Histoplasma capsulatum
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ABSTRACT:
PROVIDER: PRJNA208854 | ENA |
REPOSITORIES: ENA
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Project description:Histoplasma capsulatum is a thermally dimorphic fungus with worldwide distribution, and high incidence in the Americas. It is the etiologic agent of histoplasmosis, an important life-threatening systemic mycosis. Dimorphism is an important feature for fungal survival in different environments and it has been related to the virulence of H. capsulatum, and essential to the establishment of infection. Proteomic profiles have brought important contributions to the knowledge of metabolism and pathogenicity in several biological models. However, studies of the H. capsulatum proteome have been underexplored. In the present study, we report the first proteomic comparison between the mycelium and the yeast cells of H. capsulatum. Liquid chromatography coupled to mass spectrometry was used to evaluate the proteomic profile of the two phases of H. capsulatum. In summary, 214 proteins were only detected/or preferentially abundant in mycelium, while the same occurred to 335 proteins in yeast cells. In mycelium, enzymes related to the glycolytic pathway and to the alcoholic fermentation showed greater abundance, suggesting a higher use of anaerobic pathways for energy production. In yeast cells, proteins related to the tricarboxylic acid cycle and response to temperature stress showed high abundance. Proteins related to oxidative stress response or involved with cell wall metabolism were identified with differential abundance in both conditions. Validation of proteomic data was performed by enzymatic activity determination, western blot assays, or immunofluorescence microscopy. These experiments corroborated, directly or indirectly, the abundance of isocitrate lyase, 2-methylcitrate synthase, catalase B, and mannosyl-oligosaccharide-1,2-alpha-mannosidase in the mycelium and heat shock protein (HSP) 30, HSP60, glucosamine-fructose-6-phosphate aminotransferase, glucosamine-6-phosphate deaminase, and N-acetylglucosamine-phosphate mutase in yeast-cells. The proteomic profile associated functional classification analyzes of proteins provided a better understanding of the metabolic reorganization and cell wall remodeling on the yeast form of H. capsulatum.
2021-09-09 | PXD022623 | Pride
Project description:Thermally dimorphic human fungal pathogens undergo a reversible program of cellular differentiation in response to their environment that is essential for infectivity and pathogenicity. In the soil, these organisms grow as highly polarized, multicellular hyphal filaments that produce infectious particles. When inhaled by a mammalian host, these cells switch to a unicellular yeast form that causes disease even in healthy hosts. Temperature is considered to be the primary environmental cue that promotes reversible cellular differentiation; however, a shift to a lower temperature in vitro induces filamentous growth in an inefficient and asynchronous manner. In a search for other signals that regulate morphogenesis, we considered the monosaccharide N-acetylglucosamine (GlcNAc), which is a major component of microbial cell walls and is ubiquitous in the environment. GlcNAc was a potent and specific inducer of the yeast-to-filament transition in two thermally dimorphic fungi, Histoplasma capsulatum and Blastomyces dermatitidis. Micromolar concentrations of GlcNAc induced a robust morphological transition of H. capsulatum after temperature shift, indicating that fungal cells sense GlcNAc to promote filamentation. The synchronous morphologic transition stimulated by low temperature and GlcNAc allowed us to examine the temporal regulation of the transcriptome during morphogenesis to reveal candidate genes involved in establishing the filamentous growth program. Through this analysis, we identified two genes encoding GlcNAc transporters, NGT1 and NGT2, that were necessary for H. capsulatum cells to robustly filament in response to GlcNAc. Unexpectedly, NGT1 and NGT2 were important for efficient H. capsulatum yeast-to-filament conversion in standard glucose medium, suggesting that Ngt1 and Ngt2 monitor endogenous levels of GlcNAc to control multicellular filamentous growth in response to temperature. Overall, our work indicates that GlcNAc functions as a highly conserved cue of morphogenesis in fungi, which further enhances the significance of this ubiquitous sugar in cellular signaling in eukaryotes. For each time-course sample, cDNA was coupled to Cy5 and a reference cDNA pool was made by combining RNA from t = 0 and all late time course samples, which was coupled to Cy3. For end point microarray experiments (i.e., established yeast samples compared to established filamentous samples), G217B yeast cDNA was coupled to Cy5 and filament cDNA was coupled to Cy3.
2013-08-12 | E-GEOD-48044 | biostudies-arrayexpress
Project description:Thermally dimorphic human fungal pathogens undergo a reversible program of cellular differentiation in response to their environment that is essential for infectivity and pathogenicity. In the soil, these organisms grow as highly polarized, multicellular hyphal filaments that produce infectious particles. When inhaled by a mammalian host, these cells switch to a unicellular yeast form that causes disease even in healthy hosts. Temperature is considered to be the primary environmental cue that promotes reversible cellular differentiation; however, a shift to a lower temperature in vitro induces filamentous growth in an inefficient and asynchronous manner. In a search for other signals that regulate morphogenesis, we considered the monosaccharide N-acetylglucosamine (GlcNAc), which is a major component of microbial cell walls and is ubiquitous in the environment. GlcNAc was a potent and specific inducer of the yeast-to-filament transition in two thermally dimorphic fungi, Histoplasma capsulatum and Blastomyces dermatitidis. Micromolar concentrations of GlcNAc induced a robust morphological transition of H. capsulatum after temperature shift, indicating that fungal cells sense GlcNAc to promote filamentation. The synchronous morphologic transition stimulated by low temperature and GlcNAc allowed us to examine the temporal regulation of the transcriptome during morphogenesis to reveal candidate genes involved in establishing the filamentous growth program. Through this analysis, we identified two genes encoding GlcNAc transporters, NGT1 and NGT2, that were necessary for H. capsulatum cells to robustly filament in response to GlcNAc. Unexpectedly, NGT1 and NGT2 were important for efficient H. capsulatum yeast-to-filament conversion in standard glucose medium, suggesting that Ngt1 and Ngt2 monitor endogenous levels of GlcNAc to control multicellular filamentous growth in response to temperature. Overall, our work indicates that GlcNAc functions as a highly conserved cue of morphogenesis in fungi, which further enhances the significance of this ubiquitous sugar in cellular signaling in eukaryotes.
2013-08-12 | GSE48044 | GEO
Project description:Dimorphic fungus (anamorph Histoplasma capsulatum) that causes histoplasmosis
| PRJNA12630 | ENA
Project description:The yeast-filament transition is essential for the virulence of a variety of fungi that are pathogenic to humans. N-acetylglucosamine (GlcNAc), a ubiquitous molecule in both the environment and host, is one of the most potent inducers of filamentation in Candida albicans and thermally dimorphic fungi such as Histoplasma capsulatum and Blastomyces dermatitidis. However, GlcNAc suppresses rather than promotes filamentation in Candida tropicalis, a fungal species that is closely related to C. albicans. Furthermore, we discover that glucose induces filamentous growth in C. tropicalis. Mutation and overexpression assays demonstrate that the conserved cAMP signaling pathway plays a central role in the regulation of filamentation in C. tropicalis. Activation of this pathway promotes filamentation in C. tropicalis, while inactivation of this pathway results in a serious growth defect in filamentation. By screening an overexpression library of 154 transcription factors, we have identified approximately 40 regulators of filamentous growth in C. tropicalis. Although most of the regulators (e.g., Tec1, Gat2, Nrg1, Sfl1, Sfl2, and Ash1) demonstrate a conserved role in the regulation of filamentation, similar to their homologs in C. albicans or S. cerevisiae, some of them are specific to C. tropicalis. For example, Czf1 and Efh1 repress filamentation, while Wor1, Zcf3, and Hcm1 promote filamentation in C. tropicalis. Bcr1, Aaf1, and Csr1 play a specific role in the process of GlcNAc-regulated filamentation. Our findings indicate that multiple interconnected signaling pathways are involved in the regulation of filamentation in C. tropicalis. These mechanisms have conserved and divergent features among different Candida species. Total RNA profiles of cells grown in Lee's glucose or Lee's GlcNAc medium.
2016-07-01 | E-GEOD-73340 | biostudies-arrayexpress
Project description:Single-celled organisms have different strategies to sense and utilize nutrients in their ever-changing environments. The opportunistic fungal pathogen Candida albicans is a common member of the human microbiota, especially that of the gastrointestinal (GI) tract. An important question concerns how C. albicans gained a competitive advantage over other microbes to become a successful commensal and opportunistic pathogen. Here, we report that C. albicans uses N-acetylglucosamine (GlcNAc), an abundant carbon source present in the GI tract, as a signal for nutrient availability. When placed in water, C. albicans cells normally enter the G0 phase and remain viable for weeks. However, they quickly lose viability when cultured in water containing only GlcNAc. We term this phenomenon GlcNAc-induced cell death (GICD). GlcNAc triggers the upregulation of ribosomalbiogenesis genes, alterations of mitochondrial metabolism, and the accumulation of reactive oxygen species (ROS), followed by rapid cell death via both apoptotic and necrotic mechanisms. Multiple pathways, including the conserved cyclic AMP (cAMP) signaling and GlcNAc catabolic pathways, are involved in GICD. GlcNAc acts as a signaling molecule to regulate multiple cellular programs in a coordinated manner and therefore maximizes the efficiency of nutrient use. This adaptive behavior allows C. albicans’ more efficient colonization of the gut. Expression profiles of Candida alibcans in three different 5 hours) were determined by high throughput sequencing technology.
2015-08-22 | E-GEOD-64659 | biostudies-arrayexpress
Project description:Allergens such as house dust mites (HDM) and papain induce strong Th2 responses, including elevated IL-4, IL-5, and IL-13 and marked eosinophilia in the airways. Histoplasma capsulatum is a dimorphic fungal pathogen that induces a strong Th1 response marked by IFN-? and TNF-? production, leading to rapid clearance in nonimmunocompromised hosts. Th1 responses are generally dominant and overwhelm the Th2 response when stimuli for both are present, although there are instances when Th2 stimuli downregulate a Th1 response. We determined if the Th2 response to allergens prevents the host from mounting a Th1 response to H. capsulatum in vivo. C57BL/6 mice exposed to HDM or papain and infected with H. capsulatum exhibited a dominant Th2 response early, characterized by enhanced eosinophilia and elevated Th2 cytokines in lungs. These mice manifested exacerbated fungal burdens, suggesting that animals skewed toward a Th2 response by an allergen are less able to clear the H. capsulatum infection despite an intact Th1 response. In contrast, secondary infection is not exacerbated by allergen exposure, indicating that the memory response may suppress the Th2 response to HDM and quickly clear the infection. In conclusion, an in vivo skewing toward Th2 by allergens exacerbates fungal infection, even though there is a concurrent and unimpaired Th1 response to H. capsulatum.
| S-EPMC6246782 | biostudies-literature
Project description:Histoplasma capsulatum Yeast and Mycelia Transcriptomes
| PRJNA214093 | ENA
Project description:Comparative transcriptomics of infectious spores from the fungal pathogen Histoplasma capsulatum G186AR
| PRJNA193985 | ENA
Project description:Experimental annotation of Histoplasma capsulatum transcribed regions using high-resolution tiling arrays
| PRJNA144821 | ENA