scholarly journals Characterization of cystic fibrosis airway smooth muscle cell proliferative and contractile activities

2019 ◽  
Vol 317 (5) ◽  
pp. L690-L701
Author(s):  
Joyce Hojin Jang ◽  
Alice Panariti ◽  
Michael J. O’Sullivan ◽  
Melissa Pyrch ◽  
Chris Wong ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Airway Remodeling ◽  
Airway Smooth Muscle Cell ◽  
Cystic Fibrosis Airway ◽  
Contractile Activation ◽  
Pathological Behavior

Cystic fibrosis (CF) is a genetic disease that causes multiple airway abnormalities. Two major respiratory consequences of CF are airway hyperresponsiveness (AHR) and airway remodeling. Airway smooth muscle (ASM) is hypothesized to be responsible for the airway dysfunction, since their thickening is involved in remodeling, and excessive contraction by the ASM may cause AHR. It is unclear whether the ASM is intrinsically altered to favor increased contractility or proliferation or if microenvironmental influences induce pathological behavior in vivo. In this study, we examined the contractile and proliferative properties of ASM cells isolated from healthy donor and CF transplant lungs. Assays of proliferation showed that CF ASM proliferates at a higher rate than healthy cells. Through calcium analysis, no differences in contractile activation in response to histamine were found. However, CF ASM cells lagged in their reuptake of calcium in the sarcoplasmic reticulum. The combination CFTR corrector and potentiator, VX-809/770, used to restore CFTR function in CF ASM, resulted in a reduction in proliferation and in a normalization of calcium reuptake kinetics. These results show that impaired CFTR function in ASM cells causes intrinsic changes in their proliferative and contractile properties.

Characterization of the airway smooth muscle muscarinic receptor in vivo

1991 ◽  
Vol 197 (1-2) ◽  
pp. 109-112 ◽  
Author(s):  
Ralph E. Howell ◽  
Keith Laemont ◽  
Raymond Gaudette ◽  
Maureen Raynor ◽  
Abby Warner ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscarinic Receptor ◽  
Airway Smooth Muscle

Interleukin-8: novel roles in human airway smooth muscle cell contraction and migration

2006 ◽  
Vol 291 (5) ◽  
pp. C957-C965 ◽  
Author(s):  
Vasanthi Govindaraju ◽  
Marie-Claire Michoud ◽  
Mustafa Al-Chalabi ◽  
Pasquale Ferraro ◽  
William S. Powell ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Neutralizing Antibodies ◽  
Airway Remodeling ◽  
Fold Increase ◽  
Airway Smooth Muscle Cell ◽  
Interleukin 8 ◽  
Airway Smooth Muscle Cells ◽  
Cell Contraction ◽  
And Migration

In patients with cystic fibrosis (CF) and asthma, elevated levels of interleukin-8 (IL-8) are found in the airways. IL-8 is a CXC chemokine that is a chemoattractant for neutrophils through CXCR1 and CXCR2 G protein-coupled receptors. We hypothesized that IL-8 acts directly on airway smooth muscle cells (ASMC) in a way that may contribute to the enhanced airway responsiveness and airway remodeling observed in CF and asthma. The aim of this study was to determine whether human ASMC (HASMC) express functional IL-8 receptors (CXCR1 and CXCR2) linked to cell contraction and migration. Experiments were conducted on cells harvested from human lung specimens. Real-time PCR and fluorescence-activated cell sorting analysis showed that HASMC expressed mRNA and protein for both CXCR1 and CXCR2. Intracellular Ca2+ concentration ([Ca2+]i) increased from 115 to 170 nM in response to IL-8 (100 nM) and decreased after inhibition of phospholipase C (PLC) with U-73122. On blocking the receptors with specific neutralizing antibodies, changes in [Ca2+]i were abrogated. IL-8 also contracted the HASMC, decreasing the length of cells by 15%, and induced a 2.5-fold increase in migration. These results indicate that HASMC constitutively express functional CXCR1 and CXCR2 that mediate IL-8-triggered Ca2+ release, contraction, and migration. These data suggest a potential role for IL-8 in causing abnormal airway structure and function in asthma and CF.

scholarly journals Identification and characterization of an atypical Gαs-biased β2AR agonist that fails to evoke airway smooth muscle cell tachyphylaxis

2021 ◽  
Vol 118 (49) ◽  
pp. e2026668118
Author(s):  
Donghwa Kim ◽  
Alina Tokmakova ◽  
Lauren K. Lujan ◽  
Hannah R. Strzelinski ◽  
Nicholas Kim ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Chemical Space ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Airway Smooth Muscle Cell ◽  
Functional Studies ◽  
G Protein Coupled ◽  
Identification And Characterization

G protein–coupled receptors display multifunctional signaling, offering the potential for agonist structures to promote conformational selectivity for biased outputs. For β2-adrenergic receptors (β2AR), unbiased agonists stabilize conformation(s) that evoke coupling to Gαs (cyclic adenosine monophosphate [cAMP] production/human airway smooth muscle [HASM] cell relaxation) and β-arrestin engagement, the latter acting to quench Gαs signaling, contributing to receptor desensitization/tachyphylaxis. We screened a 40-million-compound scaffold ranking library, revealing unanticipated agonists with dihydroimidazolyl-butyl-cyclic urea scaffolds. The S-stereoisomer of compound C1 shows no detectable β-arrestin engagement/signaling by four methods. However, C1-S retained Gαs signaling—a divergence of the outputs favorable for treating asthma. Functional studies with two models confirmed the biasing: β2AR-mediated cAMP signaling underwent desensitization to the unbiased agonist albuterol but not to C1-S, and desensitization of HASM cell relaxation was observed with albuterol but not with C1-S. These HASM results indicate biologically pertinent biasing of C1-S, in the context of the relevant physiologic response, in the human cell type of interest. Thus, C1-S was apparently strongly biased away from β-arrestin, in contrast to albuterol and C5-S. C1-S structural modeling and simulations revealed binding differences compared with unbiased epinephrine at transmembrane (TM) segments 3,5,6,7 and ECL2. C1-S (R2 = cyclohexane) was repositioned in the pocket such that it lost a TM6 interaction and gained a TM7 interaction compared with the analogous unbiased C5-S (R2 = benzene group), which appears to contribute to C1-S biasing away from β-arrestin. Thus, an agnostic large chemical-space library identified agonists with receptor interactions that resulted in relevant signal splitting of β2AR actions favorable for treating obstructive lung disease.

Angiogenesis is induced by airway smooth muscle strain

2007 ◽  
Vol 293 (4) ◽  
pp. L1059-L1068 ◽  
Author(s):  
Nadia A. Hasaneen ◽  
Stanley Zucker ◽  
Richard Z. Lin ◽  
Gayle G. Vaday ◽  
Reynold A. Panettieri ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Neutralizing Antibodies ◽  
Airway Remodeling ◽  
Mechanical Strain ◽  
Microvascular Endothelial Cell ◽  
Chronic Obstructive ◽  
Vegf Expression

Angiogenesis is an important feature of airway remodeling in both chronic asthma and chronic obstructive pulmonary disease (COPD). Airways in those conditions are exposed to excessive mechanical strain during periods of acute exacerbations. We recently reported that mechanical strain of human airway smooth muscle (HASM) led to an increase in their proliferation and migration. Sustained growth in airway smooth muscle in vivo requires an increase in the nutritional supply to these muscles, hence angiogenesis. In this study, we examined the hypothesis that cyclic mechanical strain of HASM produces factors promoting angiogenic events in the surrounding vascular endothelial cells. Our results show: 1) a significant increase in human lung microvascular endothelial cell (HMVEC-L) proliferation, migration, and tube formation following incubation in conditioned media (CM) from HASM cells exposed to mechanical strain; 2) mechanical strain of HASM cells induced VEGF expression and release; 3) VEGF neutralizing antibodies inhibited the proliferation, migration, and tube formations of HMVEC-L induced by the strained airway smooth muscle CM; 4) mechanical strain of HASM induced a significant increase in hypoxia-inducible factor-1α (HIF-1α) mRNA and protein, a transcription factor required for VEGF gene transcription; and 5) mechanical strain of HASM induced HIF-1α/VEGF through dual phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and ERK pathways. In conclusion, exposing HASM cells to mechanical strain induces signal transduction pathway through PI3K/Akt/mTOR and ERK pathways that lead to an increase in HIF-1α, a transcription factor required for VEGF expression. VEGF release by mechanical strain of HASM may contribute to the angiogenesis seen with repeated exacerbation of asthma and COPD.

Airway fibrosis in rats induced by vanadium pentoxide

2000 ◽  
Vol 278 (1) ◽  
pp. L209-L216 ◽  
Author(s):  
James C. Bonner ◽  
Annette B. Rice ◽  
Cindy R. Moomaw ◽  
Daniel L. Morgan
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Vanadium Pentoxide ◽  
Airway Remodeling ◽  
Mucous Cell ◽  
Intratracheal Instillation ◽  
Muscle Layer ◽  
Airway Smooth Muscle Cell ◽  
Smooth Muscle Layer ◽  
Airway Fibrosis

Vanadium pentoxide (V2O5) is a cause of occupational asthma and bronchitis. We previously reported that intratracheal instillation of rats with V2O5causes fibrosis of the lung parenchyma (J. C. Bonner, P. M. Lindroos, A. B. Rice, C. R. Moomaw, and D. L. Morgan. Am. J. Physiol. Lung Cell. Mol. Physiol. 274: L72–L80, 1998). In this report, we show that intratracheal instillation of V2O5induces airway remodeling similar to that observed in individuals with asthma. These changes include airway smooth muscle cell thickening, mucous cell metaplasia, and airway fibrosis. The transient appearance of peribronchiolar myofibroblasts, which were desmin and vimentin positive, coincided with a twofold increase in the thickness of the airway smooth muscle layer at day 6after instillation and preceded the development of airway fibrosis by day 15. The number of nuclear profiles within the smooth muscle layer also increased twofold after V2O5instillation, suggesting that hyperplasia accounted for thickening of the smooth muscle layer. The majority of cells incorporating bromodeoxyuridine at day 3 were located in the connective tissue surrounding the airway smooth muscle wall that was positive for vimentin and desmin. These data suggest that myofibroblasts are the principal proliferating cell type that contributes to the progression of airway fibrosis after V2O5injury.

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