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Experimental Parasitology Dec 2015In the present study, a full-length cDNA encoding the Schistosoma japonicum 3-phosphoglycerate kinase (SjPGK) with an open reading frame of 1251 bp was isolated from...
In the present study, a full-length cDNA encoding the Schistosoma japonicum 3-phosphoglycerate kinase (SjPGK) with an open reading frame of 1251 bp was isolated from 42-day-old (42-d) schistosome cDNAs. Real-time quantitative reverse transcription PCR analysis revealed that SjPGK was expressed in all investigated developmental stages and at a higher transcript levels in 21- and 42-d worms. Moreover, the SjPGK mRNA level was significantly downregulated in 10-d schistosomula from Wistar rats (non-susceptible host). SjPGK was subcloned into pET28a(+) and expressed as both supernatant and inclusion bodies in Escherichia coli BL21 cells. The enzymatic activity of recombinant SjPGK protein (rSjPGK) was 125 U/mg. Kinetic analyses with respect to 3-phosphoglycerate (3-PGA) as substrate gave a Km of 2.69 mmol/L and a Vmax of 748 μmol/min/mg protein. rSjPGK was highly stable over a range of pH 8.0-9.0 and temperature of 30°C-40 °C under physiological conditions. Immunolocalization analysis showed that SjPGK was mainly distributed in the tegument and parenchyma of schistosomes. Western blotting showed that rSjPGK had good immunogenicity. We vaccinated BALB/c mice with rSjPGK combined with Seppic 206 adjuvant. However, there were no significant reductions in the numbers of worms of eggs in the liver, as compared to adjuvant or blank control groups in two independent vaccination tests. This study provides the basis for further investigations into the biological function of SjPGK, although it might not be suitable as a potential vaccine candidate against schistosomiasis.
Topics: Amino Acid Sequence; Animals; Cloning, Molecular; Gene Expression Regulation, Enzymologic; Glyceric Acids; Male; Mice; Mice, Inbred BALB C; Phosphoglycerate Kinase; Phylogeny; Rabbits; Random Allocation; Rats; Rats, Wistar; Schistosoma japonicum; Sequence Alignment; Vaccination
PubMed: 26299245
DOI: 10.1016/j.exppara.2015.08.016 -
Parasitology Research Aug 2020
Adjuvant-free schistosome cathepsin L3 is an efficacious schistosomiasis vaccine-comment on Huang et al.: Characteristics and function of cathepsin L3 from Schistosoma japonicum.
Topics: Animals; Cathepsins; Schistosoma japonicum; Schistosomiasis; Vaccines
PubMed: 32507901
DOI: 10.1007/s00436-020-06737-w -
Scientific Reports Dec 2015The global spread of human infectious diseases is of considerable public health and biomedical interest. Little is known about the relationship between the distribution...
The global spread of human infectious diseases is of considerable public health and biomedical interest. Little is known about the relationship between the distribution of ancient parasites and that of their human hosts. Schistosoma japonicum is one of the three major species of schistosome blood flukes causing the disease of schistosomiasis in humans. The parasite is prevalent in East and Southeast Asia, including the People's Republic of China, the Philippines and Indonesia. We studied the co-expansion of S. japonicum and its human definitive host. Phylogenetic reconstruction based on complete mitochondrial genome sequences showed that S. japonicum radiated from the middle and lower reaches of the Yangtze River to the mountainous areas of China, Japan and Southeast Asia. In addition, the parasite experienced two population expansions during the Neolithic agriculture era, coinciding with human migration and population growth. The data indicate that the advent of rice planting likely played a key role in the spread of schistosomiasis in Asia. Moreover, the presence of different subspecies of Oncomelania hupensis intermediate host snails in different localities in Asia allowed S. japonicum to survive in new rice-planting areas, and concurrently drove the intraspecies divergence of the parasite.
Topics: Animals; Fossils; Genome, Mitochondrial; History, Ancient; Host-Parasite Interactions; Paleontology; Phylogeny; Schistosoma japonicum; Schistosomiasis; Humans
PubMed: 26686813
DOI: 10.1038/srep18058 -
Parasitology Research Jul 2009Schistosomiasis is considered the most important human helminthiasis in terms of morbidity and mortality. In this study, comparative soluble proteomic analysis of normal... (Comparative Study)
Comparative Study
Schistosomiasis is considered the most important human helminthiasis in terms of morbidity and mortality. In this study, comparative soluble proteomic analysis of normal cercariae and ultraviolet-irradiated attenuated cercariae (UVAC) from Schistosoma japonicum were carried out in view of the high efficiency of irradiation-attenuated cercariae vaccine. The results revealed that some proteins showed significant differential expression in the parasite after treatment with ultraviolet light. Total 20 protein spots were identified by mass spectrometry, corresponded to five groups according to their functions in the main that were structural and motor proteins (actin, et al.), energy metabolism associated enzymes (glyceraldehydes-3-phosphage dehydrogenase, et al.), signaling transduction pathway-associated molecules (14-3-3 protein, et al.), heat shock protein families (HSP 70 family, et al.), and other functional proteins (20S proteasome). Furthermore, our results indicated that the differential expression of the proteins by ultraviolet irradiation may be, at least partially, acquired by regulating the mRNA levels of corresponding proteins. These results may provide new clues for further exploring the mechanism of protective immunity induced by UVAC and may shed some light on the development of vaccines against schistosomiasis.
Topics: Animals; Electrophoresis, Gel, Two-Dimensional; Gene Expression Profiling; Helminth Proteins; Mass Spectrometry; Proteome; Schistosoma japonicum; Ultraviolet Rays
PubMed: 19290541
DOI: 10.1007/s00436-009-1387-z -
PloS One 2011The reed vole, Microtus fortis, is the only known mammalian host in which schistosomes of Schistosoma japonicum are unable to mature and cause significant pathogenesis....
The reed vole, Microtus fortis, is the only known mammalian host in which schistosomes of Schistosoma japonicum are unable to mature and cause significant pathogenesis. However, little is known about how Schistosoma japonicum maturation (and, therefore, the development of schistosomiasis) is prevented in M. fortis. In the present study, the ultrastructure of 10 days post infection schistosomula from BALB/c mice and M. fortis were first compared using scanning electron microscopy and transmission electron microscopy. Electron microscopic investigations showed growth retardation and ultrastructural differences in the tegument and sub-tegumental tissues as well as in the parenchymal cells of schistosomula from M. fortis compared with those in BALB/c mice. Then, microarray analysis revealed significant differential expression between the schistosomula from the two rodents, with 3,293 down-regulated (by ≥ 2-fold) and 71 up-regulated (≥ 2 fold) genes in schistosomula from the former. The up-regulated genes included a proliferation-related gene encoding granulin (Grn) and tropomyosin. Genes that were down-regulated in schistosomula from M. fortis included apoptosis-inhibited genes encoding a baculoviral IAP repeat-containing protein (SjIAP) and cytokine-induced apoptosis inhibitor (SjCIAP), genes encoding molecules involved in insulin metabolism, long-chain fatty acid metabolism, signal transduction, the transforming growth factor (TGF) pathway, the Wnt pathway and in development. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) and PI/Annexin V-FITC assays, caspase 3/7 activity analysis, and flow cytometry revealed that the percentages of early apoptotic and late apoptotic and/or necrotic cells, as well as the level of caspase activity, in schistosomula from M. fortis were all significantly higher than in those from BALB/c mice.
Topics: Animals; Annexin A5; Apoptosis; Arvicolinae; Caspases; Cell Proliferation; Down-Regulation; Female; Fluorescein-5-isothiocyanate; Gene Expression Profiling; In Situ Nick-End Labeling; Mice; Mice, Inbred BALB C; Necrosis; Oligonucleotide Array Sequence Analysis; Polymerase Chain Reaction; Propidium; Reproducibility of Results; Schistosoma japonicum; Survival Analysis; Up-Regulation
PubMed: 21731652
DOI: 10.1371/journal.pone.0021109 -
BMC Infectious Diseases Feb 2017Current diagnostic methods for Schistosoma japonicum infection are insensitive for low-density infections. Therefore, a new diagnostic assay based on recombinase...
BACKGROUND
Current diagnostic methods for Schistosoma japonicum infection are insensitive for low-density infections. Therefore, a new diagnostic assay based on recombinase polymerase amplification (RPA) technology was established and assessed for field applification.
METHODS
The S.japonicum RPA assay was developed to target highly repetitive retrotransposon SjR2 gene of S japonicum, and its sensitivity and specificity were assessed by serial dilution of S. japonicum genomic DNA and other related worm genomic DNA respectively. The RPA diagnostic validity was first evaluated in 60 fecal samples from healthy people and patients, and then compared with other diagnostic tests in 200 high-risk individuals living in endemic areas.
RESULTS
The real time RPA assay could detect 0.9 fg S. japonicum DNA within 15 min and distinguish S. japonicum from other worms. The validity analysis of RPA for the detection of S. japonicum in stool samples from 30 S. japonicum-infected patients and 30 healthy persons indicated 100% sensitivity and specificity. When testing 200 fecal or serum samples from a high-risk population, the percentage sensitivity of RPA was 100%, whereas that of indirect hemagglutination assay (IHA) and enzyme-linked immunosorbent assay (ELISA) were 80.3% and 85.2% respectively. In addition, the RPA presented better consistency with the stool-based tests than IHA and ELISA. Overall, the RPA was superior to other detection methods with respect to detection time, sensitivity, and convenience.
CONCLUSIONS
This is the first time we applied the RPA technology to the field evaluation of S. japonicum infection. And the results suggest that RPA-based assays can be used as a promising point-of-care test for the diagnosis of schistosomiasis.
Topics: Adolescent; Adult; Aged; Animals; Case-Control Studies; China; DNA, Helminth; Enzyme-Linked Immunosorbent Assay; Female; Hemagglutination Tests; Humans; Male; Middle Aged; Point-of-Care Systems; Polymerase Chain Reaction; Recombinases; Schistosoma japonicum; Schistosomiasis japonica; Sensitivity and Specificity; Young Adult
PubMed: 28222680
DOI: 10.1186/s12879-017-2182-6 -
Parasitology International Oct 2017Wnt signaling as mediated by the Frizzled family receptors plays a vital role in the early development of animal embryos, organ formation, tissue regeneration and other...
Wnt signaling as mediated by the Frizzled family receptors plays a vital role in the early development of animal embryos, organ formation, tissue regeneration and other physiological processes. In the present study, a novel Frizzled member, SjFz8, was isolated and characterized in Schistosoma japonicum. SjFz8 encodes an 1162-amino-acid protein with typical characteristics of Frizzled proteins. Quantitative real-time polymerase chain reaction analysis indicated that SjFz8 transcript level was highest in 7-day-old schistosomula. In adult stages, SjFz8 mRNA expression remained at a low level after male-female pairing. The immunohistochemical localization of the Fz8 protein revealed that it existed in almost all tissues of S. japonicum, including subtegumental muscle, parenchyma, oral suckers, ventral suckers, testes of the male and ovaries of the female. We speculated that the Wnt signaling pathway that was mediated by Fz8 might take part in regulating histogenesis and organogenesis during the schistosomulum period, and play an important role in regulating further growth and development of male and female worms.
Topics: Animals; Cloning, Molecular; Frizzled Receptors; Gene Expression; Helminth Proteins; Immunohistochemistry; Rabbits; Real-Time Polymerase Chain Reaction; Schistosoma japonicum; Sequence Analysis, Protein; Signal Transduction; Wnt Proteins
PubMed: 28385590
DOI: 10.1016/j.parint.2017.04.001 -
Parasitology Research Mar 2014Pairing of Schistosoma japonicum initiates female development, leads to female sexual maturation, and maintains this mature state. To understand the mechanism involved...
Pairing of Schistosoma japonicum initiates female development, leads to female sexual maturation, and maintains this mature state. To understand the mechanism involved in these processes, we studied parasites isolated from single- and double-sex cercariae-infected mice using deep-sequencing analysis, Solexa, to uncover pair-regulated transcriptional profiles. In this study, we report the results of high-throughput tag-sequencing (Tag-seq) analysis of the transcriptome of female worms 18 and 23 days postsingle- and double-sex infections. We sequenced over 3 million tags, obtained a total of 14,034, 27,251, 22,755, and 22,555 distinct tags corresponding to 5,773, 9,794, 8,885, and 8,870 tag-mapped genes for 23-day-old female schistosomula from double-sex infections (23DSI), 23-day-old female schistosomula from single-sex infections (23SSI), 18-day-old female schistosomula from double-sex infections (18DSI), and 18-day-old female schistosomula from single-sex infections (18SSI), respectively. Analyses of differentially expressed genes revealed similarities in the gene expression profiles between 18SSI and 18DSI as well as rational differential gene expression between 18SSI and 23SSI. However, fewer upregulated genes were found in 23DSI compared with 18DSI. Of the 3,446 differentially expressed genes between 23DSI and 23SSI, 2,913 genes were upregulated in 23SSI, whereas only 533 genes were upregulated in 23DSI. In these upregulated genes in 23DSI, phosphoglycerate mutase, superoxide dismutase, egg antigen, ribosomal proteins, ferritin-1 heavy chain, and eukaryotic translation initiation factor 2 were detected. Detection of these genes suggests that gene expression in 23DSI is specialized for functions such as promotion and maintenance of female sexual maturation and egg production. Quantitative real-time (RT)-PCR analysis confirmed the Solexa results, thereby supporting the reliability of the system. Our results offer new insights into the biological significance of pairing, which directs the expression of genes specific for sexual maturation and egg production.
Topics: Animals; Female; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gene Library; High-Throughput Nucleotide Sequencing; Mice; Schistosoma japonicum; Sexual Maturation; Transcriptome
PubMed: 24297695
DOI: 10.1007/s00436-013-3719-2 -
Annals of Tropical Medicine and... Mar 1998Experiments were performed to determine whether Schistosoma japonicum eggs are randomly dispersed in faeces and the effect of stirring faecal specimens prior to...
Experiments were performed to determine whether Schistosoma japonicum eggs are randomly dispersed in faeces and the effect of stirring faecal specimens prior to sampling. For each of 13 patients infected with S. japonicum, eggs were counted in 150 subsamples from a single stool specimen, using the Kato-Katz smear technique. Eggs were non-randomly distributed in all 13 stools, and showed an aggregated distribution. In most patients there were significant differences in the distribution of eggs between the centre and the surface of the stool. Stirring of the stool prior to sampling decreased the variability of counts.
Topics: Animals; Feces; Humans; Parasite Egg Count; Schistosoma japonicum; Specimen Handling
PubMed: 9625914
DOI: 10.1080/00034989860021 -
Experimental Parasitology May 2021Molecular diagnostics are powerful tools for disease detection but are typically confined to the laboratory environment due to the cumbersome methods required to extract...
Molecular diagnostics are powerful tools for disease detection but are typically confined to the laboratory environment due to the cumbersome methods required to extract nucleic acids from biological samples. Accurate diagnosis is essential for early detection of parasitic worm infections and for monitoring control programs, particularly during new transmission outbreaks to limit infection spread. We optimized the recently developed DNA dipstick technology to purify Schistosoma japonicum DNA from different life stages in <60 s. We successfully detected DNA from adult worms, eggs and infected snails. The speed and simplicity of this method enables the point-of-care detection of S. japonicum.
Topics: Animals; DNA, Helminth; Liver; Mice; Molecular Diagnostic Techniques; Nucleic Acid Amplification Techniques; Point-of-Care Testing; Real-Time Polymerase Chain Reaction; Schistosoma japonicum; Schistosomiasis japonica; Snails
PubMed: 33713659
DOI: 10.1016/j.exppara.2021.108098