Mutations in TAC1B drive increased CDR1 and MDR1 expression and azole resistance in Candida auris
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PROVIDER: PRJNA1217042 | ENA |
REPOSITORIES: ENA
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Project description:Objective: Candida auris has emerged as a fungal pathogen of particular concern owing in part to its propensity to exhibit antifungal resistance, especially to the commonly prescribed antifungal fluconazole. In this work we aimed to determine how mutations in the transcription factor gene TAC1B, which are common among resistant isolates and confer fluconazole resistance, exert this effect. Methods: Selected TAC1B mutations from clinical isolates were introduced into a susceptible isolate and reverted to the wild-type sequence in select clinical isolates using CRISPR Cas9 gene editing. Disruption mutants were likewise generated for select genes of interest. TAC1B mutants were subjected to transcriptional profiling by RNA-seq, and relative expression of specific genes of interest was determined by qRT-PCR. Antifungal susceptibilities were determined by modified CLSI broth microdilution. Results: TAC1B mutations leading to A640V, A657V, and F862_N866del conferred fluconazole resistance, as well as increased resistance to other triazoles, when introduced into a susceptible isolate. RNA-seq revealed that the ATP-Binding Cassette (ABC) transporter gene CDR1 as well as the Major Facilitator Superfamily (MFS) transporter gene MDR1 were both up-regulated by these TAC1B mutations. Disruption of CDR1 greatly abrogated resistance in strains with TAC1B mutations whereas disruption of MDR1 had little to no effect. However, disruption of both CDR1 and MDR1 resulted in an additional reduction in resistance as compared to disruption of either gene alone. Conclusion: TAC1B mutations leading to A640V, A657V, and F862_N866del all result in increased resistance to fluconazole and other triazole antifungals, and increased expression of both CDR1 and MDR1 in C. auris. CDR1 is the primary driver of resistance conferred by these TAC1B mutations.
2025-07-28 | GSE288372 | GEO
Project description:Candida auris (Candidozyma auris) is a yeast pathogen that poses a public health threat because of its ability to develop antifungal resistance. Notably, most C. auris isolates are resistant to fluconazole. The efflux pump Cdr1 is a key contributor of azole resistance in C. auris. In C. albicans, Cdr1 is regulated by the transcription factor Tac1, which has two orthologs in C. auris (Tac1a and Tac1b). While the role of Tac1b has been described, little is known about Tac1a. In this study, we characterized the respective roles of Tac1a and Tac1b in azole resistance. To investigate their transcriptional regulation and binding targets, we performed RNA sequencing and ChEC-seq (Chromatin endogenous cleavage sequencing) for both transcription factors. RNA sequencing was carried out by comparing hyperactivated mutants (TAC1a-HA or TAC1b-HA) with the wild-type strain IV.1. ChEC-seq was performed in strains carrying endogenous C-terminal MNase fusions (TAC1a-MNase and TAC1b-MNase) and in a control strain expressing ectopically MNase (Free MNase). Both Tac1a and Tac1b mediate azole resistance in C. auris via regulation of Cdr1, with overlapping downstream targets and evidence of autoregulation.
2025-09-13 | GSE307436 | GEO
Project description:The limited number of antifungals and the emergence of multidrug-resistant Candida auris pose a significant challenge to human medicine. Here, we utilized combinatorial drug therapy as an approach to augment the activity of current azole antifungals against C. auris. We evaluated the fluconazole chemosensitization activity of 1547 FDA-approved drugs and clinical molecules against an azole-resistant strain of C. auris. This led to the discovery that lopinavir, an antiviral drug, is a potent agent capable of sensitizing C. auris to the effect of azole antifungals. At a therapeutically achievable concentration (4-8 µg/ml), lopinavir exhibited potent synergistic interactions with azole drugs, particularly with itraconazole, against C. auris (ΣFICI ranged from 0.05-0.50). The lopinavir/itraconazole combination enhanced the survival rate of C. auris-infected Caenorhabditis elegans by 90% and reduced the fungal burden in infected nematodes by 88.5% (p < 0.05). Moreover, lopinavir enhanced the antifungal activity of itraconazole against other medically important Candida species including C. albicans, C. tropicalis, C. glabrata, C. tropicalis, and C. parapsilosis. Comparative transcriptomic profiling revealed that lopinavir interferes with glucose permeation and ATP synthesis. This compromises the function of the efflux pumps presents in C. auris enhancing sensitivity to azole antifungals, as demonstrated by Nile red efflux assays. This study presents lopinavir as a novel, potent and broad-spectrum azole chemosensitizing agent that warrants further investigation against recalcitrant Candida infections.
2020-10-06 | GSE148341 | GEO
Project description:Combination therapies can be a promising tool to augment the antifungal activity of azole drugs against resistant Candida species. Here, we report the interaction between aprepitant, an antiemetic agent, and azole drugs against different Candida species including the emerging multidrug-resistant C. auris. Particularly, aprepitant enhanced the antifungal activity of itraconazole against C. auris by reducing its minimum inhibitory concentration (MIC) by 2-8 folds. Using Caenorhabditis elegans as an in vivo infection model, the aprepitant/itraconazole combination significantly prolonged the survival of the infected nematodes by ~90% and reduced the fungal burden by ~92% relative to the untreated control. Interestingly, the aprepitant/itraconazole combination exerted a potent fungicidal activity against both planktonic and adherent C. auris biofilms. Further, aprepitant/itraconazole displayed broad-spectrum synergistic interactions against other medically important Candida species including C. albicans, C. krusie, C. tropicalis, and C. parapsilosis (ƩFICI ranged from 0.08 to 031). Comparative transcriptomic profiling indicated aprepitant/itraconazole interferes significantly with metal ions homeostasis and compromises the ROS (reactive oxygen species) detoxification ability of C. auris. This study presents aprepitant as a novel, potent and broad-spectrum azole chemosensitizing agent that warrants further investigation.
2020-10-19 | GSE148749 | GEO
Project description:The antifungal resistance threat posed by Candida auris necessitates bold and innovative therapeutic options. Farnesol, a quorum-sensing molecule with a potential antifungal and/or adjuvant effect; it may be a promising candidate in alternative treatment regimens. To gain further insights into the farnesol-related effect on C. auris, genome-wide gene expression analysis was performed using RNA-Seq. Farnesol exposure resulted in 1,766 differentially expressed genes. Of these, 447 and 304 genes with at least 1.5-fold increase or decrease in expression, respectively, were selected for further investigation. Genes involved in morphogenesis, biofilm events (maturation and dispersion), gluconeogenesis, iron metabolism, and regulation of RNA biosynthesis showed down-regulation, whereas those related to antioxidative defense, transmembrane transport, glyoxylate cycle, fatty acid β-oxidation, and peroxisome processes were up-regulated. In addition, farnesol treatment increased the expression of certain efflux pump genes, including MDR1, CDR1, and CDR2. Growth, measured by change in CFU number, was significantly inhibited within 2 hours of the addition of farnesol (5.8×10^7±1.1×10^7 and 1.1×10^7±0.3×10^7 CFU/ml for untreated control and farnesol-exposed cells, respectively) (p<0.001). In addition, farnesol treatment caused a significant reduction in intracellular iron (152.2±21.1 vs. 116.0±10.0 mg/kg), manganese (67.9±5.1 vs. 18.6±1.8 mg/kg), and zinc (787.8±22.2 vs. 245.8±34.4 mg/kg) (p<0.05–0.001) compared to untreated control cells, whereas the level of cooper was significantly increased (274.6±15.7 vs. 828.8±106.4 mg/kg) (p<0.001). Our data demonstrate that farnesol significantly influences the growth, intracellular metal ion contents, and gene expression related to fatty acid metabolism, which could open new directions in developing alternative therapies against C. auris.
2021-09-30 | GSE180093 | GEO
Project description:From C. albicans reference strain SC5314, CDR1, CDR2, MDR1, CMP1, CNB1, CRZ1 were deleted. The deletion strains were spread on YPD plates supplemented with tebuconazole. Randomly 4 adaptors derived from each deletion strain were sequenced.
2023-08-09 | E-MTAB-13238 | biostudies-arrayexpress
Project description:Candida auris is an emerging yeast pathogen with a remarkable ability to develop antifungal resistance, in particular to fluconazole and other azoles. Azole resistance in C. auris was shown to result from different mechanisms, such as mutations in the target gene ERG11 or gain-of-function (GOF) mutations in the transcription factor TAC1b and overexpression of the drug transporter Cdr1. The roles of the transcription factor Mrr1 and of the drug transporter Mdr1 in azole resistance is still unclear. Previous works showed that deletion of MRR1 or MDR1 had no or little impact on azole susceptibility of C. auris. However, an amino acid substitution in Mrr1 (N647T) was identified in most C. auris isolates of clade III that were fluconazole resistant. This study aimed at investigating the role of the transcription factor Mrr1 in azole resistance of C. auris. While the MRR1N647T mutation was always concomitant to hot spot ERG11 mutations, MRR1 deletion in one of these isolates only resulted in a modest decrease of azole MICs. However, introduction of the MRR1N647T mutation in an azole-susceptible C. auris isolate from another clade with wild-type MRR1 and ERG11 alleles resulted in significant increase of fluconazole and voriconazole MICs. We demonstrated that this MRR1 mutation resulted in reduced azole susceptibility via upregulation of the drug transporter MDR1 and not CDR1. In conclusion, this work demonstrates that the Mrr1-Mdr1 axis may contribute to C. auris azole resistance by mechanisms that are independent from ERG11 mutations and from CDR1 upregulation.
| S-EPMC9017311 | biostudies-literature
Project description:we performed mitochondrial proteomic analysis on multiple Candida species (C. albicans, C. glabrata, C. krusei and Candida auris) and analyzed the differentially expressed mitochondrial proteins (DEMPs) between azole-sensitive and azole-resistant Candida species.
2023-09-05 | PXD045101 |
Project description:The aim of this study was to characterize the transcriptional signature of MDR1+ human memory T cells isolated from clinically inflamed gut tissue, and compare it to local MDR1- memory T cells Human mononuclear cells were isolated from the peripheral blood of a healthy adult donor (Ficol density centrifugation) or from resected lesioned gut tissue of a patient with active Crohn's disease. For cell isolation from gut tissue, tissue was rinsed with PBS, treated with 0.15% DTT to remove mucous, then with 1 mM EDTA to remove epithelial cells and intra-epithelial lymphocytes. Remaining tissue was digested using Liberase-TL (Roche) plus 10 U/mL DNase I. Mononuclear cells were then filtered through 70 mM nylon filters and isolated via a 30%/ 70% Percol gradient. Mononuclear cells from blood or gut tissue were FACS-sorted into CD3+ CD4+ CD45RO+ MDR1+ or MDR1- memory T cells, using Rhodamine 123 (Rh123) efflux as a surrogate for MDR1 expression/ activity. Sorted cells were harvested directly ex vivo (without further in vitro culture or manipulation) prior to RNA extraction. MDR1- memory CD4+ T cells vs. MDR1+ memory CD4+ T cells from healthy donor peripheral blood or from active Crohn's disease lesioned tissue; MDR1- or MDR1+ memory CD4+ T cells from blood vs. inflamed gut tissue
2013-12-17 | E-GEOD-49702 | biostudies-arrayexpress
Project description:The aim of this study was to characterize the transcriptional signature of MDR1+ human memory T cells isolated from clinically inflamed gut tissue, and compare it to local MDR1- memory T cells
2013-12-17 | GSE49702 | GEO