability to temporarily ease the flow of air into the lungs. This salutary effect of a DI is proposed to be mediated, at least partially, by momentarily increasing the operating length of airway smooth muscle (ASM). Concerningly, this premise is largely derived from a growing body of in vitro studies investigating the effect of stretching ASM by different magnitudes on its contractility. The relevance of these in vitro findings remains uncertain, as the real range of strains ASM undergoes in vivo during a DI is somewhat elusive. In order to understand the regulation of ASM contractility by a DI and to infer on its putative contribution to the bronchodilator effect of a DI, it is imperative that in vitro studies incorporate levels of strains that are physiologically relevant. This review summarizes the methods that may be used in vivo in humans to estimate the strain experienced by ASM during a DI from functional residual capacity (FRC) to total lung capacity (TLC). The strengths and limitations of each method, as well as the potential confounders, are also discussed. A rough estimated range of ASM strains is provided for the purpose of guiding future in vitro studies that aim at quantifying the regulatory effect of DI on ASM contractility. However, it is emphasized that, owing to the many limitations and confounders, more studies will be needed to reach conclusive statements.

scholarly journals Caveolae from canine airway smooth muscle contain the necessary components for a role in Ca2+ handling

2000 ◽  
Vol 279 (6) ◽  
pp. L1226-L1235 ◽  
Author(s):  
Peter J. Darby ◽  
C. Y. Kwan ◽  
Edwin E. Daniel
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Connexin 43 ◽  
Tracheal Smooth Muscle ◽  
Specific Marker ◽  
Cell Periphery ◽  
Caveolin 1 ◽  
Cytoplasmic Face ◽  
Detergent Treatment ◽  
Trisphosphate Receptor

To explain that bronchial smooth muscle undergoes sustained agonist-induced contractions in a Ca2+-free medium, we hypothesized that caveolae in the plasma membrane (PM) contain protected Ca2+. We isolated caveolae from canine tracheal smooth muscle by detergent treatment of PM-derived microsomes. Detergent-resistant membranes were enriched in caveolin-1, a specific marker for caveolae as well as for L-type Ca2+ channels and Ca2+ binding proteins (calsequestrin and calreticulin) as determined by Western blotting. Also, the PM Ca2+ pump was present but not connexin 43 (a noncaveolae PM protein), the sarcoplasmic reticulum (SR) Ca2+ pump, or the type 1 inositol 1,4,5-trisphosphate receptor, supporting the idea that SR-derived membranes were not present. Antibodies to caveolin coimmunoprecipitated caveolin with calsequestrin or calreticulin. Thus some of the cellular calsequestrin and calreticulin associated with caveolin on the cytoplasmic face of each caveola. Immunohistochemistry of tracheal smooth muscle crysosections confirmed the localization of caveolin and the PM Ca2+ pump to the cell periphery, whereas the SR Ca2+ pump was located deeper in the cell. The presence of L-type Ca2+ channels, the PM Ca2+ pump, and the Ca2+ bindng proteins calsequestrin and calreticulin in caveolin-enriched membranes supports caveola involvement in airway smooth muscle Ca2+ handling.

Sign in / Sign up

Export Citation Format

Share Document