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Experimental Parasitology Jul 2008RNA interference (RNAi) mediated by short interfering RNA (siRNA) is a powerful reverse genetics tool and holds enormous therapeutic potential for various diseases,...
RNA interference (RNAi) mediated by short interfering RNA (siRNA) is a powerful reverse genetics tool and holds enormous therapeutic potential for various diseases, including parasite infections. siRNAs bind their complementary mRNA and lead to degradation of their specific mRNA targets. RNAi has been widely used for functional analysis of specific genes in various cells and organisms. In this paper, we tested the potential of silencing the expression of the Mago nashi gene in Schistosoma japonicum by siRNAs derived from shRNA expressed by mammalian Pol III promoter H1. Schistosomula, transformed from cercariae by mechanical shearing of the tails, were electroporated with Mago nashi shRNA expression vector. Aliquots of parasites were harvested at days 1, 3, and 5 after electroporation, respectively. Levels of Mago nashi mRNA and protein were determined by RT-PCR and Western blotting analysis. The results showed that shRNA expressed from mammalian Pol III promoter H1 specifically reduced the levels of Mago nashi mRNA and proteins in S. japonicum. Changes in testicular lobes were apparent when parasites were introduced into mammalian hosts. Thus, vector-mediated gene silencing is applicable to S. japonicum, which provides a means for the functional analysis of genes in this organism.
Topics: Animals; Blotting, Western; DNA, Helminth; Electroporation; Female; Gene Expression Regulation; Helminth Proteins; Male; Mice; Mice, Inbred BALB C; Nuclear Proteins; RNA Interference; RNA, Helminth; RNA, Messenger; Reverse Transcriptase Polymerase Chain Reaction; Schistosoma japonicum
PubMed: 18466902
DOI: 10.1016/j.exppara.2008.03.015 -
Parasites & Vectors Dec 2014The esophagus of blood-feeding schistosomes has been largely neglected although its posterior portion was designated as a gland decades ago. However, we recently showed...
BACKGROUND
The esophagus of blood-feeding schistosomes has been largely neglected although its posterior portion was designated as a gland decades ago. However, we recently showed it plays a pivotal role in blood processing. It is clearly demarcated into anterior and posterior compartments, both surrounded by a mass of cell bodies. Feeding movies revealed that erythrocytes accumulate in the anterior compartment before entering the posterior, indicating that a distinct process is executed there. We therefore investigated ultrastructural aspects and possible functions of the anterior region.
METHODS
The heads of adult Schistosoma japonicum were detached and prepared for both transmission and scanning electron microscopy to define the detailed ultrastructure of the anterior esophagus. Cryosections of heads were also prepared for immunocytochemistry and confocal microscopy to define the pattern of intrinsic host antibody binding in the anterior esophageal lining.
RESULTS
The anterior syncytial lining of the esophagus is highly extended by long, thin corrugations of cytoplasm projecting towards the lumen. Strikingly in the male worm, the tips of the corrugations are further expanded by numerous threads of cytoplasm, producing a spaghetti-like appearance in the central lumen. Flattened, pitted cytoplasmic plates are interspersed in the tangled mass of threads. Abundant, morphologically distinct light vesicles of varied size and contents are manufactured in the cell bodies, from where they traffic through cytoplasmic connections to the corrugations and out to the tips. Clusters of vesicles accumulate in expanded tips in males, together with occasional mitochondria whilst females have more mitochondria but fewer vesicles. The membranous contents of light vesicles are secreted mainly from the tips, but also from the sides of the corrugations. They coat the surfaces and then form organised self-adherent membrane figures when shed into the lumen. Host antibody binds strongly in a characteristic pattern to the anterior esophageal lining indicating that the secretions are highly immunogenic.
CONCLUSIONS
We suggest that the anterior esophageal region is an independent secretory organ. The contents of light vesicles are released into the esophageal lumen via the tips of corrugation to interact with incoming blood. Our immediate task is to establish their composition and role in blood processing.
Topics: Animals; Antibodies; Antibodies, Helminth; Antibody Specificity; Esophagus; Female; Integumentary System; Male; Schistosoma japonicum
PubMed: 25490864
DOI: 10.1186/s13071-014-0565-8 -
Experimental Parasitology Jul 1990Water buffaloes were vaccinated three times with 10,000 Schistosoma japonicum cercariae irradiated with ultraviolet (uv) light at a dose of 400 microW x min/cm2. The...
Water buffaloes were vaccinated three times with 10,000 Schistosoma japonicum cercariae irradiated with ultraviolet (uv) light at a dose of 400 microW x min/cm2. The irradiation was performed with cheap, simple, and portable equipment in a rural area of Hubei Province (People's Republic of China). A challenge infection of 1000 untreated cercariae was given to six vaccinated and six naive control buffaloes, while two vaccinated animals were not challenged. The experiment was terminated 6 weeks after the challenge. Control animals had lost body weight and harbored a mean of 110 worms and 37 eggs per gram of liver. The vaccinated animals gained weight after the challenge and developed 89% resistance to infection with S. japonicum. Since schistosomiasis japonica is nowadays transmitted in China predominantly by domestic livestock, a uv-attenuated cercarial vaccine for bovines may contribute to the control of this disease.
Topics: Animals; Body Weight; Buffaloes; Male; Schistosoma japonicum; Schistosomiasis japonica; Ultraviolet Rays; Vaccination; Vaccines, Attenuated
PubMed: 2113005
DOI: 10.1016/0014-4894(90)90012-2 -
Microscopy Research and Technique Aug 1998This review discusses some of the recent advances in the characterization of potential vaccine molecules against Schistosoma japonicum, utilizing microscopy and... (Review)
Review
This review discusses some of the recent advances in the characterization of potential vaccine molecules against Schistosoma japonicum, utilizing microscopy and immunocytochemistry methods. Microscopy has demonstrated the stage-specific expression of the muscle protein paramyosin onto the parasite surface, an important consideration as a vaccine target. Other potential vaccine component proteins examined include glutathione S-transferase (GST) and fatty acid binding protein (FABP); although not associated with the adult parasite surface, their localization to internal structures such as lipid droplets and regions of the female reproductive system have provided valuable insights into the biology of the parasite. Localization of the transport protein SGTP (schistosome glucose transporter protein) has demonstrated that the protein is more prevalent in the juvenile stages of the parasite development. This further highlights the diversity of the parasite life cycle. Using both light microscopy and transmission electron microscopy, the localization of a number of schistosome proteins has demonstrated the functions and significance of these proteins within the parasite. Molecular localization studies are crucial in understanding how and when a vaccine may work against the organism and may provide insights into which can be used in the design of future vaccines.
Topics: Animals; Carrier Proteins; Fatty Acid-Binding Proteins; Female; Glutathione Transferase; Helminth Proteins; Immunohistochemistry; Male; Microscopy, Electron; Myelin P2 Protein; Neoplasm Proteins; Schistosoma japonicum; Tropomyosin
PubMed: 9764918
DOI: 10.1002/(SICI)1097-0029(19980801)42:3<176::AID-JEMT2>3.0.CO;2-R -
Pharmacogenomics Dec 2016miRNAs play a significant role in pharmacogenomics and are likely to be important in the molecular mechanism of atesunate (ART) effects on Schistosoma japonicum.
AIM
miRNAs play a significant role in pharmacogenomics and are likely to be important in the molecular mechanism of atesunate (ART) effects on Schistosoma japonicum.
METHODS
We sequenced the RNAs using an Illumina (Solexa) DNA sequencer and compared the relative expression levels of the miRNAs in 10-day-old schistosomula from ART and the parallel control group.
RESULTS
We characterized 95 known miRNAs from S. japonicum schistosomula individuals, including 38 novel miRNA families. Among the detectable 134 miRNAs differentially expressed (>2.0-fold change, p < 0.01) after ART treatment in schistosomula, a total of seven known or novel 3p- or 5p- derived S. japonicum miRNAs were characterized. We propose that sja-miR-125b may regulate the expression of ART metabolizing enzymes, glutathione synthetase or heme-binding protein 2 to help S. japonicum resists or adapts to drug stress and also ART may significantly inhibit sexual maturation of female worms mediated by mir-71b/2 miRNA cluster.
CONCLUSION
This was the first comprehensive miRNAs expression profile analysis of S. japonicum in response to ART, and provides an overview of the complex network of the mechanism of action of ART on S. japonicum.
Topics: Animals; Artemisinins; Artesunate; Computational Biology; Gene Expression Profiling; Humans; MicroRNAs; Schistosoma japonicum; Schistosomicides
PubMed: 27918238
DOI: 10.2217/pgs.16.23 -
The American Journal of Tropical... May 2012The purpose of the current study was to investigate the susceptibility of Schistosoma japonicum to praziquantel in low endemic foci of China. During the non-transmission...
The purpose of the current study was to investigate the susceptibility of Schistosoma japonicum to praziquantel in low endemic foci of China. During the non-transmission period of schistosomiasis, a total of 43 of 1,242 subjects were identified as being infected with the parasite using parasitological stool examinations in two low-endemicity areas of China, with a prevalence rate of 3.46%. All stool-egg-positive subjects were treated with praziquantel in a single oral dose of 40 mg/kg or 30 mg/kg for two successive days. Six weeks post-treatment, no S. japonicum eggs were detected in the 43 treated villagers. The results indicate that the current efficacy of praziquantel against S. japonicum seems satisfactory and has not changed over the past three decades in the low endemic areas of China. It is also suggested that no evidence of tolerance or resistance to praziquantel in S. japonicum is detected in areas with low endemicity in China.
Topics: Adolescent; Adult; Animals; Child; China; Drug Evaluation; Feces; Female; Humans; Male; Middle Aged; Praziquantel; Prevalence; Schistosoma japonicum; Schistosomiasis japonica; Schistosomicides; Young Adult
PubMed: 22556083
DOI: 10.4269/ajtmh.2012.11-0701 -
Parasitology Research Mar 2010Apoptosis is a normal process for regulating cellular death of many organisms. Here, we molecularly characterized an inhibitor of apoptosis from Schistosoma japonicum...
Apoptosis is a normal process for regulating cellular death of many organisms. Here, we molecularly characterized an inhibitor of apoptosis from Schistosoma japonicum (SjIAP). The transcription of the SjIAP predominantly occurred at the developmental stages in a final host. Functional assay indicated that the SjIAP could inhibit caspase activity either in 293T cell or in schistosome lysates. Additionally, there were differently expressed profiles of the SjIAP in S. japonicum living in different hosts. Our preliminary results suggest that the SjIAP may play important roles in parasitic living and development as well as in the host-parasite interactions, and drug target of SjIAP might be a potential for controlling schistosomiasis.
Topics: Amino Acid Sequence; Animals; Caspase Inhibitors; Cell Line; Gene Expression Profiling; Helminth Proteins; Host-Parasite Interactions; Humans; Inhibitor of Apoptosis Proteins; Molecular Sequence Data; Phylogeny; Schistosoma japonicum; Sequence Alignment
PubMed: 20162431
DOI: 10.1007/s00436-010-1752-y -
Trends in Parasitology Apr 2007Publication of the transcriptomes of Schistosoma mansoni and Schistosoma japonicum, in conjunction with the sequencing and assembly of their genomes, has generated a... (Review)
Review
Publication of the transcriptomes of Schistosoma mansoni and Schistosoma japonicum, in conjunction with the sequencing and assembly of their genomes, has generated a comprehensive picture of Schistosoma transcriptional and genomic diversity. Subsequently, researchers who study conjugal and developmental biology, tegumental composition and larval or egg, secretory and excretory products have used these data, in combination with the latest '-omics' technologies, to extend large-scale screens of the schistosome transcriptome, proteome and glycome. In this article, we review these postgenomic investigations and contend that the generated datasets provide a plethora of novel drug, vaccine and immunomodulatory targets that might be useful for developing new antischistosome agents.
Topics: Animals; Female; Gene Expression Profiling; Genome, Helminth; Helminth Proteins; Male; Morbidity; Oligonucleotide Array Sequence Analysis; Polysaccharides; Proteome; Proteomics; Schistosoma japonicum; Schistosoma mansoni; Schistosomiasis
PubMed: 17336161
DOI: 10.1016/j.pt.2007.02.007 -
Parasites & Vectors Aug 2019Schistosomiasis is a prevalent but neglected tropical disease caused by parasitic trematodes of the genus Schistosoma, with the primary disease-causing species being S....
BACKGROUND
Schistosomiasis is a prevalent but neglected tropical disease caused by parasitic trematodes of the genus Schistosoma, with the primary disease-causing species being S. haematobium, S. mansoni and S. japonicum. Male-female pairing of schistosomes is necessary for sexual maturity and the production of a large number of eggs, which are primarily responsible for schistosomiasis dissemination and pathology.
METHODS
Here, we used microarray hybridization, bioinformatics, quantitative PCR, in situ hybridization and gene silencing assays to identify genes that play critical roles in S. japonicum reproduction biology, particularly in vitellarium development, a process that affects male-female pairing, sexual maturation and subsequent egg production.
RESULTS
Microarray hybridization analyses generated a comprehensive set of genes differentially transcribed before and after male-female pairing. Although the transcript profiles of females were similar 16 and 18 days after host infection, marked gene expression changes were observed at 24 days. The 30 most abundantly transcribed genes on day 24 included those associated with vitellarium development. Among these, the gene for female-specific 800 (fs800) was substantially upregulated. Our in situ hybridization results in female S. japonicum indicated that Sjfs800 mRNA was observed only in the vitellarium, localized in mature vitelline cells. Knocking down the Sjfs800 gene in female S. japonicum by approximately 60% reduced the number of mature vitelline cells, decreased rates of pairing and oviposition, and decreased the number of eggs produced in each male-female pairing by about 50%.
CONCLUSIONS
These results indicate that Sjfs800 may play a role in vitellarium development and egg production in S. japonicum and suggest that Sjfs800 regulation may provide a novel approach for the prevention or treatment of schistosomiasis.
Topics: Animals; Computational Biology; Female; Gene Expression; Gene Silencing; Helminth Proteins; In Situ Hybridization; Male; Microarray Analysis; Oviposition; Ovum; Schistosoma japonicum; Sexual Maturation
PubMed: 31443730
DOI: 10.1186/s13071-019-3672-8 -
Parasitology Research Dec 2013Molecular genetic tools are needed to address questions as to the source and dynamics of transmission of the human blood fluke Schistosoma japonicum in regions where...
Molecular genetic tools are needed to address questions as to the source and dynamics of transmission of the human blood fluke Schistosoma japonicum in regions where human infections have reemerged, and to characterize infrapopulations in individual hosts. The life stage that interests us as a target for collecting genotypic data is the miracidium, a very small larval stage that consequently yields very little DNA for analysis. Here, we report the successful development of a multiplex format permitting genotyping of 17 microsatellite loci in four sequential multiplex reactions using a single miracidium held on a Whatman Classic FTA indicating card. This approach was successful after short storage periods, but after long storage (>4 years), considerable difficulty was encountered in multiplex genotyping, necessitating the use of whole genome amplification (WGA) methods. WGA applied to cards stored for long periods of time resulted in sufficient DNA for accurate and repeatable genotyping. Trials and tests of these methods, as well as application to some field-collected samples, are reported, along with the discussion of the potential insights to be gained from such techniques. These include recognition of sibships among miracidia from a single host, and inference of the minimum number of worm pairs that might be present in a host.
Topics: Animals; DNA; Genome, Helminth; Genotyping Techniques; Humans; Larva; Microsatellite Repeats; Polymerase Chain Reaction; Schistosoma japonicum; Sequence Analysis, DNA; Specimen Handling
PubMed: 24013341
DOI: 10.1007/s00436-013-3587-9