Bronchial inflammation induced PKCζ over-expression: involvement in mechanical properties of airway smooth muscle.
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.
Department of Physiology and Biophysics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001 12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada.
Caroline
C
Morin
Samuel
S
Fortin
Eric
E
Rousseau
D058666:Adrenergic beta-2 Receptor Agonists / Q000494:pharmacology; D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D001249:Asthma / Q000139:chemically induced / Q000188:drug therapy / Q000201:enzymology* / Q000503:physiopathology; D001696:Biomechanical Phenomena; D001980:Bronchi / Q000187:drug effects / Q000201:enzymology* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000139:chemically induced / Q000188:drug therapy / Q000201:enzymology* / Q000503:physiopathology; D001993:Bronchodilator Agents / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009124:Muscle Proteins; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000201:enzymology* / Q000503:physiopathology; D010047:Ovalbumin; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D011014:Pneumonia / Q000139:chemically induced / Q000188:drug therapy / Q000201:enzymology* / Q000503:physiopathology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D046509:Tissue Culture Techniques; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000099221:Protein Kinase C zeta
D058666:Adrenergic beta-2 Receptor Agonists; D001095:Arachidonic Acids; D001993:Bronchodilator Agents; D002118:Calcium; D047908:Intracellular Signaling Peptides and Proteins; D009124:Muscle Proteins; D010047:Ovalbumin; D010749:Phosphoprotein Phosphatases; D011493:Protein Kinase C; D047428:Protein Kinase Inhibitors; D014409:Tumor Necrosis Factor-alpha; D048051:p38 Mitogen-Activated Protein Kinases; D000099221:Protein Kinase C zeta; C107507:PPP1R14A protein, human; C070378:17,18-epoxy-5,8,11,14-eicosatetraenoic acid