Contribution of CgPDR1-regulated genes in enhanced virulence of azole-resistant Candida glabrata
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ABSTRACT:
ORGANISM(S): Nakaseomyces glabratus CBS 138 Nakaseomyces glabratus
PROVIDER: GSE23829 | GEO | 2010/12/31
SECONDARY ACCESSION(S): PRJNA130563
REPOSITORIES: GEO
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Project description:In Candida glabrata, the transcription factor CgPdr1 is involved in resistance to azole antifungals via upregulation of ATP binding cassette (ABC)-transporter genes including at least CgCDR1, CgCDR2 and CgSNQ2. A high diversity of GOF (gain-of-function) mutations in CgPDR1 exists for the upregulation of ABC-transporters. These mutations enhance C. glabrata virulence in animal models, thus indicating that CgPDR1 might regulate the expression of yet unidentified virulence factors. We hypothesized that CgPdr1-dependent virulence factor(s) should be commonly regulated by all GOF mutations in CgPDR1. As deduced from transcript profiling with microarrays, a high number of genes (up to 385) were differentially regulated by a selected number (7) of GOF mutations expressed in the same genetic background. Surprisingly, the transcriptional profiles resulting from expression of GOF mutations showed minimal overlap in co-regulated genes. Only two genes, CgCDR1 and PUP1 (for PDR1 upregulated and encoding a mitochondrial protein), were commonly upregulated by all tested GOFs. While both genes mediated azole resistance, although to different extents, their deletions in an azole-resistant isolate led to a reduction of virulence and decreased tissue burden as compared to clinical parents. As expected from their role in C. glabrata virulence, the two genes were expressed as well in vitro and in vivo. The individual overexpression of these two genes in a CgPDR1-independent manner could partially restore phenotypes obtained in clinical isolates. These data therefore demonstrate that at least these two CgPDR1-dependent and -upregulated genes contribute to the enhanced virulence of C. glabrata that acquired azole resistance.
| S-EPMC3052359 | biostudies-literature
Project description:This SuperSeries is composed of the following subset Series: GSE23827: Contribution of CgPDR1-regulated genes in enhanced virulence of azole-resistant Candida glabrata (part 1) GSE23828: Contribution of CgPDR1-regulated genes in enhanced virulence of azole-resistant Candida glabrata (part 2) Refer to individual Series
2010-12-31 | E-GEOD-23829 | biostudies-arrayexpress
Project description:In this study, we aimed to determine genome-wide changes in gene expression driven by seven individual CgPDR1 hyperactive alleles as compared to wild-type allele to identify i) the CgPdr1p target genes differentially expressed in presence of CgPDR1 hyperactive alleles and ii) potential virulence factor(s) regulated by CgPDR1 hyperactive alleles. Microarray experiments revealed a high number of genes (ranging from 80 to 400 genes) differentially regulated by individual CgPDR1 hyperactive alleles.
2010-12-31 | GSE23828 | GEO
Project description:In this study, we aimed to determine genome-wide changes in gene expression driven by seven individual CgPDR1 hyperactive alleles as compared to wild-type allele to identify i) the CgPdr1p target genes differentially expressed in presence of CgPDR1 hyperactive alleles and ii) potential virulence factor(s) regulated by CgPDR1 hyperactive alleles. Microarray experiments revealed a high number of genes (ranging from 80 to 400 genes) differentially regulated by individual CgPDR1 hyperactive alleles.
2010-12-31 | GSE23827 | GEO
Project description:In this study, we aimed to determine genome-wide changes in gene expression driven by seven individual CgPDR1 hyperactive alleles as compared to wild-type allele to identify i) the CgPdr1p target genes differentially expressed in presence of CgPDR1 hyperactive alleles and ii) potential virulence factor(s) regulated by CgPDR1 hyperactive alleles. Microarray experiments revealed a high number of genes (ranging from 80 to 400 genes) differentially regulated by individual CgPDR1 hyperactive alleles. Gene expression was measured in 2 C. glabrata clinical isolates (DSY717 and DSY2317). DSY2317 is azole-susceptible and contains a wild-type CgPDR1 allele. DSY717 is azole-resistant and contains a CgPDR1 allele with the gain-of-function mutation L1081F.
2010-12-31 | E-GEOD-23828 | biostudies-arrayexpress
Project description:In this study, we aimed to determine genome-wide changes in gene expression driven by seven individual CgPDR1 hyperactive alleles as compared to wild-type allele to identify i) the CgPdr1p target genes differentially expressed in presence of CgPDR1 hyperactive alleles and ii) potential virulence factor(s) regulated by CgPDR1 hyperactive alleles. Microarray experiments revealed a high number of genes (ranging from 80 to 400 genes) differentially regulated by individual CgPDR1 hyperactive alleles. Gene expression was measured in 7 C. glabrata laboratory strains (SFY101, SFY103, SFY105, SFY109, SFY111, SFY115, SFY116) expressing different CgPDR1 hyperactive alleles, in 1 strain (SFY114) expressing a wild-type CgPDR1 allele and in one strain deleted for CgPDR1. The one-color system was used. 3 independent experiments were performed using 3 biological replicates for each strain.
2010-12-31 | E-GEOD-23827 | biostudies-arrayexpress
Project description:Contribution of CgPDR1-regulated genes in enhanced virulence of azole-resistant Candida glabrata
| PRJNA130563 | ENA
Project description:Two isolates of Candida glabrata, one susceptible and one resistant to azole antifungals, were previously shown to differ in quantity and activity of the cytochrome P-450 14alpha-lanosterol demethylase which is the target for azole antifungals. The resistant isolate also had a lower intracellular level of fluconazole, but not of ketoconazole or itraconazole, than the susceptible isolate. In the present study a 3.7-fold increase in the copy number of the CYP51 gene, encoding the 14alpha-lanosterol demethylase, was found. The amount of CYP51 mRNA transcript in the resistant isolate was eight times greater than it was in the susceptible isolate. Hybridization experiments on chromosomal blots indicated that this increase in copy number was due to duplication of the entire chromosome containing the CYP51 gene. The phenotypic instability of the resistant isolate was demonstrated genotypically: a gradual loss of the duplicated chromosome was seen in successive subcultures of the isolate in fluconazole-free medium and correlated with reversion to susceptibility. The greater abundance of the amplified chromosome induced pronounced differences in the protein patterns of the susceptible and revertant isolates versus that of the resistant isolate, as demonstrated by two-dimensional gel electrophoresis (2D-GE). Densitometry of the 2D-GE product indicated upregulation of at least 25 proteins and downregulation of at least 76 proteins in the resistant isolate.
| S-EPMC164098 | biostudies-other
Project description:Mitochondrial dysfunction is one of the possible mechanisms by which azole resistance can occur in Candida glabrata. Cells with mitochondrial DNA deficiency (so-called "petite mutants") upregulate ATP binding cassette (ABC) transporter genes and thus display increased resistance to azoles. Isolation of such C. glabrata mutants from patients receiving antifungal therapy or prophylaxis has been rarely reported. In this study, we characterized two sequential and related C. glabrata isolates recovered from the same patient undergoing azole therapy. The first isolate (BPY40) was azole susceptible (fluconazole MIC, 4 μg/ml), and the second (BPY41) was azole resistant (fluconazole MIC, >256 μg/ml). BPY41 exhibited mitochondrial dysfunction and upregulation of the ABC transporter genes C. glabrata CDR1 (CgCDR1), CgCDR2, and CgSNQ2. We next assessed whether mitochondrial dysfunction conferred a selective advantage during host infection by testing the virulence of BPY40 and BPY41 in mice. Surprisingly, even with in vitro growth deficiency compared to BPY40, BPY41 was more virulent (as judged by mortality and fungal tissue burden) than BPY40 in both systemic and vaginal murine infection models. The increased virulence of the petite mutant correlated with a drastic gain of fitness in mice compared to that of its parental isolate. To understand this unexpected feature, genome-wide changes in gene expression driven by the petite mutation were analyzed by use of microarrays during in vitro growth. Enrichment of specific biological processes (oxido-reductive metabolism and the stress response) was observed in BPY41, all of which was consistent with mitochondrial dysfunction. Finally, some genes involved in cell wall remodelling were upregulated in BPY41 compared to BPY40, which may partially explain the enhanced virulence of BPY41. In conclusion, this study shows for the first time that mitochondrial dysfunction selected in vivo under azole therapy, even if strongly affecting in vitro growth characteristics, can confer a selective advantage under host conditions, allowing the C. glabrata mutant to be more virulent than wild-type isolates.
| S-EPMC3088236 | biostudies-literature
Project description:Microarray was used to analyze azole resistance of Candida glabrata oropharyngeal isolates from 7 hematopoietic stem cell transplant recipients receiving fluconazole prophylaxis. Transcriptional profiling of the sequential-paired clinical isolates by microarray revealed 19 genes upregulated in the majority of resistant isolates compared to their paired-susceptible isolates. All seven resistant isolates had greater than two fold upregulation of CgPDR1, a master transcriptional regulator of PDR network, and all 7 resistant isolates showed upregulation of known CgPDR1-target genes. The altered transcriptome can be explained in part by the observation that all 7 resistant isolates had acquired a single nonsynonymous mutation in their CgPDR1 ORF. Four mutations occurred in the regulatory domain (L280P, L344S, G348A, S391L) and one in the activation domain (G943S) while two mutations (N764I, R772I) occurred in an undefined region. Association of azole resistance and the CgPDR1 mutations was investigated in the same genetic background by introducing the CgPDR1 sequences from one sensitive and five resistant isolates into a laboratory azole-sensitive strain (cgpdr1) via integrative transformation. The cgpdr1 strain was restored to wild-type fluconazole susceptibility when transformed with CgPDR1 from the susceptible isolate but became resistant when transformed with CgPDR1 from the resistant isolates. However, despite the identical genetic background, upregulation of CgPDR1 and CgPDR1-target genes varied between the 5 transformants, independent of the domain locations in which the mutations occurred. In sum, gain-of-function mutations in CgPDR1 not only contributed to the clinical azole resistance but different mutations had varying degrees of impact on the CgPDR1-target genes.
2010-07-07 | GSE21355 | GEO