The long-term objectives have been to understand calcium regulation in airway smooth muscle. Intracellular calcium stores of the sarcoplasmic reticulum (SR) play a role in determining the cytosolic calcium concentrations ([Ca2+]i) that regulate smooth muscle functions, including contraction. Therefore, understanding the mechanisms by which stimuli cause release of calcium from the SR to generate a rapid increase in [Ca2+]i in the cell cytosol (calcium transient) and how the SR then refills with calcium is important. Work on SR refilling has led to the novel observation that interleukin (IL)-4 rapidly (<30 min) inhibits carbachol-stimulated calcium transients in bovine airway smooth muscle cells. This new finding is potentially important because it conceptually links calcium regulation in airway smooth muscle cells to the T helper 2-type cytokine profile characteristic of asthmatic airway inflammation. Notably, IL-4 is closely related to IL-l3, an important mediator of airway inflammation, and binds to a shared family of receptor complexes. In general, the aims are to determine how IL-4 rapidly inhibits calcium transients and to assess for effects on contraction. Specifically, the goals are to determine the effects of IL-4 on 1) SR calcium content; 2) calcium influx; and 3) coupling of receptors to inositol trisphosphate generation. Then, the goals are to 4) characterize signal transduction pathways underlying IL-4 effects on calcium and 5) characterize the effects of IL-4 on cell shortening. The principal methods are single cell, ratiometric imaging of [Ca2+]i, including three dimensional reconstruction of images; electrophysiology to assess calcium influx; and biochemistry to define signal transduction pathways. Studies will be done with freshly-dispersed bovine and cultured human airway smooth muscle cells.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL054143-07A1
Application #
6433927
Study Section
Lung Biology and Pathology Study Section (LBPA)
Program Officer
Noel, Patricia
Project Start
1995-04-01
Project End
2006-06-30
Budget Start
2002-08-09
Budget End
2003-06-30
Support Year
7
Fiscal Year
2002
Total Cost
$357,750
Indirect Cost
Name
University of Massachusetts Medical School Worcester
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
660735098
City
Worcester
State
MA
Country
United States
Zip Code
01655
Martin, Gilles; O'Connell, Robert J; Pietrzykowski, Andrzej Z et al. (2008) Interleukin-4 activates large-conductance, calcium-activated potassium (BKCa) channels in human airway smooth muscle cells. Exp Physiol 93:908-18
Ethier, Michael F; Madison, J Mark (2006) Adenosine A1 receptors mediate mobilization of calcium in human bronchial smooth muscle cells. Am J Respir Cell Mol Biol 35:496-502
Ethier, Michael F; Madison, J Mark (2006) IL-4 inhibits calcium transients in bovine trachealis cells by a ryanodine receptor-dependent mechanism. FASEB J 20:154-6
Ethier, Michael F; Cappelluti, Erika; Madison, J Mark (2005) Mechanisms of interleukin-4 effects on calcium signaling in airway smooth muscle cells. J Pharmacol Exp Ther 313:127-33
Madison, J Mark (2003) Migration of airway smooth muscle cells. Am J Respir Cell Mol Biol 29:8-11
Ethier, M F; Madison, J M (2002) LY294002, but not wortmannin, increases intracellular calcium and inhibits calcium transients in bovine and human airway smooth muscle cells. Cell Calcium 32:31-8
Ethier, M F; Yamaguchi, H; Madison, J M (2001) Effects of cyclopiazonic acid on cytosolic calcium in bovine airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 281:L126-33
Madison, J M; Ethier, M F (2001) Interleukin-4 rapidly inhibits calcium transients in response to carbachol in bovine airway smooth muscle cells. Am J Respir Cell Mol Biol 25:239-44
Ethier, M F; Dextradeur, T; Schaefer, O P et al. (2000) Effects of salmeterol on muscarinic inhibition of adenylyl cyclase in bovine trachealis cells. Life Sci 67:2753-8
Madison, J M; Ethier, M F; Yamaguchi, H (1998) Refilling of caffeine-sensitive intracellular calcium stores in bovine airway smooth muscle cells. Am J Physiol 275:L852-60

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