1
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Cabral G, Ren B, Bisio H, Otey D, Soldati-Favre D, Brown KM. Orthologs of Plasmodium ICM1 are dispensable for Ca 2+ mobilization in Toxoplasma gondii. Microbiol Spectr 2024; 12:e0122924. [PMID: 39162502 PMCID: PMC11448412 DOI: 10.1128/spectrum.01229-24] [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: 07/03/2024] [Indexed: 08/21/2024] Open
Abstract
Apicomplexan parasites mobilize ionic calcium (Ca2+) from intracellular stores to promote microneme secretion and facilitate motile processes including gliding motility, invasion, and egress. Recently, a multipass transmembrane protein, ICM1, was found to be important for calcium mobilization in Plasmodium falciparum and P. berghei. Comparative genomics and phylogenetics have revealed putative ICM orthologs in Toxoplasma gondii and other apicomplexans. T. gondii possesses two ICM-like proteins, which we have named TgICM1-L (TGGT1_305470) and TgICM2-L (TGGT1_309910). TgICM1-L and TgICM2-L localized to undefined puncta within the parasite cytosol. TgICM1-L and TgICM2-L are individually dispensable in tachyzoites, suggesting a potential compensatory relationship between the two proteins may exist. Surprisingly, mutants lacking both TgICM1-L and TgICM2-L are fully viable, exhibiting no obvious defects in growth, microneme secretion, invasion, or egress. Furthermore, loss of TgICM1-L, TgICM2-L, or both does not impair the parasite's ability to mobilize Ca2+. These findings suggest that additional proteins may participate in Ca2+ mobilization or import in Apicomplexa, reducing the dependence on ICM-like proteins in T. gondii. Collectively, these results highlight similar yet distinct mechanisms of Ca2+ mobilization between T. gondii and Plasmodium.IMPORTANCECa2+ signaling plays a crucial role in governing apicomplexan motility; yet, the mechanisms underlying Ca2+ mobilization from intracellular stores in these parasites remain unclear. In Plasmodium, the necessity of ICM1 for Ca2+ mobilization raises the question of whether this mechanism is conserved in other apicomplexans. Investigation into the orthologs of Plasmodium ICM1 in T. gondii revealed a differing requirement for ICM proteins between the two parasites. This study suggests that T. gondii employs ICM-independent mechanisms to regulate Ca2+ homeostasis and mobilization. Proteins involved in Ca2+ signaling in apicomplexans represent promising targets for therapeutic development.
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Affiliation(s)
- Gabriel Cabral
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Bingjian Ren
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Hugo Bisio
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
- Aix-Marseille Université, Centre National de la Recherche Scientifique, Information Génomique & Structurale, Marseille, France
| | - Dawson Otey
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Kevin M. Brown
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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Kaiser A. The Role of Spermidine and Its Key Metabolites in Important, Pathogenic Human Viruses and in Parasitic Infections Caused by Plasmodium falciparum and Trypanosoma brucei. Biomolecules 2023; 13:biom13050803. [PMID: 37238673 DOI: 10.3390/biom13050803] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/01/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
The triamine spermidine is a key metabolite of the polyamine pathway. It plays a crucial role in many infectious diseases caused by viral or parasitic infections. Spermidine and its metabolizing enzymes, i.e., spermidine/spermine-N1-acetyltransferase, spermine oxidase, acetyl polyamine oxidase, and deoxyhypusine synthase, fulfill common functions during infection in parasitic protozoa and viruses which are obligate, intracellular parasites. The competition for this important polyamine between the infected host cell and the pathogen determines the severity of infection in disabling human parasites and pathogenic viruses. Here, we review the impact of spermidine and its metabolites in disease development of the most important, pathogenic human viruses such as SARS-CoV-2, HIV, Ebola, and in the human parasites Plasmodium and Trypanosomes. Moreover, state-of-the-art translational approaches to manipulate spermidine metabolism in the host and the pathogen are discussed to accelerate drug development against these threatful, infectious human diseases.
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Affiliation(s)
- Annette Kaiser
- Medical Research Centre, University of Duisburg-Essen, Hufelandstrasse 55, 45147 Essen, Germany
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3
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Veale CGL, Müller R. Recent Highlights in Anti-infective Medicinal Chemistry from South Africa. ChemMedChem 2020; 15:809-826. [PMID: 32149446 DOI: 10.1002/cmdc.202000086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Indexed: 12/17/2022]
Abstract
Global advancements in biological technologies have vastly increased the variety of and accessibility to bioassay platforms, while simultaneously improving our understanding of druggable chemical space. In the South African context, this has resulted in a rapid expansion in the number of medicinal chemistry programmes currently operating, particularly on university campuses. Furthermore, the modern medicinal chemist has the advantage of being able to incorporate data from numerous related disciplines into the medicinal chemistry process, allowing for informed molecular design to play a far greater role than previously possible. Accordingly, this review focusses on recent highlights in drug-discovery programmes, in which South African medicinal chemistry groups have played a substantive role in the design and optimisation of biologically active compounds which contribute to the search for promising agents for infectious disease.
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Affiliation(s)
- Clinton G L Veale
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa
| | - Ronel Müller
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa
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4
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Moriyama Y, Hatano R, Moriyama S, Uehara S. Vesicular polyamine transporter as a novel player in amine-mediated chemical transmission. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183208. [PMID: 32004521 DOI: 10.1016/j.bbamem.2020.183208] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/23/2020] [Accepted: 01/26/2020] [Indexed: 02/06/2023]
Abstract
The solute carrier 18B1 (SLC18B1) is the most recently identified gene of the vesicular amine transporter family and is conserved in the animal kingdom from insects to humans. Proteoliposomes containing the purified human SLC18B1 protein transport not only monoamines, but also polyamines, such as spermidine (Spd) and spermine (Spm), using an electrochemical gradient of H+ established by vacuolar H+-ATPase (V-ATPase) as the driving force. SLC18B1 gene knockdown abolished the exocytosis of polyamines from mast cells, which affected the secretion of histamine. SLC18B1 gene knockout decreased polyamine levels by ~20% in the brain, and impaired short- and long-term memory. Thus, the SLC18B1 protein is responsible for the vesicular storage and release of polyamines, and functions as a vesicular polyamine transporter (VPAT). VPAT may define when, where, and how polyamine-mediated chemical transmission occurs, providing insights into the more versatile and complex features of amine-mediated chemical transmission than currently considered.
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Affiliation(s)
- Yoshinori Moriyama
- Department of Biochemistry, Matsumoto Dental University, Shiojiri 399-0781, Japan; Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, Kurume 830-0011, Japan; CYRIC Tohoku University, Sendai 980-8578, Japan.
| | - Ryo Hatano
- Department of Medicinal Physiology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Satomi Moriyama
- Laboratory of Bio-Molecular Dynamics, Department of Collaborative Research, Nara Medical University, Kashihara 634-8521, Japan
| | - Shunsuke Uehara
- Department of Biochemistry, Matsumoto Dental University, Shiojiri 399-0781, Japan
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5
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Stringer T, Wiesner L, Smith GS. Ferroquine-derived polyamines that target resistant Plasmodium falciparum. Eur J Med Chem 2019; 179:78-83. [DOI: 10.1016/j.ejmech.2019.06.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 06/07/2019] [Accepted: 06/07/2019] [Indexed: 01/14/2023]
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6
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Inducing controlled cell cycle arrest and re-entry during asexual proliferation of Plasmodium falciparum malaria parasites. Sci Rep 2018; 8:16581. [PMID: 30409996 PMCID: PMC6224408 DOI: 10.1038/s41598-018-34964-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 10/26/2018] [Indexed: 02/08/2023] Open
Abstract
The life cycle of the malaria parasite Plasmodium falciparum is tightly regulated, oscillating between stages of intense proliferation and quiescence. Cyclic 48-hour asexual replication of Plasmodium is markedly different from cell division in higher eukaryotes, and mechanistically poorly understood. Here, we report tight synchronisation of malaria parasites during the early phases of the cell cycle by exposure to DL-α-difluoromethylornithine (DFMO), which results in the depletion of polyamines. This induces an inescapable cell cycle arrest in G1 (~15 hours post-invasion) by blocking G1/S transition. Cell cycle-arrested parasites enter a quiescent G0-like state but, upon addition of exogenous polyamines, re-initiate their cell cycle. This ability to halt malaria parasites at a specific point in their cell cycle, and to subsequently trigger re-entry into the cell cycle, provides a valuable framework to investigate cell cycle regulation in these parasites. We subsequently used gene expression analyses to show that re-entry into the cell cycle involves expression of Ca2+-sensitive (cdpk4 and pk2) and mitotic kinases (nima and ark2), with deregulation of the pre-replicative complex associated with expression of pk2. Changes in gene expression could be driven through transcription factors MYB1 and two ApiAP2 family members. This new approach to parasite synchronisation therefore expands our currently limited toolkit to investigate cell cycle regulation in malaria parasites.
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Abstract
Polyamines are polycationic organic amines that are required for all eukaryotic life, exemplified by the polyamine spermidine, which plays an essential role in translation. They also play more specialized roles that differ across species, and their chemical versatility has been fully exploited during the evolution of protozoan pathogens. These eukaryotic pathogens, which cause some of the most globally widespread infectious diseases, have acquired species-specific polyamine-derived metabolites with essential cellular functions and have evolved unique mechanisms that regulate their core polyamine biosynthetic pathways. Many of these parasitic species have lost enzymes and or transporters from the polyamine metabolic pathway that are found in the human host. These pathway differences have prompted drug discovery efforts to target the parasite polyamine pathways, and indeed, the only clinically approved drug targeting the polyamine biosynthetic pathway is used to manage human African trypanosomiasis. This Minireview will primarily focus on polyamine metabolism and function in Trypanosoma, Leishmania, and Plasmodium species, which are the causative agents of human African trypanosomiasis (HAT) and Chagas disease, Leishmaniasis, and malaria, respectively. Aspects of polyamine metabolism across a diverse group of protozoan pathogens will also be explored.
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Affiliation(s)
- Margaret A Phillips
- From the Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9038
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8
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Kumar S, Bhardwaj TR, Prasad DN, Singh RK. Drug targets for resistant malaria: Historic to future perspectives. Biomed Pharmacother 2018; 104:8-27. [PMID: 29758416 DOI: 10.1016/j.biopha.2018.05.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/22/2018] [Accepted: 05/07/2018] [Indexed: 01/05/2023] Open
Abstract
New antimalarial targets are the prime need for the discovery of potent drug candidates. In order to fulfill this objective, antimalarial drug researches are focusing on promising targets in order to develop new drug candidates. Basic metabolism and biochemical process in the malaria parasite, i.e. Plasmodium falciparum can play an indispensable role in the identification of these targets. But, the emergence of resistance to antimalarial drugs is an escalating comprehensive problem with the progress of antimalarial drug development. The development of resistance has highlighted the need for the search of novel antimalarial molecules. The pharmaceutical industries are committed to new drug development due to the global recognition of this life threatening resistance to the currently available antimalarial therapy. The recent developments in the understanding of parasite biology are exhilarating this resistance issue which is further being ignited by malaria genome project. With this background of information, this review was aimed to highlights and provides useful information on various present and promising treatment approaches for resistant malaria, new progresses, pursued by some innovative targets that have been explored till date. This review also discusses modern and futuristic multiple approaches to antimalarial drug discovery and development with pictorial presentations highlighting the various targets, that could be exploited for generating promising new drugs in the future for drug resistant malaria.
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Affiliation(s)
- Sahil Kumar
- School of Pharmacy and Emerging Sciences, Baddi University of Emerging Sciences & Technology, Baddi, Dist. Solan, 173205, Himachal Pradesh, India
| | - T R Bhardwaj
- School of Pharmacy and Emerging Sciences, Baddi University of Emerging Sciences & Technology, Baddi, Dist. Solan, 173205, Himachal Pradesh, India
| | - D N Prasad
- Department of Pharmaceutical Chemistry, Shivalik College of Pharmacy, Nangal, Dist. Rupnagar, 140126, Punjab, India
| | - Rajesh K Singh
- Department of Pharmaceutical Chemistry, Shivalik College of Pharmacy, Nangal, Dist. Rupnagar, 140126, Punjab, India.
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9
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Gitto SB, Pandey V, Oyer JL, Copik AJ, Hogan FC, Phanstiel O, Altomare DA. Difluoromethylornithine Combined with a Polyamine Transport Inhibitor Is Effective against Gemcitabine Resistant Pancreatic Cancer. Mol Pharm 2018; 15:369-376. [PMID: 29299930 DOI: 10.1021/acs.molpharmaceut.7b00718] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is highly chemo-resistant and has an extremely poor patient prognosis, with a survival rate at five years of <8%. There remains an urgent need for innovative treatments. Targeting polyamine biosynthesis through inhibition of ornithine decarboxylase with difluoromethylornithine (DFMO) has had mixed clinical success due to tumor escape via an undefined transport system, which imports exogenous polyamines and sustains intracellular polyamine pools. Here, we tested DFMO in combination with a polyamine transport inhibitor (PTI), Trimer44NMe, against Gemcitabine-resistant PDAC cells. DFMO alone and with Trimer44NMe significantly reduced PDAC cell viability by inducing apoptosis or diminishing proliferation. DFMO alone and with Trimer44NMe also inhibited in vivo orthotopic PDAC growth and resulted in decreased c-Myc expression, a readout of polyamine pathway dysfunction. Moreover, dual inhibition significantly prolonged survival of tumor-bearing mice. Collectively, these studies demonstrate that targeting polyamine biosynthesis and import pathways in PDAC can lead to increased survival in pancreatic cancer.
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Affiliation(s)
- Sarah B Gitto
- Burnett School of Biomedical Sciences, University of Central Florida , 6900 Lake Nona Blvd., Orlando, Florida 32827, United States
| | - Veethika Pandey
- Burnett School of Biomedical Sciences, University of Central Florida , 6900 Lake Nona Blvd., Orlando, Florida 32827, United States
| | - Jeremiah L Oyer
- Burnett School of Biomedical Sciences, University of Central Florida , 6900 Lake Nona Blvd., Orlando, Florida 32827, United States
| | - Alicja J Copik
- Burnett School of Biomedical Sciences, University of Central Florida , 6900 Lake Nona Blvd., Orlando, Florida 32827, United States
| | - Frederick C Hogan
- Burnett School of Biomedical Sciences, University of Central Florida , 6900 Lake Nona Blvd., Orlando, Florida 32827, United States
| | - Otto Phanstiel
- Department of Medical Education, University of Central Florida , 12722 Research Parkway, Orlando, Florida 32826, United States
| | - Deborah A Altomare
- Burnett School of Biomedical Sciences, University of Central Florida , 6900 Lake Nona Blvd., Orlando, Florida 32827, United States
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10
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Hart RJ, Ghaffar A, Abdalal S, Perrin B, Aly ASI. Plasmodium AdoMetDC/ODC bifunctional enzyme is essential for male sexual stage development and mosquito transmission. Biol Open 2016; 5:1022-9. [PMID: 27387533 PMCID: PMC5004602 DOI: 10.1242/bio.016352] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Polyamines are positively-charged organic molecules that are important for cellular growth and division. Polyamines and their synthesizing enzymes are particularly abundant in rapidly proliferating eukaryotic cells such as parasitic protozoa and cancer cells. Polyamine biosynthesis inhibitors, such as Elfornithine, are now being considered for cancer prevention and have been used effectively against Trypanosoma brucei. Inhibitors of polyamine biosynthesis have caused growth arrest of Plasmodium falciparum blood stages in vitro, but in P. berghei only partial inhibition has been observed. While polyamine biosynthesis enzymes are characterized and conserved in Plasmodium spp., little is known on the biological roles of these enzymes inside malaria parasite hosts. The bifunctional polyamine biosynthesis enzyme S-adenosyl methionine decarboxylase/ornithine decarboxylase (AdoMetDC/ODC) was targeted for deletion in P. yoelii. Deletion of AdoMetDC/ODC significantly reduced blood stage parasitemia but Anopheles transmission was completely blocked. We showed that male gametocytogenesis and male gamete exflagellation were abolished and consequently no ookinetes or oocyst sporozoites could be generated from adometdc/odc(–) parasites. Supplementation of putrescine and spermidine did not rescue the defective phenotypes of male gametocytes and gametes of the knockout parasites. These results highlight the crucial role of polyamine homeostasis in the development and functions of Plasmodium erythrocytic stages in the blood and in the mosquito vector and validate polyamine biosynthesis pathway enzymes as drug targeting candidates for malaria parasite transmission blocking. Summary: We provide the first genetic evidence for the crucial roles of de novo polyamine biosynthesis in the development of Plasmodium male sexual stages and in the transmission of malaria parasite to mosquito.
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Affiliation(s)
- Robert J Hart
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Atif Ghaffar
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Shaymaa Abdalal
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Benjamin Perrin
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Ahmed S I Aly
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
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11
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Verlinden BK, Louw A, Birkholtz LM. Resisting resistance: is there a solution for malaria? Expert Opin Drug Discov 2016; 11:395-406. [PMID: 26926843 DOI: 10.1517/17460441.2016.1154037] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Currently, widely used antimalarial drugs have a limited clinical lifespan due to parasite resistance development. With resistance continuously rising, antimalarial drug discovery requires strategies to decrease the time of delivering a new antimalarial drug while simultaneously increasing the drug's therapeutic lifespan. Lessons learnt from various chemotherapeutic resistance studies in the fields of antibiotic and cancer research offer potentially useful strategies that can be applied to antimalarial drug discovery. AREAS COVERED In this review the authors discuss current strategies to circumvent resistance in malaria and alternatives that could be employed. EXPERT OPINION Scientists have been 'beating back' the malaria parasite with novel drugs for the past 49 years but the constant rise in antimalarial drug resistance is forcing the drug discovery community to explore alternative strategies. Avant-garde anti-resistance strategies from alternative fields may assist our endeavors to manage, control and prevent antimalarial drug resistance to progress beyond beating the resistant parasite back, to stopping it dead in its tracks.
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Affiliation(s)
- Bianca K Verlinden
- a Department of Biochemistry, Centre for Sustainable Malaria Control, Faculty of Natural and Agricultural Sciences , University of Pretoria , Pretoria , South Africa
| | - Abraham Louw
- a Department of Biochemistry, Centre for Sustainable Malaria Control, Faculty of Natural and Agricultural Sciences , University of Pretoria , Pretoria , South Africa
| | - Lyn-Marié Birkholtz
- a Department of Biochemistry, Centre for Sustainable Malaria Control, Faculty of Natural and Agricultural Sciences , University of Pretoria , Pretoria , South Africa
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12
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Morada M, Lee S, Gunther-Cummins L, Weiss LM, Widmer G, Tzipori S, Yarlett N. Continuous culture of Cryptosporidium parvum using hollow fiber technology. Int J Parasitol 2015; 46:21-9. [PMID: 26341006 DOI: 10.1016/j.ijpara.2015.07.006] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 07/23/2015] [Accepted: 07/24/2015] [Indexed: 02/08/2023]
Abstract
Diarrheal disease is a leading cause of pediatric death in economically low resource countries. Cryptosporidium spp. are the second largest member of this group and the only member for which no treatment exists. One of the handicaps to developing chemotherapy is the lack of a reproducible long-term culture method permitting in vitro drug screening beyond 48 h. We have adapted the well-established hollow fiber technology to provide an environment that mimics the gut by delivering nutrients and oxygen from the basal layer upwards while allowing separate redox and nutrient control of the lumen for parasite development. Using this technique, oocyst production was maintained for >6 months, producing approximately 1×10(8)oocysts ml(-1)day(-1), compared with 48 h with a yield of 1×10(6)oocysts ml(-1) in two-dimensional cultures. Oocysts, after 4 and 20 weeks in culture, produced a chronic infection in a TCR-α-deficient mouse model. In vivo infectivity of oocysts was confirmed using oocysts from a 6 week culture in a dexamethasone immunosuppressed mouse model.
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Affiliation(s)
- Mary Morada
- Haskins Laboratories, and Department of Chemistry and Physical Sciences, Pace University, New York, USA
| | - Sangun Lee
- Cummings School of Veterinary Medicine, Tufts University, N. Grafton, MA, USA
| | | | - Louis M Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Giovanni Widmer
- Cummings School of Veterinary Medicine, Tufts University, N. Grafton, MA, USA
| | - Saul Tzipori
- Cummings School of Veterinary Medicine, Tufts University, N. Grafton, MA, USA
| | - Nigel Yarlett
- Haskins Laboratories, and Department of Chemistry and Physical Sciences, Pace University, New York, USA.
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13
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Macrophage arginase-1 controls bacterial growth and pathology in hypoxic tuberculosis granulomas. Proc Natl Acad Sci U S A 2014; 111:E4024-32. [PMID: 25201986 DOI: 10.1073/pnas.1408839111] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Lung granulomas develop upon Mycobacterium tuberculosis (Mtb) infection as a hallmark of human tuberculosis (TB). They are structured aggregates consisting mainly of Mtb-infected and -uninfected macrophages and Mtb-specific T cells. The production of NO by granuloma macrophages expressing nitric oxide synthase-2 (NOS2) via l-arginine and oxygen is a key protective mechanism against mycobacteria. Despite this protection, TB granulomas are often hypoxic, and bacterial killing via NOS2 in these conditions is likely suboptimal. Arginase-1 (Arg1) also metabolizes l-arginine but does not require oxygen as a substrate and has been shown to regulate NOS2 via substrate competition. However, in other infectious diseases in which granulomas occur, such as leishmaniasis and schistosomiasis, Arg1 plays additional roles such as T-cell regulation and tissue repair that are independent of NOS2 suppression. To address whether Arg1 could perform similar functions in hypoxic regions of TB granulomas, we used a TB murine granuloma model in which NOS2 is absent. Abrogation of Arg1 expression in macrophages in this setting resulted in exacerbated lung granuloma pathology and bacterial burden. Arg1 expression in hypoxic granuloma regions correlated with decreased T-cell proliferation, suggesting that Arg1 regulation of T-cell immunity is involved in disease control. Our data argue that Arg1 plays a central role in the control of TB when NOS2 is rendered ineffective by hypoxia.
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14
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Abstract
As it grows and replicates within the erythrocytes of its host the malaria parasite takes up nutrients from the extracellular medium, exports metabolites and maintains a tight control over its internal ionic composition. These functions are achieved via membrane transport proteins, integral membrane proteins that mediate the passage of solutes across the various membranes that separate the biochemical machinery of the parasite from the extracellular environment. Proteins of this type play a key role in antimalarial drug resistance, as well as being candidate drug targets in their own right. This review provides an overview of recent work on the membrane transport biology of the malaria parasite-infected erythrocyte, encompassing both the parasite-induced changes in the membrane transport properties of the host erythrocyte and the cell physiology of the intracellular parasite itself.
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15
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le Roux D, Burger PB, Niemand J, Grobler A, Urbán P, Fernàndez-Busquets X, Barker RH, Serrano AE, I Louw A, Birkholtz LM. Novel S-adenosyl-L-methionine decarboxylase inhibitors as potent antiproliferative agents against intraerythrocytic Plasmodium falciparum parasites. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2013; 4:28-36. [PMID: 24596666 PMCID: PMC3940083 DOI: 10.1016/j.ijpddr.2013.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 12/31/2022]
Abstract
S-adenosyl-l-methionine decarboxylase (AdoMetDC) in the polyamine biosynthesis pathway has been identified as a suitable drug target in Plasmodium falciparum parasites, which causes the most lethal form of malaria. Derivatives of an irreversible inhibitor of this enzyme, 5'-{[(Z)-4-amino-2-butenyl]methylamino}-5'-deoxyadenosine (MDL73811), have been developed with improved pharmacokinetic profiles and activity against related parasites, Trypanosoma brucei. Here, these derivatives were assayed for inhibition of AdoMetDC from P. falciparum parasites and the methylated derivative, 8-methyl-5'-{[(Z)-4-aminobut-2-enyl]methylamino}-5'-deoxyadenosine (Genz-644131) was shown to be the most active. The in vitro efficacy of Genz-644131 was markedly increased by nanoencapsulation in immunoliposomes, which specifically targeted intraerythrocytic P. falciparum parasites.
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Affiliation(s)
- Dina le Roux
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Pieter B Burger
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Jandeli Niemand
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Anne Grobler
- DST/NWU Preclinical Drug Development Platform, North-West University, Potchefstroom 2531, South Africa
| | - Patricia Urbán
- Nanobioengineering Group, Institute for Bioengineering of Catalonia, Baldiri Reixac 10-12, Barcelona E08028, Spain ; Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló 149-153, Barcelona E08036, Spain ; Biomolecular Interactions Team, Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, Barcelona E08028, Spain
| | - Xavier Fernàndez-Busquets
- Nanobioengineering Group, Institute for Bioengineering of Catalonia, Baldiri Reixac 10-12, Barcelona E08028, Spain ; Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló 149-153, Barcelona E08036, Spain ; Biomolecular Interactions Team, Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, Barcelona E08028, Spain
| | - Robert H Barker
- Genzyme Corporation, 153 Second Avenue, Waltham, MA 02451, USA
| | - Adelfa E Serrano
- University of Puerto Rico-School of Medicine, Department of Microbiology and Medical Zoology, P.O. Box 365067, San Juan PR 00936-5067, Puerto Rico
| | - Abraham I Louw
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
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Anthracene-polyamine conjugates inhibit in vitro proliferation of intraerythrocytic Plasmodium falciparum parasites. Antimicrob Agents Chemother 2013; 57:2874-7. [PMID: 23545535 DOI: 10.1128/aac.00106-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anthracene-polyamine conjugates inhibit the in vitro proliferation of the intraerythrocytic human malaria parasite Plasmodium falciparum, with 50% inhibitory concentrations (IC50s) in the nM to μM range. The compounds are taken up into the intraerythrocytic parasite, where they arrest the parasite cell cycle. Both the anthracene and polyamine components of the conjugates play a role in their antiplasmodial effect.
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