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Parasitology Research Jul 2015The Vasa gene is a vital germline marker to study the origin and development of germ cells and gonads in many organisms. Until now, little information was available...
The Vasa gene is a vital germline marker to study the origin and development of germ cells and gonads in many organisms. Until now, little information was available about the characteristics of the Vasa gene in Schistosoma japonicum (S. japonicum). In this study, we cloned the open reading frame (ORF) of the S. japonicum Vasa-like gene (Sj-Vasa). The expression pattern and tissue localization of Sj-Vasa were also analyzed. Our results showed that Sj-Vasa shared the general feature of DEAD-box family member proteins. Sj-Vasa was transcribed and expressed throughout the S. japonicum life cycle with transcription exhibiting high levels at day 24 in both male and female worms, and the expression level in the female was always higher than that in the male. Sj-Vasa protein was localized in a variety of tissues of adult schistosomes, including the gonads (ovary, vitellarium, and testes), the subtegument, and some cells of the parenchyma. To our knowledge, this is the first report of preliminary characterization and expression of the Vasa-like gene that may play an important role in the development of the worm, especially in reproductive organs of S. japonicum.
Topics: Animals; Female; Gene Expression Regulation, Developmental; Helminth Proteins; Humans; Male; Ovary; Schistosoma japonicum; Schistosomiasis japonica; Testis
PubMed: 25899325
DOI: 10.1007/s00436-015-4473-4 -
Frontiers in Cellular and Infection... 2023Schistosomiasis, the second most neglected tropical disease defined by the WHO, is a significant zoonotic parasitic disease infecting approximately 250 million people...
BACKGROUND
Schistosomiasis, the second most neglected tropical disease defined by the WHO, is a significant zoonotic parasitic disease infecting approximately 250 million people globally. This debilitating disease has seriously threatened public health, while only one drug, praziquantel, is used to control it. Because of this, it highlights the significance of identifying more satisfactory target genes for drug development. Protein translocation into the endoplasmic reticulum (ER) is vital to the subsequent localization of secretory and transmembrane proteins. The signal peptidase complex (SPC) is an essential component of the translocation machinery and functions to cleave the signal peptide sequence (SP) of secretory and membrane proteins entering the ER. Inhibiting the expression of SPC can lead to the abolishment or weaker cleavage of the signal peptide, and the accumulation of uncleaved protein in the ER would affect the survival of organisms. Despite the evident importance of SPC, studies exploring its function have yet to be reported in .
METHODS
The SPC consists of four proteins: and . RNA interference was used to investigate the impact of SPC components on schistosome growth and development . qPCR and hybridization were applied to localize the expression. Mayer's carmalum and Fast Blue B staining were used to observe morphological changes in the reproductive organs of dsRNA-treated worms. The effect of inhibitor treatment on the worm's viability and pairing was also examined .
RESULTS
Our results showed that RNAi-SPC delayed the worm's normal development and was even lethal for schistosomula . Among them, the expression of was significantly higher in the developmental stages of the reproductive organs in schistosomes. Moreover, possessed high expression in the worm tegument, testes of male worms and the ovaries and vitellarium of female worms. The SPC25 knockdown led to the degeneration of reproductive organs, such as the ovaries and vitellarium of female worms. The exhaustion also reduced egg production while reducing the pathological damage of the eggs to the host. Additionally, the SPC-related inhibitor AEBSF or suppressing the expression of also impacted cultured worms' pairing and viability .
CONCLUSIONS
These data demonstrate that SPC is necessary to maintain the development and reproduction of . This research provides a promising anti-schistosomiasis drug target and discovers a new perspective on preventing worm fecundity and maturation.
Topics: Animals; Male; Female; Schistosoma japonicum; Membrane Proteins; Praziquantel; Protein Sorting Signals
PubMed: 36936776
DOI: 10.3389/fcimb.2023.1136056 -
Cell Communication and Signaling : CCS Dec 2023Macrophages and neutrophils are rapidly recruited around Schistosome eggs to form granulomas. Extracellular traps (ETs) of macrophages and neutrophils are part of the...
BACKGROUND
Macrophages and neutrophils are rapidly recruited around Schistosome eggs to form granulomas. Extracellular traps (ETs) of macrophages and neutrophils are part of the pathogen clearance armamentarium of leukocytes. Schistosome eggs possess the ability to resist attack by the host's immune cells and survive by employing various immune evasion mechanisms, including the release of extracellular vesicles (EVs). However, the specific mechanisms by which Schistosome egg-derived EVs (E-EVs) evade the immune response and resist attack from macrophage and neutrophil ETs remain poorly understood. In this study, we aimed to investigate the association between E-EVs and macrophage/neutrophil ETs.
METHODS
EVs were isolated from the culture supernatant of S. japonicum eggs and treated macrophages and neutrophils with E-EVs and Sja-miR-71a. The formation of ETs was then observed. Additionally, we infected mice with S. japonicum, administered HBAAV2/9-Sja-miR-71a, and the formation of macrophage ETs (METs) and neutrophil ETs (NETs) in the livers was measured. Sema4D-knockout mice, RNA sequencing, and trans-well assay were used to clarify Sja-miR-71a in E-EVs inhibits METs and NETs formation via the Sema4D/ PPAR-γ/ IL-10 axis.
RESULTS
Our findings revealed that E-EVs were internalized by macrophages and neutrophils, leading to the inhibition of METs and NETs formation. The highly expressed Sja-miR-71a in E-EVs targeted Sema4D, resulting in the up-regulation of IL-10 and subsequent inhibition of METs and NETs formation. Sema4D knockout up-regulated IL-10 expression and inhibited the formation of METs and NETs. Furthermore, we further demonstrated that Sja-miR-71a inhibits METs and NETs formation via the Sema4D/ PPAR-γ/ IL-10 axis.
CONCLUSIONS
In summary, our findings provide new insights into the immune evasion abilities of Schistosome eggs by demonstrating their ability to inhibit the formation of METs and NETs through the secretion of EVs. This study enhances our understanding of the host-pathogen interaction and may have implications for the development of novel therapeutic approaches. Video Abstract.
Topics: Mice; Animals; Extracellular Traps; Schistosoma japonicum; Interleukin-10; Peroxisome Proliferator-Activated Receptors; Neutrophils; Extracellular Vesicles; MicroRNAs; Macrophages
PubMed: 38129877
DOI: 10.1186/s12964-023-01395-8 -
The Journal of Parasitology May 2021We investigated the effect of Schistosoma japonicum adenylate kinase 1 (Sjak1) on the growth and development of schistosomula. Quantitative real-time PCR showed that...
We investigated the effect of Schistosoma japonicum adenylate kinase 1 (Sjak1) on the growth and development of schistosomula. Quantitative real-time PCR showed that Sjak1 mRNA was expressed in 3-, 10-, 14-, 18-, and 21-day-old schistosomula, and its levels increased gradually with the development of S. japonicum. Using immunohistochemical techniques, ak1 protein was found to be mainly distributed in the tegument and some parenchymal tissues of the schistosomula. Double-stranded RNA-mediated knockdowns of ak1 decreased ak1 mRNA transcripts by more than 90%, and western blot results showed that expression of ak1 protein was decreased by 66%. Scanning electron microscopy following the RNA-mediated ak1 knockdown showed that the sensory papillae did not develop. Transmission electron microscopy showed a lower mean thickness of the tegument in the Sjak1 interference group than in the negative control group. Terminal deoxynucleotidyl transferase dUTP nick-end labeling suggested higher apoptosis in the interference group than the negative control group. These results showed that ak1 may be involved in the growth and development of S. japonicum schistosomula and especially in the development of the integument. Consequently, ak1 may be a potential target in developing prevention methods for schistosomiasis in the future.
Topics: Adenylate Kinase; Animals; Apoptosis; Blotting, Western; DNA; Female; Gene Expression Regulation, Enzymologic; Gene Knockdown Techniques; Gene Silencing; Immunohistochemistry; In Situ Nick-End Labeling; Liver; Mice; Mice, Inbred ICR; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; RNA Interference; RNA, Messenger; Rabbits; Real-Time Polymerase Chain Reaction; Schistosoma japonicum; Snails
PubMed: 34153095
DOI: 10.1645/19-113 -
Molecular and Biochemical Parasitology Nov 2022Glutathione transferases (GSTs) are major detoxification enzymes vital for the survival and reproduction of schistosomes during infection in humans. Schistosoma encode... (Review)
Review
Glutathione transferases (GSTs) are major detoxification enzymes vital for the survival and reproduction of schistosomes during infection in humans. Schistosoma encode two GST isoenzymes, the 26- and 28-kDa isoforms, that show different substrate specificities and cellular localisations. Bromosulfophthalein (BSP) has been identified and characterised as a potent 26-kDa Schistosoma japonicum GST (Sj26GST) inhibitor with an anthelmintic potential. This study describes the structure, function, and ligandin properties of the 28-kDa Schistosoma japonicum GST (Sj28GST) towards BSP. Enzyme kinetics show that BSP is a potent enzyme inhibitor, with a specific activity decreases from 60.4 µmol/min/mg to 0.0742 µmol/min/mg and an IC in the micromolar range of 0.74 µM. Far-UV circular dichroism confirmed that purified Sj28GST follows a typical GST fold, which is predominantly alpha-helical. Fluorescence spectroscopy suggests that BSP binding occurs at a site distinct from the glutathione-binding site (G-site); however, the binding does not alter the local G-site environment. Isothermal titration calorimetry studies show that the binding of BSP to Sj28GST is exergonic (∆G°= -33 kJ/mol) and enthalpically-driven, with a stoichiometry of one BSP per dimer. The stability of Sj28GST (∆G = 4.7 kcal/mol) is notably lower than Sj26GST, owing to differences in the enzyme's dimeric interfaces. We conclude that Sj28GST shares similar biophysical characteristics with Sj26GST based on its kinetic properties and susceptibility to low concentrations of BSP. The study supports the potential benefits of re-purposing BSP as a potential drug or prodrug to mitigate the scourge of schistosomiasis.
Topics: Animals; Binding Sites; Calorimetry; Glutathione; Glutathione Transferase; Schistosoma japonicum; Sulfobromophthalein
PubMed: 36195242
DOI: 10.1016/j.molbiopara.2022.111524 -
Parasites & Vectors Jan 2018Schistosomiasis caused by Schistosoma japonicum is among the most serious endemic zoonoses in China. To study interactions between schistosomula, the pre-adult juvenile...
BACKGROUND
Schistosomiasis caused by Schistosoma japonicum is among the most serious endemic zoonoses in China. To study interactions between schistosomula, the pre-adult juvenile stage, and hosts, it is important to study the functions of key genes involved in schistosomula growth and development. Programmed cell death protein 10 (pcdp10) is an important apoptosis-related gene with various biological functions. This study described the molecular characterization of S. japonicum PCDP10 (SjPCDP10) and evaluated its functions in schistosomula.
METHODS
Real-time quantitative polymerase chain reaction (qPCR) and western blot were used to detect Sjpcdp10 mRNA and protein levels, respectively, at different developmental stages. Immunolocalization was performed to determine SjPCDP10 expression in the parasite. RNA interference (RNAi) experiments were used to assess gene functions associated with SjPCDP10 in schistosomula growth and development.
RESULTS
Real-time qPCR revealed that Sjpcdp10 was expressed during all investigated developmental stages and upregulated during schistosomula growth and development. Histochemical localization showed that SjPCDP10 was mainly distributed in the teguments of schistosomula in all investigated stages and part of the parenchymal area of 14-, 18-, and 21-day-old schistosomula. Following Sjpcdp10 knockdown by RNAi, the lengths, widths, areas, and volumes of schistosomula were significantly lower than those in the control group. Scanning electron microscopy showed that the body surfaces of schistosomula subjected to RNAi were seriously damaged, with few tegumental spines and sensory papillae. Transmission electron microscopy indicated that the teguments of Sjpcdp10-knockdown schistosomula were incomplete, the number of layers was reduced, and the thickness decreased significantly as compared with those in the control group. Furthermore, terminal deoxynucleotidyl transferase dUTP nick-end labelling results showed that the rate of apoptosis in Sjpcdp10-knockdown schistosomula was significantly higher than that in the control group.
CONCLUSIONS
Sjpcdp10-knockdown influenced the growth and development of schistosomula. Therefore, our results indicated that SjPCDP10 contributes to the regulation of cell apoptosis and is essential for schistosomula growth and development.
Topics: Animal Structures; Animals; Apoptosis; Apoptosis Regulatory Proteins; Blotting, Western; Gene Expression Profiling; Gene Knockdown Techniques; Helminth Proteins; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Real-Time Polymerase Chain Reaction; Schistosoma japonicum
PubMed: 29347959
DOI: 10.1186/s13071-018-2636-8 -
Parasites & Vectors Sep 2020Schistosoma japonicum, which inhabits the mesenteric vein of the mammalian hosts for about 20 to 30 years, is subjected to the oxidative stresses from the host defense...
BACKGROUND
Schistosoma japonicum, which inhabits the mesenteric vein of the mammalian hosts for about 20 to 30 years, is subjected to the oxidative stresses from the host defense mechanism during their intra-mammalian stages. To counteract this host immune attack, the parasite utilizes their antioxidant system for survival inside the host. Peroxiredoxins (Prxs), thiol-specific antioxidant proteins, play an essential role for protecting the parasite against oxidative stress by reducing hydrogen peroxide to water. Only three types of 2-Cys Prxs have been previously characterized in S. japonicum whereas a fourth Prx has been identified for Schistosoma mansoni as Prx-4. A sequence coding homologous to this gene in the S. japonicum database was identified, characterized and expressed as recombinant SjPrx-4 protein (rSjPrx-4). Furthermore, rSjPrx-4 was evaluated in this study for its diagnostic potentials in detecting S. japonicum infection in humans.
RESULTS
The gene found in the parasite genome contained 2 active-site cysteines with conserved sequences in the predicted amino acid (AA) sequence and showed 75% identity with that of the previously characterized Prx (TPx-1) of S. japonicum. The gene was expressed in different stages of schistosome life-cycle with highest transcription level in the adult male. The gene was cloned into a plasmid vector and then transfected into Escherichia coli for expression of rSjPrx-4. Anti-rSjPrx-4 mouse sera recognized native SjPrx-4 in egg and adult worm lysate by western blotting. The result of a mixed function oxidation assay in which rSjPrx-4 prevented the nicking of DNA from hydroxyl radicals confirmed its antioxidant activity. Subsequently, immunolocalization analysis showed the localization of SjPrx-4 inside the egg, on the tegument and in the parenchyma of the adult worm. Enzyme-linked immunosorbent assay results showed that rSjPrx-4 has 83.3% sensitivity and 87.8% specificity. Its diagnostic potential was further evaluated in combination with recombinant SjTPx-1 protein, yielding an improved sensitivity and specificity of 90% and 92.7%, respectively.
CONCLUSIONS
These results suggest that SjPrx-4 plays a role as an antioxidant dealing with oxidative stresses of S. japonicum, and its diagnostic potential improved by coupling it with SjTPx-1 is a proof for developing a serological test with better diagnostic performance for human schistosomiasis.
Topics: Animals; Antigens, Helminth; Antioxidants; Biomarkers; Enzyme-Linked Immunosorbent Assay; Gene Expression; Genes, Helminth; Immunohistochemistry; Peroxiredoxins; Schistosoma japonicum; Schistosomiasis japonica; Serologic Tests
PubMed: 32867818
DOI: 10.1186/s13071-020-04313-w -
PLoS Neglected Tropical Diseases Mar 2021Most of national schistosomiasis elimination programmes in Asia are relying on stool examination, particularly Kato Katz stool examination technique for regular... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Most of national schistosomiasis elimination programmes in Asia are relying on stool examination, particularly Kato Katz stool examination technique for regular transmission monitoring. However, the Kato-Katz technique has shown low sensitivity for the detection of light-intensity infections, and therefore highly sensitive diagnostic tools are urgently required to monitor prevalence of infection in low transmission settings. The objective of this systematic review was to evaluate and synthesize the performance of diagnostic tests for detecting Schistosoma japonicum and S. mekongi infection in people living in endemic areas.
METHODOLOGY/PRINCIPAL FINDINGS
We comprehensively searched these nine electronic databases and other resources until July 2019, with no language or publication limits: PubMed, EMBASE, MEDLINE, Web of Science, BIOSIS Citation Index, HTA, CINAHL PLUS, The Cochrane Library, and PsycINFO. We included original studies that assessed diagnostic performance using antibody, antigen, and molecular tests with stool examination test as a reference standard. Two reviewers independently extracted a standard set of data and assessed study quality. We estimated the pooled estimates of sensitivity and specificity for each index test. We used diagnostic odds ratio to determine the overall accuracy and hierarchical summary receiver operating characteristics (HSROC) curve to assess the index tests performance. Fifteen studies (S. japonicum [n = 13] and S. mekongi [n = 2]) testing 15,303 participants were included in the review. Five studies reported performance of enzyme-linked immunosorbent assay (ELISA), seven studies reported indirect hemagglutination assay (IHA), and four studies reported polymerase chain reaction (PCR) for detecting S. japonicum. The pooled sensitivity and specificity were 0.93 (95% CI: 0.84-0.98) and 0.40 (95% CI: 0.29-0.53) for ELISA, 0.97 (95% CI: 0.90-0.99) and 0.66 (95% CI: 0.58-0.73) for IHA, and 0.89 (95% CI: 0.71-0.96) and 0.49 (95% CI: 0.29-0.69) for PCR respectively. A global summary indicated the best performance for IHA, closely followed by ELISA. We were unable to perform meta-analysis for S. mekongi due to insufficient number of studies.
CONCLUSIONS/SIGNIFICANCE
IHA showed the highest detection accuracy for S. japonicum. Further studies are needed to determine the suitable diagnostic methods to verify the absence of transmission of S. mekongi and also to compare detection accuracy against more sensitive reference standards such as PCR.
Topics: Animals; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique, Indirect; Humans; Polymerase Chain Reaction; Schistosoma; Schistosoma japonicum
PubMed: 33730048
DOI: 10.1371/journal.pntd.0009244 -
The Journal of Parasitology Sep 2021The Schistosoma japonicum fatty acid-binding protein (FABP) is used in the cell membrane to absorb and transport fatty acids, which cannot be resynthesized by the...
The Schistosoma japonicum fatty acid-binding protein (FABP) is used in the cell membrane to absorb and transport fatty acids, which cannot be resynthesized by the organism and combined with hydrophobic ligands. Among the 5 stages of the worm life cycle examined, FABP messenger ribonucleic acid (mRNA) expression was highest in male adult worms, followed by the liver-stage schistosome, and was the lowest in the lung-stage schistosome. The fabp gene-coding region was cloned and expressed to obtain recombinant S. japonicum FABP (rSjFABP) with a molecular weight of approximately 18 kDa. Mice were then immunized against rSjFABP to prepare anti-FABP serum. Using immunohistochemical techniques, FABP protein was found to localize to the eggshell, parenchyma, and digestive tract. Double-stranded RNA-mediated knockdown of FABP mRNA by RNA interference decreased the number of transcripts by >70%. Moreover, the egg production rate decreased, whereas the abnormal egg ratio was significantly increased in the FABP-silenced group compared with the negative control group (P < 0.05). These results demonstrate that FABP localizes in adults and in various stages. FABP contributes to the egg-laying capacity of adults, which may be related to the reproductive function of S. japonicum.
Topics: Animals; Fatty Acid-Binding Proteins; Female; Gene Expression Regulation; Helminth Proteins; Immunohistochemistry; Liver; Lung; Male; Mice; Mice, Inbred BALB C; RNA, Messenger; Real-Time Polymerase Chain Reaction; Schistosoma japonicum
PubMed: 34198340
DOI: 10.1645/19-42 -
Frontiers in Cellular and Infection... 2021Multi-organ failure caused by the inflammatory cytokine storm induced by severe infection is the major cause of death for sepsis. -Cys is a cysteine protease inhibitor...
Multi-organ failure caused by the inflammatory cytokine storm induced by severe infection is the major cause of death for sepsis. -Cys is a cysteine protease inhibitor secreted by with strong immunomodulatory functions on host immune system. Our previous studies have shown that treatment with -Cys recombinant protein (r-Cys) attenuated inflammation caused by sepsis. However, the immunological mechanism underlying the immunomodulation of -Cys for regulating inflammatory diseases is not yet known. In this study, we investigated the effect of -Cys on the macrophage M2 polarization and subsequent therapeutic effect on sepsis. The r-Cys was expressed in yeast . Incubation of mouse bone marrow-derived macrophages (BMDMs) with yeast-expressed r-Cys significantly activated the polarization of macrophages to M2 subtype characterized by the expression of F4/80 CD206 with the elated secretion of IL-10 and TGF-β. Adoptive transfer of r-Cys treated BMDMs to mice with sepsis induced by cecal ligation and puncture (CLP) significantly improved their survival rates and the systemic clinical manifestations of sepsis compared with mice receiving non-treated normal BMDMs. The therapeutic effect of -Cys-induced M2 macrophages on sepsis was also reflected by the reduced pathological damages in organs of heart, lung, liver and kidney and reduced serological levels of tissue damage-related ALT, AST, BUN and Cr, associated with downregulated pro-inflammatory cytokines (IFN-gamma and IL-6) and upregulated regulatory anti-inflammatory cytokines (IL-10 and TGF-β). Our results demonstrated that -Cys is a strong immunomodulatory protein with anti-inflammatory features through activating M2 macrophage polarization. The findings of this study suggested that -Cys itself or -Cys-induced M2 macrophages could be used as therapeutic agents in the treatment of sepsis or other inflammatory diseases.
Topics: Animals; Cystatins; Macrophages; Mice; Saccharomycetales; Schistosoma japonicum; Sepsis
PubMed: 33718268
DOI: 10.3389/fcimb.2021.617461