Project description:Human serum amyloid A (SAA) is a major acute phase protein and shows a massive increase of concentration in plasma during inflammation. In the current study, we report that recombinant human and mouse SAA1 (rhSAA1 and rmSAA1) have a potent antifungal activity against the major fungal pathogen Candida albicans. rhSAA1 binds to the cell surface of C. albicans and promotes cell aggregation. At high concentrations, rhSAA1 disrupts the membrane integrity and induces rapid cell death of C. albicans. Further investigation demonstrates that rhSAA1 targets on the cell wall adhesin Als3 of C. albicans. Inactivation of ALS3 in C. albicans leads to remarkably decreased cell aggregation and death upon rhSAA1 treatment, implying that Als3 plays a critical role in SAA1 sensing. Moreover, deletion of the ALS3 transcriptional regulators such as AHR1, BCR1, and EFG1 in C. albicans results in a similar effect on cell responses to that of the als3/als3 mutant upon rhSAA1 treatment. Global gene expression profiling analysis indicates that rhSAA1 has a remarkable impact on the expression of cell wall- and metabolism-related genes in C. albicans. Our finding of the antifungal activity of rhSAA1 against C. albicans expands the function of this protein and would provide new insights into the understanding of the host-Candida interaction during infections.
Project description:Candida albicans were treated with a sublethal concentration of the antifungal Jagaricin for either a short time (30 min) or until an OD of 0.5 (indicating log growth) was reached. Controls were grown without any antifungal to determine cellular reactions to the compound.
Project description:The fungal pathogen Candida albicans and other pathogens of the CTG clade reassigned the leucine CUG codon to serine and tolerate highly variable levels of both serine and leucine at CUG positions in response to environmental cues. Previous studies found that increased leucine misincorporation levels enhance resistance to drugs but the underlying mechanisms are not known. To clarify the biological role of this tuneable codon ambiguity, we evolved C. albicans strains engineered to mistranslate CUG at elevated levels, in the presence and absence of the antifungal drug fluconazole
Project description:The fungal pathogen Candida albicans and other pathogens of the CTG clade reassigned the leucine CUG codon to serine and tolerate highly variable levels of both serine and leucine at CUG positions in response to environmental cues. Previous studies found that increased leucine misincorporation levels enhance resistance to drugs but the underlying mechanisms are not known. To clarify the biological role of this tuneable codon ambiguity, we evolved C. albicans strains engineered to mistranslate CUG at elevated levels, in the presence and absence of the antifungal drug fluconazole
Project description:Given the risk of Candida albicans overgrowth in the gut, novel complementary therapies should be developed to reduce fungal dominancy. This study highlights the antifungal characteristics of a Bacillus subtilis-derived secondary metabolite, surfactin with high potential against C. albicans. Surfactin inhibited the growth of C. albicans following a 1-hour exposure, in addition to reduced adhesion and morphogenesis. Specifically, surfactin did not affect the level of reactive oxygen species but increased the level of reduced glutathione. Surprisingly, ethanol production was increased following 2 hours of surfactin exposure. Surfactin treatment caused a significant reduction in intracellular iron, manganese and zinc content compared to control cells, whereas the level of copper was not affected. Alongside these physiological properties, surfactin also enhanced fluconazole efficacy. To gain detailed insights into the surfactin-related effects on C. albicans, genome-wide gene transcription analysis was performed. Surfactin treatment resulted in 1390 differentially expressed genes according to total transcriptome sequencing (RNA-Seq). Of these, 773 and 617 genes with at least a 1.5-fold increase or decrease in transcription, respectively, were selected for detailed investigation. Several genes involved in morphogenesis or related to metabolism (e.g., glycolysis, ethanol and fatty acid biosynthesis) were down-regulated. Moreover, surfactin decreased the expression of ERG1, ERG3, ERG9, ERG10 and ERG11 involved in ergosterol synthesis, whereas genes associated with ribosome biogenesis and iron metabolism and drug transport-related genes were up-regulated. Our data demonstrate that surfactin significantly influences the physiology and gene transcription of C. albicans, and could contribute to the development of a novel innovative complementary therapy.
Project description:Candida albicans is an opportunistic yeast pathogen that causes a wide range of infections especially amongst immunocompromised patients. Aureobasidin A (AbA) has been shown to inhibit inositolphosphoryl ceramide synthase (IPCS), a key enzyme responsible for sphingolipid biosynthesis. There are limited studies exploring IPCS as a target molecule for antifungal treatment. It is hypothesized that the mechanism of AbA inhibition involves alteration of C. albicans phospholipid and sphingolipid profiles. The profiling of C. albicans phospholipid and sphingolipid upon exposure to 0.5-4 µg/ml of AbA were determined using Liquid chromatography-mass spectrometry (LC-MS).
Project description:Aneuploidy and the evolution of aneuploid karyotypes of Candida albicans strains was identified using aCGH. Whole chromosome and segmental aneuploidies, (specifically on the left arm of chromosome 5 - shown to be due to isochromosome formation) are associated with the appearance of resistance to the antifungal drug fluconazole. Keywords: Comparative Genomic Hybridization
Project description:In the light of the increasing occurrence of antifungal resistance, there is an urgent need to search for new therapeutic strategies to overcome this phenomenon. One of the applied approaches is the synthesis of small-molecule compounds showing antifungal properties. Here we present a continuation of the research on the recently discovered anti-Candida albicans agent 4-AN. Using next generation sequencing and transcriptional analysis, we revealed that the treatment of C. albicans with 4-AN can change the expression profile of a large number of genes. The highest up-regulation was observed in the case of genes involved in cell stress, while the highest down-regulation was shown for genes coding sugar transporters. Real-time PCR analysis revealed 4-AN mediated reduction of the relative expression of genes engaged in fungal virulence (ALS1, ALS3, BCR1, CPH1, ECE1, EFG1, HWP1, HYR1, and SAP1). The determination of the fractional inhibitory concentration index (FICI) showed that the combination of 4-AN with Amphotericin B is synergistic. Finally, flow cytometry analysis revealed that the compound induces mainly necrosis in Candida albicans cells.
Project description:Azole resistance and varying degrees of cross-resistance to other members of the azole family in clinical isolates have been documented, which has necessitated additional and prolonged use of the antifungal agents available. 2-Amino-Nonyl-6-Methoxyl-Tetralin Muriate (10b), a novel chemical structural aminotetralin derivate, is synthesized as an antifungal agent and exibited strong antifungal activity. To further investigated the action mechanism, we used microarray analysis to investigate the genes expression profiles of C. albicans cells treated or untreated with 10b and found 957 genes were differentially expressed. Of them,457 showed a decrease in expression and 500 showed an increase in expression. 33 down-regulated genes were involved in glycolysis (e.g., PFK1, CDC19 and HXK2), fermentation (e.g., PDC11, ALD5 and ADH1) and respiratory electron transport chain (e.g., CBP3, COR1 and QCR8). 30 differentially expressed genes were found to relate to biofilm formation, filamentous or hyphal growth. It was noticed that striking up-regulation of SFL1 and marked down-regulation of YWP1 directly related to prevent C. albicans from changing its morphology from the yeast form to the hyphal. Two genes related to specifically hydrolyzing beta-1, 3 glucan (e.g., XOG1) and chitin (e.g., CHT1) were significantly increased. 40 overexpressed genes and 15 down-regulated genes were related to the lipid metabolic process. Of them, Eight were directly linked to ergosterol biosynthesis, including ERG2, ERG6 and ERG11. 99 genes related to translation were down-regulated following exposure to 10b, which account for 21.66% in down-regulated genes. This suggested that translation might be lower in SC5314 cells exposed to 10b than in control. Total RNA from the control SC5314 cells and 10b-treated SC5314 cells were used to generate target cDNA, and then hybridized to 8k Candida albicans Genome Array Genechips, representing about 7925 characterized Candida albicans genes. Two independent experiments were conducted. Reference strain was control SC5314 cells and test strain was SC5314 cells treated with 10b.