Asthmatic airway smooth muscle CXCL10 production: mitogen-activated protein kinase JNK involvement

• Published in: American journal of physiology. Lung cellular and molecular physiology 2012-05, Vol.302 (10), p.L1118-L1127
• Main Authors: Alrashdan, Yazan A, Alkhouri, Hatem, Chen, Emily, Lalor, Daniel J, Poniris, Maree, Henness, Sheridan, Brightling, Christopher E, Burgess, Janette K, Armour, Carol L, Ammit, Alaina J, Hughes, J Margaret
• Format: Article
• Language: English
• Subjects: Asthma; Asthma - immunology; Asthma - metabolism; Asthma - pathology; Cell adhesion & migration; Cell Movement - drug effects; Cells; Chemokine CXCL10 - biosynthesis; Chemokine CXCL10 - immunology; Gene Expression - drug effects; Humans; Interferon-gamma - pharmacology; Interleukin-1beta - pharmacology; MAP Kinase Kinase 4 - genetics; MAP Kinase Kinase 4 - metabolism; Mast Cells - drug effects; Mast Cells - immunology; Mast Cells - metabolism; Mast Cells - pathology; Muscle, Smooth - immunology; Muscle, Smooth - metabolism; Myocytes, Smooth Muscle - drug effects; Myocytes, Smooth Muscle - immunology; Myocytes, Smooth Muscle - metabolism; NF-kappa B - genetics; NF-kappa B - metabolism; p38 Mitogen-Activated Protein Kinases - genetics; p38 Mitogen-Activated Protein Kinases - metabolism; Phosphorylation; Protein Kinase Inhibitors - pharmacology; Proteins; Respiratory System - immunology; Respiratory System - metabolism; RNA, Messenger - biosynthesis; Signal Transduction - drug effects; Tumor Necrosis Factor-alpha - pharmacology
• ISSN: 1040-0605; 1522-1504
• DOI: 10.1152/ajplung.00232.2011

CXCL10 (IP10) is involved in mast cell migration to airway smooth muscle (ASM) bundles in asthma. We aimed to investigate the role of cytokine-induced MAPK activation in CXCL10 production by ASM cells from people with and without asthma. Confluent growth-arrested ASM cells were treated with inhibitors of the MAPKs ERK, p38, and JNK and transcription factor NF-κB, or vehicle, and stimulated with IL-1β, TNF-α, or IFN-γ, alone or combined (cytomix). CXCL10 mRNA and protein, JNK, NF-κB p65 phosphorylation, and Iκ-Bα protein degradation were assessed using real-time PCR, ELISA, and immunoblotting, respectively. Cytomix, IL-1β, and TNF-α induced CXCL10 mRNA expression more rapidly in asthmatic than nonasthmatic ASM cells. IL-1β and/or TNF-α combined with IFN-γ synergistically increased asthmatic ASM cell CXCL10 release. Inhibitor effects were similar in asthmatic and nonasthmatic cells, but cytomix-induced release was least affected, with only JNK and NF-κB inhibitors halving it. Notably, JNK phosphorylation was markedly less in asthmatic compared with nonasthmatic cells. However, in both, the JNK inhibitor SP600125 reduced JNK phosphorylation and CXCL10 mRNA levels but did not affect CXCL10 mRNA stability or Iκ-Bα degradation. Together, the JNK and NF-κB inhibitors completely inhibited their CXCL10 release. We concluded that, in asthmatic compared with nonasthmatic ASM cells, JNK activation was reduced and CXCL10 gene expression was more rapid following cytomix stimulation. However, in both, JNK activation did not regulate early events leading to NF-κB activation. Thus JNK and NF-κB provide independent therapeutic targets for limiting CXCL10 production and mast cell migration to the ASM in asthma.