title: Pyocyanin from Pseudomonas induces IL-8 production through the PKC and NF-κB pathways in U937 cells.
abstract: Pyocyanin, an extracellular product of Pseudomonas aeruginosa (P. aeruginosa), is important in invasive pulmonary infection. Pseudomonas infections are characterized by a marked influx of polymorphonuclear cells (neutrophils). An increased release of interleukin-8 (IL-8), a potent neutrophil chemoattractant, in response to pyocyanin may contribute to the marked infiltration of neutrophils and subsequent neutrophil-mediated tissue damage observed in Pseudomonas-associated lung diseases. In order to explore the pathogenesis of pyocyanin on macrophages, we treated phorbol-12-myristate-13-acetate (PMA)-differentiated U937 cells with pyocyanin in vitro and explored the expression of IL-8 using reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). In the present study, we also investigated the activation of protein kinase C (PKC) and nuclear factor (NF)-κB in PMA-differentiated U937 cells by western blotting and immunohistochemical methods. It was found that pyocyanin increased IL-8 release and mRNA expression in differentiated U937 cells in a concentration- and time-dependent manner. Calphostin C (Cal C), a protein kinase C (PKC) inhibitor, and pyrrolidine dithiocarbamate (PDTC) , an NF-κB inhibitor, blocked IL-8 expression in a concentration-dependent manner in pyocyanin-induced U937 cells. We concluded that pyocyanin promotes IL-8 secretion and mRNA expression in a concentration- and time-dependent manner and furthermore, that the PKC and NF-κΒ signaling pathways may be involved in the expression of IL-8 in pyocyanin-infected PMA-differentiated U937 cells.
authors.affiliation: Department of Respiratory Diseases, The First Affiliated Hospital, Liaoning Medical University, Jinzhou, Liaoning 121001, P.R. China.
authors.forename: Wenshu
authors.initials: W
authors.lastname: Chai
authors.forename: Jia
authors.initials: J
authors.lastname: Zhang
authors.forename: Zhitu
authors.initials: Z
authors.lastname: Zhu
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Dianzhu
authors.initials: D
authors.lastname: Pan
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Baiyi
authors.initials: B
authors.lastname: Chen
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007124:Immunoenzyme Techniques; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010703:Phorbol Esters / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000737:chemistry*; D011710:Pyocyanine / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*; D014407:Tumor Cells, Cultured; D020298:U937 Cells
chemical_list: D016209:Interleukin-8; D016328:NF-kappa B; D010703:Phorbol Esters; D012333:RNA, Messenger; C119222:phorbol-12-myristate; D011710:Pyocyanine; D011493:Protein Kinase C