The Effect of Doxycycline on PMA-Induced MUC5B Expression via MMP-9 and p38 in NCI-H292 Cells

OBJECTIVES: Doxycycline is commonly used in medicine for its bacteriostatic antimicrobial properties. Recent studies have reported that doxycycline also has anti-inflammatory effects. Matrix metalloproteinase (MMP)-9 has been found to be involved in the physiological and pathological process of inflammatory airway disease. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, is known to stimulate the expression of MMP and mucin genes in the airway and intestinal epithelial cells. Therefore, the effects and signal pathways of doxycycline on PMA-induced MUC5B expression dependent MMP-9 in human airway epithelial cells were investigated. METHODS: In human NCI-H292 airway epithelial cells, MUC5B and MMP-9 mRNA expression, MUC5B protein expression, and MMP-9 protein activity after the treatment with PMA, MMP-9 or doxycycline were determined by reverse transcriptase-polymerase chain reaction, enzyme immunoassay, gelatin zymography, and Western blot analysis. RESULTS: PMA increased MMP-9 and MUC5B expression. MMP-9 increased MUC5B expression. Doxycycline inhibited PMA-induced MUC5B expression, and PMA-induced MMP-9 mRNA expression and protein activity. Doxycycline inhibited phosphorylation of p38 induced by PMA and MMP-9. CONCLUSION: The results of this study suggest that doxycycline inhibited PMA-induced MUC5B mRNA expression and protein production through the MMP-9 and p38 pathways in human NCI-H292 airway epithelial cells.

Expression of IL-8 induced by Pyocyanin in NCI-H292 cells by PKC-NF-?B signal pathway / 中国药理学通报

Aim To study IL-8 expression of human airway epithelium-like NCI-H292 cells directly induced by Pyocyanin and its mechanism through protein kinase C(PKC) and nuclear factor-kappa B(NF-??).Methods ELISA methods were performed to test the expression of IL-8 in NCI-H292 cells infected by Pyocyanin.Western blot was employed to examine the expression of NF-?B protein.In addition,NCI-H292 cells were cultured together with PKC inhibitor,calphostin C or NF-?? inhibitor,pyrrolidine dithiocarbamate(PDTC),respectively before Pyocyanin infection,then the expression of IL-8 and NF-?? was assayed using the above methods.Results Pyocyanin was able to induce IL-8 protein secretion in NCI-H292 cells and had marked concentration-dependent relations.Pyocyanin could also significantly promote the activation of NF-?B,which peaked at 60~90 min.PDTC and calphostin C could significantly decrease the activation of NF-?? and the expression of IL-8.Conclutions Pyocyanin can induce IL-8 production.The direct induction of Pyocyanin can promote the activation of NF-?B by PKC signal pathway,then cause the expression and secretion of IL-8.