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Bronchial inflammation induced PKCζ over-expression: involvement in mechanical properties of airway smooth muscle.

Bronchial inflammation induced PKCζ over-expression: involvement in mechanical properties of airway smooth muscle.

Authors :
Morin C
Fortin S
Rousseau E
Source :
Canadian journal of physiology and pharmacology [Can J Physiol Pharmacol] 2012 Feb; Vol. 90 (2), pp. 261-9. Date of Electronic Publication: 2012 Feb 10.
Publication Year :
2012

Abstract

Protein kinase C variants (PKCs) have been involved in the control of airway smooth muscle (ASM) tone, and abnormalities in PKC-dependent signaling have been associated with respiratory diseases such as asthma. In this study, the role of atypical PKCζ in airway hyperresponsiveness was investigated, using an in-vitro model of TNFα-treated human bronchi and an in vivo guinea pig model of chronic asthma. Our results demonstrated that PKCζ-specific inhibition produced a significant increase in isoproterenol sensitivity in TNFα-treated bronchi and ovalbumin (OVA)-sensitized guinea pig bronchi. The role of epoxy-eicosanoids, known to exert anti-inflammatory effects in lung, on PKCζ expression and activity in these models was evaluated. An enhanced PKCζ protein expression was delineated in TNFα-treated bronchi when compared with control (untreated) and epoxy-eicosanoid-treated bronchi. Measurements of Ca(2+) sensitivity, performed in TNFα-treated bronchi, demonstrated that treatment with myristoylated (Myr) PKCζ peptide inhibitor resulted in significant reductions of pCa-induced tension. Epoxy-eicosanoid treatments had similar effects on Ca(2+) sensitivity in TNFα-treated bronchi. In control and epoxy-eicosanoid-treated bronchi, the phosphorylated forms of p38MAPK and CPI-17 were significantly decreased compared with the TNFα-treated bronchi. An enhanced expression of PKCζ was ascertained in our in-vivo model of allergic asthma. Hence an increased Ca(2+) sensitivity could be explained by the phosphorylation of p38-MAPK, which in turn leads to phosphorylation and activation of the CPI-17 regulatory protein. This process was reversed upon treatment with the Myr-PKCζ-peptide inhibitor. The present data provide relevant evidence regarding the role of PKCζ in human and rodent models of airways inflammation.

Details

Language :
English
ISSN :
1205-7541
Volume :
90
Issue :
2
Database :
MEDLINE
Journal :
Canadian journal of physiology and pharmacology
Publication Type :
Academic Journal
Accession number :
22324796
Full Text :
https://doi.org/10.1139/y11-117