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Jiang Z, Silva EB, Liu C, Fajtová P, Liu LJ, El-Sakkary N, Skinner DE, Syed A, Wang SC, Caffrey CR, O’Donoghue AJ. Development of subunit selective proteasome substrates for Schistosoma species. bioRxiv 2024:2024.02.13.580161. [PMID: 38405969 PMCID: PMC10888821 DOI: 10.1101/2024.02.13.580161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Schistosomiasis, or bilharzia, is a neglected tropical disease caused by Schistosoma spp. blood flukes that infects over 200 million people worldwide. Just one partially effective drug is available, and new drugs and drug targets would be welcome. The 20S proteasome is a validated drug target for many parasitic infections, including those caused by Plasmodium and Leishmania. We previously showed that anticancer proteasome inhibitors that act through the Schistosoma mansoni 20S proteasome (Sm20S) kill the parasite in vitro. To advance these initial findings, we employed Multiplex Substrate Profiling by Mass Spectrometry (MSP-MS) to define the substrate cleavage specificities of the three catalytic β subunits of purified Sm20S. The profiles in turn were used to design and synthesize subunit-specific optimized substrates that performed two to eight fold better than the equivalent substrates used to measure the activity of the constitutive human proteasome (c20S). These specific substrates also eliminated the need to purify Sm20S from parasite extracts - a single step enrichment was sufficient to accurately measure substrate hydrolysis and its inhibition with proteasome inhibitors. Finally, we show that the substrate and inhibition profiles for the 20S proteasome from the three medically important schistosome species are similar, suggesting that data arising from an inhibitor development campaign that focuses on Sm20S can be extrapolated to the other two targets with consequent time and cost savings.
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Affiliation(s)
- Zhenze Jiang
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | | | - Chenxi Liu
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | - Pavla Fajtová
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | - Lawrence J. Liu
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | - Nelly El-Sakkary
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | - Danielle E. Skinner
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | - Ali Syed
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | - Steven C Wang
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | - Anthony J. O’Donoghue
- Center for Discovery and Innovation in Parasitic Disease, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
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Yeh YT, Skinner DE, Criado-Hidalgo E, Chen NS, Garcia-De Herreros A, El-Sakkary N, Liu L, Zhang S, Kandasamy A, Chien S, Lasheras JC, del Álamo JC, Caffrey CR. Biomechanical interactions of Schistosoma mansoni eggs with vascular endothelial cells facilitate egg extravasation. PLoS Pathog 2022; 18:e1010309. [PMID: 35316298 PMCID: PMC8939816 DOI: 10.1371/journal.ppat.1010309] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 01/26/2022] [Indexed: 12/03/2022] Open
Abstract
The eggs of the parasitic blood fluke, Schistosoma, are the main drivers of the chronic pathologies associated with schistosomiasis, a disease of poverty afflicting approximately 220 million people worldwide. Eggs laid by Schistosoma mansoni in the bloodstream of the host are encapsulated by vascular endothelial cells (VECs), the first step in the migration of the egg from the blood stream into the lumen of the gut and eventual exit from the body. The biomechanics associated with encapsulation and extravasation of the egg are poorly understood. We demonstrate that S. mansoni eggs induce VECs to form two types of membrane extensions during encapsulation; filopodia that probe eggshell surfaces and intercellular nanotubes that presumably facilitate VEC communication. Encapsulation efficiency, the number of filopodia and intercellular nanotubes, and the length of these structures depend on the egg’s vitality and, to a lesser degree, its maturation state. During encapsulation, live eggs induce VEC contractility and membranous structures formation in a Rho/ROCK pathway-dependent manner. Using elastic hydrogels embedded with fluorescent microbeads as substrates to culture VECs, live eggs induce VECs to exert significantly greater contractile forces during encapsulation than dead eggs, which leads to 3D deformations on both the VEC monolayer and the flexible substrate underneath. These significant mechanical deformations cause the VEC monolayer tension to fluctuate with the eventual rupture of VEC junctions, thus facilitating egg transit out of the blood vessel. Overall, our data on the mechanical interplay between host VECs and the schistosome egg improve our understanding of how this parasite manipulates its immediate environment to maintain disease transmission. Schistosomiasis, which infects over 200 million people, is a painful disease of poverty that is caused by inflammatory responses to the Schistosoma blood fluke’s eggs. To continue the parasite’s life cycle, eggs must escape the blood vessels and migrate through tissues of the host to the alimentary canal for exit into the environment. The biomechanical processes that help the immobile eggs to cross the blood vessel’s vascular endothelial cells (VECs) as the first step in this migration are not understood. We found that live but not dead eggs induce VECs to crawl over and encapsulate them. VECs in contact with live eggs make membranous extensions (filopodia) to explore the egg’s surface and also form long intercellular nanotubes to communicate with neighboring cells. VECs stimulate particular (Rho/ROCK) biochemical pathways to increase cell contractility and the forces generated are large enough to eventually break the junctions between cells and allow passage of the eggs into the underlying tissue. Our findings show how schistosome eggs activate and interact with VECs to initiate their escape from the bloodstream.
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Affiliation(s)
- Yi-Ting Yeh
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California, United States of America
- Department of Bioengineering, University of California, San Diego, La Jolla, California, United States of America
- Institute of Engineering in Medicine, University of California, San Diego, La Jolla, California, United States of America
- * E-mail: (YTY); (JCdA); (CRC)
| | - Danielle E. Skinner
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Ernesto Criado-Hidalgo
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California, United States of America
| | - Natalie Shee Chen
- Department of Bioengineering, University of California, San Diego, La Jolla, California, United States of America
- Institute of Engineering in Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Antoni Garcia-De Herreros
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California, United States of America
| | - Nelly El-Sakkary
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Lawrence Liu
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Shun Zhang
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California, United States of America
| | - Adithan Kandasamy
- Department of Mechanical Engineering, University of Washington, Seattle, Washington, United States of America
- Center for Cardiovascular Biology, University of Washington, Seattle Washington, United States of America
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle Washington, United States of America
| | - Shu Chien
- Department of Bioengineering, University of California, San Diego, La Jolla, California, United States of America
- Institute of Engineering in Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Juan C. Lasheras
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California, United States of America
- Department of Bioengineering, University of California, San Diego, La Jolla, California, United States of America
- Institute of Engineering in Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Juan C. del Álamo
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California, United States of America
- Department of Mechanical Engineering, University of Washington, Seattle, Washington, United States of America
- Center for Cardiovascular Biology, University of Washington, Seattle Washington, United States of America
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle Washington, United States of America
- * E-mail: (YTY); (JCdA); (CRC)
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, United States of America
- * E-mail: (YTY); (JCdA); (CRC)
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3
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Probst A, Häberli C, Siegel D, Huang J, Vigneron S, Ta AP, Skinner DE, El-Sakkary N, Momper JD, Gangoiti J, Dong Y, Vennerstrom JL, Charman SA, Caffrey CR, Keiser J. Efficacy, metabolism and pharmacokinetics of Ro 15-5458, a forgotten schistosomicidal 9-acridanone hydrazone. J Antimicrob Chemother 2021; 75:2925-2932. [PMID: 32617557 DOI: 10.1093/jac/dkaa247] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Treatment of schistosomiasis, a neglected disease, relies on just one partially effective drug, praziquantel. We revisited the 9-acridanone hydrazone, Ro 15-5458, a largely forgotten antischistosomal lead compound. METHODS Ro 15-5458 was evaluated in juvenile and adult Schistosoma mansoni-infected mice. We studied dose-response, hepatic shift and stage specificity. The metabolic stability of Ro 15-5458 was measured in the presence of human and mouse liver microsomes, and human hepatocytes; the latter also served to identify metabolites. Pharmacokinetic parameters were measured in naive mice. The efficacy of Ro 15-5458 was also assessed in S. haematobium-infected hamsters and S. japonicum-infected mice. RESULTS Ro 15-5458 had single-dose ED50 values of 15 and 5.3 mg/kg in mice harbouring juvenile and adult S. mansoni infections, respectively. An ED50 value of 17 mg/kg was measured in S. haematobium-infected hamsters; however, the compound was inactive at up to 100 mg/kg in S. japonicum-infected mice. The drug-induced hepatic shift occurred between 48 and 66 h post treatment. A single oral dose of 50 mg/kg of Ro 15-5458 had high activity against all tested S. mansoni stages (1-, 7-, 14-, 21- and 49-day-old). In vitro, human hepatocytes produced N-desethyl and glucuronide metabolites; otherwise Ro 15-5458 was metabolically stable in the presence of microsomes or whole hepatocytes. The maximum plasma concentration was approximately 8.13 μg/mL 3 h after a 50 mg/kg oral dose and the half-life was approximately 4.9 h. CONCLUSIONS Ro 15-5458 has high activity against S. mansoni and S. haematobium, yet lacks activity against S. japonicum, which is striking. This will require further investigation, as a broad-spectrum antischistosomal drug is desirable.
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Affiliation(s)
- Alexandra Probst
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, PO Box, CH-4002, Basel, Switzerland
- University of Basel, PO Box, CH-4003, Basel, Switzerland
| | - Cécile Häberli
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, PO Box, CH-4002, Basel, Switzerland
- University of Basel, PO Box, CH-4003, Basel, Switzerland
| | - Dionicio Siegel
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Jianbo Huang
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Seth Vigneron
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Anh P Ta
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Danielle E Skinner
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Nelly El-Sakkary
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Jeremiah D Momper
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Jon Gangoiti
- Biochemical Genetics and Metabolomics Laboratory, Department of Pediatrics, School of Medicine, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Yuxiang Dong
- College of Pharmacy, University of Nebraska Medical Center, 986125 Nebraska Medical Center, Omaha, NE, USA
| | - Jonathan L Vennerstrom
- College of Pharmacy, University of Nebraska Medical Center, 986125 Nebraska Medical Center, Omaha, NE, USA
| | - Susan A Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Conor R Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, PO Box, CH-4002, Basel, Switzerland
- University of Basel, PO Box, CH-4003, Basel, Switzerland
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4
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Monti L, Cornec AS, Oukoloff K, Kovalevich J, Prijs K, Alle T, Brunden KR, Smith AB, El-Sakkary N, Liu LJ, Syed A, Skinner DE, Ballatore C, Caffrey CR. Congeners Derived from Microtubule-Active Phenylpyrimidines Produce a Potent and Long-Lasting Paralysis of Schistosoma mansoni In Vitro. ACS Infect Dis 2021; 7:1089-1103. [PMID: 33135408 DOI: 10.1021/acsinfecdis.0c00508] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Schistosomiasis is a parasitic disease that affects approximately 200 million people in developing countries. Current treatment relies on just one partially effective drug, and new drugs are needed. Tubulin and microtubules (MTs) are essential constituents of the cytoskeleton in all eukaryotic cells and considered potential drug targets to treat parasitic infections. The α- and β-tubulin of Schistosoma mansoni have ∼96% and ∼91% sequence identity to their respective human tubulins, suggesting that compounds which bind mammalian tubulin may interfere with MT-mediated functions in the parasite. To explore the potential of different classes of tubulin-binding molecules as antischistosomal leads, we completed a series of in vitro whole-organism screens of a target-based compound library against S. mansoni adults and somules (postinfective larvae), and identified multiple biologically active compounds, among which phenylpyrimidines were the most promising. Further structure-activity relationship studies of these hits identified a series of thiophen-2-yl-pyrimidine congeners, which induce a potent and long-lasting paralysis of the parasite. Moreover, compared to the originating compounds, which showed cytotoxicity values in the low nanomolar range, these new derivatives were 1-4 orders of magnitude less cytotoxic and exhibited weak or undetectable activity against mammalian MTs in a cell-based assay of MT stabilization. Given their selective antischistosomal activity and relatively simple drug-like structures, these molecules hold promise as candidates for the development of new treatments for schistosomiasis.
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Affiliation(s)
- Ludovica Monti
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Anne-Sophie Cornec
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, 231 South 34th St., Philadelphia, Pennsylvania 19104-6323, United States
| | - Killian Oukoloff
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Jane Kovalevich
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, 3600 Spruce Street, Philadelphia, Pennsylvania 19104-6323, United States
| | - Kristen Prijs
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, 3600 Spruce Street, Philadelphia, Pennsylvania 19104-6323, United States
| | - Thibault Alle
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Kurt R. Brunden
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, 3600 Spruce Street, Philadelphia, Pennsylvania 19104-6323, United States
| | - Amos B. Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, 231 South 34th St., Philadelphia, Pennsylvania 19104-6323, United States
| | - Nelly El-Sakkary
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Lawrence J. Liu
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Ali Syed
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Danielle E. Skinner
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Carlo Ballatore
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
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5
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Zorn KM, Sun S, McConnon CL, Ma K, Chen EK, Foil DH, Lane TR, Liu LJ, El-Sakkary N, Skinner DE, Ekins S, Caffrey CR. A Machine Learning Strategy for Drug Discovery Identifies Anti-Schistosomal Small Molecules. ACS Infect Dis 2021; 7:406-420. [PMID: 33434015 PMCID: PMC7887754 DOI: 10.1021/acsinfecdis.0c00754] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
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Schistosomiasis is a chronic and
painful disease of poverty caused
by the flatworm parasite Schistosoma. Drug discovery
for antischistosomal compounds predominantly employs in vitro whole organism (phenotypic) screens against two developmental stages
of Schistosoma mansoni, post-infective larvae (somules)
and adults. We generated two rule books and associated scoring systems
to normalize 3898 phenotypic data points to enable machine learning.
The data were used to generate eight Bayesian machine learning models
with the Assay Central software according to parasite’s developmental
stage and experimental time point (≤24, 48, 72, and >72
h).
The models helped predict 56 active and nonactive compounds from commercial
compound libraries for testing. When these were screened against S. mansoni in vitro, the prediction accuracy for active
and inactives was 61% and 56% for somules and adults, respectively;
also, hit rates were 48% and 34%, respectively, far exceeding the
typical 1–2% hit rate for traditional high throughput screens.
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Affiliation(s)
- Kimberley M. Zorn
- Collaborations Pharmaceuticals, 840 Main Campus Drive, Lab 3510, Raleigh, North Carolina 27606, United States
| | - Shengxi Sun
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0021, United States
| | - Cecelia L. McConnon
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0021, United States
| | - Kelley Ma
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0021, United States
| | - Eric K. Chen
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0021, United States
| | - Daniel H. Foil
- Collaborations Pharmaceuticals, 840 Main Campus Drive, Lab 3510, Raleigh, North Carolina 27606, United States
| | - Thomas R. Lane
- Collaborations Pharmaceuticals, 840 Main Campus Drive, Lab 3510, Raleigh, North Carolina 27606, United States
| | - Lawrence J. Liu
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0021, United States
| | - Nelly El-Sakkary
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0021, United States
| | - Danielle E. Skinner
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0021, United States
| | - Sean Ekins
- Collaborations Pharmaceuticals, 840 Main Campus Drive, Lab 3510, Raleigh, North Carolina 27606, United States
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0021, United States
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6
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Skinner DE, Popratiloff A, Alrefaei YN, Mann VH, Rinaldi G, Brindley PJ. Functional analysis of vasa/PL10-like genes in the ovary of Schistosoma mansoni. Mol Biochem Parasitol 2020; 236:111259. [PMID: 31958469 DOI: 10.1016/j.molbiopara.2020.111259] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/23/2019] [Accepted: 01/13/2020] [Indexed: 02/02/2023]
Abstract
The RNA helicase Vasa plays a pivotal role in the development of the germ line. To decipher the functional roles of vasa/PL10-like genes in the human blood fluke Schistosoma mansoni, we performed RNA interference followed by the analysis of the ovary in the adult female. Double-stranded RNA targeting the schistosome vasa-like gene Smvlg1 reduced the volume of the ovary. Changes in morphology of the ovary were analysed using carmine red-staining of the parasites followed by a novel confocal laser scanning microscopy (CLSM)-based approach to control for natural autofluorescence in female schistosome tissues. The reduction in the ovary volume may have been promoted by the loss of germ cells. By contrast, significant differences were not apparent in the number of eggs produced or hatching rate of eggs laid by the female schistosomes transfected with Smvlg1-specific dsRNA. The findings suggested a role for S. mansoni vasa/PL10-like gene -1 in germ cell development within the schistosome ovary that might impact in the pathogenesis and disease transmission by this neglected tropical disease pathogen.
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Affiliation(s)
- Danielle E Skinner
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037 USA; Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Anastas Popratiloff
- Nanofabrication and Imaging Center, The George Washington University, Washington, DC 20052, USA
| | - Yousef N Alrefaei
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037 USA; Department of Medical Laboratory Technology, The Public Authority of Applied Education and Training, Shuwaikh, Kuwait
| | - Victoria H Mann
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037 USA
| | - Gabriel Rinaldi
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037 USA; Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
| | - Paul J Brindley
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037 USA.
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7
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Skinner DE, Rinaldi G, Suttiprapa S, Mann VH, Smircich P, Cogswell AA, Williams DL, Brindley PJ. Vasa-Like DEAD-Box RNA Helicases of Schistosoma mansoni. PLoS Negl Trop Dis 2012; 6:e1686. [PMID: 22720105 PMCID: PMC3373655 DOI: 10.1371/journal.pntd.0001686] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 04/29/2012] [Indexed: 11/18/2022] Open
Abstract
Genome sequences are available for the human blood flukes, Schistosoma japonicum, S. mansoni and S. haematobium. Functional genomic approaches could aid in identifying the role and importance of these newly described schistosome genes. Transgenesis is established for functional genomics in model species, which can lead to gain- or loss-of-functions, facilitate vector-based RNA interference, and represents an effective forward genetics tool for insertional mutagenesis screens. Progress toward routine transgenesis in schistosomes might be expedited if germ cells could be reliably localized in cultured schistosomes. Vasa, a member of the ATP-dependent DEAD-box RNA helicase family, is a prototypic marker of primordial germ cells and the germ line in the Metazoa. Using bioinformatics, 33 putative DEAD-box RNA helicases exhibiting conserved motifs that characterize helicases of this family were identified in the S. mansoni genome. Moreover, three of the helicases exhibited vasa-like sequences; phylogenetic analysis confirmed the three vasa-like genes-termed Smvlg1, Smvlg2, and Smvlg3-were members of the Vasa/PL10 DEAD-box subfamily. Transcripts encoding Smvlg1, Smvlg2, and Smvlg3 were cloned from cDNAs from mixed sex adult worms, and quantitative real time PCR revealed their presence in developmental stages of S. mansoni with elevated expression in sporocysts, adult females, eggs, and miracidia, with strikingly high expression in the undeveloped egg. Whole mount in situ hybridization (WISH) analysis revealed that Smvlg1, Smvlg2 and Smvlg3 were transcribed in the posterior ovary where the oocytes mature. Germ cell specific expression of schistosome vasa-like genes should provide an informative landmark for germ line transgenesis of schistosomes, etiologic agents of major neglected tropical diseases.
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Affiliation(s)
- Danielle E. Skinner
- Department of Microbiology, Immunology & Tropical Medicine, and Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, D. C., United States of America
| | - Gabriel Rinaldi
- Department of Microbiology, Immunology & Tropical Medicine, and Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, D. C., United States of America
- Departamento de Genética, Facultad de Medicina, Universidad de la República, (UDELAR), Montevideo, Uruguay
| | - Sutas Suttiprapa
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Victoria H. Mann
- Department of Microbiology, Immunology & Tropical Medicine, and Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, D. C., United States of America
| | - Pablo Smircich
- Departamento de Genética, Facultad de Medicina, Universidad de la República, (UDELAR), Montevideo, Uruguay
| | - Alexis A. Cogswell
- Department of Microbiology and Immunology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - David L. Williams
- Department of Microbiology and Immunology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Paul J. Brindley
- Department of Microbiology, Immunology & Tropical Medicine, and Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, D. C., United States of America
- * E-mail:
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Rinaldi G, Suttiprapa S, Tort JF, Folley AE, Skinner DE, Brindley PJ. Corrigendum to ‘An antibiotic selection marker for schistosome transgenesis’ [Int. J. Parasitol. 42 (2012) 123–130]. Int J Parasitol 2012. [DOI: 10.1016/j.ijpara.2012.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rinaldi G, Suttiprapa S, Tort JF, Folley AE, Skinner DE, Brindley PJ. An antibiotic selection marker for schistosome transgenesis. Int J Parasitol 2011; 42:123-30. [PMID: 22155152 DOI: 10.1016/j.ijpara.2011.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Revised: 11/16/2011] [Accepted: 11/17/2011] [Indexed: 11/26/2022]
Abstract
Drug selection is widely used in transgene studies of microbial pathogens, mammalian cell and plant cell lines. Drug selection of transgenic schistosomes would be desirable to provide a means to enrich for populations of transgenic worms. We adapted murine leukaemia retrovirus vectors - widely used in human gene therapy research - to transduce schistosomes, leading to integration of transgenes into the genome of the blood fluke. A dose-response kill curve and lethal G418 (geneticin) concentrations were established: 125-1,000μg/ml G418 were progressively more toxic for schistosomules of Schistosoma mansoni with toxicity increasing with antibiotic concentration and with duration of exposure. By day 6 of exposure to ⩾500μg/ml, significantly fewer worms survived compared with non-exposed controls and by day 8, significantly fewer worms survived than controls at ⩾250μg/ml G418. When schistosomules were transduced with murine leukaemia retrovirus encoding the neomycin resistance (neoR) transgene and cultured in media containing G418, the neoR transgene rescued transgenic schistosomules from the antibiotic; by day 4 in 1,000μg/ml and by day 8 in 500μg/ml G418, significantly more transgenic worms survived the toxic effects of the antibiotic. More copies of neoR were detected per nanogram of genomic DNA from populations of transgenic schistosomes cultured in G418 than from transgenic schistosomes cultured without G418. This trend was G418 dose-dependent, demonstrating enrichment of transgenic worms from among the schistosomules exposed to virions. Furthermore, higher expression of neoR was detected in transgenic schistosomes cultured in the presence of G418 than in transgenic worms cultured without antibiotic. The availability of antibiotic selection can be expected to enhance progress with functional genomics research on the helminth parasites responsible for major neglected tropical diseases.
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Affiliation(s)
- Gabriel Rinaldi
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine & Health Sciences, The George Washington University, 2300 I Street NW, Washington, DC 20037, USA
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Weissert WG, Scanlon WJ, Wan TT, Skinner DE. Care for the chronically ill: nursing home incentive payment experience. Health Care Financ Rev 1983; 5:41-9. [PMID: 10310528 PMCID: PMC4191329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Nursing home reimbursement systems which do not adjust payment levels to patient care needs lead to access problems for heavy-care patients. Unnecessarily long and costly hospital stays may result. A patient-based nursing home incentive reimbursement system has been designed and is being evaluated in a controlled field experiment in 36 California skilled nursing facilities. Incentives are paid for admitting heavy-care patients, meeting outcome goals on some patients, and discharging and maintaining some patients in the community. This article describes a nursing home reimbursement system which is intended to simultaneously mitigate problems of restricted access, inefficient use of beds, and nonoptimal care. It also discusses the approach to evaluating this broad social intervention by application of a controlled experimental design.
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Deane RT, Skinner DE. Incentive reimbursement: a new approach. Nurs Homes 1978; 27:2-12. [PMID: 10308501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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