Effects of ATP release on mucin5AC secretion in airway epithelial cells by mechanical stretching

摘要

This study is to determine the effects of ATP and Ca2++ on mucin5AC (MUC5AC) overexpression in airway epithelial cells in mechanical ventilation. Oxygen was injected into the closed box used in this study to increase the pressure. Gravity-driven draining flow led to formation of a thin liquid film on the upper portion of cell monolayer, exposing cells to the tension forces at the air-liquid interface. The levels of MUC5AC protein and ATP in culture medium were detected by ELISA and high performance liquid chromatography, respectively. Ca2+ and MUC5AC mRNA in culture cells were detected by flow cytometry and RT-PCR, respectively. Mechanical stretching increased the expression of MUC5AC in cells and the concentration of MUC5AC and ATP in supernatant. BAPTA-AM and EGTA partially reduced the increases in the concentrations of MUC5AC and ATP in supernatant with mechanical ventilation. BAPTAAM completely inhibited ATP in supernatant with normal breathing conditions. Our results showed that mechanical ventilation increases the secretion of MUC5AC in airway epithelial cells. This is possibly related to Ca2+-dependent ATP release and intracellular and external Ca2+.