title: Phytosphingosine-1-phosphate is a signaling molecule involved in miconazole resistance in sessile Candida albicans cells.
abstract: Previous research has shown that 1% to 10% of sessile Candida albicans cells survive treatment with high doses of miconazole (a fungicidal imidazole). In the present study, we investigated the involvement of sphingolipid biosynthetic intermediates in this survival. We observed that the LCB4 gene, coding for the enzyme that catalyzes the phosphorylation of dihydrosphingosine and phytosphingosine, is important in governing the miconazole resistance of sessile Saccharomyces cerevisiae and C. albicans cells. The addition of 10 nM phytosphingosine-1-phosphate (PHS-1-P) drastically reduced the intracellular miconazole concentration and significantly increased the miconazole resistance of a hypersusceptible C. albicans heterozygous LCB4/lcb4 mutant, indicating a protective effect of PHS-1-P against miconazole-induced cell death in sessile cells. At this concentration of PHS-1-P, we did not observe any effect on the fluidity of the cytoplasmic membrane. The protective effect of PHS-1-P was not observed when the efflux pumps were inhibited or when tested in a mutant without functional efflux systems. Also, the addition of PHS-1-P during miconazole treatment increased the expression levels of genes coding for efflux pumps, leading to the hypothesis that PHS-1-P acts as a signaling molecule and enhances the efflux of miconazole in sessile C. albicans cells.
authors.affiliation: Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium.
authors.forename: Davy
authors.initials: D
authors.lastname: Vandenbosch
authors.forename: Anna
authors.initials: A
authors.lastname: Bink
authors.forename: Gilmer
authors.initials: G
authors.lastname: Govaert
authors.forename: Bruno P A
authors.initials: BP
authors.lastname: Cammue
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Nelis
authors.forename: Karin
authors.initials: K
authors.lastname: Thevissen
authors.forename: Tom
authors.initials: T
authors.lastname: Coenye
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D025141:Drug Resistance, Fungal / Q000187:drug effects / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D008825:Miconazole / Q000494:pharmacology*; D009154:Mutation; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000935:Antifungal Agents; D026901:Membrane Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; C117422:phytosphingosine-1-phosphate; D008825:Miconazole; C113962:LCB4 protein, S cerevisiae; D017853:Phosphotransferases (Alcohol Group Acceptor); C012491:phytosphingosine; D013110:Sphingosine; C005682:safingol