title: Effect of epithelium ATP release on cyclic pressure-induced airway mucus secretion.
abstract: The cyclic mechanical effect of airflow during breathing creates the optimal airway hydration state. MUC (mucin) 5AC is an important component of the airway mucus. The formation of MUC5AC is related to ATP and intracellular calcium in the epithelial cells. In this study, we evaluated the effect of ATP release from intracellular calcium in epithelial cells on cyclic pressure-induced mucus secretion in the airway. 16HBE (human bronchial epithelial cells) were cultured in vitro on cyclically tilted cultured plates and divided into five groups: control, tilt, tilt and BAPTA-AM (1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid-acetoxymethyl ester), tilt and EGTA and tilt and RB-2 (reactive blue-2). The shear stress and compressive stress were induced by the surface tension of the liquid, atmospheric pressure and liquid gravity. Cell activity, MUC5AC mRNA expression level, MUC5AC protein expression level and ATP release and intracellular calcium changes were measured with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay, RT-PCR (reverse transcription-PCR), HPLC and inverted fluorescence microscope, respectively. We detected that cyclic pressure significantly increased MUC5AC secretion and ATP release. The enhanced ATP release could be inhibited by both BAPTA-AM and RB-2, while EGTA did not have a suppressive effect. BAPTA-AM, EGTA and RB-2 did not obviously inhibit MUC5AC mRNA expression. Cyclic pressure did not induce MUC5AC secretion in the airway mucus epithelium via Ca2+-dependent ATP release, and nearly all Ca2+was provided by stored intracellular Ca2.
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Tong
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China longman185@163.com.
authors.forename: Xiang-Dong
authors.initials: XD
authors.lastname: Zhou
authors.affiliation: Far Eastern Scientific Centre of Physiology and Pathology of Respiration, Russian Academy of Medical Sciences, Blagoveshchensk 675000, Russia.
authors.forename: Juliy M
authors.initials: JM
authors.lastname: Perelman
authors.affiliation: Far Eastern Scientific Centre of Physiology and Pathology of Respiration, Russian Academy of Medical Sciences, Blagoveshchensk 675000, Russia.
authors.forename: Victor P
authors.initials: VP
authors.lastname: Kolosov
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D005786:Gene Expression Regulation; D006801:Humans; D055271:Mucin 5AC / Q000378:metabolism*; D011312:Pressure; D020545:Respiratory Mucosa / Q000166:cytology / Q000378:metabolism*
chemical_list: C524678:MUC5AC protein, human; D055271:Mucin 5AC; D000255:Adenosine Triphosphate; D002118:Calcium
keywords: ATP; calcium; cyclic pressure; mucins