Divergent modulation of Rho-kinase and Ca(2+) influx pathways by Src family kinases and focal adhesion kinase in airway smooth muscle.
Br J Pharmacol
; 172(22): 5265-80, 2015 Nov.
Article
in En
| MEDLINE
| ID: mdl-26294392
ABSTRACT
BACKGROUND AND PURPOSE:
The importance of tyrosine kinases in airway smooth muscle (ASM) contraction is not fully understood. The aim of this study was to investigate the role of Src-family kinases (SrcFK) and focal adhesion kinase (FAK) in GPCR-mediated ASM contraction and associated signalling events. EXPERIMENTALAPPROACH:
Contraction was recorded in intact or α-toxin permeabilized rat bronchioles. Phosphorylation of SrcFK, FAK, myosin light-chain-20 (MLC20 ) and myosin phosphatase targeting subunit-1 (MYPT-1) was evaluated in cultured human ASM cells (hASMC). [Ca(2+) ]i was evaluated in Fura-2 loaded hASMC. Responses to carbachol (CCh) and bradykinin (BK) and the contribution of SrcFK and FAK to these responses were determined. KEYRESULTS:
Contractile responses in intact bronchioles were inhibited by antagonists of SrcFK, FAK and Rho-kinase, while after α-toxin permeabilization, they were sensitive to inhibition of SrcFK and Rho-kinase, but not FAK. CCh and BK increased phosphorylation of MYPT-1 and MLC20 and auto-phosphorylation of SrcFK and FAK. MYPT-1 phosphorylation was sensitive to inhibition of Rho-kinase and SrcFK, but not FAK. Contraction induced by SR Ca(2+) depletion and equivalent [Ca(2+) ]i responses in hASMC were sensitive to inhibition of both SrcFK and FAK, while depolarization-induced contraction was sensitive to FAK inhibition only. SrcFK auto-phosphorylation was partially FAK-dependent, while FAK auto-phosphorylation was SrcFK-independent. CONCLUSIONS AND IMPLICATIONS SrcFK mediates Ca(2+) -sensitization in ASM, while SrcFK and FAK together and individually influence multiple Ca(2+) influx pathways. Tyrosine phosphorylation is therefore a key upstream signalling event in ASM contraction and may be a viable target for modulating ASM tone in respiratory disease.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Calcium
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Src-Family Kinases
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Focal Adhesion Protein-Tyrosine Kinases
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Rho-Associated Kinases
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Bronchioles
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Muscle, Smooth
Limits:
Adult
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Animals
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Female
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Humans
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Male
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Middle aged
Language:
En
Journal:
Br J Pharmacol
Year:
2015
Document type:
Article
Affiliation country: