MUC5AC In Cells Research Articles

Menthol enhances interleukin-13-induced synthesis and secretion of mucin 5AC in human bronchial epithelial cells

To investigate the effect of interleukin (IL) -13 combined with cold stimulation on synthesis and secretion of mucin (MUC) 5AC in human bronchial epithelial cell line 16HBE and explore the role of transient receptor potential 8 (TRPM8) and anti-apoptotic factor B-cell lymphoblast-2 (Bcl-2) in this process. 16HBE cells were stimulated with 10 ng/mL IL-13, 1 mmol/L menthol, or both (1 mmol/L menthol was added after 6 days of IL-13 stimulation), and the changes in the expression of MUC5AC, intracellular Ca2+ concentration and Bcl-2 expression were evaluated. The effects of ABT-263 (a Bcl-2 inhibitor) and BCTC (a TRPM8 ion channel inhibitor), alone or in combination, on MUC5AC expression in the cells were tested, and the changes in intracellular Ca2+ and Bcl-2 expression following BCTC treatment were observed. The cell viability was assessed using CCK-8 assay, the mRNA expressions of MUC5AC and Bcl-2 were detected with real-time quantitative PCR, the level of MUC5AC in the culture medium was measured with ELISA, and the intracellular Ca2+ fluorescence intensity was determined with flow cytometry. The mRNA and protein expressions of MUC5AC increased significantly in 16HBE cells following stimulation with IL-13, menthol, and both (P < 0.05), and were the highest in the combined treatment group with its peak level occurred at 24 h (P < 0.01). The intracellular Ca2+ fluorescence intensity and Bcl-2 mRNA expression were also increased in 16HBE cells after the stimulations (P < 0.05), and the increments were the most obvious in the combined treatment group (P < 0.01). Treatment with BCTC significantly lowered intracellular Ca2+ fluorescence intensity and the expressions of Bcl-2 and MUC5AC mRNA and protein in the cells stimulated with menthol or with both IL-13 and menthol (P < 0.05), but caused no significant changes in IL-13-stimulated cells (P > 0.05). Treatment with ABT-263 significantly lowered the mRNA and protein expressions of MUC5AC in the cells stimulated with IL-13 and menthol either alone or in combination (P < 0.05). Menthol combined with IL-13 produces a synergistic effect to promote the synthesis and secretion of MUC5AC in 16HBE cells possibly by activating TRPM8 receptor to upregulate the expression of Bcl-2.

BMP4 promotes a phenotype change of an esophageal squamous epithelium via up-regulation of KLF4

IntroductionBarrett's esophagus is a metaplastic lesion. However, the cellular and molecular mechanisms involved are poorly understood. The aim of this study was to investigate the roles of KLF4 and BMP4 in the pathogenesis of Barrett's epithelium. Materials and methodsImmunohistochemistry was used to analyse the expression of KLF4, BMP4, CDX2, MUC2 and MUC5AC in human esophageal specimens. Human esophageal squamous epithelial cells were subjected to bile acid treatment and used in transfection experiments. Quantitative real-time PCR and Western blot analysis were used to detect the expression of KLF4, BMP4, CDX2, MUC2 and MUC5ac. ResultsIn human tissues, Barrett's epithelium strongly expressed BMP4, p-Smad1/5/8 and KLF4. Furthermore, bile acids increased the expression of BMP4, KLF4, p-Smad1/5/8, CDX2, MUC2 and MUC5ac in esophageal epithelial cells in a time-dependent manner. Moreover, we found that BMP4 up-regulated the expression of KLF4, CDX2, MUC2 and MUC5ac, but Noggin, a specific BMP4 antagonist, can block the expression of KLF4, CDX2, MUC2 and MUC5ac induced by BMP4. However, BMP4 cannot induce the expression of CDX2, MUC2 and MUC5ac in cells with KLF4 siRNA, and Noggin cannot block the expression of KLF4, CDX2, MUC2 and MUC5ac in cells transfected with the KLF4 expression vector. ConclusionOur results demonstrate that BMP4 promotes a phenotype change of an esophageal squamous epithelium via up-regulation of KLF4.

The effects of stretch sensitive positive ion channel on the high externalization of MUC5AC in airway epithelial cells by mechanical stretching

The effects of stretch sensitive positive ion channel, the internal flow of Ca(2+) and myristoylated alanine-rich C kinase substrate (MARCKS) on the high externalization of MUC5AC in airway epithelial cells in mechanical stretching. Mini-type Multi-functional Bio-impact Machin was used to construct the model of mechanical stretching. The airway epithelial cells were divide into control group, stretch, stretch and gadolinium, stretch and low molecular weight heparin, stretch and nifedipine, stretch and the locked nucleic acids of MARCKS effective domain (ED), stretch and the control locked nucleic acids of MARCKS ED groups. The expression of MUC5AC and SNAP23 protein in cells were determined by immunohistochemistry method, contents of MUC5AC and SNAP23 protein were measured by Image Pro Plus 5.0. MUC5AC protein in supernatant was determined by ELISA methods. SNAP23 mRNA was determined by RT-PCR methods. Mechanical stretching could increase the expression of SNAP23 and MUC5AC in cells and MUC5AC in supernatant (P < 0.05). Gadolinium, nifedipine and LNA of MARCKS ED could reduce the increase the expression of SNAP23 and MUC5AC in cells and MUC5AC in supernatant (all P < 0.05). Mechanical stretching could increase the expression of MUC5AC in airway epithelial cells. This maybe is concerned with stretch sensitive positive ion channel, the internal flow of Ca(2+) and MARCKS.