Faculty Opinions recommendation of Nitric oxide induces airway smooth muscle cell relaxation by decreasing the frequency of agonist-induced Ca2+ oscillations.

Author(s):  
Jeremy Ward
2010 ◽  
Vol 135 (3) ◽  
pp. 247-259 ◽  
Author(s):  
Jose F. Perez-Zoghbi ◽  
Yan Bai ◽  
Michael J. Sanderson

Nitric oxide (NO) induces airway smooth muscle cell (SMC) relaxation, but the underlying mechanism is not well understood. Consequently, we investigated the effects of NO on airway SMC contraction, Ca2+ signaling, and Ca2+ sensitivity in mouse lung slices with phase-contrast and confocal microscopy. Airways that were contracted in response to the agonist 5-hydroxytryptamine (5-HT) transiently relaxed in response to the NO donor, NOC-5. This NO-induced relaxation was enhanced by zaprinast or vardenafil, two selective inhibitors of cGMP-specific phosphodiesterase-5, but blocked by ODQ, an inhibitor of soluble guanylyl cyclase, and by Rp-8-pCPT-cGMPS, an inhibitor of protein kinase G (PKG). Simultaneous measurements of airway caliber and SMC [Ca2+]i revealed that airway contraction induced by 5-HT correlated with the occurrence of Ca2+ oscillations in the airway SMCs. Airway relaxation induced by NOC-5 was accompanied by a decrease in the frequency of these Ca2+ oscillations. The cGMP analogues and selective PKG activators 8Br-cGMP and 8pCPT-cGMP also induced airway relaxation and decreased the frequency of the Ca2+ oscillations. NOC-5 inhibited the increase of [Ca2+]i and contraction induced by the photolytic release of inositol 1,4,5-trisphosphate (IP3) in airway SMCs. The effect of NO on the Ca2+ sensitivity of the airway SMCs was examined in lung slices permeabilized to Ca2+ by treatment with caffeine and ryanodine. Neither NOC-5 nor 8pCPT-cGMP induced relaxation in agonist-contracted Ca2+-permeabilized airways. Consequently, we conclude that NO, acting via the cGMP–PKG pathway, induced airway SMC relaxation by predominately inhibiting the release of Ca2+ via the IP3 receptor to decrease the frequency of agonist-induced Ca2+ oscillations.


2019 ◽  
Vol 865 ◽  
pp. 172779 ◽  
Author(s):  
Katarzyna Wójcik-Pszczoła ◽  
Grażyna Chłoń-Rzepa ◽  
Agnieszka Jankowska ◽  
Eugenie Ellen ◽  
Artur Świerczek ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
R. Stamatiou ◽  
E. Paraskeva ◽  
K. Gourgoulianis ◽  
P.-A. Molyvdas ◽  
A. Hatziefthimiou

Chronic airway diseases, such as asthma or chronic obstructive pulmonary disease, are characterized by the presence in the airways of inflammation factors, growth factors and cytokines, which promote airway wall remodelling. The aim of this study was to investigate the effect of cytokines and growth factors on airway smooth muscle cell (ASMC) proliferation, phenotype and responsiveness. Incubation of serum starved human bronchial ASMCs with TNF-α, TGF, bFGF, and PDGF, but not IL-1β, increased methyl-[3H]thymidine incorporation and cell number, mediated by the PI3K and MAPK signalling pathways. Regarding rabbit tracheal ASMC proliferation, TNF-α, IL-1β, TGF, and PDGF increased methyl-[3H]thymidine incorporation in a PI3K- and MAPK-dependent manner. bFGF increased both methyl-[3H]thymidine incorporation and cell number. Moreover, incubation with TGF, bFGF and PDGF appears to drive human ASMCs towards a synthetic phenotype, as shown by the reduction of the percentage of cells expressing SM-α actin. In addition, the responsiveness of epithelium-denuded rabbit tracheal strips to carbachol was not significantly altered after 3-day treatment with bFGF. In conclusion, all the tested cytokines and growth factors increased ASMC proliferation to a different degree, depending on the specific cell type, with bronchial ASMCs being more prone to proliferation than tracheal ASMCs.


Oncotarget ◽  
2016 ◽  
Vol 7 (49) ◽  
pp. 80238-80251 ◽  
Author(s):  
Hesam Movassagh ◽  
Nazanin Tatari ◽  
Lianyu Shan ◽  
Latifa Koussih ◽  
Duaa Alsubait ◽  
...  

2003 ◽  
Vol 94 (4) ◽  
pp. 1403-1409 ◽  
Author(s):  
A. Cogo ◽  
G. Napolitano ◽  
M. C. Michoud ◽  
D. Ramos Barbon ◽  
M. Ward ◽  
...  

Although it is well known that hypoxemia induces pulmonary vasoconstriction and vascular remodeling, due to the proliferation of both vascular smooth muscle cells and fibroblasts, the effects of hypoxemia on airway smooth muscle cells are not well characterized. The present study was designed to assess the in vitro effects of hypoxia (1 or 3% O2) on rat airway smooth muscle cell growth and response to mitogens (PDGF and 5-HT). Cell growth was assessed by cell counting and cell cycle analysis. Compared with normoxia (21% O2), there was a 42.2% increase in the rate of proliferation of cells exposed to 3% O2 (72 h, P = 0.006), as well as an enhanced response to PDGF (13.9% increase; P = 0.023) and to 5-HT (17.2% increase; P = 0.039). Exposure to 1% O2 (72 h) decreased cell proliferation by 21.0% ( P = 0.017) and reduced the increase in cell proliferation induced by PGDF and 5-HT by 16.2 and 15.7%, respectively ( P = 0.019 and P = 0.011). A significant inhibition in hypoxia-induced cell proliferation was observed after the administration of bisindolylmaleimide GF-109203X (a specific PKC inhibitor) or downregulation of PKC with PMA. Pretreatment with GF-109203X decreased proliferation by 21.5% ( P = 0.004) and PMA by 31.5% ( P = 0.005). These results show that hypoxia induces airway smooth muscle cell proliferation, which is at least partially dependent on PKC activation. They suggest that hypoxia could contribute to airway remodeling in patients suffering from chronic, severe respiratory diseases.


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