Project description:Sampangine, a plant-derived alkaloid found in the Annonaceae family, exhibits strong inhibitory activity against the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. In the present study, transcriptional profiling experiments coupled with the analysis of mutants were performed in an effort to elucidate its mechanism of action. Using Saccharomyces cerevisiae as a model organism, we show that sampangine produces a transcriptional response indicative of hypoxia, altering the expression of genes known to respond to low oxygen conditions. Several additional lines of evidence obtained suggest that these responses could involve effects on heme. First, the hem1 deletion mutant lacking the first enzyme in the heme biosynthetic pathway showed increased sensitivity to sampangine, and exogenously supplied hemin partially rescued the inhibitory activity of sampangine in wild-type cells. In addition, heterozygous mutants with deletions in genes involved in five out of eight steps in the heme biosynthetic pathway showed increased susceptibility to sampangine. Furthermore, spectral analysis of pyridine extracts indicated significant accumulation of free porphyrins in sampangine-treated cells. Transcriptional profiling experiments were also performed in C. albicans to investigate the response of a pathogenic fungal species to sampangine. Taking into account the known differences in the physiological responses of C. albicans and S. cerevisiae to low oxygen, significant correlations were observed between the two transcription profiles suggestive of heme-related defects. Our results indicate that the antifungal activity of the plant alkaloid sampangine is due, at least in part, to perturbations in the biosynthesis or metabolism of heme. GSE10073: Gene expression response to the antifungal compound sampangine in S. cerevisiae GSE10075: Gene expression response to the antifungal compound sampangine in C. albicans Keywords: SuperSeries Refer to individual Series
Project description:Plakortide F acid (PFA), a marine-derived polyketide endoperoxide, exhibits strong inhibitory activity against the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model organism Saccharomyces cerevisiae, to investigate the mechanism of action of this compound. PFA elicited a transcriptome response indicative of a Ca2+ imbalance, affecting the expression of genes known to be responsive to altered cellular calcium levels. Several additional lines of evidence obtained supported a role for Ca2+ in PFA's activity. First, mutants lacking calcineurin and various Ca2+ transporters including pumps (Pmr1 and Pmc1) and channels (Cch1 and Mid1) showed increased sensitivity to PFA. In addition, the calcineurin inhibitors FK506 and cyclosporine A strongly enhanced PFA activity in wild-type cells. Furthermore, PFA activated the transcription of a lacZ reporter driven by the calcineurin-dependent response element. Finally, elemental analysis indicated a significant increase in intracellular calcium levels in PFA-treated cells. Collectively, our results demonstrate that PFA mediates its antifungal activity by perturbing Ca2+ homeostasis, thus representing a potentially novel mechanism distinct from that of currently used antifungal agents. DNA microarray analysis of gene expression response to the antifungal compound plakortide F acid in yeast
Project description:Plakortide F acid (PFA), a marine-derived polyketide endoperoxide, exhibits strong inhibitory activity against the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model organism Saccharomyces cerevisiae, to investigate the mechanism of action of this compound. PFA elicited a transcriptome response indicative of a Ca2+ imbalance, affecting the expression of genes known to be responsive to altered cellular calcium levels. Several additional lines of evidence obtained supported a role for Ca2+ in PFA's activity. First, mutants lacking calcineurin and various Ca2+ transporters including pumps (Pmr1 and Pmc1) and channels (Cch1 and Mid1) showed increased sensitivity to PFA. In addition, the calcineurin inhibitors FK506 and cyclosporine A strongly enhanced PFA activity in wild-type cells. Furthermore, PFA activated the transcription of a lacZ reporter driven by the calcineurin-dependent response element. Finally, elemental analysis indicated a significant increase in intracellular calcium levels in PFA-treated cells. Collectively, our results demonstrate that PFA mediates its antifungal activity by perturbing Ca2+ homeostasis, thus representing a potentially novel mechanism distinct from that of currently used antifungal agents. DNA microarray analysis of gene expression response to the antifungal compound plakortide F acid in yeast S. cerevisiae S288C cells at OD 0.2 were treated with either plakortide F acid (PFA) at IC50 concentration (0.62 ug/ml), or solvent (0.25% DMSO), allowed to grow to OD 0.5, then harvested and frozen. Three biological replicate samples were analyzed for each treatment.
Project description:Sampangine, a plant-derived alkaloid found in the Annonaceae family, exhibits strong inhibitory activity against the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. In the present study, transcriptional profiling experiments coupled with the analysis of mutants were performed in an effort to elucidate its mechanism of action. Using Saccharomyces cerevisiae as a model organism, we show that sampangine produces a transcriptional response indicative of hypoxia, altering the expression of genes known to respond to low oxygen conditions. Several additional lines of evidence obtained suggest that these responses could involve effects on heme. First, the hem1 deletion mutant lacking the first enzyme in the heme biosynthetic pathway showed increased sensitivity to sampangine, and exogenously supplied hemin partially rescued the inhibitory activity of sampangine in wild-type cells. In addition, heterozygous mutants with deletions in genes involved in five out of eight steps in the heme biosynthetic pathway showed increased susceptibility to sampangine. Furthermore, spectral analysis of pyridine extracts indicated significant accumulation of free porphyrins in sampangine-treated cells. Transcriptional profiling experiments were also performed in C. albicans to investigate the response of a pathogenic fungal species to sampangine. Taking into account the known differences in the physiological responses of C. albicans and S. cerevisiae to low oxygen, significant correlations were observed between the two transcription profiles suggestive of heme-related defects. Our results indicate that the antifungal activity of the plant alkaloid sampangine is due, at least in part, to perturbations in the biosynthesis or metabolism of heme. Keywords: antifungal compound, transcriptional profiling, C. albicans
Project description:Sampangine, a plant-derived alkaloid found in the Annonaceae family, exhibits strong inhibitory activity against the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. In the present study, transcriptional profiling experiments coupled with the analysis of mutants were performed in an effort to elucidate its mechanism of action. Using Saccharomyces cerevisiae as a model organism, we show that sampangine produces a transcriptional response indicative of hypoxia, altering the expression of genes known to respond to low oxygen conditions. Several additional lines of evidence obtained suggest that these responses could involve effects on heme. First, the hem1 deletion mutant lacking the first enzyme in the heme biosynthetic pathway showed increased sensitivity to sampangine, and exogenously supplied hemin partially rescued the inhibitory activity of sampangine in wild-type cells. In addition, heterozygous mutants with deletions in genes involved in five out of eight steps in the heme biosynthetic pathway showed increased susceptibility to sampangine. Furthermore, spectral analysis of pyridine extracts indicated significant accumulation of free porphyrins in sampangine-treated cells. Transcriptional profiling experiments were also performed in C. albicans to investigate the response of a pathogenic fungal species to sampangine. Taking into account the known differences in the physiological responses of C. albicans and S. cerevisiae to low oxygen, significant correlations were observed between the two transcription profiles suggestive of heme-related defects. Our results indicate that the antifungal activity of the plant alkaloid sampangine is due, at least in part, to perturbations in the biosynthesis or metabolism of heme. Keywords: antifungal compound, transcriptional profiling, S. cerevisiae
Project description:6-Nonadecynoic acid (6-NDA), a plant-derived acetylenic acid, exhibits strong inhibitory activity against the human fungal pathogens Candida albicans, Aspergillus fumigatus, and Trichophyton mentagrophytes. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model organism Saccharomyces cerevisiae to investigate the mechanism of action of this compound. 6-NDA elicited a transcriptome response indicative of fatty acid stress, altering the expression of genes known to be affected when yeast cells are grown in the presence of oleate. Mutants of S. cerevisiae lacking transcription factors that regulate fatty acid beta-oxidation showed increased sensitivity to 6-NDA. Fatty acid profile analysis indicated that 6-NDA inhibited the formation of fatty acids longer than 14 carbons in length. In addition, the growth inhibitory effect of 6-NDA was rescued in the presence of exogenously supplied oleate. To investigate the response of a pathogenic fungal species to 6-NDA, transcriptional profiling and biochemical analyses were also conducted in C. albicans. The transcriptional response and fatty acid profile of C. albicans were comparable to those obtained in S. cerevisiae, and the rescue of growth inhibition with exogenous oleate was also observed in C. albicans. In addition, 6-NDA enhanced the potency of the antifungal drug fluconazole in a fluconazole-resistant clinical isolate of C. albicans. Collectively, our results indicate that the antifungal activity of 6-NDA is mediated by a disruption in fatty acid homeostasis, and that this compound has potential utility in combination therapy in the treatment of drug-resistant fungal infections.
Project description:Sampangine, a plant-derived alkaloid found in the Annonaceae family, exhibits strong inhibitory activity against the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. In the present study, transcriptional profiling experiments coupled with the analysis of mutants were performed in an effort to elucidate its mechanism of action. Using Saccharomyces cerevisiae as a model organism, we show that sampangine produces a transcriptional response indicative of hypoxia, altering the expression of genes known to respond to low oxygen conditions. Several additional lines of evidence obtained suggest that these responses could involve effects on heme. First, the hem1 deletion mutant lacking the first enzyme in the heme biosynthetic pathway showed increased sensitivity to sampangine, and exogenously supplied hemin partially rescued the inhibitory activity of sampangine in wild-type cells. In addition, heterozygous mutants with deletions in genes involved in five out of eight steps in the heme biosynthetic pathway showed increased susceptibility to sampangine. Furthermore, spectral analysis of pyridine extracts indicated significant accumulation of free porphyrins in sampangine-treated cells. Transcriptional profiling experiments were also performed in C. albicans to investigate the response of a pathogenic fungal species to sampangine. Taking into account the known differences in the physiological responses of C. albicans and S. cerevisiae to low oxygen, significant correlations were observed between the two transcription profiles suggestive of heme-related defects. Our results indicate that the antifungal activity of the plant alkaloid sampangine is due, at least in part, to perturbations in the biosynthesis or metabolism of heme. This SuperSeries is composed of the SubSeries listed below.
Project description:6-Nonadecynoic acid (6-NDA), a plant-derived acetylenic acid, exhibits strong inhibitory activity against the human fungal pathogens Candida albicans, Aspergillus fumigatus, and Trichophyton mentagrophytes. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model organism Saccharomyces cerevisiae to investigate the mechanism of action of this compound. 6-NDA elicited a transcriptome response indicative of fatty acid stress, altering the expression of genes known to be affected when yeast cells are grown in the presence of oleate. Mutants of S. cerevisiae lacking transcription factors that regulate fatty acid ?-oxidation showed increased sensitivity to 6-NDA. Fatty acid profile analysis indicated that 6-NDA inhibited the formation of fatty acids longer than 14 carbons in length. In addition, the growth inhibitory effect of 6-NDA was rescued in the presence of exogenously supplied oleate. To investigate the response of a pathogenic fungal species to 6-NDA, transcriptional profiling and biochemical analyses were also conducted in C. albicans. The transcriptional response and fatty acid profile of C. albicans were comparable to those obtained in S. cerevisiae, and the rescue of growth inhibition with exogenous oleate was also observed in C. albicans. In addition, 6-NDA enhanced the potency of the antifungal drug fluconazole in a fluconazole-resistant clinical isolate of C. albicans. Collectively, our results indicate that the antifungal activity of 6-NDA is mediated by a disruption in fatty acid homeostasis, and that this compound has potential utility in combination therapy in the treatment of drug-resistant fungal infections. Cultures of S. cerevisiae strain S288C were started at OD600 of 0.1, allowed to grow to OD600 of 0.2, then treated with either DMSO (0.25%) or 6-NDA at the IC50 concentration (2.2 ug/ml). When OD600 of 0.5 was reached, cells were harvested and frozen. Two biological replicate cultures were grown for each treatment, and RNA from each replicate was hybridized to 2 independent arrays, resulting in 4 hybridizations for each treatment. Cultures of C. albicans strain SC5314 were started at OD600 of 0.1, allowed to grow to OD600 of 0.2, then treated with either DMSO (0.25%) or 6-NDA at the IC50 concentration (4 ug/ml). When OD600 of 0.5 was reached, cells were harvested and frozen. Three biological replicate cultures were grown for each treatment, and RNA from each replicate was hybridized as dye-swap pairs, resulting in 6 hybridizations for each treatment.
Project description:The systemic infections by peptogenous fungi member of the genera Candida and Aspergillus represent a serious threat for public health. During previous research we have successfully identified a family of compounds active against different Candida spp. including strains resistant to antifungal drugs currently on the market. We have further refined our knowledge on this field by identifying a possible molecular target that could justify the activity of these compounds. The research of the mode of action of the compounds object of this manuscript was supported also by fluorescent microscopy of labeled derivatives. Transcriptional data indicates that one of the macrocyclic antifungal induces a drug response involving ATP binding cassette transporters. Moreover the data show that the macrocyclic antifungal decrease expression of cell wall biosynthesis genes. Moreover, the quality of the compounds and their potential was tested in vivo revealing a promising profile in particular against fungal infection caused by resistant strains Gene expression was measured in Candida albians CAF2-1 exposed to the macrocyclic compound FR59 at 3 µM at two time points (15 min and 45 min), The one-color system was used. Three independent experiments were performed using non-exposed cells, 15 min and 45 min exposed cells.