Calcium signaling in human airway goblet cells following purinergic activation

• Published in: American journal of physiology. Lung cellular and molecular physiology 2007-01, Vol.292 (1), p.L92-L98
• Main Authors: Rossi, Andrea H, Salmon, Wendy C, Chua, Michael, Davis, C. William
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - analogs & derivatives; Adenosine Triphosphate - pharmacology; Airway management; Bridged-Ring Compounds - pharmacology; Bronchi - cytology; Bronchi - drug effects; Bronchi - physiology; Calcium; Calcium Signaling - drug effects; Cells; Cells, Cultured; Estrenes - pharmacology; Goblet Cells - drug effects; Goblet Cells - physiology; Humans; Inflammatory diseases; Phosphatidylinositol Diacylglycerol-Lyase - antagonists & inhibitors; Phosphodiesterase Inhibitors - pharmacology; Purinergic P2 Receptor Agonists; Pyrrolidinones - pharmacology; Receptors, Purinergic P2Y2; Tetradecanoylphorbol Acetate - pharmacology; Thiones - pharmacology; Type C Phospholipases - antagonists & inhibitors
• ISSN: 1040-0605; 1522-1504
• DOI: 10.1152/ajplung.00081.2006

1 Department of Cell and Molecular Physiology, 2 Michael Hooker Microscopy Facility, and 3 Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina, Chapel Hill, North Carolina Submitted 7 March 2006 ; accepted in final form 17 August 2006 Despite the general importance of Ca 2+ signaling in signal transduction, and of goblet cell mucin hypersecretion in inflammatory pulmonary diseases, measurement of airway goblet cell intracellular Ca 2+ (Ca ) has not been reported. In this article, we describe the results of experiments measuring Ca in primary cultures of human bronchial goblet cells after stimulation with the purinergic agonist adenosine 5'- O -(3-thiotriphosphate) (ATP S) and phorbol 12-myristate 13-acetate (PMA). Ca 2+ signaling in human goblet cells after purinergic stimulation follows the classic paradigm of a Ca transient from a basal activity of 110 nM to a peak response of 260.1 ± 41.2 nM within 2 min, followed by a long superbasal plateau (155.3 ± 0.2 nM) between 10 and 15 min. The rise in Ca appears to result from a mobilization of intracellular stores, because the transient was nearly abolished by inhibition of PLC with the phosphatidylinositol-specific PLC inhibitor U-73122, and it was not affected significantly by removal of extracellular Ca 2+ . Loading goblet cells with BAPTA inhibited the ATP S-induced Ca 2+ transient by 86.0 ± 13.1%, relative to control. Finally, in contrast to the massive effects of high doses of PMA (300 nM) on mucin secretion from goblet cells, phorbol ester stimulated a small (27.1 ± 7% of the ATP S control peak), brief rise in Ca . This diminutive signal likely denotes a local Ca 2+ gradient, which may be associated with the mucin granule exocytotic process. mucus; exocytosis; purinergic signaling; P2Y 2 Address for reprint requests and other correspondence: C. W. Davis, CF/Pulmonary Research & Treatment Center, 6009 Thurston Bowles, Univ. of North Carolina, Chapel Hill, NC 27599-7248 (e-mail: cwdavis{at}med.unc.edu )