1
|
Teixeira SC, de Souza G, Junior JPDL, Rosini AM, Martínez AFF, Fernandes TADM, Ambrósio SR, Veneziani RCS, Bastos JK, Martins CHG, Barbosa BF, Ferro EAV. Copaifera spp. oleoresins and two isolated compounds (ent-kaurenoic and ent-polyalthic acid) inhibit Toxoplasma gondii growth in vitro. Exp Parasitol 2024; 262:108771. [PMID: 38723847 DOI: 10.1016/j.exppara.2024.108771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 04/18/2024] [Accepted: 05/06/2024] [Indexed: 05/12/2024]
Abstract
Toxoplasmosis affects about one-third of the world's population. The disease treatment methods pose several side effects and do not efficiently eliminate the parasite, making the search for new therapeutic approaches necessary. We aimed to assess the anti-Toxoplasma gondii activity of four Copaifera oleoresins (ORs) and two isolated diterpene acids, named ent-kaurenoic and ent-polyalthic acid. We used HeLa cells as an experimental model of toxoplasmosis. Uninfected and infected HeLa cells were submitted to the treatments, and the parasite intracellular proliferation, cytokine levels and ROS production were measured. Also, tachyzoites were pre-treated and the parasite invasion was determined. Finally, an in silico analysis was performed to identify potential parasite targets. Our data show that the non-cytotoxic concentrations of ORs and diterpene acids controlled the invasion and proliferation of T. gondii in HeLa cells, thus highlighting the possible direct action on parasites. In addition, some compounds tested controlled parasite proliferation in an irreversible manner. An additional and non-exclusive mechanism of action involves the modulation of host cell components, by affecting the upregulation of the IL-6. Additionally, molecular docking suggested that ent-polyalthic acid has a high affinity for the active site of the TgCDPK1 protein. Copaifera ORs have great antiparasitic activity against T. gondii, and this effect can be partially explained by the presence of the isolated compounds ent-kaurenoic and ent-polyalthic acid.
Collapse
Affiliation(s)
- Samuel Cota Teixeira
- Laboratory of Immunophysiology of Reproduction, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Guilherme de Souza
- Laboratory of Immunophysiology of Reproduction, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Joed Pires de Lima Junior
- Laboratory of Immunophysiology of Reproduction, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Alessandra Monteiro Rosini
- Laboratory of Immunophysiology of Reproduction, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Aryani Felixa Fajardo Martínez
- Laboratory of Immunophysiology of Reproduction, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | | | - Sergio Ricardo Ambrósio
- Nucleus of Research in Technological and Exact Sciences, Universidade de Franca, Franca, SP, Brazil
| | | | - Jairo Kenupp Bastos
- School of Pharmaceutical Sciences of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Carlos Henrique Gomes Martins
- Department of Microbiology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Bellisa Freitas Barbosa
- Laboratory of Immunophysiology of Reproduction, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Eloisa Amália Vieira Ferro
- Laboratory of Immunophysiology of Reproduction, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
| |
Collapse
|
2
|
Gharibi Z, Shahbazi B, Gouklani H, Nassira H, Rezaei Z, Ahmadi K. Computational screening of FDA-approved drugs to identify potential TgDHFR, TgPRS, and TgCDPK1 proteins inhibitors against Toxoplasma gondii. Sci Rep 2023; 13:5396. [PMID: 37012275 PMCID: PMC10070243 DOI: 10.1038/s41598-023-32388-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 03/27/2023] [Indexed: 04/05/2023] Open
Abstract
Toxoplasma gondii (T. gondii) is one of the most successful parasites in the world, because about a third of the world's population is seropositive for toxoplasmosis. Treatment regimens for toxoplasmosis have remained unchanged for the past 20 years, and no new drugs have been introduced to the market recently. This study, performed molecular docking to identify interactions of FDA-approved drugs with essential residues in the active site of proteins of T. gondii Dihydrofolate Reductase (TgDHFR), Prolyl-tRNA Synthetase (TgPRS), and Calcium-Dependent Protein Kinase 1 (TgCDPK1). Each protein was docked with 2100 FDA-approved drugs using AutoDock Vina. Also, the Pharmit software was used to generate pharmacophore models based on the TgDHFR complexed with TRC-2533, TgPRS in complex with halofuginone, and TgCDPK1 in complex with a bumped kinase inhibitor, RM-1-132. Molecular dynamics (MD) simulation was also performed for 100 ns to verify the stability of interaction in drug-protein complexes. Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) analysis evaluated the binding energy of selected complexes. Ezetimibe, Raloxifene, Sulfasalazine, Triamterene, and Zafirlukast drugs against the TgDHFR protein, Cromolyn, Cefexim, and Lactulose drugs against the TgPRS protein, and Pentaprazole, Betamethasone, and Bromocriptine drugs against TgCDPK1 protein showed the best results. These drugs had the lowest energy-based docking scores and also stable interactions based on MD analyses with TgDHFR, TgPRS, and TgCDPK1 drug targets that can be introduced as possible drugs for laboratory investigations to treat T. gondii parasite infection.
Collapse
Affiliation(s)
- Zahra Gharibi
- Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Behzad Shahbazi
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Hamed Gouklani
- Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Hoda Nassira
- Polymer Division, Department of Chemistry, Faculty of Science, University of Zanjan, Zanjan, Iran
| | - Zahra Rezaei
- Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Khadijeh Ahmadi
- Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
| |
Collapse
|
3
|
Wu RZ, Zhou HY, Song JF, Xia QH, Hu W, Mou XD, Li X. Chemotherapeutics for Toxoplasma gondii: Molecular Biotargets, Binding Modes, and Structure-Activity Relationship Investigations. J Med Chem 2021; 64:17627-17655. [PMID: 34894691 DOI: 10.1021/acs.jmedchem.1c01569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Toxoplasmosis, an infectious zoonotic disease caused by the apicomplexan parasite Toxoplasma gondii (T. gondii), is a major worldwide health problem. However, there are currently no effective options (chemotherapeutic drugs or prophylactic vaccines) for treating chronic latent toxoplasmosis infection. Accordingly, seeking more effective and safer chemotherapeutics for combating this disease remains a long-term and challenging objective. In this paper, we summarize possible molecular biotargets, with an emphasis on those that are druggable and promising, including, without limitation, calcium-dependent protein kinase 1, bifunctional thymidylate synthase-dihydrofolate reductase, and farnesyl diphosphate synthase. Meanwhile, as important components of medicinal chemistry, the binding modes and structure-activity relationship profiles of the corresponding inhibitors were also illuminated. We anticipate that this information will be helpful for further identification of more effective chemotherapeutic interventions to prevent and treat zoonotic infections caused by T. gondii.
Collapse
Affiliation(s)
- Rong-Zhen Wu
- Institute of Materia Medica, Shandong First Medical University and Shandong Academy of Medical Sciences, no. 6699 Qingdao Road, Ji'nan, Shandong 250117, PR China
| | - Huai-Yu Zhou
- Department of Pathogen Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, no. 44 Wenhua Xi Road, Ji'nan, Shandong 250012, PR China
| | - Jing-Feng Song
- School of Pharmaceutical Sciences and Yunnan Provincial Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, no. 1168 Chunrong Xi Road, Kunming, Yunnan 650500, PR China
| | - Qiao-Hong Xia
- Department of Pathogen Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, no. 44 Wenhua Xi Road, Ji'nan, Shandong 250012, PR China
| | - Wei Hu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, no. 72 Binhai Road of JiMo, Qingdao, Shandong 266237, PR China
| | - Xiao-Dong Mou
- Institute of Materia Medica, Shandong First Medical University and Shandong Academy of Medical Sciences, no. 6699 Qingdao Road, Ji'nan, Shandong 250117, PR China
| | - Xun Li
- Institute of Materia Medica, Shandong First Medical University and Shandong Academy of Medical Sciences, no. 6699 Qingdao Road, Ji'nan, Shandong 250117, PR China.,Key Laboratory of Forensic Toxicology, Ministry of Public Security, Beijing 100192, PR China
| |
Collapse
|
4
|
Sharma M, Choudhury H, Roy R, Michaels SA, Ojo KK, Bansal A. CDPKs: The critical decoders of calcium signal at various stages of malaria parasite development. Comput Struct Biotechnol J 2021; 19:5092-5107. [PMID: 34589185 PMCID: PMC8453137 DOI: 10.1016/j.csbj.2021.08.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 08/31/2021] [Accepted: 08/31/2021] [Indexed: 12/13/2022] Open
Abstract
Calcium ions are used as important signals during various physiological processes. In malaria parasites, Plasmodium spp., calcium dependent protein kinases (CDPKs) have acquired the unique ability to sense and transduce calcium signals at various critical steps during the lifecycle, either through phosphorylation of downstream substrates or mediating formation of high molecular weight protein complexes. Calcium signaling cascades establish important crosstalk events with signaling pathways mediated by other secondary messengers such as cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). CDPKs play critical roles at various important physiological steps during parasite development in vertebrates and mosquitoes. They are also important for transmission of the parasite between the two hosts. Combined with the fact that CDPKs are not present in humans, they continue to be pursued as important targets for development of anti-malarial drugs.
Collapse
Affiliation(s)
- Manish Sharma
- Molecular Parasitology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Himashree Choudhury
- Molecular Parasitology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Rajarshi Roy
- Molecular Parasitology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Samantha A. Michaels
- Center for Emerging and Re-emerging Infectious Diseases, Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA 98109 USA
| | - Kayode K. Ojo
- Center for Emerging and Re-emerging Infectious Diseases, Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA 98109 USA
| | - Abhisheka Bansal
- Molecular Parasitology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| |
Collapse
|
5
|
Hulverson MA, Choi R, McCloskey MC, Whitman GR, Ojo KK, Michaels SA, Somepalli M, Love MS, McNamara CW, Rabago LM, Barrett LK, Verlinde CLMJ, Arnold SL, Striepen B, Jimenez-Alfaro D, Ballell L, Fernández E, Greenwood MN, las Heras LD, Calderón F, Van Voorhis WC. Repurposing Infectious Disease Hits as Anti- Cryptosporidium Leads. ACS Infect Dis 2021; 7:1275-1282. [PMID: 33740373 DOI: 10.1021/acsinfecdis.1c00076] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New drugs are critically needed to treat Cryptosporidium infections, particularly for malnourished children under 2 years old in the developing world and persons with immunodeficiencies. Bioactive compounds from the Tres-Cantos GSK library that have activity against other pathogens were screened for possible repurposing against Cryptosporidium parvum growth. Nineteen compounds grouped into nine structural clusters were identified using an iterative process to remove excessively toxic compounds and screen related compounds from the Tres-Cantos GSK library. Representatives of four different clusters were advanced to a mouse model of C. parvum infection, but only one compound, an imidazole-pyrimidine, led to significant clearance of infection. This imidazole-pyrimidine compound had a number of favorable safety and pharmacokinetic properties and was maximally active in the mouse model down to 30 mg/kg given daily. Though the mechanism of action against C. parvum was not definitively established, this imidazole-pyrimidine compound inhibits the known C. parvum drug target, calcium-dependent protein kinase 1, with a 50% inhibitory concentration of 2 nM. This compound, and related imidazole-pyrimidine molecules, should be further examined as potential leads for Cryptosporidium therapeutics.
Collapse
Affiliation(s)
- Matthew A. Hulverson
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Ryan Choi
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Molly C. McCloskey
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Grant R. Whitman
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Kayode K. Ojo
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Samantha A. Michaels
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Mastanbabu Somepalli
- Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Melissa S. Love
- Calibr, a division of The Scripps Research Institute, La Jolla, California 92037, United States
| | - Case W. McNamara
- Calibr, a division of The Scripps Research Institute, La Jolla, California 92037, United States
| | - Lesley M. Rabago
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Lynn K. Barrett
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | | | - Samuel L.M. Arnold
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Boris Striepen
- Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Dolores Jimenez-Alfaro
- Medicines Development Campus, Global Health Pharma Unit, GlaxoSmithKline, Tres Cantos, 28760, Madrid Spain
| | - Lluis Ballell
- Medicines Development Campus, Global Health Pharma Unit, GlaxoSmithKline, Tres Cantos, 28760, Madrid Spain
| | - Elena Fernández
- Medicines Development Campus, Global Health Pharma Unit, GlaxoSmithKline, Tres Cantos, 28760, Madrid Spain
| | - M. Nicole Greenwood
- Academic Liaison, GlaxoSmithKline, Upper Providence, Pennsylvania 19426, United States
| | | | - Felix Calderón
- Medicines Development Campus, Global Health Pharma Unit, GlaxoSmithKline, Tres Cantos, 28760, Madrid Spain
| | - Wesley C. Van Voorhis
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| |
Collapse
|
6
|
Gaji RY, Sharp AK, Brown AM. Protein kinases in Toxoplasma gondii. Int J Parasitol 2021; 51:415-429. [PMID: 33581139 PMCID: PMC11065138 DOI: 10.1016/j.ijpara.2020.11.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/10/2020] [Accepted: 11/15/2020] [Indexed: 02/06/2023]
Abstract
Toxoplasma gondii is an obligatory intracellular pathogen that causes life threatening illness in immunodeficient individuals, miscarriage in pregnant woman, and blindness in newborn children. Similar to any other eukaryotic cell, protein kinases play critical and essential roles in the Toxoplasma life cycle. Accordingly, many studies have focused on identifying and defining the mechanism of function of these signalling proteins with a long-term goal to develop anti-Toxoplasma therapeutics. In this review, we briefly discuss classification and key components of the catalytic domain which are critical for functioning of kinases, with a focus on domains, families, and groups of kinases within Toxoplasma. More importantly, this article provides a comprehensive, current overview of research on kinase groups in Toxoplasma including the established eukaryotic AGC, CAMK, CK1, CMGC, STE, TKL families and the apicomplexan-specific FIKK, ROPK and WNG family of kinases. This work provides an overview and discusses current knowledge on Toxoplasma kinases including their localization, function, signalling network and role in acute and chronic pathogenesis, with a view towards the future in probing kinases as viable drug targets.
Collapse
Affiliation(s)
- Rajshekhar Y Gaji
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech University, Blacksburg, VA, USA; Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA.
| | - Amanda K Sharp
- Interdisciplinary Program in Genetics, Bioinformatics, and Computational Biology, Virginia Tech, Blacksburg, VA, USA
| | - Anne M Brown
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA; University Libraries, Virginia Tech, Blacksburg, VA, USA
| |
Collapse
|
7
|
Ghartey-Kwansah G, Yin Q, Li Z, Gumpper K, Sun Y, Yang R, Wang D, Jones O, Zhou X, Wang L, Bryant J, Ma J, Boampong JN, Xu X. Calcium-dependent Protein Kinases in Malaria Parasite Development and Infection. Cell Transplant 2021; 29:963689719884888. [PMID: 32180432 PMCID: PMC7444236 DOI: 10.1177/0963689719884888] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Apicomplexan parasites have challenged researchers for nearly a century. A major challenge to developing efficient treatments and vaccines is the parasite's ability to change its cellular and molecular makeup to develop intracellular and extracellular niches in its hosts. Ca2+ signaling is an important messenger for the egress of the malaria parasite from the infected erythrocyte, gametogenesis, ookinete motility in the mosquito, and sporozoite invasion of mammalian hepatocytes. Calcium-dependent protein kinases (CDPKs) have crucial functions in calcium signaling at various stages of the parasite's life cycle; this therefore makes them attractive drug targets against malaria. Here, we summarize the functions of the various CDPK isoforms in relation to the malaria life cycle by emphasizing the molecular mechanism of developmental progression within host tissues. We also discuss the current development of anti-malarial drugs, such as how specific bumped kinase inhibitors (BKIs) for parasite CDPKs have been shown to reduce infection in Toxoplasma gondii, Cryptosporidium parvum, and Plasmodium falciparum. Our suggested combinations of BKIs, artemisinin derivatives with peroxide bridge, and inhibitors on the Ca(2+)-ATPase PfATP6 as a potential target should be inspected further as a treatment against malaria.
Collapse
Affiliation(s)
- George Ghartey-Kwansah
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China.,Department of Biomedical Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana.,Authors contributed equally to this article
| | - Qinan Yin
- Clinical Center of National Institutes of Health, Bethesda, MD, USA.,Authors contributed equally to this article
| | - Zhongguang Li
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China.,Ohio State University School of Medicine, Columbus, OH, USA.,Authors contributed equally to this article
| | - Kristyn Gumpper
- Ohio State University School of Medicine, Columbus, OH, USA.,Authors contributed equally to this article
| | - Yuting Sun
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China
| | - Rong Yang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China
| | - Dan Wang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China
| | - Odell Jones
- University of Pennsylvania School of Medicine, Animal Center, Philadelphia, PA, USA
| | - Xin Zhou
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China.,Ohio State University School of Medicine, Columbus, OH, USA
| | - Liyang Wang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China.,Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Joseph Bryant
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jianjie Ma
- Ohio State University School of Medicine, Columbus, OH, USA
| | - Johnson Nyarko Boampong
- Department of Biomedical Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Xuehong Xu
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China
| |
Collapse
|
8
|
Winzer P, Imhof D, Anghel N, Ritler D, Müller J, Boubaker G, Aguado-Martinez A, Ortega-Mora LM, Ojo KK, VanVoorhis WC, Hemphill A. The Impact of BKI-1294 Therapy in Mice Infected With the Apicomplexan Parasite Neospora caninum and Re-infected During Pregnancy. Front Vet Sci 2020; 7:587570. [PMID: 33195616 PMCID: PMC7593410 DOI: 10.3389/fvets.2020.587570] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 09/08/2020] [Indexed: 01/10/2023] Open
Abstract
Exposure of Neospora caninum tachyzoites to BKI-1294 in vitro results in the formation of long-lived multinucleated complexes (MNCs). However, in vivo treatment of BALB/c mice with BKI-1294 shortly after N. caninum infection during pregnancy was safe and profoundly reduced pup mortality and vertical transmission. We hypothesized that the formation of MNCs could trigger immune responses that contribute to BKI efficacy in vivo. In this study, mice were first vaccinated with a sublethal dose of N. caninum tachyzoites and were treated with BKI-1294. We then investigated the effects of these treatments after mating and re-infection during pregnancy. Effects on fertility, pup survival, vertical transmission, and parasite load in dams were evaluated. Cytokines in sera or splenocyte culture supernatants were assessed by either ELISA or the Luminex™ 200 system, and humoral immune responses against tachyzoite and MNC antigens were compared by ELISA, Western blotting and immunoproteomics. Our results showed that BKI-1294 treatment of live-vaccinated mice reduced the cerebral parasite load in the dams, but resulted in higher neonatal pup mortality and vertical transmission. In live-vaccinated mice, cytokine levels, most notably IFN-y, IL-10, and IL-12, were consistently lower in BKI-1294 treated animals compared to non-treated mice. In addition, comparative Western blotting identified two protein bands in MNC extracts that were only recognized by sera of live-vaccinated mice treated with BKI-1294, and were not found in tachyzoite extracts. We conclude that treatment of live-vaccinated mice with BKI-1294 influenced the cellular and humoral immune responses against infection, affected the safety of the live-vaccine, and decreased protection against re-infection and vertical transmission during pregnancy.
Collapse
Affiliation(s)
- Pablo Winzer
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Dennis Imhof
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Nicoleta Anghel
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Dominic Ritler
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Joachim Müller
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Ghalia Boubaker
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | | | - Luis-Miguel Ortega-Mora
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Kayode K Ojo
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, United States
| | - Wesley C VanVoorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, United States.,Departments of Global Health and Microbiology, University of Washington, Seattle, WA, United States
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| |
Collapse
|
9
|
Love MS, McNamara CW. Phenotypic screening techniques for Cryptosporidium drug discovery. Expert Opin Drug Discov 2020; 16:59-74. [PMID: 32892652 DOI: 10.1080/17460441.2020.1812577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: Two landmark epidemiological studies identified Cryptosporidium spp. as a significant cause of diarrheal disease in pediatric populations in resource-limited countries. Notably, nitazoxanide is the only approved drug for treatment of cryptosporidiosis but shows limited efficacy. As a result, many drug discovery efforts have commenced to find improved treatments. The unique biology of Cryptosporidium presents challenges for traditional drug discovery methods, which has inspired new assay platforms to study parasite biology and drug screening. Areas covered: The authors review historical advancements in phenotypic-based assays and techniques for Cryptosporidium drug discovery, as well as recent advances that will define future drug discovery. The reliance on phenotypic-based screens and repositioning of phenotypic hits from other pathogens has quickly created a robust pipeline of potential cryptosporidiosis therapeutics. The latest advances involve new in vitro culture methods for oocyst generation, continuous culturing capabilities, and more physiologically relevant assays for testing compounds. Expert opinion: Previous phenotypic screening techniques have laid the groundwork for recent cryptosporidiosis drug discovery efforts. The resulting improved methodologies characterize compound activity, identify, and validate drug targets, and prioritize new compounds for drug development. The most recent improvements in phenotypic assays are poised to help advance compounds into clinical development.
Collapse
Affiliation(s)
- Melissa S Love
- Calibr, a division of The Scripps Research Institute , La Jolla, CA, USA
| | - Case W McNamara
- Calibr, a division of The Scripps Research Institute , La Jolla, CA, USA
| |
Collapse
|
10
|
Three-Dimensional Interactions Analysis of the Anticancer Target c-Src Kinase with Its Inhibitors. Cancers (Basel) 2020; 12:cancers12082327. [PMID: 32824733 PMCID: PMC7466017 DOI: 10.3390/cancers12082327] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/07/2020] [Accepted: 08/16/2020] [Indexed: 12/13/2022] Open
Abstract
Src family kinases (SFKs) constitute the biggest family of non-receptor tyrosine kinases considered as therapeutic targets for cancer therapy. An aberrant expression and/or activation of the proto-oncogene c-Src kinase, which is the oldest and most studied member of the family, has long been demonstrated to play a major role in the development, growth, progression and metastasis of numerous human cancers, including colon, breast, gastric, pancreatic, lung and brain carcinomas. For these reasons, the pharmacological inhibition of c-Src activity represents an effective anticancer strategy and a few compounds targeting c-Src, together with other kinases, have been approved as drugs for cancer therapy, while others are currently undergoing preclinical studies. Nevertheless, the development of potent and selective inhibitors of c-Src aimed at properly exploiting this biological target for the treatment of cancer still represents a growing field of study. In this review, the co-crystal structures of c-Src kinase in complex with inhibitors discovered in the past two decades have been described, highlighting the key ligand-protein interactions necessary to obtain high potency and the features to be exploited for addressing selectivity and drug resistance issues, thus providing useful information for the design of new and potent c-Src kinase inhibitors.
Collapse
|
11
|
Anghel N, Winzer PA, Imhof D, Müller J, Langa X, Rieder J, Barrett LK, Vidadala RSR, Huang W, Choi R, Hulverson MA, Whitman GR, Arnold SL, Van Voorhis WC, Ojo KK, Maly DJ, Fan E, Hemphill A. Comparative assessment of the effects of bumped kinase inhibitors on early zebrafish embryo development and pregnancy in mice. Int J Antimicrob Agents 2020; 56:106099. [PMID: 32707170 DOI: 10.1016/j.ijantimicag.2020.106099] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 07/07/2020] [Accepted: 07/13/2020] [Indexed: 01/30/2023]
Abstract
Bumped kinase inhibitors (BKIs) are effective against a variety of apicomplexan parasites. Fifteen BKIs with promising in vitro efficacy against Neospora caninum tachyzoites, low cytotoxicity in mammalian cells, and no toxic effects in non-pregnant BALB/c mice were assessed in pregnant mice. Drugs were emulsified in corn oil and were applied by gavage for 5 days. Five BKIs did not affect pregnancy, five BKIs exhibited ~15-35% neonatal mortality and five compounds caused strong effects (infertility, abortion, stillbirth and pup mortality). Additionally, the impact of these compounds on zebrafish (Danio rerio) embryo development was assessed by exposing freshly fertilised eggs to 0.2-50 μM of BKIs and microscopic monitoring of embryo development in a blinded manner for 4 days. We propose an algorithm that includes quantification of malformations and embryo deaths, and established a scoring system that allows the calculation of an impact score (Si) indicating at which concentrations BKIs visibly affect zebrafish embryo development. Comparison of the two models showed that for nine compounds no clear correlation between Si and pregnancy outcome was observed. However, the three BKIs affecting zebrafish embryos only at high concentrations (≥40 μM) did not impair mouse pregnancy at all, and the three compounds that inhibited zebrafish embryo development already at 0.2 μM showed detrimental effects in the pregnancy model. Thus, the zebrafish embryo development test has limited predictive value to foresee pregnancy outcome in BKI-treated mice. We conclude that maternal health-related factors such as cardiovascular, pharmacokinetic and/or bioavailability properties also contribute to BKI-pregnancy effects.
Collapse
Affiliation(s)
- Nicoleta Anghel
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland
| | - Pablo A Winzer
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland
| | - Dennis Imhof
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland
| | - Joachim Müller
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland
| | - Xavier Langa
- Department of Developmental Biology and Regeneration, Institute of Anatomy, University of Bern, Baltzerstrasse 2, CH-3000 Bern, Switzerland
| | - Jessica Rieder
- Centre for Fish and Wildlife Health (FIWI), Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, 3012 Bern, Switzerland
| | - Lynn K Barrett
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | | | - Wenlin Huang
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Ryan Choi
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Mathew A Hulverson
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Grant R Whitman
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Samuel L Arnold
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Wesley C Van Voorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Kayode K Ojo
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Dustin J Maly
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Erkang Fan
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Andrew Hemphill
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland.
| |
Collapse
|
12
|
Choi R, Michaels SA, Onu EC, Hulverson MA, Saha A, Coker ME, Weeks JC, Van Voorhis WC, Ojo KK. Taming the Boys for Global Good: Contraceptive Strategy to Stop Malaria Transmission. Molecules 2020; 25:molecules25122773. [PMID: 32560085 PMCID: PMC7356879 DOI: 10.3390/molecules25122773] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/10/2020] [Accepted: 06/14/2020] [Indexed: 12/21/2022] Open
Abstract
Transmission of human malaria parasites (Plasmodium spp.) by Anopheles mosquitoes is a continuous process that presents a formidable challenge for effective control of the disease. Infectious gametocytes continue to circulate in humans for up to four weeks after antimalarial drug treatment, permitting prolonged transmission to mosquitoes even after clinical cure. Almost all reported malaria cases are transmitted to humans by mosquitoes, and therefore decreasing the rate of Plasmodium transmission from humans to mosquitoes with novel transmission-blocking remedies would be an important complement to other interventions in reducing malaria incidence.
Collapse
Affiliation(s)
- Ryan Choi
- Center for Emerging and Re-Emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA 98109, USA; (R.C.); (S.A.M.); (M.A.H.); (A.S.); (W.C.V.V.)
| | - Samantha A. Michaels
- Center for Emerging and Re-Emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA 98109, USA; (R.C.); (S.A.M.); (M.A.H.); (A.S.); (W.C.V.V.)
| | - Emmanuel C. Onu
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria; (E.C.O.); (M.E.C.)
| | - Matthew A. Hulverson
- Center for Emerging and Re-Emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA 98109, USA; (R.C.); (S.A.M.); (M.A.H.); (A.S.); (W.C.V.V.)
| | - Aparajita Saha
- Center for Emerging and Re-Emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA 98109, USA; (R.C.); (S.A.M.); (M.A.H.); (A.S.); (W.C.V.V.)
| | - Morenike E. Coker
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria; (E.C.O.); (M.E.C.)
| | - Janis C. Weeks
- Department of Biology, University of Oregon, Eugene, OR 97403, USA;
| | - Wesley C. Van Voorhis
- Center for Emerging and Re-Emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA 98109, USA; (R.C.); (S.A.M.); (M.A.H.); (A.S.); (W.C.V.V.)
| | - Kayode K. Ojo
- Center for Emerging and Re-Emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA 98109, USA; (R.C.); (S.A.M.); (M.A.H.); (A.S.); (W.C.V.V.)
- Correspondence: ; Tel.: +1-206-543-0821
| |
Collapse
|
13
|
Janetka JW, Hopper AT, Yang Z, Barks J, Dhason MS, Wang Q, Sibley LD. Optimizing Pyrazolopyrimidine Inhibitors of Calcium Dependent Protein Kinase 1 for Treatment of Acute and Chronic Toxoplasmosis. J Med Chem 2020; 63:6144-6163. [PMID: 32420739 PMCID: PMC7325724 DOI: 10.1021/acs.jmedchem.0c00419] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Calcium dependent protein kinase 1 (CDPK1) is an essential Ser/Thr kinase that controls invasion and egress by the protozoan parasite Toxoplasma gondii. The Gly gatekeeper of CDPK1 makes it exquisitely sensitive to inhibition by small molecule 1H-pyrazolo[3,4-d]pyrimidine-4-amine (PP) compounds that are bulky ATP mimetics. Here we rationally designed, synthesized, and tested a series of novel PP analogs that were evaluated for inhibition of CDPK1 enzyme activity in vitro and parasite growth in cell culture. Optimal substitution on the PP scaffold included 2-pyridyl ethers directed into the hydrophobic pocket and small carbocyclic rings accessing the ribose-binding pocket. Further optimization of the series led to identification of the lead compound 3a that displayed excellent potency, selectivity, safety profile, and efficacy in vivo. The results of these studies provide a foundation for further work to optimize CDPK1 inhibitors for the treatment of acute and chronic toxoplasmosis.
Collapse
Affiliation(s)
- James W. Janetka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis. MO 63110
| | | | - Ziping Yang
- Vyera Pharmaceuticals, 600 Third Avenue, New York, NY 10016
| | - Jennifer Barks
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| | - Mary Savari Dhason
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| | - Qiuling Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| |
Collapse
|
14
|
Bumped Kinase Inhibitors as therapy for apicomplexan parasitic diseases: lessons learned. Int J Parasitol 2020; 50:413-422. [PMID: 32224121 DOI: 10.1016/j.ijpara.2020.01.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 11/24/2022]
Abstract
Bumped Kinase Inhibitors, targeting Calcium-dependent Protein Kinase 1 in apicomplexan parasites with a glycine gatekeeper, are promising new therapeutics for apicomplexan diseases. Here we will review advances, as well as challenges and lessons learned regarding efficacy, safety, and pharmacology that have shaped our selection of pre-clinical candidates.
Collapse
|
15
|
Zhang P, Jia L, Tian Y, Xi L, Duan R, Chen X, Xiao J, Yao X, Lan J, Li S. Discovery of potential Toxoplasma gondii CDPK1 inhibitors with new scaffolds based on the combination of QSAR and scaffold-hopping method with in vitro validation. Chem Biol Drug Des 2020; 95:476-484. [PMID: 31436911 DOI: 10.1111/cbdd.13603] [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: 05/21/2019] [Revised: 07/04/2019] [Accepted: 07/27/2019] [Indexed: 02/06/2023]
Abstract
To discover drugs for toxoplasmosis with less side-effects and less probability to get drug resistance is eagerly appealed for pregnant women, infant or immunocompromised patients. In this work, using TgCDPK1 as drug target, we design a method to discover new inhibitors for CDPK1 as potential drug lead for toxoplasmosis with novel scaffolds based on the combination of 2D/3D-QSAR and scaffold-hopping methods. All the binding sites of the potential inhibitors were checked by docking method, and only the ones that docked to the most conserved sites of TgCDPK1, which make them have less probability to get drug resistance, were remained. As a result, 10 potential inhibitors within two new scaffolds were discovered for TgCDPK1 with experimentally verified inhibitory activities in micromole level. The discovery of these inhibitors may contribute to the drug development for toxoplasmosis. Besides, the pipeline which is composed in this work as the combination of QSAR and scaffold-hopping is simple, easy to repeat for researchers without need of in-depth knowledge of pharmacology to get inhibitors with novel scaffolds, which will accelerate the procedure of drug discovery and contribute to the drug repurposing study.
Collapse
Affiliation(s)
- Pengyi Zhang
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, China
| | - Lipei Jia
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, China
| | - Yafei Tian
- Department of Burn Orthopedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Lili Xi
- Department of Pharmacy, First Hospital of Lanzhou University, Lanzhou, China
| | - Ruizhi Duan
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, China
| | - Ximing Chen
- Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Beijing, China
| | - Jianxi Xiao
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, China
| | - Xiaojun Yao
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, China
| | - Jingfeng Lan
- National Demonstration Centre for Experimental Chemistry Education, Lanzhou University, Lanzhou, China
| | - Shuyan Li
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, China
| |
Collapse
|
16
|
Leso A, Bihaqi SW, Masoud A, Chang JK, Lahouel A, Zawia N. Loss in efficacy measures of tolfenamic acid in a tau knock-out model: Relevance to Alzheimer's disease. Exp Biol Med (Maywood) 2019; 244:1062-1069. [PMID: 31450960 DOI: 10.1177/1535370219871249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In the healthy human brain, the protein tau serves the essential function of stabilizing microtubules. However, in a diseased state, tau becomes destabilized and aggregates into a pathogenic form that ultimately creates one of the two major hallmarks of Alzheimer’s disease (AD), tau tangles. Multiple neurodegenerative diseases, termed tauopathies, such as Pick’s disease, and progressive supranuclear palsy, are also linked to mutations in tau. While AD does include a second hallmark in the form of amyloid beta (Aβ) plaques, to date all therapeutics aimed at these hallmark features have failed. The nonsteroidal anti-inflammatory drug tolfenamic acid (TA) has been shown to reduce the levels of multiple neurodegenerative endpoints viz amyloid precursor protein (APP), Aβ, tau, phosphorylated tau (p-tau) and improve cognitive function, in various murine models, via a new mechanism that targets specificity protein 1 ( SP1). Sp1 is a zinc-finger transcription factor essential for the regulation of tau and CDK5 genes (among others). The impact of TA on these neurodegenerative endpoints occurred in animal models and systems in which both the tau and the APP genes were present. The experimental model utilized in this paper tested whether the same beneficial outcomes of TA can take place after the removal of endogenous murine tau. We found that the impact of TA, both molecular and behavioral, was no longer significant in the absence of the tau gene. This ability of TA occurred independently of its action on anti-inflammatory targets. Therefore, these findings suggest the essentiality of tau for the novel mechanism of action of TA. Impact statement The number of people suffering from Alzheimer’s disease (AD) is expected to increase exponentially in the coming decades. It is estimated to cost the economy about $200 billion annually. With the failure of standard therapeutic approaches, there is a need to develop new drugs in order to avoid an “epidemic crisis” in the future. We have discovered that tolfenamic acid (TA) lowers the levels of proteins associated with AD, by targeting common transcriptional mechanisms that regulate genes involved in common pathogenic pathways. Here, we investigated whether TA had effects on both the amyloid and tau pathways, or whether it selectively targets one of these pathways which impacted the other. Behavioral and molecular studies revealed that TA loses its AD therapeutic potential when tau gene is removed. This ability of TA occurred independently of its action on anti-inflammatory targets. These findings suggest that tau is essential for the new action of TA.
Collapse
Affiliation(s)
- Allison Leso
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI 02881, USA
| | - Syed W Bihaqi
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA
| | - Anwar Masoud
- Biochemical Technology Program, Faculty of Applied Science, Thamar University, Thamar 87246, Yemen
| | - Joanna K Chang
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Asma Lahouel
- Department of Molecular and Cellular Biology, Jijel University, Jijel 18000, Algeria
| | - Nasser Zawia
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI 02881, USA.,George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA.,Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| |
Collapse
|
17
|
Bumped kinase inhibitor 1369 is effective against Cystoisospora suis in vivo and in vitro. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2019; 10:9-19. [PMID: 30959327 PMCID: PMC6453670 DOI: 10.1016/j.ijpddr.2019.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 03/25/2019] [Accepted: 03/28/2019] [Indexed: 12/22/2022]
Abstract
Cystoisosporosis is a leading diarrheal disease in suckling piglets. With the confirmation of resistance against the only available drug toltrazuril, there is a substantial need for novel therapeutics to combat the infection and its negative effects on animal health. In closely related apicomplexan species, bumped kinase inhibitors (BKIs) targeting calcium-dependent protein kinase 1 (CDPK1) were shown to be effective in inhibiting host-cell invasion and parasite growth. Therefore, the gene coding for Cystoisospora suis CDPK1 (CsCDPK1) was identified and cloned to investigate activity and thermal stabilization of the recombinant CsCDPK1 enzyme by BKI 1369. In this comprehensive study, the efficacy, safety and pharmacokinetics of BKI 1369 in piglets experimentally infected with Cystoisospora suis (toltrazuril-sensitive, Wien-I and toltrazuril-resistant, Holland-I strains) were determined in vivo and in vitro using an established animal infection model and cell culture, respectively. BKI 1369 inhibited merozoite proliferation in intestinal porcine epithelial cells-1 (IPEC-1) by at least 50% at a concentration of 40 nM, and proliferation was almost completely inhibited (>95%) at 200 nM. Nonetheless, exposure of infected cultures to 200 nM BKI 1369 for five days did not induce structural alterations in surviving merozoites as confirmed by transmission electron microscopy. Five-day treatment with BKI 1369 (10 mg/kg BW twice a day) effectively suppressed oocyst excretion and diarrhea and improved body weight gains in treated piglets without obvious side effects for both toltrazuril-sensitive, Wien-I and resistant, Holland-I C. suis strains. The plasma concentration of BKI 1369 in piglets increased to 11.7 μM during treatment, suggesting constant drug accumulation and exposure of parasites to the drug. Therefore, oral applications of BKI 1369 could potentially be a therapeutic alternative against porcine cystoisosporosis. For use in pigs, future studies on BKI 1369 should be directed towards ease of drug handling and minimizing treatment frequencies. Oral application of BKI 1369 effectively reduced oocyst excretion and diarrhea in Cystoisospora suis infected piglets. 200 nM of BKI 1369 almost completely suppressed parasite proliferation in vitro. IC50 and IC95 concentrations of BKI 1369 did not induce morphological alterations in in vitro cultured merozoites. Cystoisosporasuis CDPK1, the putative target of BKI 1369, has glycine as gatekeeper residue.
Collapse
|
18
|
Veale CGL. Unpacking the Pathogen Box-An Open Source Tool for Fighting Neglected Tropical Disease. ChemMedChem 2019; 14:386-453. [PMID: 30614200 DOI: 10.1002/cmdc.201800755] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 12/13/2022]
Abstract
The Pathogen Box is a 400-strong collection of drug-like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in-depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure-activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.
Collapse
Affiliation(s)
- Clinton G L Veale
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa
| |
Collapse
|
19
|
Protein targets of thiazolidinone derivatives in Toxoplasma gondii and insights into their binding to ROP18. BMC Genomics 2018; 19:856. [PMID: 30497375 PMCID: PMC6267824 DOI: 10.1186/s12864-018-5223-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 11/05/2018] [Indexed: 01/20/2023] Open
Abstract
Background Thiazolidinone derivatives show inhibitory activity (IC50) against the Toxoplasma gondii parasite, as well as high selectivity with high therapeutic index. To disclose the target proteins of the thiazolidinone core in this parasite, we explored in silico the active sites of different T. gondii proteins and estimated the binding-free energy of reported thiazolidinone molecules with inhibitory effect on invasion and replication of the parasite inside host cells. This enabled us to describe some of the most suitable structural characteristics to design a compound derived from the thiazolidinone core. Results The best binding affinity was observed in the active site of kinase proteins, we selected the active site of the T. gondii ROP18 kinase, because it is an important factor for the virulence and survival of the parasite. We present the possible effect of a derivative of thiazolidinone core in the active site of T. gondii ROP18 and described some characteristics of substituent groups that could improve the affinity and specificity of compounds derived from the thiazolidinone core against T. gondii. Conclusions The results of our study suggest that compounds derived from the thiazolidinone core have a preference for protein kinases of T. gondii, being promising compounds for the development of new drugs with potential anti-toxoplasmosis activity. Our findings highlight the importance of use computational studies for the understanding of the action mechanism of compounds with biological activity. Electronic supplementary material The online version of this article (10.1186/s12864-018-5223-7) contains supplementary material, which is available to authorized users.
Collapse
|
20
|
In vitro growth inhibition of Theileria equi by bumped kinase inhibitors. Vet Parasitol 2018; 251:90-94. [PMID: 29426483 DOI: 10.1016/j.vetpar.2017.12.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 11/20/2017] [Accepted: 12/31/2017] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Theileria equi, an etiologic agent of equine piroplasmosis, is a tick-transmitted hemoprotozoan of the phylum Apicomplexa. Recent outbreaks of piroplasmosis in the United States have renewed interest in safe and effective treatment options. Although imidocarb dipropionate (IMD) is the drug of choice for clearance of T. equi, adverse reactions and recently documented resistance support the need for alternative therapeutic strategies. The recently described bumped kinase inhibitors (BKIs) are a new class of compounds that could potentially be used as safe and effective alternatives to IMD. In an initial effort to evaluate this potential, herein we determined the T. equi growth inhibitory activity of 11 BKIs relative to that of IMD and the previously tested BKI 1294. Because some BKIs have known human ether-à-go-go related gene (hERG) channel activity, we also assessed the hERG activity of each compound with the goal to identify those with the highest potency against T. equi coupled with the lowest potential for cardiotoxicity. RESULTS Six BKIs inhibited T. equi growth in vitro, including the previously evaluated BKI 1294 which was used as a positive control. All six compounds were significantly less potent (higher 50% effective concentration (EC50)) than IMD. Two of those compounds were more potent than BKI 1294 control but had similar hERG activity. Although the remaining three compounds had similar to lower potency than BKI 1294, hERG EC50 was higher for three of them (BKI 1735, BKI 1369 and BKI 1318). CONCLUSIONS The BKI compounds evaluated in this study inhibited T. equi in vitro and had diverse hERG activity. Based on these considerations, three compounds would be suitable for further evaluation. While these results provide a foundation for future work, in vivo pharmacokinetic, pharmacodynamics, and safety studies are needed before BKI compounds can be recommended for clinical use in T. equi infected horses.
Collapse
|
21
|
Rutaganira FU, Barks J, Dhason MS, Wang Q, Lopez MS, Long S, Radke JB, Jones NG, Maddirala AR, Janetka JW, El Bakkouri M, Hui R, Shokat KM, Sibley LD. Inhibition of Calcium Dependent Protein Kinase 1 (CDPK1) by Pyrazolopyrimidine Analogs Decreases Establishment and Reoccurrence of Central Nervous System Disease by Toxoplasma gondii. J Med Chem 2017; 60:9976-9989. [PMID: 28933846 DOI: 10.1021/acs.jmedchem.7b01192] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Calcium dependent protein kinase 1 (CDPK1) is an essential enzyme in the opportunistic pathogen Toxoplasma gondii. CDPK1 controls multiple processes that are critical to the intracellular replicative cycle of T. gondii including secretion of adhesins, motility, invasion, and egress. Remarkably, CDPK1 contains a small glycine gatekeeper residue in the ATP binding pocket making it sensitive to ATP-competitive inhibitors with bulky substituents that complement this expanded binding pocket. Here we explored structure-activity relationships of a series of pyrazolopyrimidine inhibitors of CDPK1 with the goal of increasing selectivity over host enzymes, improving antiparasite potency, and improving metabolic stability. The resulting lead compound 24 exhibited excellent enzyme inhibition and selectivity for CDPK1 and potently inhibited parasite growth in vitro. Compound 24 was also effective at treating acute toxoplasmosis in the mouse, reducing dissemination to the central nervous system, and decreasing reactivation of chronic infection in severely immunocompromised mice. These findings provide proof of concept for the development of small molecule inhibitors of CDPK1 for treatment of CNS toxoplasmosis.
Collapse
Affiliation(s)
- Florentine U Rutaganira
- Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco , San Francisco, California 94158, United States
| | - Jennifer Barks
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Mary Savari Dhason
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Qiuling Wang
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Michael S Lopez
- Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco , San Francisco, California 94158, United States
| | - Shaojun Long
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Joshua B Radke
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Nathaniel G Jones
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Amarendar R Maddirala
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - James W Janetka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Majida El Bakkouri
- Structural Genomics Consortium, University of Toronto , MaRS South Tower, 101 College St, Toronto, ON M5G 1L7, Canada
| | - Raymond Hui
- Structural Genomics Consortium, University of Toronto , MaRS South Tower, 101 College St, Toronto, ON M5G 1L7, Canada.,Toronto General Hospital Research Institute , 200 Elizabeth St., Toronto, ON M5G 2C4, Canada
| | - Kevan M Shokat
- Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco , San Francisco, California 94158, United States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| |
Collapse
|
22
|
Alday PH, Doggett JS. Drugs in development for toxoplasmosis: advances, challenges, and current status. DRUG DESIGN DEVELOPMENT AND THERAPY 2017; 11:273-293. [PMID: 28182168 PMCID: PMC5279849 DOI: 10.2147/dddt.s60973] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Toxoplasma gondii causes fatal and debilitating brain and eye diseases. Medicines that are currently used to treat toxoplasmosis commonly have toxic side effects and require prolonged courses that range from weeks to more than a year. The need for long treatment durations and the risk of relapsing disease are in part due to the lack of efficacy against T. gondii tissue cysts. The challenges for developing a more effective treatment for toxoplasmosis include decreasing toxicity, achieving therapeutic concentrations in the brain and eye, shortening duration, eliminating tissue cysts from the host, safety in pregnancy, and creating a formulation that is inexpensive and practical for use in resource-poor areas of the world. Over the last decade, significant progress has been made in identifying and developing new compounds for the treatment of toxoplasmosis. Unlike clinically used medicines that were repurposed for toxoplasmosis, these compounds have been optimized for efficacy against toxoplasmosis during preclinical development. Medicines with enhanced efficacy as well as features that address the unique aspects of toxoplasmosis have the potential to greatly improve toxoplasmosis therapy. This review discusses the facets of toxoplasmosis that are pertinent to drug design and the advances, challenges, and current status of preclinical drug research for toxoplasmosis.
Collapse
Affiliation(s)
- P Holland Alday
- Division of Infectious Diseases, Oregon Health & Science University
| | - Joseph Stone Doggett
- Division of Infectious Diseases, Oregon Health & Science University; Portland Veterans Affairs Medical Center, Portland, OR, USA
| |
Collapse
|
23
|
Van Voorhis WC, Doggett JS, Parsons M, Hulverson MA, Choi R, Arnold SLM, Riggs MW, Hemphill A, Howe DK, Mealey RH, Lau AOT, Merritt EA, Maly DJ, Fan E, Ojo KK. Extended-spectrum antiprotozoal bumped kinase inhibitors: A review. Exp Parasitol 2017; 180:71-83. [PMID: 28065755 DOI: 10.1016/j.exppara.2017.01.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 01/02/2017] [Accepted: 01/04/2017] [Indexed: 01/08/2023]
Abstract
Many life-cycle processes in parasites are regulated by protein phosphorylation. Hence, disruption of essential protein kinase function has been explored for therapy of parasitic diseases. However, the difficulty of inhibiting parasite protein kinases to the exclusion of host orthologues poses a practical challenge. A possible path around this difficulty is the use of bumped kinase inhibitors for targeting calcium-dependent protein kinases that contain atypically small gatekeeper residues and are crucial for pathogenic apicomplexan parasites' survival and proliferation. In this article, we review efficacy against the kinase target, parasite growth in vitro, and in animal infection models, as well as the relevant pharmacokinetic and safety parameters of bumped kinase inhibitors.
Collapse
Affiliation(s)
- Wesley C Van Voorhis
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98195, USA.
| | | | - Marilyn Parsons
- Department of Global Health, University of Washington, Seattle, WA 98195, USA; Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Matthew A Hulverson
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, WA 98109, USA
| | - Ryan Choi
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, WA 98109, USA
| | - Samuel L M Arnold
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, WA 98109, USA
| | - Michael W Riggs
- School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Berne, Switzerland
| | - Daniel K Howe
- Department of Veterinary Science, University of Kentucky, Lexington, KY 40546, USA
| | - Robert H Mealey
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA
| | - Audrey O T Lau
- The National Institutes of Health, NIAID, DEA, 5601 Fishers Lane, Rockville, MD 20892, USA
| | - Ethan A Merritt
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Dustin J Maly
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Erkang Fan
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Kayode K Ojo
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, WA 98109, USA.
| |
Collapse
|
24
|
Review of Experimental Compounds Demonstrating Anti-Toxoplasma Activity. Antimicrob Agents Chemother 2016; 60:7017-7034. [PMID: 27600037 DOI: 10.1128/aac.01176-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Toxoplasma gondii is a ubiquitous apicomplexan parasite capable of infecting humans and other animals. Current treatment options for T. gondii infection are limited and most have drawbacks, including high toxicity and low tolerability. Additionally, no FDA-approved treatments are available for pregnant women, a high-risk population due to transplacental infection. Therefore, the development of novel treatment options is needed. To aid this effort, this review highlights experimental compounds that, at a minimum, demonstrate inhibition of in vitro growth of T. gondii When available, host cell toxicity and in vivo data are also discussed. The purpose of this review is to facilitate additional development of anti-Toxoplasma compounds and potentially to extend our knowledge of the parasite.
Collapse
|
25
|
Vidadala RSR, Rivas KL, Ojo KK, Hulverson MA, Zambriski JA, Bruzual I, Schultz TL, Huang W, Zhang Z, Scheele S, DeRocher AE, Choi R, Barrett LK, Siddaramaiah LK, Hol WGJ, Fan E, Merritt EA, Parsons M, Freiberg G, Marsh K, Kempf DJ, Carruthers VB, Isoherranen N, Doggett JS, Van Voorhis WC, Maly DJ. Development of an Orally Available and Central Nervous System (CNS) Penetrant Toxoplasma gondii Calcium-Dependent Protein Kinase 1 (TgCDPK1) Inhibitor with Minimal Human Ether-a-go-go-Related Gene (hERG) Activity for the Treatment of Toxoplasmosis. J Med Chem 2016; 59:6531-46. [PMID: 27309760 DOI: 10.1021/acs.jmedchem.6b00760] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New therapies are needed for the treatment of toxoplasmosis, which is a disease caused by the protozoan parasite Toxoplasma gondii. To this end, we previously developed a potent and selective inhibitor (compound 1) of Toxoplasma gondii calcium-dependent protein kinase 1 (TgCDPK1) that possesses antitoxoplasmosis activity in vitro and in vivo. Unfortunately, 1 has potent human ether-a-go-go-related gene (hERG) inhibitory activity, associated with long Q-T syndrome, and consequently presents a cardiotoxicity risk. Here, we describe the identification of an optimized TgCDPK1 inhibitor 32, which does not have a hERG liability and possesses a favorable pharmacokinetic profile in small and large animals. 32 is CNS-penetrant and highly effective in acute and latent mouse models of T. gondii infection, significantly reducing the amount of parasite in the brain, spleen, and peritoneal fluid and reducing brain cysts by >85%. These properties make 32 a promising lead for the development of a new antitoxoplasmosis therapy.
Collapse
Affiliation(s)
- Rama Subba Rao Vidadala
- Department of Chemistry, University of Washington , Seattle, Washington 98195, United States
| | - Kasey L Rivas
- Department of Medicine, Division of Allergy and Infectious Diseases, and the Center for Emerging and Re-Emerging Infectious Diseases (CERID), University of Washington , Seattle, Washington 98109, United States
| | - Kayode K Ojo
- Department of Medicine, Division of Allergy and Infectious Diseases, and the Center for Emerging and Re-Emerging Infectious Diseases (CERID), University of Washington , Seattle, Washington 98109, United States
| | - Matthew A Hulverson
- Department of Medicine, Division of Allergy and Infectious Diseases, and the Center for Emerging and Re-Emerging Infectious Diseases (CERID), University of Washington , Seattle, Washington 98109, United States
| | - Jennifer A Zambriski
- Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University , Pullman, Washington 99164, United States
| | - Igor Bruzual
- Portland VA Medical Center , Portland, Oregon 97239, United States
| | - Tracey L Schultz
- Department of Microbiology and Immunology, University of Michigan Medical School , Ann Arbor, Michigan 48109, United States
| | - Wenlin Huang
- Department of Biochemistry, University of Washington , Seattle, Washington 98195, United States
| | - Zhongsheng Zhang
- Department of Biochemistry, University of Washington , Seattle, Washington 98195, United States
| | - Suzanne Scheele
- Center for Infectious Disease Research (formerly Seattle Biomedical Research Institute), Seattle, Washington 98109, United States
| | - Amy E DeRocher
- Center for Infectious Disease Research (formerly Seattle Biomedical Research Institute), Seattle, Washington 98109, United States
| | - Ryan Choi
- Department of Medicine, Division of Allergy and Infectious Diseases, and the Center for Emerging and Re-Emerging Infectious Diseases (CERID), University of Washington , Seattle, Washington 98109, United States
| | - Lynn K Barrett
- Department of Medicine, Division of Allergy and Infectious Diseases, and the Center for Emerging and Re-Emerging Infectious Diseases (CERID), University of Washington , Seattle, Washington 98109, United States
| | | | - Wim G J Hol
- Department of Biochemistry, University of Washington , Seattle, Washington 98195, United States
| | - Erkang Fan
- Department of Biochemistry, University of Washington , Seattle, Washington 98195, United States
| | - Ethan A Merritt
- Department of Biochemistry, University of Washington , Seattle, Washington 98195, United States
| | - Marilyn Parsons
- Center for Infectious Disease Research (formerly Seattle Biomedical Research Institute), Seattle, Washington 98109, United States.,Department of Global Health, University of Washington , Seattle, Washington 98195, United States
| | - Gail Freiberg
- AbbVie , North Chicago, Illinois 60064, United States
| | - Kennan Marsh
- AbbVie , North Chicago, Illinois 60064, United States
| | - Dale J Kempf
- AbbVie , North Chicago, Illinois 60064, United States
| | - Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School , Ann Arbor, Michigan 48109, United States
| | - Nina Isoherranen
- Department of Pharmaceutics, University of Washington , Seattle, Washington 98195, United States
| | - J Stone Doggett
- Portland VA Medical Center , Portland, Oregon 97239, United States
| | - Wesley C Van Voorhis
- Department of Medicine, Division of Allergy and Infectious Diseases, and the Center for Emerging and Re-Emerging Infectious Diseases (CERID), University of Washington , Seattle, Washington 98109, United States.,Department of Global Health, University of Washington , Seattle, Washington 98195, United States
| | - Dustin J Maly
- Department of Biochemistry, University of Washington , Seattle, Washington 98195, United States.,Department of Chemistry, University of Washington , Seattle, Washington 98195, United States
| |
Collapse
|
26
|
Abstract
INTRODUCTION Despite the fact that diseases caused by protozoan parasites represent serious challenges for public health, animal production and welfare, only a limited panel of drugs has been marketed for clinical applications. AREAS COVERED Herein, the authors investigate two strategies, namely whole organism screening and target-based drug design. The present pharmacopoeia has resulted from whole organism screening, and the mode of action and targets of selected drugs are discussed. However, the more recent extensive genome sequencing efforts and the development of dry and wet lab genomics and proteomics that allow high-throughput screening of interactions between micromolecules and recombinant proteins has resulted in target-based drug design as the predominant focus in anti-parasitic drug development. Selected examples of target-based drug design studies are presented, and calcium-dependent protein kinases, important drug targets in apicomplexan parasites, are discussed in more detail. EXPERT OPINION Despite the enormous efforts in target-based drug development, this approach has not yet generated market-ready antiprotozoal drugs. However, whole-organism screening approaches, comprising of both in vitro and in vivo investigations, should not be disregarded. The repurposing of already approved and marketed drugs could be a suitable strategy to avoid fastidious approval procedures, especially in the case of neglected or veterinary parasitoses.
Collapse
Affiliation(s)
- Joachim Müller
- a Institute of Parasitology, Vetsuisse Faculty , University of Bern , Bern , Switzerland
| | - Andrew Hemphill
- a Institute of Parasitology, Vetsuisse Faculty , University of Bern , Bern , Switzerland
| |
Collapse
|
27
|
Crowther GJ, Hillesland HK, Keyloun KR, Reid MC, Lafuente-Monasterio MJ, Ghidelli-Disse S, Leonard SE, He P, Jones JC, Krahn MM, Mo JS, Dasari KS, Fox AMW, Boesche M, El Bakkouri M, Rivas KL, Leroy D, Hui R, Drewes G, Maly DJ, Van Voorhis WC, Ojo KK. Biochemical Screening of Five Protein Kinases from Plasmodium falciparum against 14,000 Cell-Active Compounds. PLoS One 2016; 11:e0149996. [PMID: 26934697 PMCID: PMC4774911 DOI: 10.1371/journal.pone.0149996] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 02/08/2016] [Indexed: 11/18/2022] Open
Abstract
In 2010 the identities of thousands of anti-Plasmodium compounds were released publicly to facilitate malaria drug development. Understanding these compounds' mechanisms of action--i.e., the specific molecular targets by which they kill the parasite--would further facilitate the drug development process. Given that kinases are promising anti-malaria targets, we screened ~14,000 cell-active compounds for activity against five different protein kinases. Collections of cell-active compounds from GlaxoSmithKline (the ~13,000-compound Tres Cantos Antimalarial Set, or TCAMS), St. Jude Children's Research Hospital (260 compounds), and the Medicines for Malaria Venture (the 400-compound Malaria Box) were screened in biochemical assays of Plasmodium falciparum calcium-dependent protein kinases 1 and 4 (CDPK1 and CDPK4), mitogen-associated protein kinase 2 (MAPK2/MAP2), protein kinase 6 (PK6), and protein kinase 7 (PK7). Novel potent inhibitors (IC50 < 1 μM) were discovered for three of the kinases: CDPK1, CDPK4, and PK6. The PK6 inhibitors are the most potent yet discovered for this enzyme and deserve further scrutiny. Additionally, kinome-wide competition assays revealed a compound that inhibits CDPK4 with few effects on ~150 human kinases, and several related compounds that inhibit CDPK1 and CDPK4 yet have limited cytotoxicity to human (HepG2) cells. Our data suggest that inhibiting multiple Plasmodium kinase targets without harming human cells is challenging but feasible.
Collapse
Affiliation(s)
- Gregory J. Crowther
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Heidi K. Hillesland
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Katelyn R. Keyloun
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Molly C. Reid
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | | | - Sonja Ghidelli-Disse
- Cellzome GmbH, Molecular Discovery Research, GlaxoSmithKline R&D, Heidelberg, Germany
| | - Stephen E. Leonard
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Panqing He
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Jackson C. Jones
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Mallory M. Krahn
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Jack S. Mo
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Kartheek S. Dasari
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Anna M. W. Fox
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Markus Boesche
- Cellzome GmbH, Molecular Discovery Research, GlaxoSmithKline R&D, Heidelberg, Germany
| | - Majida El Bakkouri
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Kasey L. Rivas
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Didier Leroy
- Drug Discovery, Medicines for Malaria Venture, Geneva, Switzerland
| | - Raymond Hui
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Gerard Drewes
- Cellzome GmbH, Molecular Discovery Research, GlaxoSmithKline R&D, Heidelberg, Germany
| | - Dustin J. Maly
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Wesley C. Van Voorhis
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Kayode K. Ojo
- Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| |
Collapse
|
28
|
Ma S, Zhou S, Lin W, Zhang R, Wu W, Zheng K. Study of novel pyrazolo[3,4-d]pyrimidine derivatives as selective TgCDPK1 inhibitors: molecular docking, structure-based 3D-QSAR and molecular dynamics simulation. RSC Adv 2016. [DOI: 10.1039/c6ra20277b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We explored the structural features that have an impact on TgCDPK1 activity and TgCDPK1/Src selectivity by multi-computational methods with different statistical models.
Collapse
Affiliation(s)
- Shaojie Ma
- Department of Physical Chemistry
- College of Pharmacy
- Guangdong Pharmaceutical University
- Guangzhou 510006
- PR China
| | - Shengfu Zhou
- Department of Physical Chemistry
- College of Pharmacy
- Guangdong Pharmaceutical University
- Guangzhou 510006
- PR China
| | - Weicong Lin
- Department of Physical Chemistry
- College of Pharmacy
- Guangdong Pharmaceutical University
- Guangzhou 510006
- PR China
| | - Rong Zhang
- Department of Physical Chemistry
- College of Pharmacy
- Guangdong Pharmaceutical University
- Guangzhou 510006
- PR China
| | - Wenjuan Wu
- Department of Physical Chemistry
- College of Pharmacy
- Guangdong Pharmaceutical University
- Guangzhou 510006
- PR China
| | - Kangcheng Zheng
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
- Guangzhou 510275
- PR China
| |
Collapse
|
29
|
Huang W, Ojo KK, Zhang Z, Rivas K, Vidadala RSR, Scheele S, DeRocher AE, Choi R, Hulverson MA, Barrett LK, Bruzual I, Siddaramaiah LK, Kerchner KM, Kurnick MD, Freiberg GM, Kempf D, Hol WGJ, Merritt EA, Neckermann G, de Hostos EL, Isoherranen N, Maly DJ, Parsons M, Doggett JS, Van Voorhis WC, Fan E. SAR Studies of 5-Aminopyrazole-4-carboxamide Analogues as Potent and Selective Inhibitors of Toxoplasma gondii CDPK1. ACS Med Chem Lett 2015; 6:1184-1189. [PMID: 26693272 PMCID: PMC4677665 DOI: 10.1021/acsmedchemlett.5b00319] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/22/2015] [Indexed: 12/19/2022] Open
Abstract
We previously discovered compounds based on a 5-aminopyrazole-4-carboxamide scaffold to be potent and selective inhibitors of CDPK1 from T. gondii. The current work, through structure-activity relationship studies, led to the discovery of compounds (34 and 35) with improved characteristics over the starting inhibitor 1 in terms of solubility, plasma exposure after oral administration in mice, or efficacy on parasite growth inhibition. Compounds 34 and 35 were further demonstrated to be more effective than 1 in a mouse infection model and markedly reduced the amount of T. gondii in the brain, spleen, and peritoneal fluid, and 35 given at 20 mg/kg eliminated T. gondii from the peritoneal fluid.
Collapse
Affiliation(s)
- Wenlin Huang
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Kayode K. Ojo
- Department
of Medicine, Division of Allergy and Infectious Diseases, and the
Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, Washington 98109, United States
| | - Zhongsheng Zhang
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Kasey Rivas
- Department
of Medicine, Division of Allergy and Infectious Diseases, and the
Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, Washington 98109, United States
| | | | - Suzanne Scheele
- Center for Infectious Disease Research (formerly Seattle Biomedical
Research Institute), Seattle, Washington 98109, United States
| | - Amy E. DeRocher
- Center for Infectious Disease Research (formerly Seattle Biomedical
Research Institute), Seattle, Washington 98109, United States
| | - Ryan Choi
- Department
of Medicine, Division of Allergy and Infectious Diseases, and the
Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, Washington 98109, United States
| | - Matthew A. Hulverson
- Department
of Medicine, Division of Allergy and Infectious Diseases, and the
Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, Washington 98109, United States
| | - Lynn K. Barrett
- Department
of Medicine, Division of Allergy and Infectious Diseases, and the
Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, Washington 98109, United States
| | - Igor Bruzual
- Portland VA Medical Center, Portland, Oregon 97239, United States
| | | | - Keshia M. Kerchner
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | | | | | - Dale Kempf
- AbbVie, N. Chicago, Illinois 60064, United States
| | - Wim G. J. Hol
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Ethan A. Merritt
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | | | | | - Nina Isoherranen
- Department
of Pharmaceutics, University of Washington, Seattle, Washington 98195, United States
| | - Dustin J. Maly
- Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Marilyn Parsons
- Center for Infectious Disease Research (formerly Seattle Biomedical
Research Institute), Seattle, Washington 98109, United States
- Department
of Global Health, University of Washington, Seattle, Washington 98195, United States
| | - J. Stone Doggett
- Portland VA Medical Center, Portland, Oregon 97239, United States
| | - Wesley C. Van Voorhis
- Department
of Medicine, Division of Allergy and Infectious Diseases, and the
Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, Washington 98109, United States
- Department
of Global Health, University of Washington, Seattle, Washington 98195, United States
| | - Erkang Fan
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| |
Collapse
|
30
|
Inhibition of Calcium-Dependent Protein Kinase 1 (CDPK1) In Vitro by Pyrazolopyrimidine Derivatives Does Not Correlate with Sensitivity of Cryptosporidium parvum Growth in Cell Culture. Antimicrob Agents Chemother 2015; 60:570-9. [PMID: 26552986 DOI: 10.1128/aac.01915-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 11/06/2015] [Indexed: 11/20/2022] Open
Abstract
Cryptosporidiosis is a serious diarrheal disease in immunocompromised patients and malnourished children, and treatment is complicated by a lack of adequate drugs. Recent studies suggest that the natural occurrence of a small gatekeeper residue in serine threonine calcium-dependent protein kinase 1 (CDPK1) of Cryptosporidium parvum might be exploited to target this enzyme and block parasite growth. Here were explored the potency with which a series of pyrazolopyrimidine analogs, which are selective for small gatekeeper kinases, inhibit C. parvum CDPK1 and block C. parvum growth in tissue culture in vitro. Although these compounds potently inhibited kinase activity in vitro, most had no effect on parasite growth. Moreover, among those that were active against parasite growth, there was a very poor correlation with their 50% inhibitory concentrations against the enzyme. Active compounds also had no effect on cell invasion, unlike the situation in Toxoplasma gondii, where these compounds block CDPK1, prevent microneme secretion, and disrupt cell invasion. These findings suggest that CPDK1 is not essential for C. parvum host cell invasion or growth and therefore that it is not the optimal target for therapeutic intervention. Nonetheless, several inhibitors with low micromolar 50% effective concentrations were identified, and these may affect other essential targets in C. parvum that are worthy of further exploration.
Collapse
|
31
|
Pedroni MJ, Vidadala RSR, Choi R, Keyloun KR, Reid MC, Murphy RC, Barrett LK, Van Voorhis WC, Maly DJ, Ojo KK, Lau AOT. Bumped kinase inhibitor prohibits egression in Babesia bovis. Vet Parasitol 2015; 215:22-8. [PMID: 26790733 DOI: 10.1016/j.vetpar.2015.10.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 10/16/2015] [Accepted: 10/19/2015] [Indexed: 11/19/2022]
Abstract
Babesiosis is a global zoonotic disease acquired by the bite of a Babesia-infected Ixodes tick or through blood transfusion with clinical relevance affecting humans and animals. In this study, we evaluated a series of small molecule compounds that have previously been shown to target specific apicomplexan enzymes in Plasmodium, Toxoplasma and Cryptosporidium. The compounds, bumped kinase inhibitors (BKIs), have strong therapeutic potential targeting apicomplexa-specific calcium dependent protein kinases (CDPKs). We investigated if BKIs also show inhibitory activities against piroplasms such as Babesia. Using a subset of BKIs that have promising inhibitory activities to Plasmodium and Toxoplasma, we determined that their actions ranged from 100% and no inhibition against Babesia bovis blood stages. One specific BKI, RM-1-152, showed complete inhibition against B. bovis within 48h and was the only BKI that showed noticeable phenotypic changes to the parasites. Focusing our study on this BKI, we further demonstrated that RM-1-152 has Babesia-static activity and involves the prohibition of merozoite egress while replication and re-invasion of host cells are unaffected. The distinct, abnormal phenotype induced by RM-1-152 suggests that this BKI can be used to investigate less studied cellular processes such as egression in piroplasm.
Collapse
Affiliation(s)
- Monica J Pedroni
- Department of Veterinary Microbiology & Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | | | - Ryan Choi
- Department of Medicine, Division of Allergy and Infectious Diseases, Center of Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, USA
| | - Katelyn R Keyloun
- Department of Medicine, Division of Allergy and Infectious Diseases, Center of Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, USA; Department of Pharmacy, University of Washington, Seattle, WA, USA
| | - Molly C Reid
- Department of Medicine, Division of Allergy and Infectious Diseases, Center of Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, USA
| | - Ryan C Murphy
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Lynn K Barrett
- Department of Medicine, Division of Allergy and Infectious Diseases, Center of Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, USA
| | - Wesley C Van Voorhis
- Department of Medicine, Division of Allergy and Infectious Diseases, Center of Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, USA
| | - Dustin J Maly
- Department of Chemistry, University of Washington, Seattle, WA, USA; Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Kayode K Ojo
- Department of Medicine, Division of Allergy and Infectious Diseases, Center of Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, USA.
| | - Audrey O T Lau
- Department of Veterinary Microbiology & Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA.
| |
Collapse
|
32
|
Moine E, Dimier-Poisson I, Enguehard-Gueiffier C, Logé C, Pénichon M, Moiré N, Delehouzé C, Foll-Josselin B, Ruchaud S, Bach S, Gueiffier A, Debierre-Grockiego F, Denevault-Sabourin C. Development of new highly potent imidazo[1,2-b]pyridazines targeting Toxoplasma gondii calcium-dependent protein kinase 1. Eur J Med Chem 2015; 105:80-105. [PMID: 26479029 DOI: 10.1016/j.ejmech.2015.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/02/2015] [Accepted: 10/03/2015] [Indexed: 11/16/2022]
Abstract
Using a structure-based design approach, we have developed a new series of imidazo[1,2-b]pyridazines, targeting the calcium-dependent protein kinase-1 (CDPK1) from Toxoplasma gondii. Twenty derivatives were thus synthesized. Structure-activity relationships and docking studies confirmed the binding mode of these inhibitors within the ATP binding pocket of TgCDPK1. Two lead compounds (16a and 16f) were then identified, which were able to block TgCDPK1 enzymatic activity at low nanomolar concentrations, with a good selectivity profile against a panel of mammalian kinases. The potential of these inhibitors was confirmed in vitro on T. gondii growth, with EC50 values of 100 nM and 70 nM, respectively. These best candidates also displayed low toxicity to mammalian cells and were selected for further in vivo investigations on murine model of acute toxoplasmosis.
Collapse
Affiliation(s)
- Espérance Moine
- Université François-Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France; INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France
| | - Isabelle Dimier-Poisson
- Université François-Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France; INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France
| | - Cécile Enguehard-Gueiffier
- Université François-Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France; INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France
| | - Cédric Logé
- Université de Nantes, Nantes Atlantique Universités, Laboratoire de Chimie Thérapeutique, Cibles et Médicaments des Infections et du Cancer, IICiMed-EA 1155, UFR de Sciences Pharmaceutiques et Biologiques, F-44035 Nantes, France
| | - Mélanie Pénichon
- Université François-Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France; INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France
| | - Nathalie Moiré
- Université François-Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France; INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France
| | - Claire Delehouzé
- USR3151 CNRS/UPMC, Plate-forme de Criblage KISSf (Kinase Inhibitor Specialized Screening Facility), Station Biologique de Roscoff, F-29688 Roscoff, France
| | - Béatrice Foll-Josselin
- USR3151 CNRS/UPMC, Plate-forme de Criblage KISSf (Kinase Inhibitor Specialized Screening Facility), Station Biologique de Roscoff, F-29688 Roscoff, France
| | - Sandrine Ruchaud
- USR3151 CNRS/UPMC, Plate-forme de Criblage KISSf (Kinase Inhibitor Specialized Screening Facility), Station Biologique de Roscoff, F-29688 Roscoff, France
| | - Stéphane Bach
- USR3151 CNRS/UPMC, Plate-forme de Criblage KISSf (Kinase Inhibitor Specialized Screening Facility), Station Biologique de Roscoff, F-29688 Roscoff, France
| | - Alain Gueiffier
- Université François-Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France; INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France
| | - Françoise Debierre-Grockiego
- Université François-Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France; INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France
| | - Caroline Denevault-Sabourin
- Université François-Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France; INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
| |
Collapse
|
33
|
In Vitro and In Vivo Effects of the Bumped Kinase Inhibitor 1294 in the Related Cyst-Forming Apicomplexans Toxoplasma gondii and Neospora caninum. Antimicrob Agents Chemother 2015; 59:6361-74. [PMID: 26248379 DOI: 10.1128/aac.01236-15] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 07/22/2015] [Indexed: 12/11/2022] Open
Abstract
We report on the in vitro effects of the bumped kinase inhibitor 1294 (BKI-1294) in cultures of virulent Neospora caninum isolates Nc-Liverpool (Nc-Liv) and Nc-Spain7 and in two strains of Toxoplasma gondii (RH and ME49), all grown in human foreskin fibroblasts. In these parasites, BKI-1294 acted with 50% inhibitory concentrations (IC50s) ranging from 20 nM (T. gondii RH) to 360 nM (N. caninum Nc-Liv), and exposure of intracellular stages to 1294 led to the nondisjunction of newly formed tachyzoites, resulting in the formation of multinucleated complexes similar to complexes previously observed in BKI-1294-treated N. caninum beta-galactosidase-expressing parasites. However, such complexes were not seen in a transgenic T. gondii strain that expressed CDPK1 harboring a mutation (G to M) in the gatekeeper residue. In T. gondii ME49 and N. caninum Nc-Liv, exposure of cultures to BKI-1294 resulted in the elevated expression of mRNA coding for the bradyzoite marker BAG1. Unlike in bradyzoites, SAG1 expression was not repressed. Immunofluorescence also showed that these multinucleated complexes expressed SAG1 and BAG1 and the monoclonal antibody CC2, which binds to a yet unidentified bradyzoite antigen, also exhibited increased labeling. In a pregnant mouse model, BKI-1294 efficiently inhibited vertical transmission in BALB/c mice experimentally infected with one of the two virulent isolates Nc-Liv or Nc-Spain7, demonstrating proof of concept that this compound protected offspring from vertical transmission and disease. The observed deregulated antigen expression effect may enhance the immune response during BKI-1294 therapy and will be the subject of future studies.
Collapse
|
34
|
Hui R, El Bakkouri M, Sibley LD. Designing selective inhibitors for calcium-dependent protein kinases in apicomplexans. Trends Pharmacol Sci 2015; 36:452-60. [PMID: 26002073 DOI: 10.1016/j.tips.2015.04.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/17/2015] [Accepted: 04/23/2015] [Indexed: 12/21/2022]
Abstract
Apicomplexan parasites cause some of the most severe human diseases, including malaria (caused by Plasmodium), toxoplasmosis, and cryptosporidiosis. Treatments are limited by the lack of effective drugs and development of resistance to available agents. By exploiting novel features of protein kinases in these parasites, it may be possible to develop new treatments. We summarize here recent advances in identifying small molecule inhibitors against a novel family of plant-like, calcium-dependent kinases that are uniquely expanded in apicomplexan parasites. Analysis of the 3D structure, activation mechanism, and sensitivity to small molecules had identified several attractive chemical scaffolds that are potent and selective inhibitors of these parasite kinases. Further optimization of these leads may yield promising new drugs for treatment of these parasitic infections.
Collapse
Affiliation(s)
- Raymond Hui
- Structural Genomics Consortium, University of Toronto, MaRS South Tower, 101 College St, Toronto, ON, M5G 1L7, Canada; Toronto General Hospital Research Institute, 610 University Avenue, Toronto, ON, M5G 2M9, Canada
| | - Majida El Bakkouri
- Structural Genomics Consortium, University of Toronto, MaRS South Tower, 101 College St, Toronto, ON, M5G 1L7, Canada
| | - L David Sibley
- Department of Molecular Microbiology, 660 S. Euclid Ave., Washington University School of Medicine, St Louis, MO 63130, USA.
| |
Collapse
|
35
|
Assessing protein kinase target similarity: Comparing sequence, structure, and cheminformatics approaches. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1605-16. [PMID: 26001898 DOI: 10.1016/j.bbapap.2015.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 05/08/2015] [Accepted: 05/11/2015] [Indexed: 11/22/2022]
Abstract
In just over two decades, structure based protein kinase inhibitor discovery has grown from trial and error approaches, using individual target structures, to structure and data driven approaches that may aim to optimize inhibition properties across several targets. This is increasingly enabled by the growing availability of potent compounds and kinome-wide binding data. Assessing the prospects for adapting known compounds to new therapeutic uses is thus a key priority for current drug discovery efforts. Tools that can successfully link the diverse information regarding target sequence, structure, and ligand binding properties now accompany a transformation of protein kinase inhibitor research, away from single, block-buster drug models, and toward "personalized medicine" with niche applications and highly specialized research groups. Major hurdles for the transformation to data driven drug discovery include mismatches in data types, and disparities of methods and molecules used; at the core remains the problem that ligand binding energies cannot be predicted precisely from individual structures. However, there is a growing body of experimental data for increasingly successful focussing of efforts: focussed chemical libraries, drug repurposing, polypharmacological design, to name a few. Protein kinase target similarity is easily quantified by sequence, and its relevance to ligand design includes broad classification by key binding sites, evaluation of resistance mutations, and the use of surrogate proteins. Although structural evaluation offers more information, the flexibility of protein kinases, and differences between the crystal and physiological environments may make the use of crystal structures misleading when structures are considered individually. Cheminformatics may enable the "calibration" of sequence and crystal structure information, with statistical methods able to identify key correlates to activity but also here, "the devil is in the details." Examples from specific repurposing and polypharmacology applications illustrate these points. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases.
Collapse
|
36
|
Hol WGJ. Three-dimensional structures in the design of therapeutics targeting parasitic protozoa: reflections on the past, present and future. Acta Crystallogr F Struct Biol Commun 2015; 71:485-99. [PMID: 25945701 PMCID: PMC4427157 DOI: 10.1107/s2053230x15004987] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 03/11/2015] [Indexed: 11/10/2022] Open
Abstract
Parasitic protozoa cause a range of diseases which threaten billions of human beings. They are responsible for tremendous mortality and morbidity in the least-developed areas of the world. Presented here is an overview of the evolution over the last three to four decades of structure-guided design of inhibitors, leads and drug candidates aiming at targets from parasitic protozoa. Target selection is a crucial and multi-faceted aspect of structure-guided drug design. The major impact of advances in molecular biology, genome sequencing and high-throughput screening is touched upon. The most advanced crystallographic techniques, including XFEL, have already been applied to structure determinations of drug targets from parasitic protozoa. Even cryo-electron microscopy is contributing to our understanding of the mode of binding of inhibitors to parasite ribosomes. A number of projects have been selected to illustrate how structural information has assisted in arriving at promising compounds that are currently being evaluated by pharmacological, pharmacodynamic and safety tests to assess their suitability as pharmaceutical agents. Structure-guided approaches are also applied to incorporate properties into compounds such that they are less likely to become the victim of resistance mechanisms. A great increase in the number of novel antiparasitic compounds will be needed in the future. These should then be combined into various multi-compound therapeutics to circumvent the diverse resistance mechanisms that render single-compound, or even multi-compound, drugs ineffective. The future should also see (i) an increase in the number of projects with a tight integration of structural biology, medicinal chemistry, parasitology and pharmaceutical sciences; (ii) the education of more `medicinal structural biologists' who are familiar with the properties that compounds need to have for a high probability of success in the later steps of the drug-development process; and (iii) the expansion of drug-development capabilities in middle- and low-income countries.
Collapse
Affiliation(s)
- Wim G. J. Hol
- Department of Biochemistry and Biomolecular Structure Center, University of Washington, Seattle, WA 98195, USA
| |
Collapse
|
37
|
Hines SA, Ramsay JD, Kappmeyer LS, Lau AO, Ojo KK, Van Voorhis WC, Knowles DP, Mealey RH. Theileria equi isolates vary in susceptibility to imidocarb dipropionate but demonstrate uniform in vitro susceptibility to a bumped kinase inhibitor. Parasit Vectors 2015; 8:33. [PMID: 25600252 PMCID: PMC4311422 DOI: 10.1186/s13071-014-0611-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/17/2014] [Indexed: 11/29/2022] Open
Abstract
Background The apicomplexan hemoparasite Theileria equi is a causative agent of equine piroplasmosis, eradicated from the United States in 1988. However, recent outbreaks have sparked renewed interest in treatment options for infected horses. Imidocarb dipropionate is the current drug of choice, however variation in clinical response to therapy has been observed. Methods We quantified the in vitro susceptibility of two T. equi isolates and a lab generated variant to both imidocarb dipropionate and a bumped kinase inhibitor compound 1294. We also evaluated the capacity of in vitro imidocarb dipropionate exposure to decrease susceptibility to that drug. The efficacy of imidocarb dipropionate for clearing infection in four T. equi infected ponies was also assessed. Results We observed an almost four-fold difference in imidocarb dipropionate susceptibility between two distinct isolates of T. equi. Four ponies infected with the less susceptible USDA Florida strain failed to clear the parasite despite two rounds of treatment. Importantly, a further 15-fold decrease in susceptibility was produced in this strain by continuous in vitro imidocarb dipropionate exposure. Despite a demonstrated difference in imidocarb dipropionate susceptibility, there was no difference in the susceptibility of two T. equi isolates to bumped kinase inhibitor 1294. Conclusions The observed variation in imidocarb dipropionate susceptibility, further reduction in susceptibility caused by drug exposure in vitro, and failure to clear T. equi infection in vivo, raises concern for the emergence of drug resistance in clinical cases undergoing treatment. Bumped kinase inhibitors may be effective as alternative drugs for the treatment of resistant T. equi parasites.
Collapse
Affiliation(s)
- Siddra A Hines
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164-7040, USA.
| | - Joshua D Ramsay
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164-7040, USA.
| | - Lowell S Kappmeyer
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164-7040, USA. .,Animal Disease Research Unit, Agricultural Research Service, USDA, Pullman, WA, 99164-6630, USA.
| | - Audrey Ot Lau
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164-7040, USA.
| | - Kayode K Ojo
- Division of Allergy and Infectious Diseases and Center for Emerging and Re-emerging Infectious Diseases, School of Medicine, University of Washington, Seattle, WA, 98109-4766, USA.
| | - Wesley C Van Voorhis
- Division of Allergy and Infectious Diseases and Center for Emerging and Re-emerging Infectious Diseases, School of Medicine, University of Washington, Seattle, WA, 98109-4766, USA.
| | - Donald P Knowles
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164-7040, USA. .,Animal Disease Research Unit, Agricultural Research Service, USDA, Pullman, WA, 99164-6630, USA.
| | - Robert H Mealey
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164-7040, USA.
| |
Collapse
|
38
|
Checkley W, White AC, Jaganath D, Arrowood MJ, Chalmers RM, Chen XM, Fayer R, Griffiths JK, Guerrant RL, Hedstrom L, Huston CD, Kotloff KL, Kang G, Mead JR, Miller M, Petri WA, Priest JW, Roos DS, Striepen B, Thompson RCA, Ward HD, Van Voorhis WA, Xiao L, Zhu G, Houpt ER. A review of the global burden, novel diagnostics, therapeutics, and vaccine targets for cryptosporidium. THE LANCET. INFECTIOUS DISEASES 2014; 15:85-94. [PMID: 25278220 DOI: 10.1016/s1473-3099(14)70772-8] [Citation(s) in RCA: 605] [Impact Index Per Article: 60.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cryptosporidium spp are well recognised as causes of diarrhoeal disease during waterborne epidemics and in immunocompromised hosts. Studies have also drawn attention to an underestimated global burden and suggest major gaps in optimum diagnosis, treatment, and immunisation. Cryptosporidiosis is increasingly identified as an important cause of morbidity and mortality worldwide. Studies in low-resource settings and high-income countries have confirmed the importance of cryptosporidium as a cause of diarrhoea and childhood malnutrition. Diagnostic tests for cryptosporidium infection are suboptimum, necessitating specialised tests that are often insensitive. Antigen-detection and PCR improve sensitivity, and multiplexed antigen detection and molecular assays are underused. Therapy has some effect in healthy hosts and no proven efficacy in patients with AIDS. Use of cryptosporidium genomes has helped to identify promising therapeutic targets, and drugs are in development, but methods to assess the efficacy in vitro and in animals are not well standardised. Partial immunity after exposure suggests the potential for successful vaccines, and several are in development; however, surrogates of protection are not well defined. Improved methods for propagation and genetic manipulation of the organism would be significant advances.
Collapse
Affiliation(s)
- William Checkley
- Program in Global Disease Epidemiology and Control, Department of International Health, Johns Hopkins University, Baltimore, MD, USA; Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
| | - A Clinton White
- Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX, USA
| | - Devan Jaganath
- Program in Global Disease Epidemiology and Control, Department of International Health, Johns Hopkins University, Baltimore, MD, USA
| | | | - Rachel M Chalmers
- National Cryptosporidium Reference Unit, Public Health Wales, Swansea, UK
| | - Xian-Ming Chen
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE, USA
| | - Ronald Fayer
- Environmental Microbial Food Safety Laboratory, USDA, Beltsville, MD, USA
| | - Jeffrey K Griffiths
- Department of Public Health and Community Medicine, Tufts University, Boston, MA, USA
| | - Richard L Guerrant
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | - Lizbeth Hedstrom
- Department of Biology and Department of Chemistry, Brandeis University, Waltham, MA, USA
| | | | - Karen L Kotloff
- Division of Infectious Disease and Tropical Pediatrics, Department of Pediatrics, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Gagandeep Kang
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Jan R Mead
- Department of Pediatrics, Emory University, Atlanta, GA, USA; Atlanta VA Medical Center, Decatur, GA, USA
| | - Mark Miller
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - William A Petri
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | | | - David S Roos
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Boris Striepen
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - R C Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, Perth, WA, Australia
| | - Honorine D Ward
- Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center Boston, MA, USA
| | - Wesley A Van Voorhis
- Allergy and Infectious Diseases Division, Departments of Medicine, Global Health, and Microbiology, University of Washington, Seattle, WA, USA
| | - Lihua Xiao
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Guan Zhu
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - Eric R Houpt
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| |
Collapse
|
39
|
The gatekeeper residue and beyond: homologous calcium-dependent protein kinases as drug development targets for veterinarian Apicomplexa parasites. Parasitology 2014; 141:1499-1509. [PMID: 24927073 DOI: 10.1017/s0031182014000857] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Specific roles of individual CDPKs vary, but in general they mediate essential biological functions necessary for parasite survival. A comparative analysis of the structure-activity relationships (SAR) of Neospora caninum, Eimeria tenella and Babesia bovis calcium-dependent protein kinases (CDPKs) together with those of Plasmodium falciparum, Cryptosporidium parvum and Toxoplasma gondii was performed by screening against 333 bumped kinase inhibitors (BKIs). Structural modelling and experimental data revealed that residues other than the gatekeeper influence compound-protein interactions resulting in distinct sensitivity profiles. We subsequently defined potential amino-acid structural influences within the ATP-binding cavity for each orthologue necessary for consideration in the development of broad-spectrum apicomplexan CDPK inhibitors. Although the BKI library was developed for specific inhibition of glycine gatekeeper CDPKs combined with low inhibition of threonine gatekeeper human SRC kinase, some library compounds exhibit activity against serine- or threonine-containing CDPKs. Divergent BKI sensitivity of CDPK homologues could be explained on the basis of differences in the size and orientation of the hydrophobic pocket and specific variation at other amino-acid positions within the ATP-binding cavity. In particular, BbCDPK4 and PfCDPK1 are sensitive to a larger fraction of compounds than EtCDPK1 despite the presence of a threonine gatekeeper in all three CDPKs.
Collapse
|
40
|
Bumped kinase inhibitor 1294 treats established Toxoplasma gondii infection. Antimicrob Agents Chemother 2014; 58:3547-9. [PMID: 24687502 DOI: 10.1128/aac.01823-13] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Toxoplasma gondii is a unicellular parasite that causes severe brain and eye disease. Current drugs for T. gondii are limited by toxicity. Bumped kinase inhibitors (BKIs) selectively inhibit calcium-dependent protein kinases of the apicomplexan pathogens T. gondii, cryptosporidia, and plasmodia. A lead anti-Toxoplasma BKI, 1294, has been developed to be metabolically stable and orally bioavailable. Herein, we demonstrate the oral efficacy of 1294 against toxoplasmosis in vivo.
Collapse
|
41
|
Ojo KK, Reid MC, Kallur Siddaramaiah L, Müller J, Winzer P, Zhang Z, Keyloun KR, Vidadala RSR, Merritt EA, Hol WGJ, Maly DJ, Fan E, Van Voorhis WC, Hemphill A. Neospora caninum calcium-dependent protein kinase 1 is an effective drug target for neosporosis therapy. PLoS One 2014; 9:e92929. [PMID: 24681759 PMCID: PMC3969379 DOI: 10.1371/journal.pone.0092929] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 02/27/2014] [Indexed: 11/18/2022] Open
Abstract
Despite the enormous economic importance of Neospora caninum related veterinary diseases, the number of effective therapeutic agents is relatively small. Development of new therapeutic strategies to combat the economic impact of neosporosis remains an important scientific endeavor. This study demonstrates molecular, structural and phenotypic evidence that N. caninum calcium-dependent protein kinase 1 (NcCDPK1) is a promising molecular target for neosporosis drug development. Recombinant NcCDPK1 was expressed, purified and screened against a select group of bumped kinase inhibitors (BKIs) previously shown to have low IC50s against Toxoplasma gondii CDPK1 and T. gondii tachyzoites. NcCDPK1 was inhibited by low concentrations of BKIs. The three-dimensional structure of NcCDPK1 in complex with BKIs was studied crystallographically. The BKI-NcCDPK1 structures demonstrated the structural basis for potency and selectivity. Calcium-dependent conformational changes in solution as characterized by small-angle X-ray scattering are consistent with previous structures in low Calcium-state but different in the Calcium-bound active state than predicted by X-ray crystallography. BKIs effectively inhibited N. caninum tachyzoite proliferation in vitro. Electron microscopic analysis of N. caninum cells revealed ultra-structural changes in the presence of BKI compound 1294. BKI compound 1294 interfered with an early step in Neospora tachyzoite host cell invasion and egress. Prolonged incubation in the presence of 1294 interfered produced observable interference with viability and replication. Oral dosing of BKI compound 1294 at 50 mg/kg for 5 days in established murine neosporosis resulted in a 10-fold reduced cerebral parasite burden compared to untreated control. Further experiments are needed to determine the PK, optimal dosage, and duration for effective treatment in cattle and dogs, but these data demonstrate proof-of-concept for BKIs, and 1294 specifically, for therapy of bovine and canine neosporosis.
Collapse
Affiliation(s)
- Kayode K. Ojo
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail: (KKO); (WCVV); (AH)
| | - Molly C. Reid
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | | | - Joachim Müller
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Pablo Winzer
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Zhongsheng Zhang
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Katelyn R. Keyloun
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Rama Subba Rao Vidadala
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Ethan A. Merritt
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Wim G. J. Hol
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Dustin J. Maly
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Erkang Fan
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Wesley C. Van Voorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail: (KKO); (WCVV); (AH)
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Berne, Switzerland
- * E-mail: (KKO); (WCVV); (AH)
| |
Collapse
|
42
|
Vidadala RSR, Ojo KK, Johnson SM, Zhang Z, Leonard SE, Mitra A, Choi R, Reid MC, Keyloun KR, Fox AMW, Kennedy M, Silver-Brace T, Hume JCC, Kappe S, Verlinde CLMJ, Fan E, Merritt EA, Van Voorhis WC, Maly DJ. Development of potent and selective Plasmodium falciparum calcium-dependent protein kinase 4 (PfCDPK4) inhibitors that block the transmission of malaria to mosquitoes. Eur J Med Chem 2014; 74:562-73. [PMID: 24531197 DOI: 10.1016/j.ejmech.2013.12.048] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 12/23/2013] [Accepted: 12/26/2013] [Indexed: 12/16/2022]
Abstract
Malaria remains a major health concern for a large percentage of the world's population. While great strides have been made in reducing mortality due to malaria, new strategies and therapies are still needed. Therapies that are capable of blocking the transmission of Plasmodium parasites are particularly attractive, but only primaquine accomplishes this, and toxicity issues hamper its widespread use. In this study, we describe a series of pyrazolopyrimidine- and imidazopyrazine-based compounds that are potent inhibitors of PfCDPK4, which is a calcium-activated Plasmodium protein kinase that is essential for exflagellation of male gametocytes. Thus, PfCDPK4 is essential for the sexual development of Plasmodium parasites and their ability to infect mosquitoes. We demonstrate that two structural features in the ATP-binding site of PfCDPK4 can be exploited in order to obtain potent and selective inhibitors of this enzyme. Furthermore, we demonstrate that pyrazolopyrimidine-based inhibitors that are potent inhibitors of the in vitro activity of PfCDPK4 are also able to block Plasmodium falciparum exflagellation with no observable toxicity to human cells. This medicinal chemistry effort serves as a valuable starting point in the development of safe, transmission-blocking agents for the control of malaria.
Collapse
Affiliation(s)
| | - Kayode K Ojo
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Steven M Johnson
- Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA
| | - Zhongsheng Zhang
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Stephen E Leonard
- Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA
| | - Arinjay Mitra
- Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA
| | - Ryan Choi
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Molly C Reid
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Katelyn R Keyloun
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Anna M W Fox
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Mark Kennedy
- Seattle Biomedical Research Institute, Seattle, WA, USA
| | | | - Jen C C Hume
- Seattle Biomedical Research Institute, Seattle, WA, USA
| | - Stefan Kappe
- Seattle Biomedical Research Institute, Seattle, WA, USA; Departments of Global Health, University of Washington, Seattle, WA, USA
| | | | - Erkang Fan
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Ethan A Merritt
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Wesley C Van Voorhis
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA; Departments of Global Health, University of Washington, Seattle, WA, USA; Departments of Microbiology, University of Washington, Seattle, WA, USA.
| | - Dustin J Maly
- Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA.
| |
Collapse
|
43
|
Zhang Z, Ojo KK, Vidadala R, Huang W, Geiger JA, Scheele S, Choi R, Reid MC, Keyloun KR, Rivas K, Kallur Siddaramaiah L, Comess KM, Robinson KP, Merta PJ, Kifle L, Hol WGJ, Parsons M, Merritt EA, Maly DJ, Verlinde CLMJ, Van Voorhis WC, Fan E. Potent and selective inhibitors of CDPK1 from T. gondii and C. parvum based on a 5-aminopyrazole-4-carboxamide scaffold. ACS Med Chem Lett 2014; 5:40-44. [PMID: 24494061 DOI: 10.1021/ml400315s] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
5-Aminopyrazole-4-carboxamide was used as an alternative scaffold to substitute for the pyrazolopyrimidine of a known "bumped kinase inhibitor" to create selective inhibitors of calcium-dependent protein kinase-1 from both Toxoplasma gondii and Cryptosporidium parvum. Compounds with low nanomolar inhibitory potencies against the target enzymes were obtained. The most selective inhibitors also exhibited submicromolar activities in T. gondii cell proliferation assays and were shown to be non-toxic to mammalian cells.
Collapse
Affiliation(s)
- Zhongsheng Zhang
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Kayode K. Ojo
- Division
of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | - RamaSubbaRao Vidadala
- Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Wenlin Huang
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Jennifer A. Geiger
- Seattle Biomedical Research Institute, Seattle, Washington 98109, United States
| | - Suzanne Scheele
- Seattle Biomedical Research Institute, Seattle, Washington 98109, United States
| | - Ryan Choi
- Division
of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | - Molly C. Reid
- Division
of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | - Katelyn R. Keyloun
- Division
of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | - Kasey Rivas
- Division
of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | | | - Kenneth M. Comess
- High Throughput Biology, Global Pharmaceutical R&D, AbbVie, North Chicago, Illinois 60064, United States
| | - Kenneth P. Robinson
- High Throughput Biology, Global Pharmaceutical R&D, AbbVie, North Chicago, Illinois 60064, United States
| | - Philip J. Merta
- High Throughput Biology, Global Pharmaceutical R&D, AbbVie, North Chicago, Illinois 60064, United States
| | - Lemma Kifle
- High Throughput Biology, Global Pharmaceutical R&D, AbbVie, North Chicago, Illinois 60064, United States
| | - Wim G. J. Hol
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Marilyn Parsons
- Seattle Biomedical Research Institute, Seattle, Washington 98109, United States
| | - Ethan A. Merritt
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Dustin J. Maly
- Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | | | - Wesley C. Van Voorhis
- Division
of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | - Erkang Fan
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| |
Collapse
|
44
|
Devine SM, Lim SS, Chandrashekaran IR, MacRaild CA, Drew DR, Debono CO, Lam R, Anders RF, Beeson JG, Scanlon MJ, Scammells PJ, Norton RS. A critical evaluation of pyrrolo[2,3-d]pyrimidine-4-amines as Plasmodium falciparum apical membrane antigen 1 (AMA1) inhibitors. MEDCHEMCOMM 2014. [DOI: 10.1039/c4md00090k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pyrrolo[2,3-d]pyrimidines are low affinity AMA1 binders that are also prone to aggregation.
Collapse
Affiliation(s)
- Shane M. Devine
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville, Australia
| | - San Sui Lim
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville, Australia
| | - Indu R. Chandrashekaran
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville, Australia
| | - Christopher A. MacRaild
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville, Australia
| | - Damien R. Drew
- Centre for Biomedical Research
- Burnet Institute
- Melbourne, Australia
| | - Cael O. Debono
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville, Australia
| | - Raymond Lam
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville, Australia
| | - Robin F. Anders
- Department of Biochemistry
- La Trobe University
- Melbourne, Australia
| | - James G. Beeson
- Centre for Biomedical Research
- Burnet Institute
- Melbourne, Australia
| | - Martin J. Scanlon
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville, Australia
- Centre of Excellence for Coherent X-Ray Science
| | - Peter J. Scammells
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville, Australia
| | - Raymond S. Norton
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville, Australia
| |
Collapse
|
45
|
Castellanos-Gonzalez A, White AC, Ojo KK, Vidadala RSR, Zhang Z, Reid MC, Fox AMW, Keyloun KR, Rivas K, Irani A, Dann SM, Fan E, Maly DJ, Van Voorhis WC. A novel calcium-dependent protein kinase inhibitor as a lead compound for treating cryptosporidiosis. J Infect Dis 2013; 208:1342-8. [PMID: 23878324 DOI: 10.1093/infdis/jit327] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cryptosporidium parasites infect intestinal cells, causing cryptosporidiosis. Despite its high morbidity and association with stunting in the developing world, current therapies for cryptosporidiosis have limited efficacy. Calcium-dependent protein kinases (CDPKs) are essential enzymes in the biology of protozoan parasites. CDPK1 was cloned from the genome of Cryptosporidium parvum, and potent and specific inhibitors have been developed based on structural studies. In this study, we evaluated the anti-Cryptosporidium activity of a novel CDPK1 inhibitor, 1294, and demonstrated that 1294 significantly reduces parasite infection in vitro, with a half maximal effective concentration of 100 nM. Pharmacokinetic studies revealed that 1294 is well absorbed, with a half-life supporting daily administration. Oral therapy with 1294 eliminated Cryptosporidium parasites from 6 of 7 infected severe combined immunodeficiency-beige mice, and the parasites did not recur in these immunosuppressed mice. Mice treated with 1294 had less epithelial damage, corresponding to less apoptosis. Thus, 1294 is an important lead for the development of drugs for treatment of cryptosporidiosis.
Collapse
|
46
|
Sugi T, Kobayashi K, Takemae H, Gong H, Ishiwa A, Murakoshi F, Recuenco FC, Iwanaga T, Horimoto T, Akashi H, Kato K. Identification of mutations in TgMAPK1 of Toxoplasma gondii conferring resistance to 1NM-PP1. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2013; 3:93-101. [PMID: 24533298 PMCID: PMC3862444 DOI: 10.1016/j.ijpddr.2013.04.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1NM-PP1 resistant clones were established from chemically random mutated parasites. Resistant clones had a mutation in TgMAPK1. Resistant clones had less susceptibility to 1NM-PP1 at cell division. The mutation was not found at the gatekeeper residue.
Toxoplasma gondii is an important food and waterborne pathogen that causes severe disease in immunocompromised patients. Bumped kinase inhibitors (BKIs) have an antiparasitic effect on T. gondii tachyzoite growth by targeting T. gondii calmodulin-domain protein kinase 1 (TgCDPK1). To identify mutations that confer resistance to BKIs, chemical mutagenesis was performed, followed by selection in media containing either 250 or 1000 nM 1NM-PP1. Whole-genome sequence analysis of resistant clones revealed single nucleotide mutations in T. gondii mitogen-activated protein kinase 1 (TgMAPK1) at amino acids 162 (L162Q) and 171 (I171N). Plasmid constructs having the TgMAPK1 L162Q mutant sequence successfully replaced native TgMAPK1 genome locus in the presence of 1000 nM 1NM-PP1. The inhibitory effect of 1NM-PP1 on cell division observed in the parent clone was decreased in 1NM-PP1-resistant clones; however, effects on parasite invasion and calcium-induced egress were similar in both parent and resistant clones. A plasmid construct expressing the full length TgMAPK1 splicing isoform with L162Q mutation successfully complemented TgMAPK1 function in the pressure of 250 nM 1NM-PP1 in plaque assay. 1NM-PP1-resistant clones showed resistance to other BKIs (3MB-PP1 and 3BrB-PP1) with different levels. Here we identify TgMAPK1 as a novel target for 1NM-PP1 activity. This inhibitory effect is mediated through inhibition of tachyzoite cell division, and can be overcome through mutations at multiple residues in TgMAPK1.
Collapse
Affiliation(s)
- Tatsuki Sugi
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kyousuke Kobayashi
- Department of Host-Parasite Interaction, Division of Microbiology and Immunology, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Hitoshi Takemae
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Haiyan Gong
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Akiko Ishiwa
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Fumi Murakoshi
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Frances C Recuenco
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tatsuya Iwanaga
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Taisuke Horimoto
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiroomi Akashi
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kentaro Kato
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan ; National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| |
Collapse
|
47
|
Protein kinases of Toxoplasma gondii: functions and drug targets. Parasitol Res 2013; 112:2121-9. [DOI: 10.1007/s00436-013-3451-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 04/10/2013] [Indexed: 10/26/2022]
|
48
|
Lourido S, Zhang C, Lopez MS, Tang K, Barks J, Wang Q, Wildman SA, Shokat KM, Sibley LD. Optimizing small molecule inhibitors of calcium-dependent protein kinase 1 to prevent infection by Toxoplasma gondii. J Med Chem 2013; 56:3068-77. [PMID: 23470217 DOI: 10.1021/jm4001314] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Toxoplasma gondii is sensitive to bulky pyrazolo [3,4-d] pyrimidine (PP) inhibitors due to the presence of a Gly gatekeeper in the essential calcium dependent protein kinase 1 (CDPK1). Here we synthesized a number of new derivatives of 3-methyl-benzyl-PP (3-MB-PP, or 1). The potency of PP analogues in inhibiting CDPK1 enzyme activity in vitro (low nM IC(50) values) and blocking parasite growth in host cell monolayers in vivo (low μM EC(50) values) were highly correlated and occurred in a CDPK1-specific manner. Chemical modification of the PP scaffold to increase half-life in the presence of microsomes in vitro led to identification of compounds with enhanced stability while retaining activity. Several of these more potent compounds were able to prevent lethal infection with T. gondii in the mouse model. Collectively, the strategies outlined here provide a route for development of more effective compounds for treatment of toxoplasmosis and perhaps related parasitic diseases.
Collapse
Affiliation(s)
- Sebastian Lourido
- Department of Molecular Microbiology, Washington University School of Medicine, 660 South Euclid Avenue, St Louis Missouri 63110, United States
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Müller J, Hemphill A. New approaches for the identification of drug targets in protozoan parasites. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 301:359-401. [PMID: 23317822 DOI: 10.1016/b978-0-12-407704-1.00007-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Antiparasitic chemotherapy is an important issue for drug development. Traditionally, novel compounds with antiprotozoan activities have been identified by screening of compound libraries in high-throughput systems. More recently developed approaches employ target-based drug design supported by genomics and proteomics of protozoan parasites. In this chapter, the drug targets in protozoan parasites are reviewed. The gene-expression machinery has been among the first targets for antiparasitic drugs and is still under investigation as a target for novel compounds. Other targets include cytoskeletal proteins, proteins involved in intracellular signaling, membranes, and enzymes participating in intermediary metabolism. In apicomplexan parasites, the apicoplast is a suitable target for established and novel drugs. Some drugs act on multiple subcellular targets. Drugs with nitro groups generate free radicals under anaerobic growth conditions, and drugs with peroxide groups generate radicals under aerobic growth conditions, both affecting multiple cellular pathways. Mefloquine and thiazolides are presented as examples for antiprotozoan compounds with multiple (side) effects. The classic approach of drug discovery employing high-throughput physiological screenings followed by identification of drug targets has yielded the mainstream of current antiprotozoal drugs. Target-based drug design supported by genomics and proteomics of protozoan parasites has not produced any antiparasitic drug so far. The reason for this is discussed and a synthesis of both methods is proposed.
Collapse
Affiliation(s)
- Joachim Müller
- Institute of Parasitology, University of Berne, Berne, Switzerland.
| | | |
Collapse
|
50
|
Rotella DP. Recent results in protein kinase inhibition for tropical diseases. Bioorg Med Chem Lett 2012; 22:6788-93. [DOI: 10.1016/j.bmcl.2012.09.044] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 09/11/2012] [Accepted: 09/14/2012] [Indexed: 11/30/2022]
|