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Sickinger M, Joerling J, Büttner K, Roth J, Wehrend A. Influence of an iron dextran injection in various diseases on hematological blood parameters, including serum ferritin, neonatal dairy calves. BMC Vet Res 2024; 20:379. [PMID: 39182079 PMCID: PMC11344462 DOI: 10.1186/s12917-024-04229-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Accepted: 08/12/2024] [Indexed: 08/27/2024] Open
Abstract
BACKGROUND Feeding milk substitutes with low iron content or whole milk without iron supplementation is considered a major factor in developing iron-deficiency anemia in neonatal dairy calves. Young calves are often supplemented with iron dextran injections on the first day of life to prevent anemia. However, the effects of preventive treatment and the presence of disease on serum iron (Fe) concentrations, serum ferritin levels, and hematological blood parameters during the early neonatal stages have not been examined in detail. Therefore, we examined and evaluated the effects of iron dextran injections and health status on the development of hematocrit (Ht), red blood cells (RBC), hemoglobin concentration (Hb), erythrocyte indices (mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration), Fe, and serum ferritin concentrations in dairy calves within the first 10 days of life. The suitability of serum ferritin as a reliable indicator of anemia in very young calves was evaluated by correlating ferritin concentrations with known laboratory diagnostic parameters of anemia. RESULTS Iron supplementation significantly increased Fe levels (P = 0.048) but did not affect serum ferritin levels in neonatal calves. Fe concentrations were significantly lower in diseased than healthy calves (P = 0.0417). Iron supplementation significantly affected the health status, as observed in Ht (Ptreat=0.0057; Phealth=0.0097), RBC (Ptreat=0.0342; Phealth=0.0243), and Hb (Ptreat=0.0170; Phealth=0.0168). Serum ferritin levels did not significantly correlate with Fe levels. Both groups showed marked differences in ferritin levels, with the highest levels measured on day 2. Fe concentrations showed weak negative correlations with Hb and Ht levels on day 3 (ρ=-0.45; P = 0.0034 and ρ=-0.045; P = 0.0032, respectively). RBC count showed strong positive correlations with Hb and Ht levels (ρ = 0.91 and ρ = 0.93; P < 0.001). CONCLUSION Iron dextran injections increased Fe concentrations but reduced Ht level, RBC count, and Hb level. The presence of diseases led to a reduction in Fe and higher values of Ht, RBC, and Hb in moderate disease than in severe disease. Due to physiological fluctuations during the first 3 days of life, serum ferritin level seems unuseful for evaluating iron storage before day 4 of life.
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Affiliation(s)
- Marlene Sickinger
- Clinic for Ruminants and Herd Health Management, Justus-Liebig-University of Giessen, Frankfurter Str. 104, 35392, Giessen, Germany.
| | | | - Kathrin Büttner
- Department for Biomathematics and Data Processing, Justus-Liebig-University of Giessen, Giessen, Germany
| | - Joachim Roth
- Institute for Veterinary Physiology, Justus-Liebig-University of Giessen, Giessen, Germany
| | - Axel Wehrend
- Veterinary Clinic for Reproduction and Neonatology, Justus-Liebig-University of Giessen, Giessen, Germany
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Monika G, Melanie Kim SR, Kumar PS, Gayathri KV, Rangasamy G, Saravanan A. Biofortification: A long-term solution to improve global health- a review. CHEMOSPHERE 2023; 314:137713. [PMID: 36596329 DOI: 10.1016/j.chemosphere.2022.137713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 11/20/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Biofortification is a revolutionary technique for improving plant nutrition and alleviating human micronutrient deficiency. Fertilizers can help increase crop yield and growth, but applying too much fertilizer can be a problem because it leads to the release of greenhouse gases and eutrophication. One of the major global hazards that affects more than two million people globally is the decreased availability of micronutrients in food crops, which results in micronutrient deficiencies or "hidden hunger" in people. Micronutrients, like macronutrients, perform a variety of roles in plant and human nutrition. This review has highlighted the importance of micronutrients as well as their advantages. The uneven distribution of micronutrients in geological areas is not the only factor responsible for micronutrient deficiencies, other parameters including soil moisture, temperature, texture of the soil, and soil pH significantly affects the micronutrient concentration and their availability in the soil. To overcome this, different biofortification approaches are assessed in the review in which microbes mediated, Agronomic approaches, Plant breeding, and transgenic approaches are discussed. Hidden hunger can result in risky health conditions and diseases such as cancer, cardiovascular disease, osteoporosis, neurological disorders, and many more. Microbes-mediated biofortification is a novel and promising solution for the bioavailability of nutrients to plants in order to address these problems. Biofortification is cost effective, feasible, and environmentally sustainable. Bio-fortified crops boost our immunity, which helps us to combat these deadly viruses. The studies we discussed in this review have demonstrated that they can aid in the alleviation of hidden hunger.
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Affiliation(s)
- G Monika
- Department of Biotechnology, Stella Maris College (Autonomous), Chennai, India
| | - S Rhoda Melanie Kim
- Department of Biotechnology, Stella Maris College (Autonomous), Chennai, India
| | - P Senthil Kumar
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam, 603110, Tamil Nadu, India; Centre of Excellence in Water Research (CEWAR), Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam, 603110, Tamil Nadu, India; School of Engineering, Lebanese American University, Byblos, Lebanon
| | - K Veena Gayathri
- Department of Biotechnology, Stella Maris College (Autonomous), Chennai, India.
| | - Gayathri Rangasamy
- School of Engineering, Lebanese American University, Byblos, Lebanon; University Centre for Research and Development & Department of Civil Engineering, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India.
| | - A Saravanan
- Department of Sustainable Engineering, Institute of Biotechnology, Saveetha School of Engineering, SIMATS, Chennai, 602105, India
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Pecoraro L, Wang X, Shah D, Song X, Kumar V, Shakoor A, Tripathi K, Ramteke PW, Rani R. Biosynthesis Pathways, Transport Mechanisms and Biotechnological Applications of Fungal Siderophores. J Fungi (Basel) 2021; 8:21. [PMID: 35049961 PMCID: PMC8781417 DOI: 10.3390/jof8010021] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 12/21/2021] [Accepted: 12/21/2021] [Indexed: 11/16/2022] Open
Abstract
Iron (Fe) is the fourth most abundant element on earth and represents an essential nutrient for life. As a fundamental mineral element for cell growth and development, iron is available for uptake as ferric ions, which are usually oxidized into complex oxyhydroxide polymers, insoluble under aerobic conditions. In these conditions, the bioavailability of iron is dramatically reduced. As a result, microorganisms face problems of iron acquisition, especially under low concentrations of this element. However, some microbes have evolved mechanisms for obtaining ferric irons from the extracellular medium or environment by forming small molecules often regarded as siderophores. Siderophores are high affinity iron-binding molecules produced by a repertoire of proteins found in the cytoplasm of cyanobacteria, bacteria, fungi, and plants. Common groups of siderophores include hydroxamates, catecholates, carboxylates, and hydroximates. The hydroxamate siderophores are commonly synthesized by fungi. L-ornithine is a biosynthetic precursor of siderophores, which is synthesized from multimodular large enzyme complexes through non-ribosomal peptide synthetases (NRPSs), while siderophore-Fe chelators cell wall mannoproteins (FIT1, FIT2, and FIT3) help the retention of siderophores. S. cerevisiae, for example, can express these proteins in two genetically separate systems (reductive and nonreductive) in the plasma membrane. These proteins can convert Fe (III) into Fe (II) by a ferrous-specific metalloreductase enzyme complex and flavin reductases (FREs). However, regulation of the siderophore through Fur Box protein on the DNA promoter region and its activation or repression depend primarily on the Fe availability in the external medium. Siderophores are essential due to their wide range of applications in biotechnology, medicine, bioremediation of heavy metal polluted environments, biocontrol of plant pathogens, and plant growth enhancement.
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Affiliation(s)
- Lorenzo Pecoraro
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Tianjin 300072, China; (X.W.); (D.S.); (X.S.); (A.S.); (R.R.)
| | - Xiao Wang
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Tianjin 300072, China; (X.W.); (D.S.); (X.S.); (A.S.); (R.R.)
| | - Dawood Shah
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Tianjin 300072, China; (X.W.); (D.S.); (X.S.); (A.S.); (R.R.)
- Institute of Biotechnology and Genetic Engineering, The University of Agriculture Peshawar, Peshawar 25000, Pakistan
| | - Xiaoxuan Song
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Tianjin 300072, China; (X.W.); (D.S.); (X.S.); (A.S.); (R.R.)
| | - Vishal Kumar
- Department of Food Science and Technology, Yeungnam University, Gyongsan 38541, Korea;
| | - Abdul Shakoor
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Tianjin 300072, China; (X.W.); (D.S.); (X.S.); (A.S.); (R.R.)
- College of Geography and Environmental Science, Henan University, Kaifeng 475004, China
| | - Keshawanand Tripathi
- Center for Conservation and Utilization of Blue-Green Algae, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India;
| | - Pramod W. Ramteke
- Faculty of Life Sciences, Mandsaur University, Mandsaur 458001, India;
| | - Rupa Rani
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Tianjin 300072, China; (X.W.); (D.S.); (X.S.); (A.S.); (R.R.)
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India
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Conservation and Loss of a Putative Iron Utilization Gene Cluster among Genotypes of Aspergillus flavus. Microorganisms 2021; 9:microorganisms9010137. [PMID: 33435439 PMCID: PMC7827000 DOI: 10.3390/microorganisms9010137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/04/2021] [Accepted: 01/07/2021] [Indexed: 11/20/2022] Open
Abstract
Iron is an essential component for growth and development. Despite relative abundance in the environment, bioavailability of iron is limited due to oxidation by atmospheric oxygen into insoluble ferric iron. Filamentous fungi have developed diverse pathways to uptake and use iron. In the current study, a putative iron utilization gene cluster (IUC) in Aspergillus flavus was identified and characterized. Gene analyses indicate A. flavus may use reductive as well as siderophore-mediated iron uptake and utilization pathways. The ferroxidation and iron permeation process, in which iron transport depends on the coupling of these two activities, mediates the reductive pathway. The IUC identified in this work includes six genes and is located in a highly polymorphic region of the genome. Diversity among A. flavus genotypes is manifested in the structure of the IUC, which ranged from complete deletion to a region disabled by multiple indels. Molecular profiling of A. flavus populations suggests lineage-specific loss of IUC. The observed variation among A. flavus genotypes in iron utilization and the lineage-specific loss of the iron utilization genes in several A. flavus clonal lineages provide insight on evolution of iron acquisition and utilization within Aspergillus section Flavi. The potential divergence in capacity to acquire iron should be taken into account when selecting A. flavus active ingredients for biocontrol in niches where climate change may alter iron availability.
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Leprêtre M, Almunia C, Armengaud J, Le Guernic A, Salvador A, Geffard A, Palos-Ladeiro M. Identification of immune-related proteins of Dreissena polymorpha hemocytes and plasma involved in host-microbe interactions by differential proteomics. Sci Rep 2020; 10:6226. [PMID: 32277127 PMCID: PMC7148315 DOI: 10.1038/s41598-020-63321-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 03/27/2020] [Indexed: 12/04/2022] Open
Abstract
Biological responses of zebra mussel Dreissena polymorpha are investigated to assess the impact of contaminants on aquatic organisms and ecosystems. In addition to concentrate chemical contaminants in their tissues, zebra mussels accumulate several microorganisms such as viruses, protozoa and bacteria. In order to understand the molecular mechanisms involved in the defence against microorganisms this study aims at identifying immune proteins from D. polymorpha hemolymph involved in defence against protozoa and viruses. For this purpose, hemolymph were exposed ex vivo to Cryptosporidium parvum and RNA poly I:C. Differential proteomics on both hemocytes and plasma revealed immune proteins modulated under exposures. Different patterns of response were observed after C. parvum and RNA poly I:C exposures. The number of modulated proteins per hemolymphatic compartments suggest that C. parvum is managed in cells while RNA poly I:C is managed in plasma after 4 h exposure. BLAST annotation and GO terms enrichment analysis revealed further characteristics of immune mechanisms. Results showed that many proteins involved in the recognition and destruction of microorganisms were modulated in both exposure conditions, while proteins related to phagocytosis and apoptosis were exclusively modulated by C. parvum. This differential proteomic analysis highlights in zebra mussels modulated proteins involved in the response to microorganisms, which reflect a broad range of immune mechanisms such as recognition, internalization and destruction of microorganisms. This study paves the way for the identification of new markers of immune processes that can be used to assess the impact of both chemical and biological contaminations on the health status of aquatic organisms.
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Affiliation(s)
- Maxime Leprêtre
- Université de Reims Champagne-Ardenne, UMR-I 02 INERIS-URCA-ULH SEBIO Stress Environnementaux et BIOsurveillance des milieux aquatiques, UFR Sciences Exactes et Naturelles, Campus du Moulin de la Housse, BP 1039, 51687, Reims, CEDEX, France
- Université de Lyon, Université Claude Bernard Lyon 1, Institut des Sciences Analytiques, CNRS UMR 5280, F-69100, Villeurbanne, France
| | - Christine Almunia
- Laboratoire Innovations Technologiques pour la Détection et le Diagnostic (Li2D), Service de Pharmacologie et Immunoanalyse (SPI), CEA, INRA, F-30207, Bagnols-sur-Cèze, France
| | - Jean Armengaud
- Laboratoire Innovations Technologiques pour la Détection et le Diagnostic (Li2D), Service de Pharmacologie et Immunoanalyse (SPI), CEA, INRA, F-30207, Bagnols-sur-Cèze, France
| | - Antoine Le Guernic
- Université de Reims Champagne-Ardenne, UMR-I 02 INERIS-URCA-ULH SEBIO Stress Environnementaux et BIOsurveillance des milieux aquatiques, UFR Sciences Exactes et Naturelles, Campus du Moulin de la Housse, BP 1039, 51687, Reims, CEDEX, France
| | - Arnaud Salvador
- Université de Lyon, Université Claude Bernard Lyon 1, Institut des Sciences Analytiques, CNRS UMR 5280, F-69100, Villeurbanne, France
| | - Alain Geffard
- Université de Reims Champagne-Ardenne, UMR-I 02 INERIS-URCA-ULH SEBIO Stress Environnementaux et BIOsurveillance des milieux aquatiques, UFR Sciences Exactes et Naturelles, Campus du Moulin de la Housse, BP 1039, 51687, Reims, CEDEX, France
| | - Mélissa Palos-Ladeiro
- Université de Reims Champagne-Ardenne, UMR-I 02 INERIS-URCA-ULH SEBIO Stress Environnementaux et BIOsurveillance des milieux aquatiques, UFR Sciences Exactes et Naturelles, Campus du Moulin de la Housse, BP 1039, 51687, Reims, CEDEX, France.
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Gastelum-Martínez A, León-Sicairos C, Plata-Guzmán L, Soto-Castro L, León-Sicairos N, de la Garza M. Iron-modulated virulence factors of Entamoeba histolytica. Future Microbiol 2018; 13:1329-1341. [PMID: 30238768 DOI: 10.2217/fmb-2018-0066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Entamoeba histolytica is a human parasite that causes amoebiasis, a disease that affects the colon and liver and is prevalent worldwide. This protozoan requires a high concentration of iron to survive and reproduce. Iron modulates the expression of parasite virulence factors, including hemoglobinases, hemoglobin-binding proteins and cysteine proteases, as well as proteins related to the amoebic cytoskeleton. This review summarizes the virulence factors that are affected by iron, resulting in upregulation or downregulation of E. histolytica genes. This review also discusses the functionality of iron in the mechanisms of pathogenesis.
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Affiliation(s)
- Aurora Gastelum-Martínez
- Programa Regional del Noroeste para el Posgrado en Biotecnología de la Facultad de Ciencias Químico Biológicas. Universidad Autónoma de Sinaloa. Av. de las Américas y Josefa Ortiz (Cd. Universitaria) Culiacán 80030, Sinaloa, Mexico
| | - Claudia León-Sicairos
- Programa Regional del Noroeste para el Posgrado en Biotecnología de la Facultad de Ciencias Químico Biológicas. Universidad Autónoma de Sinaloa. Av. de las Américas y Josefa Ortiz (Cd. Universitaria) Culiacán 80030, Sinaloa, Mexico
| | - Laura Plata-Guzmán
- Programa Regional del Noroeste para el Posgrado en Biotecnología de la Facultad de Ciencias Químico Biológicas. Universidad Autónoma de Sinaloa. Av. de las Américas y Josefa Ortiz (Cd. Universitaria) Culiacán 80030, Sinaloa, Mexico
| | - Liliana Soto-Castro
- Programa Regional del Noroeste para el Posgrado en Biotecnología de la Facultad de Ciencias Químico Biológicas. Universidad Autónoma de Sinaloa. Av. de las Américas y Josefa Ortiz (Cd. Universitaria) Culiacán 80030, Sinaloa, Mexico
| | - Nidia León-Sicairos
- CIASaP Facultad de Medicina. Universidad Autónoma de Sinaloa. Cedros y Sauces Frac. Fresnos. Culiacán 80246, Sinaloa, México; Departamento de Investigación, Hospital Pediátrico de Sinaloa. Boulevard Constitución S/N, Col. Jorge Almada, Culiacán 80200, Sinaloa, Mexico
| | - Mireya de la Garza
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Av. Instituto Politécnico Nacional 2508, Colonia San Pedro Zacatenco 07360, CdMx, Mexico
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Gamngoen R, Putim C, Salee P, Phunpae P, Butr-Indr B. A comparison of Rv0559c and Rv0560c expression in drug-resistant Mycobacterium tuberculosis in response to first-line antituberculosis drugs. Tuberculosis (Edinb) 2017. [PMID: 29523329 DOI: 10.1016/j.tube.2017.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Drug resistance to Mycobacterium tuberculosis is a major health problem worldwide. Mycobacterium tuberculosis can progress to be mono-drug resistant or multi-drug resistant by improper treatment. The chemical stress of M. tuberculosis was performed in this study. Rv0559c is an unknown secreted protein. Rv0560c is a putative benzoquinone methyltransferase of M. tuberculosis cell. Rv0559c gene is located downstream of Rv0560c gene. Both genes respond to salicylate stress. Drug susceptible, isoniazid resistant, rifampicin resistant and multi-drug resistant phenotypes of M. tuberculosis clinical isolates were used to determine the expression of Rv0559c and Rv0560c by qRT-PCR. In all of mycobacteria strains there was up-regulation in both genes when stressed with isoniazid. This study determined the expression of both genes, which may play important roles in the drug resistance mechanism of mycobacteria.
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Affiliation(s)
- Ratikorn Gamngoen
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Chanyanuch Putim
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Parichat Salee
- Division of Infectious Diseases, Department of Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Ponrut Phunpae
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Bordin Butr-Indr
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, 50200, Thailand.
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Szebesczyk A, Olshvang E, Shanzer A, Carver PL, Gumienna-Kontecka E. Harnessing the power of fungal siderophores for the imaging and treatment of human diseases. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2016.05.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Miller EM. The reproductive ecology of iron in women. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 159:S172-95. [PMID: 26808104 DOI: 10.1002/ajpa.22907] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Reproductive ecology focuses on the sensitivity of human reproduction to environmental variation. While reproductive ecology has historically focused on the relationship between energy status and reproductive outcomes, iron status is equally critical to women's reproductive health, given the wide-ranging detrimental effects of iron-deficiency anemia on maternal and infant well-being. This review interprets the vast literature on iron status and women's reproduction through an evolutionary framework. First, it will critique the evidence for iron deficiency caused by blood loss during menstruation, reinterpreting the available data as ecological variation in menses within and between populations of women. Second, it will highlight the scant but growing evidence that iron status is implicated in fertility, a relationship that has deep evolutionary roots. Third, this review proposes a new hypothesis for the transfer of iron from mother to infant via pregnancy and breastfeeding: reproductive iron withholding. In this hypothesis, mothers transfer iron to infants in a manner that helps infants avoid iron-mediated infection and oxidative stress, but trades off with potential risk of maternal and infant iron deficiency. Finally, this review explores two main factors that can modify the relationship between iron status and the gestation-lactation cycle: (1) the relationship between long-term reproductive effort (parity) and iron status and (2) supplementation schemes before and during pregnancy. The review concludes by suggesting continued research into iron homeostasis in women using evolutionary, ecological, and biocultural frameworks.
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Affiliation(s)
- Elizabeth M Miller
- Department of Anthropology, University of South Florida, Tampa, FL, 33620
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Kuan CS, Cham CY, Singh G, Yew SM, Tan YC, Chong PS, Toh YF, Atiya N, Na SL, Lee KW, Hoh CC, Yee WY, Ng KP. Genomic Analyses of Cladophialophora bantiana, a Major Cause of Cerebral Phaeohyphomycosis Provides Insight into Its Lifestyle, Virulence and Adaption in Host. PLoS One 2016; 11:e0161008. [PMID: 27570972 PMCID: PMC5003357 DOI: 10.1371/journal.pone.0161008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 07/28/2016] [Indexed: 11/18/2022] Open
Abstract
Cladophialophora bantiana is a dematiaceous fungus with a predilection for causing central nervous system (CNS) infection manifesting as brain abscess in both immunocompetent and immunocompromised patients. In this paper, we report comprehensive genomic analyses of C. bantiana isolated from the brain abscess of an immunocompetent man, the first reported case in Malaysia and Southeast Asia. The identity of the fungus was determined using combined morphological analysis and multilocus phylogeny. The draft genome sequence of a neurotrophic fungus, C. bantiana UM 956 was generated using Illumina sequencing technology to dissect its genetic fundamental and basic biology. The assembled 37.1 Mb genome encodes 12,155 putative coding genes, of which, 1.01% are predicted transposable elements. Its genomic features support its saprophytic lifestyle, renowned for its versatility in decomposing hemicellulose and pectin components. The C. bantiana UM 956 was also found to carry some important putative genes that engaged in pathogenicity, iron uptake and homeostasis as well as adaptation to various stresses to enable the organism to survive in hostile microenvironment. This wealth of resource will further catalyse more downstream functional studies to provide better understanding on how this fungus can be a successful and persistent pathogen in human.
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Affiliation(s)
- Chee Sian Kuan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Chun Yoong Cham
- Department of Neurosurgery, Hospital Pulau Pinang, Jalan Residensi, Georgetown, Pulau Pinang, Malaysia
- Department of Surgery, Neurosurgical Division, University of Malaya, Kuala Lumpur, Malaysia
| | - Gurmit Singh
- Department of Neurosurgery, Hospital Pulau Pinang, Jalan Residensi, Georgetown, Pulau Pinang, Malaysia
| | - Su Mei Yew
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | | | | | - Yue Fen Toh
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Nadia Atiya
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Shiang Ling Na
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kok Wei Lee
- Codon Genomics SB, Selangor Darul Ehsan, Malaysia
| | | | - Wai-Yan Yee
- Codon Genomics SB, Selangor Darul Ehsan, Malaysia
| | - Kee Peng Ng
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- * E-mail:
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Reininger V, Schlegel M. Analysis of the Phialocephala subalpina Transcriptome during Colonization of Its Host Plant Picea abies. PLoS One 2016; 11:e0150591. [PMID: 26954682 PMCID: PMC4783019 DOI: 10.1371/journal.pone.0150591] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 02/16/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Phialocephala subalpina belongs to the Phialocephala fortinii s.l.-Acepphala applanata species complex (PAC) forming one of the major groups belonging to the dark septate endophytes (DSE). Depending on the strain, PAC was shown to form neutral to pathogenic associations with its host plant Picea abies. To understand PACs lifestyle we investigated the effect of presence/absence of Picea abies on the transcriptome of strain 6_70_1. MATERIALS AND METHODS PAC strain 6_70_1 was grown in liquid Pachlewski media either induced by its host plant Picea abies or without host plant as a control. Mycelia were harvested in a time course (1, 2, 3, 4, 7, 11, 18 days) with and without induction by the host plant and the fungal transcriptome revealed by Illumina sequencing. Differential gene expression analysis over the time course comparing control and treatment at each time point using the 'edgeR glm approach' and a gene enrichment analysis using GO categories were performed. RESULTS The three main functional groups within differentially expressed genes were 'metabolism', 'transport' and 'cell rescue, defense and virulence'. Additionally, genes especially involved in iron metabolism could be detected by gene set enrichment analysis. CONCLUSION In conclusion, we found PAC strain 6_70_1 to be metabolically very active during colonization of its host plant Picea abies. A major shift in functional groups over the time course of this experiment could not be observed but GO categories which were found to be enriched showed different emphasis depending in the day post induction.
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Affiliation(s)
- Vanessa Reininger
- ETH Zurich, Institute of Integrative Biology, Universitätstrasse 16, 8092, Zurich
| | - Markus Schlegel
- ETH Zurich, Institute of Integrative Biology, Universitätstrasse 16, 8092, Zurich
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Song HO. Influence of 120 kDa Pyruvate:Ferredoxin Oxidoreductase on Pathogenicity of Trichomonas vaginalis. THE KOREAN JOURNAL OF PARASITOLOGY 2016; 54:71-4. [PMID: 26951982 PMCID: PMC4792314 DOI: 10.3347/kjp.2016.54.1.71] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 12/30/2015] [Accepted: 01/07/2016] [Indexed: 12/03/2022]
Abstract
Trichomonas vaginalis is a flagellate protozoan parasite and commonly infected the lower genital tract in women and men. Iron is a known nutrient for growth of various pathogens, and also reported to be involved in establishment of trichomoniasis. However, the exact mechanism was not clarified. In this study, the author investigated whether the 120 kDa protein of T. vaginalis may be involved in pathogenicity of trichomonads. Antibodies against 120 kDa protein of T. vaginalis, which was identified as pyruvate:ferredoxin oxidoreductase (PFOR) by peptide analysis of MALDI-TOF-MS, were prepared in rabbits. Pretreatment of T. vaginalis with anti-120 kDa Ab decreased the proliferation and adherence to vaginal epithelial cells (MS74) of T. vaginalis. Subcutaneous tissue abscess in anti-120 kDa Ab-treated T. vaginalis-injected mice was smaller in size than that of untreated T. vaginalis-infected mice. Collectively, the 120 kDa protein expressed by iron may be involved in proliferation, adhesion to host cells, and abscess formation, thereby may influence on the pathogenicity of T. vaginalis.
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Affiliation(s)
- Hyun-Ouk Song
- Department of Parasitology, School of Medicine, Catholic University of Daegu, Daegu 42472, Korea
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13
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Binding and Endocytosis of Bovine Hololactoferrin by the Parasite Entamoeba histolytica. BIOMED RESEARCH INTERNATIONAL 2015; 2015:375836. [PMID: 26090404 PMCID: PMC4450225 DOI: 10.1155/2015/375836] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/11/2014] [Accepted: 09/16/2014] [Indexed: 11/26/2022]
Abstract
Entamoeba histolytica is a human parasite that requires iron (Fe) for its metabolic function and virulence. Bovine lactoferrin (B-Lf) and its peptides can be found in the digestive tract after dairy products are ingested. The aim of this study was to compare virulent trophozoites recently isolated from hamster liver abscesses with nonvirulent trophozoites maintained for more than 30 years in cultures in vitro regarding their interaction with iron-charged B-Lf (B-holo-Lf). We performed growth kinetics analyses of trophozoites in B-holo-Lf and throughout several consecutive transfers. The virulent parasites showed higher growth and tolerance to iron than nonvirulent parasites. Both amoeba variants specifically bound B-holo-Lf with a similar Kd. However, averages of 9.45 × 105 and 6.65 × 106 binding sites/cell were found for B-holo-Lf in nonvirulent and virulent amoebae, respectively. Virulent amoebae bound more efficiently to human and bovine holo-Lf, human holo-transferrin, and human and bovine hemoglobin than nonvirulent amoebae. Virulent amoebae showed two types of B-holo-Lf binding proteins. Although both amoebae endocytosed this glycoprotein through clathrin-coated vesicles, the virulent amoebae also endocytosed B-holo-Lf through a cholesterol-dependent mechanism. Both amoeba variants secreted cysteine proteases cleaving B-holo-Lf. These data demonstrate that the B-Lf endocytosis is more efficient in virulent amoebae.
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14
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Wiemann P, Lechner BE, Baccile JA, Velk TA, Yin WB, Bok JW, Pakala S, Losada L, Nierman WC, Schroeder FC, Haas H, Keller NP. Perturbations in small molecule synthesis uncovers an iron-responsive secondary metabolite network in Aspergillus fumigatus. Front Microbiol 2014; 5:530. [PMID: 25386169 PMCID: PMC4208449 DOI: 10.3389/fmicb.2014.00530] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 09/23/2014] [Indexed: 11/13/2022] Open
Abstract
Iron plays a critical role in survival and virulence of the opportunistic pathogen Aspergillus fumigatus. Two transcription factors, the GATA-factor SreA and the bZip-factor HapX oppositely monitor iron homeostasis with HapX activating iron acquisition pathways (e.g., siderophores) and shutting down iron consumptive pathways (and SreA) during iron starvation conditions whereas SreA negatively regulates HapX and corresponding pathways during iron sufficiency. Recently the non-ribosomal peptide, hexadehydroastechrome (HAS; a tryptophan-derived iron (III)-complex), has been found important in A. fumigatus virulence. We found that HAS overproduction caused an iron starvation phenotype, from alteration of siderophore pools to regulation of iron homeostasis gene expression including sreA. Moreover, we uncovered an iron dependent secondary metabolism network where both SreA and HapX oppositely regulate multiple other secondary metabolites including HAS. This circuitry links iron-acquisition and consumption pathways with secondary metabolism-thus placing HAS as part of a metabolic feedback circuitry designed to balance iron pools in the fungus and presenting iron availability as one environmental trigger of secondary metabolism.
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Affiliation(s)
- Philipp Wiemann
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison Madison, WI, USA
| | - Beatrix E Lechner
- Division of Molecular Biology/Biocenter, Innsbruck Medical University Innsbruck, Austria
| | - Joshua A Baccile
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University Ithaca, NY, USA
| | - Thomas A Velk
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison Madison, WI, USA
| | - Wen-Bing Yin
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison Madison, WI, USA
| | - Jin Woo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison Madison, WI, USA
| | - Suman Pakala
- The J. Craig Venter Institute Rockville, MD, USA
| | | | | | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University Ithaca, NY, USA
| | - Hubertus Haas
- Division of Molecular Biology/Biocenter, Innsbruck Medical University Innsbruck, Austria
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison Madison, WI, USA ; Department of Bacteriology, University of Wisconsin-Madison Madison, WI, USA
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15
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Szigeti Z, Szaniszló S, Fazekas E, Gyémánt G, Szabon J, Antal K, Emri T, Balla J, Balla G, Csernoch L, Pócsi I. Optimization of triacetylfusarinine C and ferricrocin productions in Aspergillus fumigatus. Acta Microbiol Immunol Hung 2014; 61:107-19. [PMID: 24939680 DOI: 10.1556/amicr.61.2014.2.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Iron is an essential element for all microorganisms. Bacteria and fungi produce versatile siderophores for binding and storing this essential transition metal when its availability is limited in the environment. The aim of the study was to optimize the fermentation medium of Aspergillus fumigatus for siderophore production. Triacetyl-fusarinine C and ferricrocin yields were dependent on glucose and glycine supplementations as well as the initial pH of the culture media. The optimal fermentation medium for triacetylfusarinine C production contained 8% glucose, 0.4% glycine and the initial pH was set to 5.9. Meanwhile, maximal ferricrocin yields were recorded in the presence of 10% glucose, 0.5% glycine and at an initial pH of 7.4. Under optimized fermentation conditions, the yields for triacetylfusarinine C and ferricrocin increased up to 2.9 g/l culture medium and 18.9 mg/g mycelium, respectively.
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Affiliation(s)
- Zsuzsa Szigeti
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Szilvia Szaniszló
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Erika Fazekas
- 2 University of Debrecen Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology Debrecen Hungary
| | - Gyöngyi Gyémánt
- 2 University of Debrecen Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology Debrecen Hungary
| | - Judit Szabon
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Károly Antal
- 3 Eszterházy Károly College Department of Zoology, Faculty of Sciences Eger Hungary
| | - Tamás Emri
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | | | | | - László Csernoch
- 7 University of Debrecen Department of Physiology, Medical and Health Science Center Debrecen Hungary
| | - István Pócsi
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
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16
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Dean P, Major P, Nakjang S, Hirt RP, Embley TM. Transport proteins of parasitic protists and their role in nutrient salvage. FRONTIERS IN PLANT SCIENCE 2014; 5:153. [PMID: 24808897 PMCID: PMC4010794 DOI: 10.3389/fpls.2014.00153] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 04/01/2014] [Indexed: 05/02/2023]
Abstract
The loss of key biosynthetic pathways is a common feature of important parasitic protists, making them heavily dependent on scavenging nutrients from their hosts. This is often mediated by specialized transporter proteins that ensure the nutritional requirements of the parasite are met. Over the past decade, the completion of several parasite genome projects has facilitated the identification of parasite transporter proteins. This has been complemented by functional characterization of individual transporters along with investigations into their importance for parasite survival. In this review, we summarize the current knowledge on transporters from parasitic protists and highlight commonalities and differences in the transporter repertoires of different parasitic species, with particular focus on characterized transporters that act at the host-pathogen interface.
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Affiliation(s)
- Paul Dean
- *Correspondence: Paul Dean and T. Martin Embley, The Medical School, Institute for Cell and Molecular Biosciences, Newcastle University, Catherine Cookson Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK e-mail: ;
| | | | | | | | - T. Martin Embley
- *Correspondence: Paul Dean and T. Martin Embley, The Medical School, Institute for Cell and Molecular Biosciences, Newcastle University, Catherine Cookson Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK e-mail: ;
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17
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Krishnan K, Askew DS. The fungal UPR: a regulatory hub for virulence traits in the mold pathogen Aspergillus fumigatus. Virulence 2013; 5:334-40. [PMID: 24189125 PMCID: PMC3956511 DOI: 10.4161/viru.26571] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic pathogen that is responsible for a life-threatening fungal infection known as invasive aspergillosis. Current therapies for the treatment of this disease continue to be associated with a poor outcome, so there is a need for more information about aspects of the fungus-host interaction that could offer novel targets for drug intervention. One attractive possibility is the unfolded protein response (UPR), an intracellular signaling network that helps the fungus meet the demand for secretion in the host environment. The major function of the UPR is to mitigate ER stress by maintaining an equilibrium between the load of client proteins entering the endoplasmic reticulum (ER) and the protein folding capacity of the organelle. However, recent findings suggest that A. fumigatus, as well as several other pathogenic fungi, also rely upon this pathway for virulence. In this review, we provide an update on the A. fumigatus UPR, discuss emerging evidence that the UPR is situated at the nexus of a number of physiological functions that are vital for the virulence of this fungus, and suggest exciting possibilities for future therapeutic targeting of this pathway for the treatment of aspergillosis.
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Affiliation(s)
- Karthik Krishnan
- Department of Pathology & Laboratory Medicine; University of Cincinnati College of Medicine; Cincinnati, OH USA
| | - David S Askew
- Department of Pathology & Laboratory Medicine; University of Cincinnati College of Medicine; Cincinnati, OH USA
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18
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Novel Regulatory Mechanisms of Pathogenicity and Virulence to Combat MDR in Candida albicans. Int J Microbiol 2013; 2013:240209. [PMID: 24163696 PMCID: PMC3791847 DOI: 10.1155/2013/240209] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 08/15/2013] [Accepted: 08/15/2013] [Indexed: 01/19/2023] Open
Abstract
Continuous deployment of antifungals in treating infections caused by dimorphic opportunistic pathogen Candida albicans has led to the emergence of drug resistance resulting in cross-resistance to many unrelated drugs, a phenomenon termed multidrug resistance (MDR). Despite the current understanding of major factors which contribute to MDR mechanisms, there are many lines of evidence suggesting that it is a complex interplay of multiple factors which may be contributed by still unknown mechanisms. Coincidentally with the increased usage of antifungal drugs, the number of reports for antifungal drug resistance has also increased which further highlights the need for understanding novel molecular mechanisms which can be explored to combat MDR, namely, ROS, iron, hypoxia, lipids, morphogenesis, and transcriptional and signaling networks. Considering the worrying evolution of MDR and significance of C. albicans being the most prevalent human fungal pathogen, this review summarizes these new regulatory mechanisms which could be exploited to prevent MDR development in C. albicans as established from recent studies.
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19
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Vale-Costa S, Gomes-Pereira S, Teixeira CM, Rosa G, Rodrigues PN, Tomás A, Appelberg R, Gomes MS. Iron overload favors the elimination of Leishmania infantum from mouse tissues through interaction with reactive oxygen and nitrogen species. PLoS Negl Trop Dis 2013; 7:e2061. [PMID: 23459556 PMCID: PMC3573095 DOI: 10.1371/journal.pntd.0002061] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 01/02/2013] [Indexed: 02/07/2023] Open
Abstract
Iron plays a central role in host-parasite interactions, since both intervenients need iron for survival and growth, but are sensitive to iron-mediated toxicity. The host's iron overload is often associated with susceptibility to infection. However, it has been previously reported that iron overload prevented the growth of Leishmania major, an agent of cutaneous leishmaniasis, in BALB/c mice. In order to further clarify the impact of iron modulation on the growth of Leishmania in vivo, we studied the effects of iron supplementation or deprivation on the growth of L. infantum, the causative agent of Mediterranean visceral leishmaniasis, in the mouse model. We found that dietary iron deficiency did not affect the protozoan growth, whereas iron overload decreased its replication in the liver and spleen of a susceptible mouse strain. The fact that the iron-induced inhibitory effect could not be seen in mice deficient in NADPH dependent oxidase or nitric oxide synthase 2 suggests that iron eliminates L. infantum in vivo through the interaction with reactive oxygen and nitrogen species. Iron overload did not significantly alter the mouse adaptive immune response against L. infantum. Furthermore, the inhibitory action of iron towards L. infantum was also observed, in a dose dependent manner, in axenic cultures of promastigotes and amastigotes. Importantly, high iron concentrations were needed to achieve such effects. In conclusion, externally added iron synergizes with the host's oxidative mechanisms of defense in eliminating L. infantum from mouse tissues. Additionally, the direct toxicity of iron against Leishmania suggests a potential use of this metal as a therapeutic tool or the further exploration of iron anti-parasitic mechanisms for the design of new drugs. Leishmania are important vector-borne protozoan pathogens that cause different forms of disease, ranging from cutaneous self-healing lesions to life-threatening visceral infection. L. infantum is the most common species causing visceral leishmaniasis in Europe and the Mediterranean basin. Iron plays a critical role in host-pathogen interactions. Both the microorganism and its host need iron for growth. However, iron may promote the formation of toxic reactive oxygen species, which contribute to pathogen elimination, but also to host tissue pathology. We investigated the effect of manipulating host iron status on the outcome of L. infantum infection, using the mouse as an experimental model. We found that dietary iron deprivation had no effect on L. infantum growth, and iron-dextran injection decreased the multiplication of L. infantum in mouse organs. The fact that this anti-parasitic effect of iron was not observed in mice genetically deficient in superoxide and nitric oxide synthesis pathways indicates that iron is likely to act in synergy with reactive oxygen and nitrogen species produced by the host's macrophages. This work clearly shows that iron supplementation improves the host's capacity to eliminate L. infantum parasites and suggests that iron may be further explored as a therapeutic tool to fight this type of infection.
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Affiliation(s)
- Sílvia Vale-Costa
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Sandra Gomes-Pereira
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- CISA-ESTSP - Núcleo de Investigação em Farmácia, Centro de Investigação em Saúde e Ambiente, Escola Superior de Tecnologia da Saúde do Porto, Instituto Politécnico do Porto, Porto, Portugal
| | - Carlos Miguel Teixeira
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Gustavo Rosa
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Pedro Nuno Rodrigues
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Ana Tomás
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Rui Appelberg
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Maria Salomé Gomes
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
- * E-mail:
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20
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Proteases from Entamoeba spp. and Pathogenic Free-Living Amoebae as Virulence Factors. J Trop Med 2013; 2013:890603. [PMID: 23476670 PMCID: PMC3582061 DOI: 10.1155/2013/890603] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 11/28/2012] [Indexed: 02/01/2023] Open
Abstract
The standard reference for pathogenic and nonpathogenic amoebae is the human parasite Entamoeba histolytica; a direct correlation between virulence and protease expression has been demonstrated for this amoeba. Traditionally, proteases are considered virulence factors, including those that produce cytopathic effects in the host or that have been implicated in manipulating the immune response. Here, we expand the scope to other amoebae, including less-pathogenic Entamoeba species and highly pathogenic free-living amoebae. In this paper, proteases that affect mucin, extracellular matrix, immune system components, and diverse tissues and cells are included, based on studies in amoebic cultures and animal models. We also include proteases used by amoebae to degrade iron-containing proteins because iron scavenger capacity is currently considered a virulence factor for pathogens. In addition, proteases that have a role in adhesion and encystation, which are essential for establishing and transmitting infection, are discussed. The study of proteases and their specific inhibitors is relevant to the search for new therapeutic targets and to increase the power of drugs used to treat the diseases caused by these complex microorganisms.
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21
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Iron metabolism and its relationship to anemia and immune system in Trypanosoma evansi infected rats. Exp Parasitol 2012; 133:357-64. [PMID: 23270806 DOI: 10.1016/j.exppara.2012.12.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Revised: 12/14/2012] [Accepted: 12/15/2012] [Indexed: 11/22/2022]
Abstract
The aim of this study was to evaluate biochemical parameters of iron metabolism in rats experimentally infected with Trypanosoma evansi. To this end, 20 rats (Wistar) were intraperitoneally inoculated with blood containing trypomastigotes 10(6) (Group T) and 12 animals were used as negative control (Group C) and received saline (0.2 mL) through same route. Blood samples were collected by cardiac puncture on day 5 (C5, T5) and 30 (C30, T30) post-inoculation (pi) to perform complete blood count and determination of serum iron, transferrin, ferritin, total and latent iron fixation capacity, transferrin saturation and prohepcidin concentration. Also, bone marrow samples were collected, to perform Pearls staining reaction. Levels of iron, total and latent iron binding capacity and prohepcidin concentration were lower (P<0.05) in infected rats (T5 and T30 groups) compared to controls. On the other hand, levels of transferrin and ferritin were higher when compared to controls (P<0.05). The transferrin saturation increased on day 5 pi, but decreased on day 30 pi. The Pearls reaction showed a higher accumulation of iron in the bone marrow of infected animals in day 5 pi (P<0.01). Infection with T. evansi in rats caused anemia and changes in iron metabolism associated to the peaks of parasitemia. These results suggest that changes in iron metabolism may be related to the host immune response to infection and anemic status of infected animals.
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22
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Chung D, Haas H, Cramer RA. Coordination of hypoxia adaptation and iron homeostasis in human pathogenic fungi. Front Microbiol 2012; 3:381. [PMID: 23133438 PMCID: PMC3490150 DOI: 10.3389/fmicb.2012.00381] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 10/11/2012] [Indexed: 12/11/2022] Open
Abstract
In mammals, hypoxia causes facilitated erythropoiesis that requires increased iron availability with established links between oxygen and iron in regulation of the transcription factor hypoxia-inducible factor. Therefore, cellular responses to hypoxia and iron starvation are linked in mammals and are host conditions that pathogens encounter during infection. In human pathogenic fungi, molecular mechanisms underlying hypoxia adaptation and iron homeostasis have been investigated. However, the interconnected regulation of hypoxia adaptation and iron homeostasis remains to be fully elucidated. This review discusses the potential transcriptional regulatory links between hypoxia adaptation and iron homeostasis in human pathogenic fungi. Transcriptome analyses demonstrate that core regulators of hypoxia adaptation and iron homeostasis are involved in regulation of several common genes responsible for iron acquisition and ergosterol biosynthesis. Importantly, iron starvation increases susceptibility of fungal cells to antifungal drugs and decreased levels of ergosterol, while key hypoxia regulators are also involved in responses to antifungal drugs and mediating ergosterol levels. We suggest that pathogenic fungi have developed a coordinated regulatory system in response to hypoxia and iron starvation through (i) regulation of expression of hypoxia-responsive and iron-responsive genes via cross-linked key regulators, and/or (ii) regulation of factors involved in ergosterol biosynthesis. Thus, both oxygen and iron availability are intimately tied with fungal virulence and responses to existing therapeutics and further elucidation of their interrelationship should have significant clinical implications.
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Affiliation(s)
- Dawoon Chung
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth Hanover, NH, USA
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23
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Abstract
The human fungal pathogen Cryptococcus neoformans is characterized by its ability to induce a distinct polysaccharide capsule in response to a number of host-specific environmental stimuli. The induction of capsule is a complex biological process encompassing regulation at multiple steps, including the biosynthesis, transport, and maintenance of the polysaccharide at the cell surface. By precisely regulating the composition of its cell surface and secreted polysaccharides, C. neoformans has developed intricate ways to establish chronic infection and dormancy in the human host. The plasticity of the capsule structure in response to various host conditions also underscores the complex relationship between host and parasite. Much of this precise regulation of capsule is achieved through the transcriptional responses of multiple conserved signaling pathways that have been coopted to regulate this C. neoformans-specific virulence-associated phenotype. This review focuses on specific host stimuli that trigger the activation of the signal transduction cascades and on the downstream transcriptional responses that are required for robust encapsulation around the cell.
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24
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López-Berges MS, Capilla J, Turrà D, Schafferer L, Matthijs S, Jöchl C, Cornelis P, Guarro J, Haas H, Di Pietro A. HapX-mediated iron homeostasis is essential for rhizosphere competence and virulence of the soilborne pathogen Fusarium oxysporum. THE PLANT CELL 2012; 24:3805-22. [PMID: 22968717 PMCID: PMC3480304 DOI: 10.1105/tpc.112.098624] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Soilborne fungal pathogens cause devastating yield losses and are highly persistent and difficult to control. During the infection process, these organisms must cope with limited availability of iron. Here we show that the bZIP protein HapX functions as a key regulator of iron homeostasis and virulence in the vascular wilt fungus Fusarium oxysporum. Deletion of hapX does not affect iron uptake but causes derepression of genes involved in iron-consuming pathways, leading to impaired growth under iron-depleted conditions. F. oxysporum strains lacking HapX are reduced in their capacity to invade and kill tomato (Solanum lycopersicum) plants and immunodepressed mice. The virulence defect of ΔhapX on tomato plants is exacerbated by coinoculation of roots with a biocontrol strain of Pseudomonas putida, but not with a siderophore-deficient mutant, indicating that HapX contributes to iron competition of F. oxysporum in the tomato rhizosphere. These results establish a conserved role for HapX-mediated iron homeostasis in fungal infection of plants and mammals.
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Affiliation(s)
- Manuel S. López-Berges
- Departamento de Genética, Universidad de Córdoba, 14071 Córdoba, Spain
- Campus de Excelencia Internacional Agroalimentario ceiA3, 14071 Córdoba, Spain
| | - Javier Capilla
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, 43201 Reus, Spain
| | - David Turrà
- Departamento de Genética, Universidad de Córdoba, 14071 Córdoba, Spain
- Campus de Excelencia Internacional Agroalimentario ceiA3, 14071 Córdoba, Spain
| | - Lukas Schafferer
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Sandra Matthijs
- Institut de Recherches Microbiologiques Jean-Marie Wiame, 1070 Brussels, Belgium
| | - Christoph Jöchl
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Pierre Cornelis
- Department of Bioengineering Sciences, Research Group Microbiology, and Flanders Institute for Biotechnology, Department of Structural Biology, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - Josep Guarro
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, 43201 Reus, Spain
| | - Hubertus Haas
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Antonio Di Pietro
- Departamento de Genética, Universidad de Córdoba, 14071 Córdoba, Spain
- Campus de Excelencia Internacional Agroalimentario ceiA3, 14071 Córdoba, Spain
- Address correspondence to
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25
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Development of a sensitive HPLC method to measure in vitro permeability of E- and Z-isomeric forms of thiosemicarbazones in Caco-2 monolayers. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 906:25-32. [PMID: 22954966 DOI: 10.1016/j.jchromb.2012.08.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 08/06/2012] [Accepted: 08/09/2012] [Indexed: 11/22/2022]
Abstract
In the current study, we developed a HPLC method to quantitatively measure the permeability of the BpT-based chelators, 2-benzoylpyridine 4-ethyl-3-thiosemicarbazone (Bp4eT) and 2-benzoylpyridine 4-allyl-3-thiosemicarbazone (Bp4aT), across human colorectal adenocarcinoma (Caco-2) monolayers as a model of gut absorption. In aqueous solution, Bp4eT and Bp4aT formed inter-convertible Z and E isomers that were resolved by HPLC. Peak area was linear with respect to chelator concentration. Acceptable within-day and between-day precision (<22%) and accuracy (85-115% of true values) were obtained over a range of 1.0-100μM for Bp4eT and 1.5-300μM for Bp4aT. Limits of detection were 0.3μM and 1μM for Bp4eT and Bp4aT, respectively, while corresponding limits of quantification were 1μM and 5μM. Both chelators showed significant ability to chelate iron in THP-1 cells using a calcein-based assay and no apparent cytotoxicity was observed within 24h. Ratios of the apical to basolateral and basolateral to apical transport for Bp4eT were 1.10 and 0.89 at 100μM and 300μM respectively, indicating equal bi-directional movement of the compounds. Similarly, ratios were 0.77 and 0.92 for Bp4aT, respectively. This study demonstrates that Bp4eT and Bp4aT can be efficiently transported through Caco-2 cells and can potentially be formulated for oral delivery.
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Marcos CM, de Fátima da Silva J, de Oliveira HC, Moraes da Silva RA, Mendes-Giannini MJS, Fusco-Almeida AM. Surface-expressed enolase contributes to the adhesion of Paracoccidioides brasiliensis to host cells. FEMS Yeast Res 2012; 12:557-70. [PMID: 22443156 DOI: 10.1111/j.1567-1364.2012.00806.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 02/13/2012] [Accepted: 03/21/2012] [Indexed: 11/28/2022] Open
Abstract
Paracoccidioidomycosis is a systemic mycosis caused by the dimorphic fungus Paracoccidioides brasiliensis. Understanding the interactions between P. brasiliensis and the host tissue depends on the study of the different steps of the process of colonization, especially adhesion, in which the pathogen recognizes ligands on the surface of host cells. This study aimed to verify the role of enolase in the host cell-fungus interaction and the ability of enolase to bind to extracellular matrix components, to determine its subcellular localization, and to study the P. brasiliensis enolase amino acid sequence. The data revealed that fibronectin is the major ligand of enolase. Evaluation of the location of enolase at an ultrastructural level revealed that it is distributed in various cellular compartments, but at a high level in the cell wall. The analysis of the amino acid sequence revealed an internal plasminogen-binding motif ((254)FYKADEKKY(262)), which is conserved in most organisms and described as an important interaction site of the enolase with the host cell surface. This suggests that enolase performs additional functions related to the glycolytic pathway and also plays a role of adhesion in P. brasiliensis. Therefore, this study increases the knowledge about the characteristics of enolase and its influence on the binding process of P. brasiliensis.
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Affiliation(s)
- Caroline Maria Marcos
- Faculty of Pharmaceutical Sciences, UNESP - Univ Estadual Paulista Araraquara, Department of Clinical Analysis, Clinical Mycology Laboratory, SP, Brazil
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Schuessler DL, Parish T. The promoter of Rv0560c is induced by salicylate and structurally-related compounds in Mycobacterium tuberculosis. PLoS One 2012; 7:e34471. [PMID: 22485172 PMCID: PMC3317779 DOI: 10.1371/journal.pone.0034471] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 03/02/2012] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is a major global health threat. During infection, bacteria are believed to encounter adverse conditions such as iron depletion. Mycobacteria synthesize iron-sequestering mycobactins, which are essential for survival in the host, via the intermediate salicylate. Salicylate is a ubiquitous compound which is known to induce a mild antibiotic resistance phenotype. In M. tuberculosis salicylate highly induces the expression of Rv0560c, a putative methyltransferase. We identified and characterized the promoter and regulatory elements of Rv0560c. PRv0560c activity was highly inducible by salicylate in a dose-dependent manner. The induction kinetics of PRv0560c were slow, taking several days to reach maximal activity, which was sustained over several weeks. Promoter activity could also be induced by compounds structurally related to salicylate, such as aspirin or para-aminosalicylic acid, but not by benzoate, indicating that induction is specific to a structural motif. The −10 and −35 promoter elements were identified and residues involved in regulation of promoter activity were identified in close proximity to an inverted repeat spanning the −35 promoter element. We conclude that Rv0560c expression is controlled by a yet unknown repressor via a highly-inducible promoter.
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Affiliation(s)
| | - Tanya Parish
- Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
- * E-mail:
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Murgia I, Arosio P, Tarantino D, Soave C. Biofortification for combating 'hidden hunger' for iron. TRENDS IN PLANT SCIENCE 2012; 17:47-55. [PMID: 22093370 DOI: 10.1016/j.tplants.2011.10.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 09/14/2011] [Accepted: 10/07/2011] [Indexed: 05/20/2023]
Abstract
Micronutrient deficiencies are responsible for so-called 'hidden undernutrition'. In particular, iron (Fe) deficiency adversely affects growth, immune function and can cause anaemia. However, supplementation of iron can exacerbate infectious diseases and current policies of iron therapy carefully evaluate the risks and benefits of these interventions. Here we review the approaches of biofortification of valuable crops for reducing 'hidden undernutrition' of iron in the light of the latest nutritional and medical advances. The increase of iron and prebiotics in edible parts of plants is expected to improve health, whereas the reduction of phytic acid concentration, in crops valuable for human diet, might be less beneficial for the developed countries, or for the developing countries exposed to endemic infections.
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Affiliation(s)
- Irene Murgia
- Sezione di Fisiologia e Biochimica delle Piante, Dipartimento di Biologia, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy.
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Feng X, Krishnan K, Richie DL, Aimanianda V, Hartl L, Grahl N, Powers-Fletcher MV, Zhang M, Fuller KK, Nierman WC, Lu LJ, Latgé JP, Woollett L, Newman SL, Cramer RA, Rhodes JC, Askew DS. HacA-independent functions of the ER stress sensor IreA synergize with the canonical UPR to influence virulence traits in Aspergillus fumigatus. PLoS Pathog 2011; 7:e1002330. [PMID: 22028661 PMCID: PMC3197630 DOI: 10.1371/journal.ppat.1002330] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 09/06/2011] [Indexed: 12/20/2022] Open
Abstract
Endoplasmic reticulum (ER) stress is a condition in which the protein folding capacity of the ER becomes overwhelmed by an increased demand for secretion or by exposure to compounds that disrupt ER homeostasis. In yeast and other fungi, the accumulation of unfolded proteins is detected by the ER-transmembrane sensor IreA/Ire1, which responds by cleaving an intron from the downstream cytoplasmic mRNA HacA/Hac1, allowing for the translation of a transcription factor that coordinates a series of adaptive responses that are collectively known as the unfolded protein response (UPR). Here, we examined the contribution of IreA to growth and virulence in the human fungal pathogen Aspergillus fumigatus. Gene expression profiling revealed that A. fumigatus IreA signals predominantly through the canonical IreA-HacA pathway under conditions of severe ER stress. However, in the absence of ER stress IreA controls dual signaling circuits that are both HacA-dependent and HacA-independent. We found that a ΔireA mutant was avirulent in a mouse model of invasive aspergillosis, which contrasts the partial virulence of a ΔhacA mutant, suggesting that IreA contributes to pathogenesis independently of HacA. In support of this conclusion, we found that the ΔireA mutant had more severe defects in the expression of multiple virulence-related traits relative to ΔhacA, including reduced thermotolerance, decreased nutritional versatility, impaired growth under hypoxia, altered cell wall and membrane composition, and increased susceptibility to azole antifungals. In addition, full or partial virulence could be restored to the ΔireA mutant by complementation with either the induced form of the hacA mRNA, hacAi, or an ireA deletion mutant that was incapable of processing the hacA mRNA, ireAΔ10. Together, these findings demonstrate that IreA has both HacA-dependent and HacA-independent functions that contribute to the expression of traits that are essential for virulence in A. fumigatus. Aspergillus fumigatus is the predominant mold pathogen of humans, responsible for life-threatening infections in patients with depressed immunity. The fungus is highly adapted for secretion, a feature that it uses to extract nutrients from the host environment. High rates of protein secretion can overwhelm the protein folding capacity of the endoplasmic reticulum (ER). The resulting ER stress is alleviated by the unfolded protein response (UPR), a signaling pathway that is triggered by the ER-membrane sensor IreA and executed by the downstream transcription factor HacA. This paper uncovers a novel role for IreA in the expression of multiple adaptive traits that allow the fungus to cope with stress conditions that are encountered during infection. Gene expression profiling of ΔireA and ΔhacA mutants revealed that IreA signals predominantly through the canonical IreA-HacA UPR pathway under extreme conditions of ER stress, but has unexpected HacA-dependent and HacA-independent functions even in the absence of ER stress. These findings establish IreA as an important regulator of A. fumigatus pathogenicity and suggest that therapeutic targeting of the dual functions of this protein could be an effective antifungal strategy.
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Affiliation(s)
- Xizhi Feng
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Karthik Krishnan
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Daryl L. Richie
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | | | - Lukas Hartl
- Unité des Aspergillus, Institut Pasteur, Paris, France
| | - Nora Grahl
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Margaret V. Powers-Fletcher
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Minlu Zhang
- Division of Biomedical Informatics, Cincinnati Children's Hospital Research Foundation, Cincinnati, Ohio, United States of America
| | - Kevin K. Fuller
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - William C. Nierman
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Long Jason Lu
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | | | - Laura Woollett
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Simon L. Newman
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Robert A. Cramer
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Judith C. Rhodes
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - David S. Askew
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail:
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Hartmann T, Sasse C, Schedler A, Hasenberg M, Gunzer M, Krappmann S. Shaping the fungal adaptome--stress responses of Aspergillus fumigatus. Int J Med Microbiol 2011; 301:408-16. [PMID: 21565548 DOI: 10.1016/j.ijmm.2011.04.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Aspergillus fumigatus as prime pathogen to cause aspergillosis has evolved as a saprophyte, but is also able to infect and colonise immunocompromised hosts. Based on the 'dual use' hypothesis of fungal pathogenicity, general characteristics have to be considered as unspecific virulence determinants, among them stress adaptation capacities. The susceptible, warm-blooded mammalian host represents a specific ecological niche that poses several kinds of stress conditions to the fungus during the course of infection. Detailed knowledge about the cellular pathways and adaptive traits that have evolved in A. fumigatus to counteract situations of stress and varying environmental conditions is crucial for the identification of novel and specific antifungal targets. Comprehensive profiling data accompanied by mutant analyses have shed light on such stressors, and nutritional deprivation, oxidative stress, hypoxia, elevated temperature, alkaline pH, extensive secretion, and, in particular during treatment with antifungals, cell membrane perturbations appear to represent the major hazards A. fumigatus has to cope with during infection. Further efforts employing innovative approaches and advanced technologies will have to be made to expand our knowledge about the scope of the A. fumigatus adaptome that is relevant for disease.
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Affiliation(s)
- Thomas Hartmann
- Research Center for Infectious Diseases, Julius-Maximilians-University Würzburg, Germany
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Simão MF, Leite RB, Rocha C, Cancela ML. Changes in bioturbation of iron biogeochemistry and in molecular response of the clam Ruditapes decussates upon Perkinsus olseni infection. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2010; 59:433-443. [PMID: 20232199 DOI: 10.1007/s00244-010-9490-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Accepted: 02/16/2010] [Indexed: 05/28/2023]
Abstract
A series of artificial microcosms was used to test the effect of clam density on benthic iron biogeochemistry and, subsequently, if the response of clam Ruditapes decussatus to infection with Perkinsus olseni, a common opportunistic parasite known to be iron dependent, was correlated with the dynamics of iron sediment pore waters within the chambers. Three series of benthic microcosms were used in the experiment, comparing similar densities of clams (none, one, two, three, or four individuals/chamber) between a control set (no deliberate infection) and two parallel sets of clams that were deliberately infected with the parasite after 10 days of incubation. Fifteen chambers were used simultaneously and the experiment was conducted for 35 days. In order to avoid spurious effects of differential organic loading and clam feeding efficiency on the oxidative state of the sediment, the iron balance was tentatively shifted during incubation toward decreased dissolved iron in pore water. This was done by applying a constant flow of air to all chambers and refraining from supplying extra organic matter during the experimental run, which led to the reduction of benthic oxygen demand as the experiment progressed. Results showed that microcosms bearing both higher clam densities and lower infection levels were able to exert a quantitative influence in iron biogeochemistry through bioturbation activity. This effect was significantly depressed in chambers hosting clams with high infection levels. In addition, analysis of molecular markers responsive to iron and parasite stress revealed an upper regulation of HSP70 and ferritin in infected clams, thus suggesting a role of those molecules on both host protection and response to parasite presence by limiting iron availability. Together, these findings suggest a correlation between the expression of clam molecular iron/stress markers and iron bioavailability, which can be modified by the presence or absence of Perkinsus infection. In turn, we propose that clam lethargy in response to parasite invasion might help to combat infection by reducing iron mobilization in the surrounding sediment through a decrease in bioturbation activity, thus reducing its availability to the parasite.
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Schrettl M, Beckmann N, Varga J, Heinekamp T, Jacobsen ID, Jöchl C, Moussa TA, Wang S, Gsaller F, Blatzer M, Werner ER, Niermann WC, Brakhage AA, Haas H. HapX-mediated adaption to iron starvation is crucial for virulence of Aspergillus fumigatus. PLoS Pathog 2010; 6:e1001124. [PMID: 20941352 PMCID: PMC2947994 DOI: 10.1371/journal.ppat.1001124] [Citation(s) in RCA: 216] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 08/30/2010] [Indexed: 11/19/2022] Open
Abstract
Iron is essential for a wide range of cellular processes. Here we show that the bZIP-type regulator HapX is indispensable for the transcriptional remodeling required for adaption to iron starvation in the opportunistic fungal pathogen Aspergillus fumigatus. HapX represses iron-dependent and mitochondrial-localized activities including respiration, TCA cycle, amino acid metabolism, iron-sulfur-cluster and heme biosynthesis. In agreement with the impact on mitochondrial metabolism, HapX-deficiency decreases resistance to tetracycline and increases mitochondrial DNA content. Pathways positively affected by HapX include production of the ribotoxin AspF1 and siderophores, which are known virulence determinants. Iron starvation causes a massive remodeling of the amino acid pool and HapX is essential for the coordination of the production of siderophores and their precursor ornithine. Consistent with HapX-function being limited to iron depleted conditions and A. fumigatus facing iron starvation in the host, HapX-deficiency causes significant attenuation of virulence in a murine model of aspergillosis. Taken together, this study demonstrates that HapX-dependent adaption to conditions of iron starvation is crucial for virulence of A. fumigatus. Due to its requirement for a wide range of cellular processes, iron is an essential nutrient for virtually every organism. The mammalian immune system utilizes iron-withholding mechanisms to deny access to free iron. Therefore, pathogens must overcome extreme iron limitation. Patients with suppressed immune systems due to cancer treatments, organ transplantation, or genetic disorders are at high risk of infection with the ubiquitously present fungal pathogen Aspergillus fumigatus. In this study we found that in Aspergillus fumigatus iron starvation results in drastic metabolic changes depending on the transcription factor HapX. During iron starvation, HapX functions include the repression of iron-consuming pathways to spare iron and activation of iron uptake by siderophores. Siderophores are small molecules able to “steal” iron from host molecules and have previously been shown to play a crucial role in the virulence of Aspergillus fumigatus. Genetic inactivation of HapX attenuates virulence of Aspergillus fumigatus in a murine model of aspergillosis, demonstrating that adaption to iron limitation is a crucial virulence determinant. The identification of numerous HapX-affected genes with a yet uncharacterized link to iron will aid in the further characterization of the metabolic pathways required for fungal adaption to iron starvation and virulence traits.
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Affiliation(s)
- Markus Schrettl
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Nicola Beckmann
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - John Varga
- J. Craig Venter Institute, Rockville, Maryland, United States of America, and The George Washington University School of Medicine, Department of Biochemistry and Molecular Biology, Washington, D.C., United States of America
| | - Thorsten Heinekamp
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), and Friedrich Schiller University Jena, Jena, Germany
| | - Ilse D. Jacobsen
- Department for Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology (HKI), and Friedrich Schiller University Jena, Jena, Germany
| | - Christoph Jöchl
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Tarek A. Moussa
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Shaohua Wang
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Fabio Gsaller
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Michael Blatzer
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Ernst R. Werner
- Division of Biological Chemistry/Biocenter, Medical University Innsbruck, Innsbruck, Austria
| | - William C. Niermann
- J. Craig Venter Institute, Rockville, Maryland, United States of America, and The George Washington University School of Medicine, Department of Biochemistry and Molecular Biology, Washington, D.C., United States of America
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), and Friedrich Schiller University Jena, Jena, Germany
| | - Hubertus Haas
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
- * E-mail:
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Holbein BE, Mira de Orduña R. Effect of trace iron levels and iron withdrawal by chelation on the growth of Candida albicans and Candida vini. FEMS Microbiol Lett 2010; 307:19-24. [DOI: 10.1111/j.1574-6968.2010.01956.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Interaction of Cryptococcus neoformans Rim101 and protein kinase A regulates capsule. PLoS Pathog 2010; 6:e1000776. [PMID: 20174553 PMCID: PMC2824755 DOI: 10.1371/journal.ppat.1000776] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 01/18/2010] [Indexed: 11/19/2022] Open
Abstract
Cryptococcus neoformans is a prevalent human fungal pathogen that must survive within various tissues in order to establish a human infection. We have identified the C. neoformans Rim101 transcription factor, a highly conserved pH-response regulator in many fungal species. The rim101Δ mutant strain displays growth defects similar to other fungal species in the presence of alkaline pH, increased salt concentrations, and iron limitation. However, the rim101Δ strain is also characterized by a striking defect in capsule, an important virulence-associated phenotype. This capsular defect is likely due to alterations in polysaccharide attachment to the cell surface, not in polysaccharide biosynthesis. In contrast to many other C. neoformans capsule-defective strains, the rim101Δ mutant is hypervirulent in animal models of cryptococcosis. Whereas Rim101 activation in other fungal species occurs through the conserved Rim pathway, we demonstrate that C. neoformans Rim101 is also activated by the cAMP/PKA pathway. We report here that C. neoformans uses PKA and the Rim pathway to regulate the localization, activation, and processing of the Rim101 transcription factor. We also demonstrate specific host-relevant activating conditions for Rim101 cleavage, showing that C. neoformans has co-opted conserved signaling pathways to respond to the specific niche within the infected host. These results establish a novel mechanism for Rim101 activation and the integration of two conserved signaling cascades in response to host environmental conditions. Cryptococcus neoformans is an environmental fungus and an opportunistic human pathogen. Survival of this fungus within a human host depends on its ability to sense the host environment and respond with protective cellular changes. It is known that the cAMP/PKA signal transduction cascade is important for sensing host-specific environments and regulating the cellular adaptations, such as capsule and increased iron uptake, that are necessary for growth inside the infected host. Here we document that, unlike what has been described in other fungal species, a C. neoformans Rim101 homologue is directly regulated by PKA. The Rim101 signaling pathway is also involved in capsule regulation and virulence. Our study demonstrates that Rim101 integrates two conserved signal transduction cascades, and it is important in regulating microbial pathogenesis.
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Jang HJ, Nde C, Toghrol F, Bentley WE. Microarray analysis of Mycobacterium bovis BCG revealed induction of iron acquisition related genes in response to hydrogen peroxide. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:9465-9472. [PMID: 19924887 DOI: 10.1021/es902255q] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Mycobacterium bovis BCG strain Pasteur 1173P2 responds with adaptive and protective strategies against oxidative stress. Despite advances in our understanding of the responses to oxidative stress in many specific cases, the connectivity between targeted protective genes and the rest of cell metabolism remains obscure. This study was therefore carried out to investigate the genome-wide response of M. bovis BCG to hydrogen peroxide after 10 and 60 min of treatment. ATP measurements were carried out in order to monitor the changes in M. bovis BCG growth over a 1 h period. The furA gene in Mycobacterium bovis, a pleiotropic regulator that couples iron metabolism to the oxidative stress response was involved in the response to hydrogen peroxide stress. There were also increased levels of catalase/ peroxidase (KatG) and the biosynthesis operon of mycobactin. This study revealed significant upregulation of the oxidative response group of M. bovis, amino acid transport and metabolism, defense mechanisms, DNA replication, recombination and repair, and downregulation of cell cycle control, mitosis, and meiosis, lipid transport and metabolism, and cell wall/membrane biogenesis. This study shows that the treatment of M. bovis BCG with hydrogen peroxide induces iron acquisition related genes and oxidative stress response genes within one hour of treatment.
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Affiliation(s)
- Hyeung-Jin Jang
- Department of Biochemistry, College of Oriental Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea
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37
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38
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Weinberg ED. Iron loading in humans: A risk factor for enhanced morbidity and mortality. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/13590840601167685] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Use and endocytosis of iron-containing proteins by Entamoeba histolytica trophozoites. INFECTION GENETICS AND EVOLUTION 2009; 9:1038-50. [PMID: 19539057 DOI: 10.1016/j.meegid.2009.05.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 04/16/2009] [Accepted: 05/19/2009] [Indexed: 11/20/2022]
Abstract
Iron is essential for nearly all organisms; in mammals, it is part of proteins such as haemoglobin, and it is captured by transferrin and lactoferrin. Transferrin is present in serum, and lactoferrin is secreted by the mucosa and by neutrophils at infection sites, as a host iron-withholding response, sequestering iron away from invading microorganisms. Additionally, all cells contain ferritin, which sequesters iron when its intracellular levels are increased, detoxifying and preventing damage. Liver ferritin contains 50% of iron corporal reserves. During evolution, pathogens have evolved diverse strategies to obtain iron from their hosts in order to survive. The protozoan Entamoeba histolytica invades the intestinal mucosa, causing dysentery, and the trophozoites often travel to the liver producing hepatic abscesses; thus, intestine and liver proteins could be important iron supplies for E. histolytica. We found that E. histolytica trophozoites can grow in both ferrous and ferric iron, and that they can use haemoglobin, holo-transferrin, holo-lactoferrin, and ferritin as in vitro iron sources. These proteins supported the amoeba growth throughout consecutive passages, similarly to ferric citrate. By confocal microscopy and immunoblotting, iron-binding proteins were observed specifically bound to the amoeba surface, and they were endocytosed, trafficked through the endosomal/lysosomal route, and degraded by neutral and acidic cysteine-proteases. Transferrin and ferritin were mainly internalized through clathrin-coated vesicles, and holo-lactoferrin was mainly internalized by caveola-like structures. In contrast, apo-lactoferrin bound to membrane lipids and cholesterol, inducing cell death. The results suggest that in vivo trophozoites secrete products that can destroy enterocytes, erythrocytes, and hepatocytes, releasing transferrin, haemoglobin, ferritin, and other iron-containing proteins, which, together with lactoferrin derived from neutrophils and acinar cells, could be used as abundant iron supplies by amoebas.
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Wander K, Shell-Duncan B, McDade TW. Evaluation of iron deficiency as a nutritional adaptation to infectious disease: an evolutionary medicine perspective. Am J Hum Biol 2009; 21:172-9. [PMID: 18949769 DOI: 10.1002/ajhb.20839] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
An evolutionary perspective suggests that iron deficiency may have opposing effects on infectious disease risk, decreasing susceptibility by restricting iron availability to pathogens, and increasing susceptibility by compromising cellular immunocompetence. In some environments, the trade-off between these effects may result in optimal iron intake that is inadequate to fully meet body iron needs. Thus, it has been suggested that moderate iron deficiency may protect against acute infection, and may represent a nutritional adaptation to endemic infectious disease stress. To test this assertion, we examined the association between infection, reflected by C-reactive protein, a biomarker of inflammation, and iron status, reflected by transferrin receptor (TfR) and zinc protoporphyrin to heme ratio (ZPP:H), among school-age Kenyan children, and evaluated the hypothesis that moderate iron deficiency is associated with lower odds of infectious disease. TfR > 5.0 mg/l, with sensitivity and specificity for iron deficiency (ZPP:H > 80 micromol/mol) of 0.807 and 0.815, was selected as the TfR definition of iron deficiency. Controlling for age and triceps skinfold thickness (TSF), the odds ratio (OR) for acute viral or bacterial infection associated with iron deficiency (compared to normal/replete) was 0.50 (P = 0.11). Controlling for age and TSF, the OR for infection associated with an unequivocally iron replete state (compared to all others) was 2.9 (P = 0.01). We conclude that iron deficiency may protect against acute infection in children.
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Affiliation(s)
- Katherine Wander
- Department of Anthropology, University of Washington, Seattle, Washington 98195, USA.
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41
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de Mast Q, Nadjm B, Reyburn H, Kemna EHJM, Amos B, Laarakkers CMM, Silalye S, Verhoef H, Sauerwein RW, Swinkels DW, van der Ven AJAM. Assessment of urinary concentrations of hepcidin provides novel insight into disturbances in iron homeostasis during malarial infection. J Infect Dis 2009; 199:253-62. [PMID: 19032104 DOI: 10.1086/595790] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Disturbances in iron homeostasis are frequently observed in individuals with malaria. To study the effect of malaria and its treatment on iron homeostasis and to provide a mechanistic explanation for observed alterations in iron distribution, we studied the course of the iron regulatory hormone hepcidin in anemic Tanzanian children with febrile Plasmodium falciparum malaria. Before initiation of antimalarial treatment, urinary concentrations of hepcidin were strongly elevated and were associated with iron maldistribution, as was suggested by the presence of hypoferremia and high serum concentrations of ferritin. Antimalarial treatment resulted in a rapid decrease in urinary concentrations of hepcidin and reversal of the hypoferremia. Exploration of regulatory pathways of hepcidin production by analysis of iron, erythropoietic, and inflammatory indices suggested that reduced erythropoietic activity and inflammation stimulated hepcidin production. We conclude that high concentrations of hepcidin explain the observed disturbances in host iron homeostasis associated with malaria and may contribute to malarial anemia and an impaired erythropoietic response to iron supplementation.
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Affiliation(s)
- Quirijn de Mast
- Department of General Internal Medicine, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
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López-Soto F, González-Robles A, Salazar-Villatoro L, León-Sicairos N, Piña-Vázquez C, Salazar EP, de la Garza M. Entamoeba histolytica uses ferritin as an iron source and internalises this protein by means of clathrin-coated vesicles. Int J Parasitol 2008; 39:417-26. [PMID: 18848948 DOI: 10.1016/j.ijpara.2008.08.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 08/27/2008] [Accepted: 08/31/2008] [Indexed: 01/05/2023]
Abstract
Entamoeba histolytica is a parasitic protozoan that produces dysentery and often reaches the liver, leading to abscess formation. Ferritin is an iron-storage protein that is mainly found in liver and spleen in mammals. The liver contains a plentiful source of iron for amoebae multiplying in that organ, making it a prime target for infection since iron is essential for the growth of this parasite. The aim of this study was to determine whether trophozoites are able to take up ferritin and internalise this protein for their growth in axenic culture. Interaction between the amoebae and ferritin was studied by flow cytometry, confocal laser-scanning microscopy and transmission electron microscopy. Amoebae were viable in iron supplied by ferritin. Trophozoites quickly internalised ferritin via clathrin-coated vesicles, a process that was initiated within the first 2 min of incubation. In 30 min, ferritin was found colocalizing with the LAMP-2 protein at vesicles in the cytosol. The uptake of ferritin was time- temperature- and concentration-dependent, specific and saturated at 46 nM of ferritin. Haemoglobin and holo-transferrin did not compete with ferritin for binding to amoebae. Amoebae cleaved ferritin leading to the production of several different sized fragments. Cysteine proteases of 100, 75 and 50 kDa from amoeba extracts were observed in gels copolymerised with ferritin. For a pathogen such as E. histolytica, the capacity to utilise ferritin as an iron source may well explain its high pathogenic potential in the liver.
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Affiliation(s)
- Fernando López-Soto
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, México DF 07000, Mexico
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Seifert M, Nairz M, Schroll A, Schrettl M, Haas H, Weiss G. Effects of the Aspergillus fumigatus siderophore systems on the regulation of macrophage immune effector pathways and iron homeostasis. Immunobiology 2008; 213:767-78. [PMID: 18926292 DOI: 10.1016/j.imbio.2008.07.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Accepted: 07/23/2008] [Indexed: 02/08/2023]
Abstract
The saprophytic fungus Aspergillus fumigatus is the most prevalent airborne fungal pathogen, which is responsible for invasive aspergillosis in immunocompromised patients. Iron plays an essential role for the growth and proliferation of A. fumigatus. This fungus synthesizes three major siderophores. It excretes triacetylfusarinine C to capture iron, while it accumulates ferricrocin and hydroxyferricrocin for hyphal and conidial iron storage, respectively. Herein, we investigated the role of the siderophore system of A. fumigatus in the modulation of immune effector pathways and iron homeostasis in macrophages. We set up a co-culture system consisting of the murine macrophage cell line RAW264.7 and either A. fumigatus wild type or a siderophore-deficient mutant (DeltasidA). We used real-time quantitative RT-PCR and Western blot analyses to study the expression of macrophage iron metabolism and innate immune response genes in response to pathogen challenge. Infection of macrophages with A. fumigatus wild type, but not with the DeltasidA mutant, induced expression of TNF and phagocyte oxidase subunit 47 at the transcriptional level. Moreover, infection with A. fumigatus wild type, but not with the DeltasidA mutant, compromised macrophage iron homeostasis. Infection with wild-type A. fumigatus decreased expression of the two cellular iron importers, the divalent metal transporter-1 and the transferrin receptor, and the only known iron exporter ferroportin. At the same time, it increased macrophage iron retention and ferritin synthesis. These data indicate that A. fumigatus affects the regulation of macrophage iron homeostasis and innate immune effector pathways via its siderophore system. The changes in immune response may be a consequence of macrophage iron restriction.
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Affiliation(s)
- M Seifert
- Department of General Internal Medicine, Clinical Immunology and Infectious Diseases, Medical University, Anichstr. 35, A-6020 Innsbruck, Austria
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Nairz M, Fritsche G, Brunner P, Talasz H, Hantke K, Weiss G. Interferon-gamma limits the availability of iron for intramacrophage Salmonella typhimurium. Eur J Immunol 2008; 38:1923-36. [PMID: 18581323 DOI: 10.1002/eji.200738056] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In stimulating effector functions of mononuclear phagocytes, IFN-gamma is of pivotal importance in host defense against intramacrophage pathogens including salmonellae. As the activity of IFN-gamma is modulated by iron and since a sufficient availability of iron is essential for the growth of pathogens, we investigated the regulatory effects of IFN-gamma on iron homeostasis and immune function in murine macrophages infected with Salmonella typhimurium. In Salmonella-infected phagocytes, IFN-gamma caused a significant reduction of iron uptake via transferrin receptor 1 and resulted in an increased iron efflux caused by an enhanced expression of the iron exporter ferroportin 1. Moreover, the expression of haem oxygenase 1 and of the siderophore-capturing antimicrobial peptide lipocalin 2 was markedly elevated following bacterial invasion, with IFN-gamma exerting a super-inducing effect. This observed regulatory impact of IFN-gamma reduced the intracellular iron pools within infected phagocytes, thus restricting the acquisition of iron by engulfed Salmonella typhimurium while concomitantly promoting NO and TNF-alpha production. Our data suggest that the modulation of crucial pathways of macrophage iron metabolism in response to IFN-gamma concordantly aims at withdrawing iron from intracellular Salmonella and at strengthening macrophage immune response functions. These regulations are thus consistent with the principles of nutritional immunity.
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Affiliation(s)
- Manfred Nairz
- Department of General Internal Medicine, Clinical Immunology and Infectious Diseases, Medical University Innsbruck, Anichstrasse 35, Innsbruck, Austria
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Zarnowski R, Cooper KG, Brunold LS, Calaycay J, Woods JP. Histoplasma capsulatum secreted gamma-glutamyltransferase reduces iron by generating an efficient ferric reductant. Mol Microbiol 2008; 70:352-68. [PMID: 18761625 DOI: 10.1111/j.1365-2958.2008.06410.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The intracellular fungal pathogen Histoplasma capsulatum (Hc) resides in mammalian macrophages and causes respiratory and systemic disease. Iron limitation is an important host antimicrobial defence, and iron acquisition is critical for microbial pathogenesis. Hc displays several iron acquisition mechanisms, including secreted glutathione-dependent ferric reductase activity (GSH-FeR). We purified this enzyme from culture supernatant and identified a novel extracellular iron reduction strategy involving gamma-glutamyltransferase (Ggt1) activity. The 320 kDa complex was composed of glycosylated protein subunits of about 50 and 37 kDa. The purified enzyme exhibited gamma-glutamyl transfer activity as well as iron reduction activity in the presence of glutathione. We cloned and manipulated expression of the encoding gene. Overexpression or RNAi silencing affected both GGT and GSH-FeR activities concurrently. Enzyme inhibition experiments showed that the activity is complex and involves two reactions. First, Ggt1 initiates enzymatic breakdown of GSH by cleavage of the gamma-glutamyl bond and release of cysteinylglycine. Second, the thiol group of the released dipeptide reduces ferric to ferrous iron. A combination of kinetic properties of both reactions resulted in efficient iron reduction over a broad pH range. Our findings provide novel insight into Hc iron acquisition strategies and reveal a unique aspect of Ggt1 function in this dimorphic mycopathogen.
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Affiliation(s)
- Robert Zarnowski
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, USA.
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Schrettl M, Kim HS, Eisendle M, Kragl C, Nierman WC, Heinekamp T, Werner ER, Jacobsen I, Illmer P, Yi H, Brakhage AA, Haas H. SreA-mediated iron regulation in Aspergillus fumigatus. Mol Microbiol 2008; 70:27-43. [PMID: 18721228 PMCID: PMC2610380 DOI: 10.1111/j.1365-2958.2008.06376.x] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Aspergillus fumigatus, the most common airborne fungal pathogen of humans, employs two high-affinity iron uptake systems: iron uptake mediated by the extracellular siderophore triacetylfusarinine C and reductive iron assimilation. Furthermore, A. fumigatus utilizes two intracellular siderophores, ferricrocin and hydroxyferricrocin, to store iron. Siderophore biosynthesis, which is essential for virulence, is repressed by iron. Here we show that this control is mediated by the GATA factor SreA. During iron-replete conditions, SreA deficiency partially derepressed synthesis of triacetylfusarinine C and uptake of iron resulting in increased cellular accumulation of both iron and ferricrocin. Genome-wide DNA microarray analysis identified 49 genes that are repressed by iron in an SreA-dependent manner. This gene set, termed SreA regulon, includes all known genes involved in iron acquisition, putative novel siderophore biosynthetic genes, and also genes not directly linked to iron metabolism. SreA deficiency also caused upregulation of iron-dependent and antioxidative pathways, probably due to the increased iron content and iron-mediated oxidative stress. Consistently, the sreA disruption mutant displayed increased sensitivity to iron, menadion and phleomycin but retained wild-type virulence in a mouse model. As all detrimental effects of sreA disruption are restricted to iron-replete conditions these data underscore that A. fumigatus faces iron-depleted conditions during infection.
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Affiliation(s)
- Markus Schrettl
- Divisions of Molecular Biology/Biocenter, Medical University Innsbruck, Fritz-Pregl-Str.3, A-6020 Innsbruck, Austria
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47
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Hameed S, Prasad T, Banerjee D, Chandra A, Mukhopadhyay CK, Goswami SK, Lattif AA, Chandra J, Mukherjee PK, Ghannoum MA, Prasad R. Iron deprivation inducesEFG1-mediated hyphal development inCandida albicanswithout affecting biofilm formation. FEMS Yeast Res 2008; 8:744-55. [DOI: 10.1111/j.1567-1364.2008.00394.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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48
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Daily J, Wylie B. Iron Deficiency during Pregnancy: Blessing or Curse? J Infect Dis 2008; 198:157-8. [DOI: 10.1086/589513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Long KZ, Rosado JL, Fawzi W. The Comparative Impact of Iron, the B-Complex Vitamins, Vitamins C and E, and Selenium on Diarrheal Pathogen Outcomes Relative to the Impact Produced by Vitamin A and Zinc. Nutr Rev 2008; 65:218-32. [PMID: 17566548 DOI: 10.1111/j.1753-4887.2007.tb00299.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Micronutrient supplementation offers one of the most cost-effective means of improving the health and survival of children in developing countries. However, the effects of supplementation with single micronutrients on diarrhea are not always consistent, and supplementation with multi-micronutrient supplements can have negative effects. These inconsistencies may result from the failure to consider the diverse etiological agents that cause diarrhea and the unique effects each micronutrient has on the immune response to each of these agents. This review examines the separate effects that supplementation with the B-complex vitamins, vitamin C, vitamin E, selenium, and iron have on diarrheal disease-related outcomes. Supplementation with iron may increase the risk of infection by invasive diarrheal pathogens, while supplementation with the remaining micronutrients may reduce this risk. These differences may be due to distinct regulatory effects each micronutrient has on the pathogen-specific immune response, as well as on the virulence of specific pathogens. The findings of these studies suggest that micronutrient supplementation of children must take into account the pathogens prevalent within communities as reflected by their diarrheal disease burdens. The effectiveness of combining multiple micronutrients into one supplement must also be reconsidered.
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Affiliation(s)
- Kurt Z Long
- Harvard School of Public Health, Department of Nutrition, Harvard School of Public Health, 1663 Tremont Street, Boston, MA 02115, USA.
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50
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Abstract
The numerous acute and chronic diseases associated with excessive/misplaced iron are categorized in this review in the following sections: 1) iron, by itself, can initiate the disease; 2) iron can be a cofactor in promoting the disease; 3) iron deposits are observed in disease-associated tissue sites; 4) body iron loading is associated with above normal incidence of the disease; and 5) maternal antibodies can impair fetal iron metabolism. Also discussed is the anomalous condition in which persons whose macrophages are low in iron are resistant to microbial pathogens that require iron loaded macrophages for in vivo growth. Thus, hemochromatotic mutations have apparently had survival value during outbreaks of tuberculosis, plague and typhoid fever.
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Affiliation(s)
- Eugene D Weinberg
- Department of Biology and Program in Medical Sciences, Indiana University, Bloomington, Indiana 47405, USA.
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