title: Candida albicans induces selectively transcriptional activation of cyclooxygenase-2 in HeLa cells: pivotal roles of Toll-like receptors, p38 mitogen-activated protein kinase, and NF-kappa B.
abstract: Candidiasis, in its mucocutaneous form as well as in an invasive form, is frequently associated with high morbidity. PGE(2), which is generated by enzymatic activity of cyclooxygenases (COXs) 1 and 2, has been shown to trigger morphogenesis in Candida albicans. In the present study, we investigated whether C. albicans altered COX-2 expression in HeLa cells. RT-PCR and Western blot analyses revealed a time-dependent biphasic behavior of COX-2 mRNA expression and COX-2 protein level. COX-1 protein remained unaffected. Neutralization with Abs against Toll-like receptors (TLR) 2 and 4 inhibited the Candida-induced production of PGE(2), suggesting a vital role for TLRs in the recognition and signaling in mammalian cells upon infection with C. albicans. Transient transfections with COX-2 promoter-luciferase construct and various inhibitors of mitogen-activated protein kinases (MAPK), such as protein kinase C (PKC) inhibitor GF203190X, p38(MAPK) inhibitor SB203109, and extracellular-regulated kinases 1 and 2 inhibitor PD98509 showed that C. albicans up-regulates selectively COX-2, but not COX-1, through p38(MAPK) and PKC pathways. No involvement of other stress kinases, e.g., c-Jun NH(2)-terminal kinase and extracellular-regulated kinases 1 and 2, was observed. Transient transfection of NF-kappaB promoter construct and dominant negative plasmid of IkappaBbeta kinase showed that COX-2 transcription is mediated through p38(MAPK) and NF-kappaB pathways. That NF-kappaB up-regulates p38(MAPK) is novel and is in contradiction to earlier reports in which NF-kappaB was shown to inhibit p38(MAPK). In conclusion, multiple converging signaling pathways, involving TLRs followed by PKC, p38(MAPK), and/or NF-kappaB, are triggered by C. albicans in activation of COX-2 gene.
authors.affiliation: Eicosanoid and Lipid Research Division and Centre for Experimental Gynecology and Breast Research, Department of Gynecology, University Medical Centre Benjamin Franklin, Free University of Berlin, Berlin, Germany.
authors.forename: Rupal
authors.initials: R
authors.lastname: Deva
authors.forename: Pattabhiraman
authors.initials: P
authors.lastname: Shankaranarayanan
authors.forename: Roberto
authors.initials: R
authors.lastname: Ciccoli
authors.forename: Santosh
authors.initials: S
authors.lastname: Nigam
mesh_terms: D002176:Candida albicans / Q000187:drug effects / Q000502:physiology*; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000096:biosynthesis; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D008562:Membrane Glycoproteins / Q000502:physiology*; D008565:Membrane Proteins; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D016328:NF-kappa B / Q000502:physiology*; D018384:Oxidative Stress / Q000502:physiology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors; D011956:Receptors, Cell Surface / Q000502:physiology*; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors; D015533:Transcriptional Activation / Q000502:physiology*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D015232:Dinoprostone