1
|
Romano PS, Akematsu T, Besteiro S, Bindschedler A, Carruthers VB, Chahine Z, Coppens I, Descoteaux A, Alberto Duque TL, He CY, Heussler V, Le Roch KG, Li FJ, de Menezes JPB, Menna-Barreto RFS, Mottram JC, Schmuckli-Maurer J, Turk B, Tavares Veras PS, Salassa BN, Vanrell MC. Autophagy in protists and their hosts: When, how and why? Autophagy Rep 2023; 2:2149211. [PMID: 37064813 PMCID: PMC10104450 DOI: 10.1080/27694127.2022.2149211] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 11/15/2022] [Indexed: 03/12/2023]
Abstract
Pathogenic protists are a group of organisms responsible for causing a variety of human diseases including malaria, sleeping sickness, Chagas disease, leishmaniasis, and toxoplasmosis, among others. These diseases, which affect more than one billion people globally, mainly the poorest populations, are characterized by severe chronic stages and the lack of effective antiparasitic treatment. Parasitic protists display complex life-cycles and go through different cellular transformations in order to adapt to the different hosts they live in. Autophagy, a highly conserved cellular degradation process, has emerged as a key mechanism required for these differentiation processes, as well as other functions that are crucial to parasite fitness. In contrast to yeasts and mammals, protist autophagy is characterized by a modest number of conserved autophagy-related proteins (ATGs) that, even though, can drive the autophagosome formation and degradation. In addition, during their intracellular cycle, the interaction of these pathogens with the host autophagy system plays a crucial role resulting in a beneficial or harmful effect that is important for the outcome of the infection. In this review, we summarize the current state of knowledge on autophagy and other related mechanisms in pathogenic protists and their hosts. We sought to emphasize when, how, and why this process takes place, and the effects it may have on the parasitic cycle. A better understanding of the significance of autophagy for the protist life-cycle will potentially be helpful to design novel anti-parasitic strategies.
Collapse
Affiliation(s)
- Patricia Silvia Romano
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
| | - Takahiko Akematsu
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | | | | | - Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Zeinab Chahine
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology. Department of Molecular Microbiology and Immunology. Johns Hopkins Malaria Research Institute. Johns Hopkins University Bloomberg School of Public Health. Baltimore 21205, MD, USA
| | - Albert Descoteaux
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique, Laval, QC
| | - Thabata Lopes Alberto Duque
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Cynthia Y He
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Volker Heussler
- Institute of Cell Biology.University of Bern. Baltzerstr. 4 3012 Bern
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Feng-Jun Li
- Department of Biological Sciences, National University of Singapore, Singapore
| | | | | | - Jeremy C Mottram
- York Biomedical Research Institute, Department of Biology, University of York, York, UK
| | | | - Boris Turk
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Patricia Sampaio Tavares Veras
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia
- National Institute of Science and Technology of Tropical Diseases - National Council for Scientific Research and Development (CNPq)
| | - Betiana Nebai Salassa
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
| | - María Cristina Vanrell
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
| |
Collapse
|
2
|
Abstract
In recent decades, studies have shown that, depending on parasite species and host background, autophagy can either favor infection or promote parasite clearance. To date, relatively few studies have attempted to assess the role played by autophagy in Leishmania infection. While it has been consistently shown that Leishmania spp. induce autophagy in a variety of cell types, published results regarding the effects of autophagic modulation on Leishmania survival are contradictory. The present review, after a short overview of the general aspects of autophagy, aims to summarize the current body of knowledge surrounding how Leishmania spp. adaptively interact with macrophages, the host cells mainly involved in controlling leishmaniasis. We then explore the scarce studies that have investigated interactions between these parasite species and the autophagic pathway, and finally present a critical perspective on how autophagy influences infection outcome.
Collapse
Affiliation(s)
- Patricia Sampaio Tavares Veras
- Laboratory of Host - Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil.,National Institute of Science and Technology of Tropical Diseases - CNPq, Salvador, Brazil
| | | | - Beatriz Rocha Simões Dias
- Laboratory of Host - Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| |
Collapse
|
3
|
de Menezes JPB, Khouri R, Oliveira CVS, Petersen ALDOA, de Almeida TF, Mendes FRL, Rebouças ADAD, Lorentz AL, Luz NF, Lima JB, Ramos PIP, Soares RP, Rugani JN, Buck GA, Krieger MA, Marchini FK, Vivarini ÁDC, Lopes UG, Borges VDM, Veras PST. Proteomic Analysis Reveals a Predominant NFE2L2 (NRF2) Signature in Canonical Pathway and Upstream Regulator Analysis of Leishmania-Infected Macrophages. Front Immunol 2019; 10:1362. [PMID: 31316499 PMCID: PMC6611007 DOI: 10.3389/fimmu.2019.01362] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 05/29/2019] [Indexed: 12/31/2022] Open
Abstract
CBA mice macrophages (MØ) control infection by Leishmania major and are susceptive to Leishmania amazonensis, suggesting that both parasite species induce distinct responses that play important roles in infection outcome. To evaluate the MØ responses to infection arising from these two Leishmania species, a proteomic study using a Multidimensional Protein Identification Technology (MudPIT) approach with liquid chromatography tandem mass spectrometry (LC-MS/MS) was carried out on CBA mice bone-marrow MØ (BMMØ). Following SEQUEST analysis, which revealed 2,838 proteins detected in BMMØ, data mining approach found six proteins significantly associated with the tested conditions. To investigate their biological significance, enrichment analysis was performed using Ingenuity Pathway Analysis (IPA). A three steps IPA approach revealed 4 Canonical Pathways (CP) and 7 Upstream Transcriptional Factors (UTFs) strongly associated with the infection process. NRF2 signatures were present in both CPs and UTFs pathways. Proteins involved in iron metabolism, such as heme oxigenase 1 (HO-1) and ferritin besides sequestosome (SQSMT1 or p62) were found in the NRF2 CPs and the NRF2 UTFs. Differences in the involvement of iron metabolism pathway in Leishmania infection was revealed by the presence of HO-1 and ferritin. Noteworty, HO-1 was strongly associated with L. amazonensis infection, while ferritin was regulated by both species. As expected, higher HO-1 and p62 expressions were validated in L. amazonensis-infected BMMØ, in addition to decreased expression of ferritin and nitric oxide production. Moreover, BMMØ incubated with L. amazonensis LPG also expressed higher levels of HO-1 in comparison to those stimulated with L. major LPG. In addition, L. amazonensis-induced uptake of holoTf was higher than that induced by L. major in BMMØ, and holoTf was also detected at higher levels in vacuoles induced by L. amazonensis. Taken together, these findings indicate that NRF2 pathway activation and increased HO-1 production, together with higher levels of holoTf uptake, may promote permissiveness to L. amazonensis infection. In this context, differences in protein signatures triggered in the host by L. amazonensis and L. major infection could drive the outcomes in distinct clinical forms of leishmaniasis.
Collapse
Affiliation(s)
| | - Ricardo Khouri
- Laboratory of Vector Born Infectious Diseases, Gonçalo Moniz Institute, Salvador, Brazil.,Department of Pathology and Legal Medicine, Faculty of Medicine, Federal University of Bahia, Salvador, Brazil
| | | | | | - Tais Fontoura de Almeida
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia, Salvador, Brazil.,Laboratory of Physiopathology, Federal University of Rio de Janeiro, Macaé, Brazil
| | - Flávia R L Mendes
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia, Salvador, Brazil
| | | | - Amanda Lopes Lorentz
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia, Salvador, Brazil
| | - Nívea Farias Luz
- Laboratory of Inflammation and Biomarkers, Gonçalo Moniz Institute, Salvador, Brazil
| | - Jonilson Berlink Lima
- Centro de Ciências Biológicas e da Saúde, Federal University of the Western of Bahia, Barreiras, Brazil
| | - Pablo Ivan Pereira Ramos
- Center for Data and Knowledge Integration for Health, Gonçalo Moniz Institute, Fiocruz-Bahia, Salvador, Brazil
| | | | | | - Gregory A Buck
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, United States
| | | | | | - Áislan de Carvalho Vivarini
- Laboratory of Molecular Parasitology, Center of Health Science, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ulisses Gazos Lopes
- Laboratory of Molecular Parasitology, Center of Health Science, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Patricia Sampaio Tavares Veras
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia, Salvador, Brazil.,National Institute of Science and Technology of Tropical Disease, Patos, Brazil
| |
Collapse
|
4
|
Veras PST, Ramos PIP, de Menezes JPB. In Search of Biomarkers for Pathogenesis and Control of Leishmaniasis by Global Analyses of Leishmania-Infected Macrophages. Front Cell Infect Microbiol 2018; 8:326. [PMID: 30283744 PMCID: PMC6157484 DOI: 10.3389/fcimb.2018.00326] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/27/2018] [Indexed: 12/12/2022] Open
Abstract
Leishmaniasis is a vector-borne, neglected tropical disease with a worldwide distribution that can present in a variety of clinical forms, depending on the parasite species and host genetic background. The pathogenesis of this disease remains far from being elucidated because the involvement of a complex immune response orchestrated by host cells significantly affects the clinical outcome. Among these cells, macrophages are the main host cells, produce cytokines and chemokines, thereby triggering events that contribute to the mediation of the host immune response and, subsequently, to the establishment of infection or, alternatively, disease control. There has been relatively limited commercial interest in developing new pharmaceutical compounds to treat leishmaniasis. Moreover, advances in the understanding of the underlying biology of Leishmania spp. have not translated into the development of effective new chemotherapeutic compounds. As a result, biomarkers as surrogate disease endpoints present several potential advantages to be used in the identification of targets capable of facilitating therapeutic interventions considered to ameliorate disease outcome. More recently, large-scale genomic and proteomic analyses have allowed the identification and characterization of the pathways involved in the infection process in both parasites and the host, and these analyses have been shown to be more effective than studying individual molecules to elucidate disease pathogenesis. RNA-seq and proteomics are large-scale approaches that characterize genes or proteins in a given cell line, tissue, or organism to provide a global and more integrated view of the myriad biological processes that occur within a cell than focusing on an individual gene or protein. Bioinformatics provides us with the means to computationally analyze and integrate the large volumes of data generated by high-throughput sequencing approaches. The integration of genomic expression and proteomic data offers a rich multi-dimensional analysis, despite the inherent technical and statistical challenges. We propose that these types of global analyses facilitate the identification, among a large number of genes and proteins, those that hold potential as biomarkers. The present review focuses on large-scale studies that have identified and evaluated relevant biomarkers in macrophages in response to Leishmania infection.
Collapse
Affiliation(s)
- Patricia Sampaio Tavares Veras
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia, Salvador, Brazil.,National Institute of Tropical Disease, Brasilia, Brazil
| | - Pablo Ivan Pereira Ramos
- Center for Data and Knowledge Integration for Health, Gonçalo Moniz Institute, Fiocruz-Bahia, Salvador, Brazil
| | | |
Collapse
|
5
|
Guedes CES, Dias BRS, Petersen ALDOA, Cruz KP, Almeida NDJ, Andrade DR, Menezes JPBD, Borges VDM, Veras PST. In vitro evaluation of the anti-leishmanial activity and toxicity of PK11195. Mem Inst Oswaldo Cruz 2018; 113:e170345. [PMID: 29412342 PMCID: PMC5851033 DOI: 10.1590/0074-02760170345] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/30/2017] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Leishmaniasis, one of the most neglected diseases, is a serious public health problem in many countries, including Brazil. Currently available treatments require long-term use and have serious side effects, necessitating the development of new therapeutic interventions. Because translocator protein (TSPO) levels are reduced in Leishmania amazonensis-infected cells and because this protein participates in apoptosis and immunomodulation, TSPO represents a potential target for Leishmania chemotherapy. The present study evaluated PK11195, a ligand of this protein, as an anti-leishmanial agent. OBJECTIVE To evaluate the leishmanicidal activity of PK11195 against L. amazonensis in infected CBA mouse macrophages in vitro. METHODS The viability of axenic L. amazonensis, Leishmania major, and Leishmania braziliensis promastigotes was assessed after 48 h treatment with PK11195 (0.2-400 µM). Additionally, intracellular parasite viability was evaluated to determine IC50 values and the number of viable parasites in infected macrophages treated with PK11195 (50-100 µM). Infected macrophages were then treated with PK11195 (25-100 µM) to determine the percentage of L. amazonensis-infected cells and the number of parasites per infected cell. Electron microscopy was used to investigate morphological changes caused by PK11195. The production of free oxygen radicals, nitric oxide, and pro-inflammatory cytokines was also evaluated in infected macrophages treated with PK11195 and primed or not primed with IFN-γ. FINDINGS Median IC50 values for PK11195 were 14.2 µM for L. amazonensis, 8.2 µM for L. major, and 3.5 µM for L. braziliensis. The selective index value for L. amazonensis was 13.7, indicating the safety of PK11195 for future testing in mammals. Time- and dose-dependent reductions in the percentage of infected macrophages, the number of parasites per infected macrophage, and the number of viable intracellular parasites were observed. Electron microscopy revealed some morphological alterations suggestive of autophagy. Interestingly, MCP-1 and superoxide levels were reduced in L. amazonensis-infected macrophages treated with PK11195. MAIN CONCLUSIONS PK11195 causes the killing of amastigotes in vitro by mechanisms independent of inflammatory mediators and causes morphological alterations within Leishmania parasites, suggestive of autophagy, at doses that are non-toxic to macrophages. Thus, this molecule has demonstrated potential as an anti-leishmanial agent.
Collapse
Affiliation(s)
- Carlos Eduardo Sampaio Guedes
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | - Beatriz Rocha Simões Dias
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | | | - Kercia Pinheiro Cruz
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | - Niara de Jesus Almeida
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | - Daniela Rodrigues Andrade
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório Integrado de Microbiologia e Imunoregulação, Salvador, BA, Brasil
| | | | - Valéria de Matos Borges
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório Integrado de Microbiologia e Imunoregulação, Salvador, BA, Brasil
| | - Patricia Sampaio Tavares Veras
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| |
Collapse
|
6
|
Mittra B, Laranjeira-Silva MF, Miguel DC, Perrone Bezerra de Menezes J, Andrews NW. The iron-dependent mitochondrial superoxide dismutase SODA promotes Leishmania virulence. J Biol Chem 2017; 292:12324-12338. [PMID: 28550086 DOI: 10.1074/jbc.m116.772624] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 05/25/2017] [Indexed: 12/17/2022] Open
Abstract
Leishmaniasis is one of the leading globally neglected diseases, affecting millions of people worldwide. Leishmania infection depends on the ability of insect-transmitted metacyclic promastigotes to invade mammalian hosts, differentiate into amastigotes, and replicate inside macrophages. To counter the hostile oxidative environment inside macrophages, these protozoans contain anti-oxidant systems that include iron-dependent superoxide dismutases (SODs) in mitochondria and glycosomes. Increasing evidence suggests that in addition to this protective role, Leishmania mitochondrial SOD may also initiate H2O2-mediated redox signaling that regulates gene expression and metabolic changes associated with differentiation into virulent forms. To investigate this hypothesis, we examined the specific role of SODA, the mitochondrial SOD isoform in Leishmania amazonensis Our inability to generate L. amazonensis SODA null mutants and the lethal phenotype observed following RNAi-mediated silencing of the Trypanosoma brucei SODA ortholog suggests that SODA is essential for trypanosomatid survival. L. amazonensis metacyclic promastigotes lacking one SODA allele failed to replicate in macrophages and were severely attenuated in their ability to generate cutaneous lesions in mice. Reduced expression of SODA also resulted in mitochondrial oxidative damage and failure of SODA/ΔsodA promastigotes to differentiate into axenic amastigotes. SODA expression above a critical threshold was also required for the development of metacyclic promastigotes, as SODA/ΔsodA cultures were strongly depleted in this infective form and more susceptible to reactive oxygen species (ROS)-induced stress. Collectively, our data suggest that SODA promotes Leishmania virulence by protecting the parasites against mitochondrion-generated oxidative stress and by initiating ROS-mediated signaling mechanisms required for the differentiation of infective forms.
Collapse
Affiliation(s)
- Bidyottam Mittra
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815
| | | | - Danilo Ciccone Miguel
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815
| | | | - Norma W Andrews
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815.
| |
Collapse
|
7
|
de Menezes JPB, Koushik A, Das S, Guven C, Siegel A, Laranjeira-Silva MF, Losert W, Andrews NW. Leishmania infection inhibits macrophage motility by altering F-actin dynamics and the expression of adhesion complex proteins. Cell Microbiol 2016; 19. [PMID: 27641840 DOI: 10.1111/cmi.12668] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/16/2016] [Accepted: 09/15/2016] [Indexed: 02/07/2023]
Abstract
Leishmania is an intracellular protozoan parasite that causes a broad spectrum of clinical manifestations, ranging from self-healing skin lesions to fatal visceralizing disease. As the host cells of choice for all species of Leishmania, macrophages are critical for the establishment of infections. How macrophages contribute to parasite homing to specific tissues and how parasites modulate macrophage function are still poorly understood. In this study, we show that Leishmania amazonensis infection inhibits macrophage roaming motility. The reduction in macrophage speed is not dependent on particle load or on factors released by infected macrophages. L. amazonensis-infected macrophages also show reduced directional migration in response to the chemokine MCP-1. We found that infected macrophages have lower levels of total paxillin, phosphorylated paxillin, and phosphorylated focal adhesion kinase when compared to noninfected macrophages, indicating abnormalities in the formation of signaling adhesion complexes that regulate motility. Analysis of the dynamics of actin polymerization at peripheral sites also revealed a markedly enhanced F-actin turnover frequency in L. amazonensis-infected macrophages. Thus, Leishmania infection inhibits macrophage motility by altering actin dynamics and impairing the expression of proteins that function in plasma membrane-extracellular matrix interactions.
Collapse
Affiliation(s)
- Juliana Perrone Bezerra de Menezes
- Department of Cell Biology and Molecular Genetics, University of Maryland, Maryland, USA.,Laboratório de Patologia e Biointervenção, CPqGM, FIOCRUZ, Salvador, Bahia, Brazil
| | - Amrita Koushik
- Department of Cell Biology and Molecular Genetics, University of Maryland, Maryland, USA
| | - Satarupa Das
- Department of Physics, University of Maryland, Maryland, USA
| | - Can Guven
- Department of Physics, University of Maryland, Maryland, USA
| | - Ariel Siegel
- Department of Cell Biology and Molecular Genetics, University of Maryland, Maryland, USA
| | | | - Wolfgang Losert
- Department of Physics, University of Maryland, Maryland, USA
| | - Norma W Andrews
- Department of Cell Biology and Molecular Genetics, University of Maryland, Maryland, USA
| |
Collapse
|
8
|
Mittra B, Laranjeira-Silva MF, Perrone Bezerra de Menezes J, Jensen J, Michailowsky V, Andrews NW. A Trypanosomatid Iron Transporter that Regulates Mitochondrial Function Is Required for Leishmania amazonensis Virulence. PLoS Pathog 2016; 12:e1005340. [PMID: 26741360 PMCID: PMC4704735 DOI: 10.1371/journal.ppat.1005340] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/22/2015] [Indexed: 11/20/2022] Open
Abstract
Iron, an essential co-factor of respiratory chain proteins, is critical for mitochondrial function and maintenance of its redox balance. We previously reported a role for iron uptake in differentiation of Leishmania amazonensis into virulent amastigotes, by a mechanism that involves reactive oxygen species (ROS) production and is independent of the classical pH and temperature cues. Iron import into mitochondria was proposed to be essential for this process, but evidence supporting this hypothesis was lacking because the Leishmania mitochondrial iron transporter was unknown. Here we describe MIT1, a homolog of the mitochondrial iron importer genes mrs3 (yeast) and mitoferrin-1 (human) that is highly conserved among trypanosomatids. MIT1 expression was essential for the survival of Trypanosoma brucei procyclic but not bloodstream forms, which lack functional respiratory complexes. L. amazonensis LMIT1 null mutants could not be generated, suggesting that this mitochondrial iron importer is essential for promastigote viability. Promastigotes lacking one LMIT1 allele (LMIT1/Δlmit1) showed growth defects and were more susceptible to ROS toxicity, consistent with the role of iron as the essential co-factor of trypanosomatid mitochondrial superoxide dismutases. LMIT1/Δlmit1 metacyclic promastigotes were unable to replicate as intracellular amastigotes after infecting macrophages or cause cutaneous lesions in mice. When induced to differentiate axenically into amastigotes, LMIT1/Δlmit1 showed strong defects in iron content and function of mitochondria, were unable to upregulate the ROS-regulatory enzyme FeSOD, and showed mitochondrial changes suggestive of redox imbalance. Our results demonstrate the importance of mitochondrial iron uptake in trypanosomatid parasites, and highlight the role of LMIT1 in the iron-regulated process that orchestrates differentiation of L. amazonensis into infective amastigotes. Leishmaniasis is a serious parasitic disease that affects 12 million people worldwide, with clinical manifestations ranging from self-healing cutaneous lesions to deadly visceralizing disease. A vaccine is not available, and new and less toxic drugs against this protozoan parasite are urgently needed. Following introduction into vertebrate hosts during a sand fly blood meal, Leishmania parasites undergo extensive changes in morphology and metabolism that are critical for adaptation to life inside host macrophages and replication as amastigotes. Earlier studies identified major events that occur during amastigote differentiation, but the signaling mechanism initiating this process remained poorly understood. Previously we demonstrated a novel role for the reactive oxygen species (ROS) H2O2 in initiating amastigote differentiation, a process proposed to be dependent on iron availability inside the parasite’s mitochondria. In this study we identify LMIT1, a Leishmania transmembrane protein that functions as a mitochondrial iron transporter and is conserved in other trypanosomatid protozoan parasites. Reduced LMIT1 expression impairs mitochondrial function in the infective amastigote stage, abolishing parasite virulence. Our findings identify LMIT1 as a promising new drug target, and support the conclusion that iron-dependent ROS signals generated in the mitochondria regulate differentiation of virulent Leishmania amastigotes.
Collapse
Affiliation(s)
- Bidyottam Mittra
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
| | | | - Juliana Perrone Bezerra de Menezes
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
- Laboratório de Patologia e Biointervenção, CPqGM, FIOCRUZ, Candeal, Salvador, Bahia, Brazil
| | - Jennifer Jensen
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
| | - Vladimir Michailowsky
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
- Faculdade de Medicina, Setor Parasitologia, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
| | - Norma W. Andrews
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
- * E-mail:
| |
Collapse
|