ASTHMA

Functional K_Ca3.1 K⁺ channels are required for human lung mast cell migration

G Cruse, S M Duffy, C E Brightling, P Bradding

Institute for Lung Health, Department of Infection, Immunity and Inflammation, University of Leicester Medical School, Glenfield Hospital, Leicester, UK

Correspondence to:
MrG Cruse
Department of Respiratory Medicine, Glenfield Hospital, Groby Road, Leicester LE3 9QP, UK; glenncruse{at}hotmail.com

Background: Mast cell recruitment and activation are critical for the initiation and progression of inflammation and fibrosis. Mast cells infiltrate specific structures in many diseased tissues such as the airway smooth muscle (ASM) in asthma. This microlocalisation of mast cells is likely to be key to disease pathogenesis. Human lung mast cells (HLMC) express the Ca²⁺ activated K⁺ channel K_Ca3.1 which modulates mediator release, and is proposed to facilitate the retraction of the cell body during migration of several cell types. A study was undertaken to test the hypothesis that blockade of K_Ca3.1 would attenuate HLMC proliferation and migration.

Methods: HLMC were isolated and purified from lung material resected for bronchial carcinoma. HLMC proliferation was assessed by cell counts at various time points following drug exposure. HLMC chemotaxis was assayed using standard Transwell chambers (8 µm pore size). Ion currents were measured using the single cell patch clamp technique.

Results: K_Ca3.1 blockade with triarylmethane-34 (TRAM-34) did not inhibit HLMC proliferation and clotrimazole had cytotoxic effects. In contrast, HLMC migration towards the chemokine CXCL10, the chemoattractant stem cell factor, and the supernatants from tumour necrosis factor stimulated asthmatic ASM was markedly inhibited with both the non-selective K_Ca3.1 blocker charybdotoxin and the highly specific K_Ca3.1 blocker TRAM-34 in a dose dependent manner. Although K_Ca3.1 blockade inhibits HLMC migration, K_Ca3.1 is not opened by the chemotactic stimulus, suggesting that it must be involved downstream of the initial receptor-ligand interactions.

Conclusions: Since modulation of K_Ca3.1 can inhibit HLMC chemotaxis to diverse chemoattractants, the use of K_Ca3.1 blockers such as TRAM-34 could provide new therapeutic strategies for mast cell mediated diseases such as asthma.

Abbreviations: ASM, airway smooth muscle; HLMC, human lung mast cell; IL, interleukin; SCF, stem cell factor; TGF-ß, transforming growth factor ß; TNF-, tumour necrosis factor ; TRAM-34, triarylmethane-34

Keywords: mast cell; migration; asthma; CXCL10; KCa3.1

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Bardou, O., Trinh, N. T. N., Brochiero, E. (2009). Molecular diversity and function of K+ channels in airway and alveolar epithelial cells. Am. J. Physiol. Lung Cell. Mol. Physiol. 296: L145-L155 [Abstract] [Full Text]  
• Garneau, L., Klein, H., Banderali, U., Longpre-Lauzon, A., Parent, L., Sauve, R. (2009). Hydrophobic Interactions as Key Determinants to the KCa3.1 Channel Closed Configuration: AN ANALYSIS OF KCa3.1 MUTANTS CONSTITUTIVELY ACTIVE IN ZERO Ca2+. J. Biol. Chem. 284: 389-403 [Abstract] [Full Text]  
• Trinh, N. T. N., Prive, A., Maille, E., Noel, J., Brochiero, E. (2008). EGF and K+ channel activity control normal and cystic fibrosis bronchial epithelia repair. Am. J. Physiol. Lung Cell. Mol. Physiol. 295: L866-L880 [Abstract] [Full Text]  
• Hollins, F., Kaur, D., Yang, W., Cruse, G., Saunders, R., Sutcliffe, A., Berger, P., Ito, A., Brightling, C. E., Bradding, P. (2008). Human Airway Smooth Muscle Promotes Human Lung Mast Cell Survival, Proliferation, and Constitutive Activation: Cooperative Roles for CADM1, Stem Cell Factor, and IL-6. J. Immunol. 181: 2772-2780 [Abstract] [Full Text]  
• Schwab, A., Hanley, P., Fabian, A., Stock, C. (2008). Potassium Channels Keep Mobile Cells on the Go. Physiology 23: 212-220 [Abstract] [Full Text]  
• Shumilina, E., Lam, R. S., Wolbing, F., Matzner, N., Zemtsova, I. M., Sobiesiak, M., Mahmud, H., Sausbier, U., Biedermann, T., Ruth, P., Sausbier, M., Lang, F. (2008). Blunted IgE-Mediated Activation of Mast Cells in Mice Lacking the Ca2+-Activated K+ Channel KCa3.1. J. Immunol. 180: 8040-8047 [Abstract] [Full Text]  
• Lee, E. L., Hasegawa, Y., Shimizu, T., Okada, Y. (2008). IK1 channel activity contributes to cisplatin sensitivity of human epidermoid cancer cells. Am. J. Physiol. Cell Physiol. 294: C1398-C1406 [Abstract] [Full Text]  
• deHart, G. W., Jin, T., McCloskey, D. E., Pegg, A. E., Sheppard, D. (2008). The {alpha}9{beta}1 integrin enhances cell migration by polyamine-mediated modulation of an inward-rectifier potassium channel. Proc. Natl. Acad. Sci. USA 105: 7188-7193 [Abstract] [Full Text]  
• Siddiqui, S., Hollins, F., Saha, S., Brightling, C. E. (2007). Inflammatory cell microlocalisation and airway dysfunction: cause and effect?. Eur Respir J 30: 1043-1056 [Abstract] [Full Text]  
• Shepherd, M. C., Duffy, S. M., Harris, T., Cruse, G., Schuliga, M., Brightling, C. E., Neylon, C. B., Bradding, P., Stewart, A. G. (2007). KCa3.1 Ca2+Activated K+ Channels Regulate Human Airway Smooth Muscle Proliferation. Am. J. Respir. Cell Mol. Bio. 37: 525-531 [Abstract] [Full Text]  
• Bradding, P. (2007). Mast cell regulation of airway smooth muscle function in asthma. Eur Respir J 29: 827-830 [Full Text]  
• Kaushal, V., Koeberle, P. D., Wang, Y., Schlichter, L. C. (2007). The Ca2+-Activated K+ Channel KCNN4/KCa3.1 Contributes to Microglia Activation and Nitric Oxide-Dependent Neurodegeneration. J. Neurosci. 27: 234-244 [Abstract] [Full Text]