Project description:The project aimmed to characterize the proteomic response of the human pathogenic fungus Histoplasma capsulatum to zinc poor environment. For that yeast cells were incubated in two conditions: zinc replete (with 20uM fo zinc sulfate) and zinc depleted (suppplemented with diethylenetriaminepentaacetic acid. Finaly teh proteins regulaed by zinc availability were identified.
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.
Project description:Analyzed 84 genes from macrophages infected with Histoplasma capsulatum for changes in expression over 24 hours Macrophages infected with Histoplasma capsulatum were analyzed for alterations in apoptosis genes, 5 biological replicate (rep1-5)
Project description:Histoplasmosis is a frequent mycosis in people living with HIV/AIDS and other immunocompromised hosts. Histoplasmosis has high rates of mortality in these patients if treatment is unsuccessful. Itraconazole and amphotericin B are used to treat histoplasmosis; however, both antifungals have potentially severe pharmacokinetic drug interactions and toxicity. The present study determined the minimal inhibitory and fungicidal concentrations of mebendazole, a drug present in the NIH Clinical Collection, to establish whether it has fungicidal or fungistatic activity against Histoplasma capsulatum. Protein extracts from H. capsulatum yeasts, treated or not with mebendazole, were analyzed by proteomics to understand the metabolic changes driven by this benzimidazole. Mebendazole inhibited the growth of 10 H. capsulatum strains, presenting minimal inhibitory concentrations ranging from 5.0 to 0.08 µM. Proteomics revealed 30 and 18 proteins exclusively detected in untreated and mebendazole-treated H. capsulatum yeast cells, respectively. Proteins related to the tricarboxylic acid cycle, cytoskeleton, and ribosomes were highly abundant in untreated cells. Proteins related to the nitrogen, sulfur, and pyrimidine metabolisms were enriched in mebendazole-treated cells. Furthermore, mebendazole was able to inhibit the oxidative metabolism, disrupt the cytoskeleton, and decrease ribosomal proteins in H. capsulatum. These results suggest mebendazole as a drug to be repurposed for histoplasmosis treatment.
Project description:To identify signaling pathways that are induced by macrophages infected with Histoplasma capsulatum, we examined the whole genome expression profile of murine bone marrow derived macrophages infected with conidia, the natural infectious particle of Histoplasma. Conidia induced the expression of signature Type I interferon response genes. The induction of a Type I interferon response was specific to conidia, yeast cells did not trigger the response. Macrophages that lack the Type I interferon receptor, IFNAR1, were infected and compared to wild-type macrophages. The expression of some Type I IFN response genes are dependent upon Keywords: Murine bone marrow derived macrophage transcriptional response to infection with Histoplasma capsulatum conidia We analyzed a series of 24 MEEBO arrays on which were hybed RNA amplified from bone marrow derived macrophages from C57BL/6 (WT) or ifnar1-/- mice either mock infected or infected with H. capsulatum conidia or yeast cells.
Project description:To identify signaling pathways that are induced by macrophages infected with Histoplasma capsulatum, we examined the whole genome expression profile of murine bone marrow derived macrophages infected with conidia, the natural infectious particle of Histoplasma. Conidia induced the expression of signature Type I interferon response genes. The induction of a Type I interferon response was specific to conidia, yeast cells did not trigger the response. Macrophages that lack the Type I interferon receptor, IFNAR1, were infected and compared to wild-type macrophages. The expression of some Type I IFN response genes are dependent upon Keywords: Murine bone marrow derived macrophage transcriptional response to infection with Histoplasma capsulatum conidia