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El-Sakkary N, Chen S, Arkin MR, Caffrey CR, Ribeiro P. Octopamine signaling in the metazoan pathogen Schistosoma mansoni: localization, small-molecule screening and opportunities for drug development. Dis Model Mech 2018; 11:dmm033563. [PMID: 29925529 PMCID: PMC6078403 DOI: 10.1242/dmm.033563] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 06/12/2018] [Indexed: 11/20/2022] Open
Abstract
Schistosomiasis is a tropical disease caused by a flatworm trematode parasite that infects over 200 million people worldwide. Treatment and control of the disease rely on just one drug, praziquantel. The possibility of drug resistance coupled with praziquantel's variable efficacy encourages the identification of new drugs and drug targets. Disruption of neuromuscular homeostasis in parasitic worms is a validated strategy for drug development. In schistosomes, however, much remains to be understood about the organization of the nervous system, its component neurotransmitters and potential for drug discovery. Using synapsin as a neuronal marker, we map the central and peripheral nervous systems in the Schistosoma mansoni adult and schistosomulum (post-infective larva). We discover the widespread presence of octopamine (OA), a tyrosine-derived and invertebrate-specific neurotransmitter involved in neuromuscular coordination. OA labeling facilitated the discovery of two pairs of ganglia in the brain of the adult schistosome, rather than the one pair thus far reported for this and other trematodes. In quantitative phenotypic assays, OA and the structurally related tyrosine-derived phenolamine and catecholamine neurotransmitters differentially modulated schistosomulum motility and length. Similarly, from a screen of 28 drug agonists and antagonists of tyrosine-derivative signaling, certain drugs that act on OA and dopamine receptors induced robust and sometimes complex concentration-dependent effects on schistosome motility and length; in some cases, these effects occurred at concentrations achievable in vivo The present data advance our knowledge of the organization of the nervous system in this globally important pathogen and identify a number of drugs that interfere with tyrosine-derivative signaling, one or more of which might provide the basis for a new chemotherapeutic approach to treat schistosomiasis.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Nelly El-Sakkary
- Institute of Parasitology, McGill University, Macdonald Campus, 21, 111 Lakeshore Road, Ste Anne de Bellevue, Quebec, Canada H9X-3V9
| | - Steven Chen
- Small Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Michelle R Arkin
- Small Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Conor R Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, Department of Pathology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Paula Ribeiro
- Institute of Parasitology, McGill University, Macdonald Campus, 21, 111 Lakeshore Road, Ste Anne de Bellevue, Quebec, Canada H9X-3V9
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Ataev GL, Bazhenova DR, Tokmakova AS. [REPRODUCTION OF SCHISTOSOMA MANSONI MOTHER SPOROCYST]. Parazitologiia 2016; 50:114-120. [PMID: 28777526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The development of generative elements of Schistosoma mansoni mother sporocysts (MS) was examined by histological methods. About 20 large cells, on average, determined as germinal cells (GC) were found in the miracidium. These cells formed a C-shape cellular aggregation (a band) beginning in the caudal part of the larva, and reaching the nerve ganglion in the anterior part. At the level of the 3d tier of epithelial plates of the miracidium, this band shifted to the external body wall, bypassing the zone of excretory channels. Apparently, this shift resulted in the subdivision of a single pool of GC into two structurally associated groups. A group of several undifferentiated cells (UC) was also revealed in the caudal part of the body. After the metamorphosis of the miracidium into sporocysts, GC had increased in size and on the 3d day started to divide, forming first embryos of daughter sporocysts. During the same time, germinal masses were being formed in the subtegumental area of the MS body. Since this time point, proliferation of UC occured only in germinal masses. A part of UC also differentiated there into GC. These cells formed sporocystoid embryos, developing as far as the germinal ball, and then came out into the sporocyst schizocoel (approximately in 10 days p. i.). Thus, in S. mansoni, the formation of generative elements into MS occurs in two stages. Primary GC are formed during the development of the miracidium into the egg, whereas secondary GC develop in germinal masses of the sporocyst.
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Jurberg AD, Gonçalves T, Costa TA, de Mattos ACA, Pascarelli BM, de Manso PPA, Ribeiro-Alves M, Pelajo-Machado M, Peralta JM, Coelho PMZ, Lenzi HL. The embryonic development of Schistosoma mansoni eggs: proposal for a new staging system. Dev Genes Evol 2009; 219:219-34. [PMID: 19415326 DOI: 10.1007/s00427-009-0285-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Accepted: 04/03/2009] [Indexed: 11/25/2022]
Abstract
Schistosomiasis is a water-borne parasitic illness caused by neoophoran trematodes of the genus Schistosoma. Using classical histological techniques and whole-mount preparations, the present work describes the embryonic development of Schistosoma mansoni eggs in the murine host and compares it with eggs maintained under in vitro conditions. Two pre-embryonic stages occur inside the female worm: the prezygotic stage is characterized by the release of mature oocytes from the female ovary until its fertilization. The zygotic stage encompasses the migration of the zygote through the ootype, where the eggshell is formed, to the uterus. Fully formed eggs are laid still undeveloped, without having suffered any cleavage. In the outside environment, eight embryonic stages can be defined: stage 1 refers to early cleavages and the beginning of yolk fusion. Stage 2 represents late cleavage, with the formation of a stereoblastula and the onset of outer envelope differentiation. Stage 3 is defined by the elongation of the embryonic primordium and the onset of inner envelope formation. At stage 4, the first organ primordia arise. During stages 5 to 7, tissue and organ differentiation occurs (neural mass, epidermis, terebratorium, musculature, and miracidial glands). Stage 7 is characterized by the nuclear condensation of neurons of the central neural mass. Stage 8 refers to the fully formed larva, presenting muscular contraction, cilia, and flame-cell beating. This staging system was compared to a previous classification and could underlie further studies on egg histoproteomics (morphological localizome). The differentiation of embryonic structures and their probable roles in granulomatogenesis are discussed herein.
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Affiliation(s)
- Arnon D Jurberg
- Laboratório de Patologia, Instituto Oswaldo Cruz/Fundação Oswaldo Cruz, Pavilhão Gomes de Faria. Av. Brasil, 4365-Manguinhos, Rio de Janeiro 21040-900, RJ, Brazil.
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Abstract
Over 200 million people have, and another 600 million are at risk of contracting, schistosomiasis, one of the major neglected tropical diseases. Transmission of this infection, which is caused by helminth parasites of the genus Schistosoma, depends upon the release of parasite eggs from the human host. However, approximately 50% of eggs produced by schistosomes fail to reach the external environment, but instead become trapped in host tissues where pathological changes caused by the immune responses to secreted egg antigens precipitate disease. Despite the central importance of egg production in transmission and disease, relatively little is understood of the molecular processes underlying the development of this key life stage in schistosomes. Here, we describe a novel parasite-encoded TGF-β superfamily member, Schistosoma mansoni Inhibin/Activin (SmInAct), which is key to this process. In situ hybridization localizes SmInAct expression to the reproductive tissues of the adult female, and real-time RT-PCR analyses indicate that SmInAct is abundantly expressed in ovipositing females and the eggs they produce. Based on real-time RT-PCR analyses, SmInAct transcription continues, albeit at a reduced level, both in adult worms isolated from single-sex infections, where reproduction is absent, and in parasites from IL-7R−/− mice, in which viable egg production is severely compromised. Nevertheless, Western analyses demonstrate that SmInAct protein is undetectable in parasites from single-sex infections and from infections of IL-7R−/− mice, suggesting that SmInAct expression is tightly linked to the reproductive potential of the worms. A crucial role for SmInAct in successful embryogenesis is indicated by the finding that RNA interference–mediated knockdown of SmInAct expression in eggs aborts their development. Our results demonstrate that TGF-β signaling plays a major role in the embryogenesis of a metazoan parasite, and have implications for the development of new strategies for the treatment and prevention of an important and neglected human disease. Schistosomes are parasitic worms that infect hundreds of millions of people in developing countries. They cause disease by virtue of the fact that the eggs that they produce, which are intended for release from the host in order to allow transmission of infection, can become trapped in target organs such as the liver, where they induce damaging inflammation. Egg production by female schistosomes is critically dependent on the presence of male parasites, without which females never fully develop, and (counterintuitively) on the contribution of signals from the host's immune system. Very little is understood about the molecular basis of these interactions. Here, we describe a newly discovered schistosome gene, which is expressed in the reproductive tract of the female parasite and in parasite eggs. The protein encoded by this gene is made only when females are paired with males in an immunologically competent setting. Using recently developed tools that allow gene function to be inhibited in schistosomes, we show that the product of this gene plays a crucial role in egg development. Examining how the expression of this gene is controlled has the potential to provide insight into the molecular nature of the interactions between male and female parasites and their hosts. Moreover, the pivotal role of this gene in the egg makes it a potential target for blocking transmission and disease development.
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Affiliation(s)
- Tori C Freitas
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Euihye Jung
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Edward J Pearce
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * To whom correspondence should be addressed. E-mail:
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Schramm G, Falcone FH, Gronow A, Haisch K, Mamat U, Doenhoff MJ, Oliveira G, Galle J, Dahinden CA, Haas H. Molecular characterization of an interleukin-4-inducing factor from Schistosoma mansoni eggs. J Biol Chem 2003; 278:18384-92. [PMID: 12624091 DOI: 10.1074/jbc.m300497200] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The eggs of the parasitic trematode Schistosoma mansoni are powerful inducers of a T helper type 2 (Th2) immune response and immunoglobulin E (IgE) production. S. mansoni egg extract (SmEA) stimulates human basophils to rapidly release large amounts of interleukin (IL)-4, the key promoter of a Th2 response. Here we show purification and sequence of the IL-4-inducing principle of S. mansoni eggs (IPSE). Stimulation studies with human basophils using SmEA fractions and natural and recombinant IPSE as well as neutralization and immunodepletion studies using antibodies to recombinant IPSE demonstrate that IPSE is the bioactive principle in SmEA leading to activation of basophils and to expression of IL-4 and IL-13. Regarding the mechanism of action, blot analysis showed that IPSE is an IgE-binding factor, suggesting that it becomes effective via cross-linking receptor-bound IgE on basophils. Immunohistology revealed that IPSE is enriched in and secreted from the subshell area of the schistosome egg. We conclude from these data that IPSE may be an important parasite-derived component for skewing the immune response toward Th2.
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Maldonado A, Coura R, Lanfredi RM, Rey L. Changes on Schistosoma mansoni (Digenea: Schistosomatidae) worm load in Nectomys squamipes (Rodentia: Sigmodontinae) concurrently infected with Echinostoma paraensei (Digenea: Echinostomatidae). Mem Inst Oswaldo Cruz 2002; 96 Suppl:193-8. [PMID: 11586449 DOI: 10.1590/s0074-02762001000900030] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The water rat, Nectomys squamipes, closely involved in schistosomiasis transmission in Brazil, has been found naturally infected simultaneously by Schistosoma mansoni and Echinostoma paraensei. Laboratory experiments were conducted to verify parasitic interaction in concurrent infection. It was replicated four times with a total of 42 water rats and essayed two times with 90 mice pre-infected with E. paraensei. Rodents were divided into three groups in each replication. A wild strain recently isolated from Sumidouro, RJ, and a laboratory strain of S. mansoni from Belo Horizonte (BH) was used. Rats infected with E. paraensei were challenged 4 weeks later with S. mansoni and mice 2 or 6 weeks after the infection with S. mansoni. Necropsy took place 8 weeks following S. mansoni infection. The N. squamipes treatment groups challenged with S. mansoni RJ strain showed a significant decrease (80 and 65%) in the S. mansoni parasite load when compared with their respective control groups. There was a significant change or no change in the hosts challenged with the BH strain. The persistence time of E. paraensei within host was extended in relation to control groups, with a consequent enhancement of the number of recovered worm. An E. paraensei strain-specific influence on S. mansoni parasitism is reported. This paper presents some experimental data about this interaction in N. squamipes and Mus musculus.
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Affiliation(s)
- A Maldonado
- Laboratório de Biologia e Controle da Esquistossomose, Departamento de Medicina Tropical, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, 21045-900, Brasil.
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Abstract
The A subunit of NF-Y nuclear factor from Schistosoma mansoni was expressed in E. coli fused to a histidine tag and purified by affinity chromatography using a Ni(2+)-Agarose matrix. Antibodies against the recombinant protein were prepared and used for Western blot and immunolocalization. The presence of SMNF-YA in all stages of the parasite life-cycle was determined by RT-PCR and Western blot analysis. The immunolocalization of SMNF-YA showed the presence of this factor in a parenchymal cell population of cercariae and adult worms and in embryos within eggs. The expression of SMNF-YA was demonstrated to decrease in maturating spermatozoites whereas an accumulation of this factor was observed in the nucleus from oocytes during their maturation processes.
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Affiliation(s)
- E Serra
- Unité INSERM 167, Institut Pasteur Lille, France
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Pan SC. Schistosoma mansoni: the ultrastructure of larval morphogenesis in Biomphalaria glabrata and of associated host-parasite interactions. Jpn J Med Sci Biol 1996; 49:129-49. [PMID: 9086392 DOI: 10.7883/yoken1952.49.129] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
An electron microscopic study has been carried out to describe the transformation of the miracidium of S. mansoni into the mother sporocysts in the susceptible B. glabrata and the associated host-parasite interactions. The miracidium enters the snail host without morphological alterations. Within 3 hr after entering, all the ciliary epidermal plates of the miracidium are discarded. A new tegument is quickly formed by 5 hr postinfection by the expansion of epidermal ridges. The rapid formation of the new tegument reflects the participation of membrane-bound vesicles in the ridge cytons. The membranes of these vesicles become the new tegument membranes with the discharge of their electron-dense contents into the snail tissues. The vesicular contents discharged into the tissues apparently prevent snail amoebocytes (phagocytes) from attachment to the parasite tegument and thus prevent their interference with the further development of the postmiracidium. If a postmiracidium fails to mobilize membrane-bound vesicles in the formation of tegument, the parasite becomes surrounded by closely attached concentric layers of fibroblasts formed by amoebocytes and histiocytes within 24 hr. The membrane-bound vesicles are present in small numbers in the ridge cytons of the miracidium and become numerous in the postmiracidium stage and with many migrate to the ridges through connecting bridges within 24 hr. By 3 days postinfection when extensive microvilli have formed on the tegument the vesicles have disappeared and are replaced by mitochondria, ribosomes and complex carbohydrate particles. Many fibroblasts in the snail connective tissues have phagocytic capacities and are regarded as snail tissue histiocytes or fixed amoebocytes that eventually may become hypertrophic and detached.
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Affiliation(s)
- S C Pan
- Department of Tropical Public Health, Harvard School of Public Health, Boston, MA 02115, USA
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Edson DC, Smith JW. Comparison of concentration procedures for detection of Schistosoma mansoni eggs in a CAP Parasitology Survey specimen. Am J Clin Pathol 1982; 78:671-2. [PMID: 7137108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
A comparison of concentration procedures for the detection of Schistosoma mansoni is presented. Ethyl-acetate or formalin-ether centrifugal sedimentation technics are not only the most commonly used, they also lead to more accurate identification of the organism's eggs.
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Theron A. [Evaluation of the drift of cercariae by a single daily sampling in the site of schistosomiasis transmission. Example of Guadeloupean sites of Schistosoma mansoni transmission (author's transl)]. Rev Epidemiol Sante Publique 1980; 28:131-9. [PMID: 7465909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Research on cercarian density in running water transmission sites of intestinal schistosomiasis in Guadeloupe has allowed the construction of a representative model of the rhythm of presence of Schistosoma mansoni cercariae. This model allows, with a single daily sampling between 11 a.m. and 2 p.m., the evaluation of the daily sum of hourly densities. We propose to measure the parasite component of the risk of contamination in a bilharzial site by the drift of cercariae expressed in cercariae/day. The drift of cercariae takes account of variations in cercarian density and of the flow of the channel. It expresses the daily quantity of cercariae available for human contamination.
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Zicker F, Katz N, Wolf J. [Evaluation of the hatching test for eggs of Schistosoma mansoni]. Rev Inst Med Trop Sao Paulo 1977; 19:202-7. [PMID: 601429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Hsü SY, Hsü HF, Isacson P, Cheng HF. Schistosoma mansoni and S. japonicum: methylene blue test for the viability of schistosomula in vitro. Exp Parasitol 1977; 41:329-34. [PMID: 66154 DOI: 10.1016/0014-4894(77)90105-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Buecher EJ, Perez-Mendez G, Hansen EL, Yarwood E. Sulfhydryl compounds under controlled gas in culture of Schistosoma mansoni sporocysts. Proc Soc Exp Biol Med 1974; 146:1101-5. [PMID: 4420922 DOI: 10.3181/00379727-146-38253] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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