Changing seroprevalence of schistosomiasis japonica in China from 1982 to 2020: A systematic review and spatial analysis.

BACKGROUND: Schistosomiasis is a global public health issue. In China, while the seroprevalence of Schistosomiasis japonica has currently reduced to a relatively low level, risk of infection still exists in certain areas. However, there has been a lack of comprehensive research on the long-term trends of national seroprevalence, changes across age groups, and characteristics in spatial distribution, which is crucial for effectively targeting interventions and achieving the goal of eliminating schistosomiasis by 2030. Our study aimed to address this gap by analyzing the long-term trends of Schistosomiasis japonica seroprevalence in China from 1982 to 2020 based on the data from diverse sources spanning a period of 39 years. METHODOLOGY: Seroprevalence data were collected from literature databases and national schistosomiasis surveillance system. Meta-analysis was conducted to estimate the seroprevalence. Joinpoint model was used to identify changing trend and inflection point. Inverse distance weighted interpolation was used to determine the spatial distribution of seroprevalence. PRINCIPAL FINDINGS: The seroprevalence decreased from 34.8% in 1982 to 2.4% in 2020 in China. Before 2006, the seroprevalence was higher in the middle age group, and a pattern of increasing with age was observed afterwards. The areas with high seroprevalence existed in Dongting Lake, Poyang Lake, Jianghan Plain, the Anhui branch of the Yangtze River and some localized mountainous regions in Sichuan and Yunnan provinces. CONCLUSIONS/SIGNIFICANCE: There was a significant decline in the seroprevalence of Schistosomiasis japonica from 1982 to 2020 in China. Nevertheless, schistosomiasis has not been eradicated; thus, implementing precise and personalized monitoring measures is crucial for the elimination of schistosomiasis, especially in endemic areas and with a particular focus on the elderly.

Induction of hepatic fibrosis in mice with schistosomiasis by extracellular microRNA-30 derived from Schistosoma japonicum eggs.

Background: Schistosomiasis is a zoonotic parasitic disorder induced by the infestation of schistosomes, a genus of trematodes. MicroRNAs (miRNAs) in egg-derived exosomes are crucial for modulating the host's immune responses and orchestrating the pathophysiological mechanisms. Although the exosomes secreted by S. japonicum contain abundant miRNAs, the specific roles of these miRNAs in the pathogenesis of schistosomiasis-induced hepatic fibrosis are yet to be comprehensively elucidated. The egg exosomes of S. japonicum secrete miRNA-30, a novel miRNA. Methods: In vitro, the effect of miRNA-30 was evaluated by transfecting HSCs with miRNA mimics. The target gene biosignature for miRNA-30 was predicted using the miRDB software. The effect of miRNA-30 in hepatic fibrosis was evaluated by either elevating its expression in healthy mice or by inhibiting its activity in infected mice by administration of recombinant adeno-associated virus serotype eight vectors expressing miRNA-30 or miRNA sponges. Results: This novel miRNA can activate hepatic stellate cells (HSCs), the prinary effector cells of hepatic fibrosis, in vitro, i.e., it significantly increases the fibrogenic factors Col1(α1), Col3(α1), and α-SMA at both mRNA and protein levels. In addition, miRNA-30 may activate HSCs by targeting the host RORA gene. In addition, in vivo experiments were conducted by administering a recombinant adeno-associated viral vector to modulate the expression levels of miRNA-30. The overexpression of miRNA-30 in healthy mice significantly elevated the expression of Col1(α1), Col3(α1), and α-SMA at both the transcriptomic and proteomic scales. This overexpression was coupled with a pronounced augmentation in the hepatic hydroxyproline content. Conversely, the in vivo silencing of miRNA-30 in infected mice induced a considerable reduction in the size of hepatic granulomas and areas of collagen deposition. Hence, in vivo, modulation of miRNA-30 expression may play a pivotal role in ameliorating the severity of hepatic fibrosis in mice afflicted with S. japonica. Conclusions: The study results suggest that miRNA-30 may augment schistosomiasis-induced hepatic fibrosis through a probable interaction with the host RORA. Our study may improve the current theoretical framework regarding cross-species regulation by miRNAs of hepatic fibrosis in schistosomiasis.

Artemisitene shows superiority over artemisinin in preventing Schistosoma japonica-induced liver disease.

BACKGROUND: Artemisinin (ART) analogs, such as dihydroartemisinin, arteether, artemether, and artesunate, all featuring an endoperoxide bridge, have demonstrated efficacy against schistosomiasis. Artemisitene (ATT), which contains an additional α, ß-unsaturated carbonyl structure, has shown enhanced biological activities. This study aims to evaluate the anti-schistosomaiasis japonica activity of ATT and compare it with ART. METHODS: We assessed liver inflammation and fibrosis in mice using hematoxylin and eosin staining and Sirius red staining, respectively. RNA sequencing analyzed transcriptomics in female and male Schistosoma japonicum (S. japonicum) adult worms and mice livers, with cytokine profiling and flow cytometry to study immune responses under ART or ATT treatment. RESULTS: ATT exhibits a marked reduction in female S. japonicum adult worms and egg numbers, damaging the adult worms' surface. It also influences the transcription of genes related to cellular anatomical structures. Notably, ATT treatment resulted in significant reductions in liver granuloma size and collagen area, alongside lowering serum levels of glutamic pyruvic and glutamic oxaloacetic transaminase more effectively than ART. Both ART and ATT markedly decreased neutrophil frequency in the liver and elevated eosinophil counts. However, only ATT treatment significantly reduced the M1/M2 and Th1/Th2 indices, indicating a pronounced shift in immune response profiles. ATT-affected host immunity correlated with the extent of liver fibrosis and the count of single males more strongly than ART. CONCLUSION: ATT, as a novel preventive strategy for schistosomiasis japonica in mice, significantly outperforms ART.

Total flavonoids of litchi Seed alleviates schistosomiasis liver fibrosis in mice by suppressing hepatic stellate cells activation and modulating the gut microbiomes.

Infection with Schistosoma japonicum (S. japonicum) is an important zoonotic parasitic disease that causes liver fibrosis in both human and domestic animals. The activation of hepatic stellate cells (HSCs) is a crucial phase in the development of liver fibrosis, and inhibiting their activation can alleviate this progression. Total flavonoids of litchi seed (TFL) is a naturally extracted drug, and modern pharmacological studies have shown its anti-fibrotic and liver-protective effects. However, the role of TFL in schistosomiasis liver fibrosis is still unclear. This study investigated the therapeutic effects of TFL on liver fibrosis in S. japonicum infected mice and explored its potential mechanisms. Animal study results showed that TFL significantly reduced the levels of Interleukin-1ß (IL-1ß), Tumor Necrosis Factor-α (TNF-α), Interleukin-4 (IL-4), and Interleukin-6 (IL-6) in the serum of S. japonicum infected mice. TFL reduced the spleen index of mice and markedly improved the pathological changes in liver tissues induced by S. japonicum infection, decreasing the expression of alpha-smooth muscle actin (α-SMA), Collagen I and Collagen III protein in liver tissues. In vitro studies indicated that TFL also inhibited the activation of HCSs induced by Transforming Growth Factor-ß1 (TGF-ß1) and reduced the levels of α-SMA. Gut microbes metagenomics study revealed that the composition, abundance, and functions of the mice gut microbiomes changed significantly after S. japonicum infection, and TLF treatment reversed these changes. Therefore, our study indicated that TFL alleviated granulomatous lesions and improved S. japonicum induced liver fibrosis in mice by inhibiting the activation of HSCs and by improving the gut microbiomes.

Schistosomicidal effects of histone acetyltransferase inhibitors against Schistosoma japonicum juveniles and adult worms in vitro.

BACKGROUND: Schistosomiasis is a relatively neglected parasitic disease that afflicts more than 250 million people worldwide, for which the control strategy relies mainly on mass treatment with the only available drug, praziquantel (PZQ). This approach is not sustainable and is a priority for developing novel drug candidates for the treatment and control of schistosomiasis. METHODOLOGYS/PRINCIPAL FINDINGS: In our previous study, we found that DW-3-15, a kind of PZQ derivative, could significantly downregulate the expression of the histone acetyltransferase of Schistosoma japonicum (SjHAT). In this study, several commercially available HAT inhibitors, A485, C646 and curcumin were screened in vitro to verify their antischistosomal activities against S. japonicum juveniles and adults. Parasitological studies and scanning electron microscopy were used to study the primary action characteristics of HAT inhibitors in vitro. Quantitative real-time PCR was employed to detect the mRNA level of SjHAT after treatment with different HAT inhibitors. Our results demonstrated that curcumin was the most effective inhibitor against both juveniles and adults of S. japonicum, and its schistosomicidal effects were time- and dose dependent. However, A485 and C646 had limited antischistosomal activity. Scanning electron microscopy demonstrated that in comparison with DW-3-15, curcumin caused similar tegumental changes in male adult worms. Furthermore, both curcumin and DW-3-15 significantly decreased the SjHAT mRNA level, and curcumin dose-dependently reduced the SjHAT expression level in female, male and juvenile worms. CONCLUSIONS: Among the three commercially available HATs, curcumin was the most potent against schistosomes. Both curcumin and our patent compound DW-3-15 markedly downregulated the expression of SjHAT, indicating that SjHAT may be a potential therapeutic target for developing novel antischistosomal drug candidates.

Proliferation of MDSCs may indicate a lower CD4+ T cell immune response in schistosomiasis japonica.

BACKGROUND: Schistosoma japonicum (S. japonicum) is the main species of Schistosoma prevalent in China. Myeloid-derived suppressor cells (MDSCs) are important immunoregulatory cells and generally expand in parasite infection, but there is little research relating to MDSCs in Schistosoma infection. METHODS: Fifty-six S. japonicum-infected patients were included in this study. MDSCs and percentages and absolute cell numbers of lymphocyte subsets, including CD3+ T cells, CD4+ T cells, CD8+ T cells, B cells and natural killer (NK) cells were detected using flow cytometry. The degree of liver fibrosis was determined using color Doppler ultrasound. RESULTS: Patients infected with S. japonicum had a much higher percentage of MDSCs among peripheral blood mononuclear cells (PBMCs) than the healthy control. Regarding subpopulations of MDSCs, the percentage of granulocytic myeloid-derived suppressor cells (G-MDSCs) was clearly increased. Correlation analysis showed that the absolute cell counts of T-cell subsets correlated negatively with the percentages of MDSCs and G-MDSCs among PBMCs. The percentage of G-MDSCs in PBMCs was also significantly higher in patients with liver fibrosis diagnosed by color doppler ultrasound (grade > 0), and the percentage of G-MDSCs in PBMCs and liver fibrosis grading based on ultrasound showed a positive correlation. CONCLUSION: S. japonicum infection contributes to an increase in MDSCs, especially G-MDSCs, whose proliferation may inhibit the number of CD4+ T cells in peripheral blood. Meanwhile, there is a close relationship between proliferation of G-MDSCs and liver fibrosis in S. japonicum-infected patients.

Title: La prolifération des MDSC peut indiquer une réponse immunitaire des lymphocytes T CD4+ plus faible dans la schistosomiase japonica. Abstract: Contexte : Schistosoma japonicum est la principale espèce de Schistosoma répandue en Chine. Les cellules myéloïdes suppressives (MDSC) sont des cellules immunorégulatrices importantes et se développent généralement lors d'une infection parasitaire, mais il existe peu de recherches sur les MDSC dans l'infection à Schistosoma. Méthodes : Cinquante-six patients infectés par S. japonicum ont été inclus dans cette étude. Les MDSC, les pourcentages et les nombres absolus des sous-ensembles de lymphocytes, notamment les lymphocytes T CD3+, les lymphocytes T CD4+, les lymphocytes T CD8+, les lymphocytes B et les cellules tueuses naturelles (NK) ont été détectés par cytométrie en flux. Le degré de fibrose hépatique a été déterminé par échographie Doppler couleur. Résultats : Les patients infectés par S. japonicum présentaient un pourcentage beaucoup plus élevé de MDSC parmi les cellules mononucléées du sang périphérique (CMSP) que les patients sains. En ce qui concerne les sous-populations de MDSC, le pourcentage de cellules suppressives granulocytaires dérivées de myéloïdes (G-MDSC) était augmenté de manière évidente. L'analyse de corrélation a montré que le nombre absolu des cellules des sous-ensembles de lymphocytes T était en corrélation négative avec les pourcentages de MDSC et de G-MDSC parmi les CMSP. Le pourcentage de G-MDSC dans les CMSP était également significativement plus élevé chez les patients présentant une fibrose hépatique diagnostiquée par échographie Doppler couleur (grade > 0), et le pourcentage de G-MDSC dans les CMSP et le classement de la fibrose hépatique basé sur l'échographie ont montré une corrélation positive. Conclusion : L'infection à S. japonicum contribue à une augmentation des MDSC, notamment des G-MDSC, dont la prolifération pourrait inhiber le nombre de lymphocytes T CD4+ dans le sang périphérique. Parallèlement, il existe une relation étroite entre la prolifération des G-MDSC et la fibrose hépatique chez les patients infectés par S. japonicum.

Interactive and lag effects of environmental factors on the density of schistosome-transmitting Oncomelania hupensis: A twelve-year monthly repeated survey.

Schistosomiasis is a significant public health threat, and Oncomelania hupensis is the only intermediate host for schistosoma japonicum. We conducted 12-year monthly repeated surveys to explore the interactive and lag effects of environmental factors on snail density and to monitor their long-term and seasonal trends in a bottomland around the Dongting Lake region in China. Relevant environmental data were obtained from multiple sources. A Bayesian kernel machine regression model and a Bayesian temporal model combined with a distributed lag model were constructed to analyze interactive and lag effects of environmental factors on snail density. The results indicated the average annual snail density in the study site exhibited an increasing and then decreasing trend, peaking in 2013. Snail densities were the highest in October and the lowest in January in a year. Normalized Difference Vegetation Index (NDVI) and water level were the most effective predictors of snail density, with potential interactions among temperature, precipitation, and NDVI. The mean minimum temperature in January, water level, precipitation and NDVI were positively correlated with snail density at lags ranging from 1 to 4 months. These findings could serve as references for relevant authorities to monitor the changing trend of snail density and implement control measures, thereby reducing the occurrence of schistosomiasis.

Immunization with the glutathione S-transferase Sj26GST with Chi-CpG NP against Schistosoma japonicum in mice.

Schistosomiasis caused by Schistosoma japonicum (S. japonicum) is a major public health problem in the Philippines, China and Indonesia. In this study, the immunopotentiator CpG-ODN was encapsulated within chitosan nanoparticles (Chi NPs) to create a combination adjuvant (Chi-CpG NP). This approach was employed to enhance the immunogenicity of 26 kDa glutathione S-transferase (Sj26GST) from S. japonicum through intranasal immunization. The results demonstrated higher levels of specific anti-Sj26GST antibodies and Sj26GST-specific splenocyte proliferation compared to mice that were immunized with Sj26GST + Chi-CpG NP. Cytokine analysis of splenocytes revealed that the Sj26GST + Chi-CpG NP induced a slight Th1-biased immune response, with increased production of IFN-γ by CD4+ T-cells in the spleen. Subsequently, mice were intradermally inoculated with 1 × 107 organisms in the Coeliac cavity. The bacterial organ burden detected in the liver of immunized mice suggested that Sj26GST + Chi-CpG NP enhances protective immunity to inhibit S. japonicum colonization. Therefore, Sj26GST + Chi-CpG NP vaccination enhances Sj26GST-specific immunogenicity and provides protection against S. japonicum.

Metabolomics analysis of patients with Schistosoma japonicum infection based on UPLC-MS method.

BACKGROUND: Schistosomiasis is still one of the most serious parasitic diseases. Evidence showed that the metabolite profile in serum can potentially act as a marker for parasitic disease diagnosis and evaluate disease progression and prognosis. However, the serum metabolome in patients with Schistosoma japonicum infection is not well defined. In this study, we investigated the metabolite profiles of patients with chronic and with advanced S. japonicum infection. METHODS: The sera of 33 chronic S. japonicum patients, 15 patients with advanced schistosomiasis and 17 healthy volunteers were collected. Samples were extracted for metabolites and analyzed with ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). RESULTS: We observed significant differences in metabolite profiles in positive and negative ion modes between patients with advanced and chronic S. japonicum infection. In patients with chronic S. japonicum infection, 199 metabolites were significantly upregulated while 207 metabolites were downregulated in advanced infection. These differential metabolites were mainly concentrated in steroid hormone biosynthesis, cholesterol metabolism and bile secretion pathways. We also found that certain bile acid levels were significantly upregulated in the progression from chronic to advanced S. japonicum infection. In receiver operator characteristic (ROC) analysis, we identified three metabolites with area under the curve (AUC) > 0.8, including glycocholic (GCA), glycochenodeoxycholate (GCDCA) and taurochenodeoxycholic acid (TCDCA) concentrated in cholesterol metabolism, biliary secretion and primary bile acid biosynthesis. CONCLUSIONS: This study provides evidence that GCA, GCDCA and TCDCA can potentially act as novel metabolite biomarkers to distinguish patients in different stages of S. japonicum infection. This study will contribute to the understanding of the metabolite mechanisms of the transition from chronic to advanced S. japonicum infection, although more studies are needed to validate this potential role and explore the underlying mechanisms.

Molecular characterization of miR-31 for regulating egg production in female Schistosoma japonicum.

Schistosomiasis is caused by Schistosoma infection and affects more than 200 million people worldwide. A large number of eggs produced by adult Schistosoma play central the role in host pathology and subsequent disease dissemination. However, the underlying mechanisms of egg production in Schistosoma still need to be further elucidated. Previously, we found that miR-31 was highly enriched in the female reproductive organs of Schistosoma japonicum (S. japonicum), which was shown to be associated with ovarian development. In the present study, we analyzed the potential targets of miR-31 including mRNA and long noncoding RNAs (lncRNAs) in S. japonicum by RNA seq combined with bioinformatics. Then, six putative targets of miR-31 including three mRNAs such as EWB00_000918, EWB00_004242, and EWB00_009323 and three lncRNAs such as LncSJG_010465, LncSJG_015374 and LncSJG_013128 were further analyzed their expressions in the parasites treated with miR-31 inhibitor by qPCR to confirm their potential regulations. Whole mount in suit hybridization (WISH) analysis of some miR-31 targets were carried out to determine their colocalizations with miR-31. Furthermore, we selected EWB00_009323, which is an eggshell synthetic protein and also a target of miR-31, to inhibit its functions by small interfering RNA. The results indicated that inhibition of EB00_009323 led to decreased oviposition and defective ovarian morphology. Overall, the potential targets of miR-31 including mRNA and lncRNAs were identified in female S. japonicum and the results indicated that miR-31 coordinates with its targets, at least EWB00_009323, play an important role in ovarian development and egg production.

[Recombinant Schistosoma japonicum cystatin alleviates acute liver injury in mice by inhibiting endoplasmic reticulum stress, inflammation and hepatocyte apoptosis].

OBJECTIVE: To investigate the protective effect of recombinant Schistosoma japonicum cystatin (rSj-Cys) against acute liver injury induced by lipopolysaccharide (LPS) and D-GalN in mice. METHODS: Adult male C57BL/6J mice with or without LPS/D-GaIN-induced acute liver injury were given intraperitoneal injections of rSj-Cys or PBS 30 min after modeling (n=18), and serum and liver tissues samples were collected from 8 mice in each group 6 h after modeling. The survival of the remaining 10 mice in each group within 24 h was observed. Serum levels of ALT, AST, TNF-α and IL-6 of the mice were measured, and liver pathologies was observed with HE staining. The hepatic expressions of macrophage marker CD68, Bax, Bcl-2 and endoplasmic reticulum stress (ERS)-related proteins were detected using immunohistochemistry or immunoblotting, and TUNEL staining was used to detect hepatocyte apoptosis. RESULTS: The survival rates of PBS- and rSj-Cys-treated mouse models of acute liver injury were 30% and 80% at 12 h and were 10% and 60% at 24 h after modeling, respectively; no death occurred in the two control groups within 24 h. The mouse models showed significantly increased serum levels of AST, ALT, IL-6 and TNF-α and serious liver pathologies with increased hepatic expressions of CD68 and Bax, lowered expression of Bcl-2, increased hepatocyte apoptosis, and up-regulated expressions of ERS-related signaling pathway proteins GRP78, CHOP and NF-κB p-p65. Treatment of the mouse models significantly lowered the levels of AST, ALT, IL-6 and TNF-α, alleviated liver pathologies, reduced hepatic expressions of CD68, Bax, GRP78, CHOP and NF-κB p-p65, and enhanced the expression of Bcl-2. In the normal control mice, rSj-Cys injection did not produce any significant changes in these parameters compared with PBS. CONCLUSION: rSj-Cys alleviates LPS/D-GalN-induced acute liver injury in mice by suppressing ERS, attenuating inflammation and inhibiting hepatocyte apoptosis.

ATF3 is involved in rSjP40-mediated inhibition of HSCs activation in Schistosoma japonicum-infected mice.

Schistosomiasis is a parasitic disease characterized by liver fibrosis, a process driven by the activation of hepatic stellate cells (HSCs) and subsequent collagen production. Previous studies from our laboratory have demonstrated the ability of Schistosoma japonicum protein P40 (SjP40) to inhibit HSCs activation and exert an antifibrotic effect. In this study, we aimed to elucidate the molecular mechanism underlying the inhibitory effect of recombinant SjP40 (rSjP40) on HSCs activation. Using a cell model in which rSjP40 inhibited LX-2 cell activation, we performed RNA-seq analyses and identified ATF3 as the most significantly altered gene. Further investigation revealed that rSjP40 inhibited HSCs activation partly by suppressing ATF3 activation. Knockdown of ATF3 in mouse liver significantly alleviated S. japonicum-induced liver fibrosis. Moreover, our results indicate that ATF3 is a direct target of microRNA-494-3p, a microRNA associated with anti-liver fibrosis effects. rSjP40 was found to downregulate ATF3 expression by upregulating microRNA-494-3p in LX-2 cells. This downregulation led to the inhibition of the expression of liver fibrosis proteins α-SMA and COL1A1, ultimately alleviating liver fibrosis caused by S. japonicum.

Assessment of the influence of levees along Yangtze River on Oncomelania hupensis, the intermediate host of Schistosoma japonicum.

BACKGROUND: Oncomelania hupensis is the exclusive intermediate host of Schistosoma japonicum in China. Snail control is an essential component of schistosomiasis elimination programme. With 70 years of continuous efforts, the range of O. hupensis had reduced significantly, but slowed down in last decades. A large number of levees against flooding were constructed along Yangtze River and its affiliated lakes in the middle and lower reaches, which influenced the hydrology and ecology in the alluvial plains. The purpose of this study was to assess the impact of levees on the distribution of O. hupensis in the middle and lower reaches of the Yangtze River. METHODS: The snail habitats were digitalised by hand-held GPS system. The years for discovery and elimination of snail habitats were extracted from historical records. The accumulated snail-infested range for each habitat was calculated on the basis of annual reports. The current distribution of O. hupensis was determined by systematic and environmental sampling. The geographical distribution of levees was obtained from satellite imagery. To assess the impact of levees, the data pertaining to O. hupensis were divided into two parts: inside and outside the Yangtze River. Joinpoint regression was utilised to divide the study time span and further characterise the regression in each period. The 5-year-period moving averages of eliminated area infested by snails were calculated for the habitats inside and outside Yangtze River. The moving routes of corresponding geographical median centres were simulated in ArcGIS. Hotspot analysis was used to determine the areas with statistical significance clustering of O. hupensis density. RESULTS: Three periods were identified according to Joinpoint regression both inside and outside Yangtze River. The area infested by O. hupensis increased in the first two periods. It decreased rapidly outside Yangtze River year over year after 1970, while that inside the Yangtze River did not change significantly. Furthermore, the latter was significantly higher than the former. It was observed that the present density of O. hupensis inside Yangtze River was lower than outside the Yangtze River. The median centre for eliminated ranges inside Yangtze River wavered between the east (lower reach) and the west (middle reach). In contrast, the median centre for eliminated ranges continuously moved from the east to the west. CONCLUSIONS: Our findings indicated that the levees had a considerable negative impact on the distribution of O. hupensis outside Yangtze River. Some hotspots observed in the irrigation areas need a sluice system at the inlet of branch for snail control. The major distribution of O. hupensis located in Hubei might be caused by severe waterlogging. The intensive surveillance should be implemented there. The biggest two freshwater lakes, the major endemic regions historically, were identified as cold spots. The long-term impact of Three Gorges Dam on the distribution of O. hupensis in the lakes should be monitored and evaluated.

The impact of ICOSL/ICOS pathway-regulated long non-coding RNAs on liver fibrosis in mice infected with Schistosoma japonicum.

BACKGROUND: The primary pathogenic mechanism of schistosomiasis-associated liver fibrosis involves the deposition of schistosome eggs, leading to the formation of liver egg granulomas and subsequent liver fibrosis. Hepatic stellate cells are abnormally activated, resulting in excessive collagen deposition and fibrosis development. While specific long non-coding RNAs (lncRNAs) have been associated with fibrotic processes, their roles in schistosomiasis-associated liver fibrosis remain unclear. METHODS: Our previous research indicated that downregulating the ICOSL/ICOS could partially alleviate liver fibrosis. In this study, we established a schistosomiasis infection model in C57BL/6 and ICOSL knockout (KO) mice, and the liver pathology changes were observed at various weeks postinfection (wpi) using hematoxylin and eosin and Masson's trichrome staining. Within the first 4 wpi, no significant liver abnormalities were observed. However, mice exhibited evident egg granulomas and fibrosis in their livers at 7 wpi. Notably, ICOSL-KO mice had significantly smaller pathological variations compared with simultaneously infected C57BL/6 mice. To investigate the impact of lncRNAs on schistosomiasis-associated liver fibrosis, quantitative real-time polymerase chain reaction (RT-qPCR) was used to monitor the dynamic changes of lncRNAs in hepatic stellate cells of infected mice. RESULTS: The results demonstrated that lncRNA-H19, -MALAT1, -PVT1, -P21 and -GAS5 all participated in liver fibrosis formation after schistosome infection. In addition, ICOSL-KO mice exhibited significantly inhibited expression of lncRNA-H19, -MALAT1 and -PVT1 after 7 wpi. In contrast, they showed enhanced expression of lncRNA-P21 and -GAS5 compared with C57BL/6 mice, influencing liver fibrosis development. Furthermore, small interfering RNA transfection (siRNA) in JS-1 cells in vitro confirmed that lncRNA-H19, -MALAT1, and -PVT1 promoted liver fibrosis, whereas lncRNA-P21 and -GAS5 had the opposite effect on key fibrotic molecules, including α- smooth muscle actin and collagen I expression. CONCLUSIONS: This study uncovers that ICOSL/ICOS may play a role in activating hepatic stellate cells and promoting liver fibrosis in mice infected with Schistosoma japonicum by dynamically regulating the expression of specific lncRNAs. These findings offer potential therapeutic targets for schistosomiasis-associated liver fibrosis.

Schistosoma japonicum cystatin alleviates paraquat poisoning caused acute lung injury in mice through activating regulatory macrophages.

BACKGROUND: Paraquat (PQ) is a widely used herbicide that poisons human by accident or intentional ingestion. PQ poisoning causes systemic inflammatory response syndrome (SIRS) resulting in acute lung injury (ALI) with an extremely high mortality rate. Blood trematode Schistosoma japonicum-produced cystatin (Sj-Cys) is a strong immunomodulatory protein that has been experimentally used to treat inflammation related diseases. In this study, Sj-Cys recombinant protein (rSj-Cys) was used to treat PQ-induced lung injury and the immunological mechanism underlying the therapeutic effect was investigated. METHODS: PQ-induced acute lung injury mouse model was established by intraperitoneally injection of 20 mg/kg of paraquat. The poisoned mice were treated with rSj-Cys and the survival rate was observed up to 7 days compared with the group without treatment. The pathological changes of PQ-induced lung injury were observed by examining the histochemical sections of affected lung tissue and the wet to dry ratio of lung as a parameter for inflammation and edema. The levels of the inflammation related cytokines IL-6 and TNF-α and regulatory cytokines IL-10 and TGF-ß were measured in sera and in affected lung tissue using ELISA and their mRNA levels in lung tissue using RT-PCR. The macrophages expressing iNOS were determined as M1 and those expressing Arg-1 as M2 macrophages. The effect of rSj-Cys on the transformation of inflammatory M1 to regulatory M2 macrophages was measured in affected lung tissue in vivo (EKISA and RT-PCR) and in MH-S cell line in vitro (flow cytometry). The expression levels of TLR2 and MyD88 in affected lung tissue were also measured to determine their role in the therapy of rSj-Cys on PQ-induced lung injury. RESULT: We identified that treatment with rSj-Cys significantly improved the survival rate of mice with PQ-induced lung injury from 30 % (untreated) to 80 %, reduced the pathological damage of poisoning lung tissue, associated with significantly reduced levels of proinflammatory cytokines (IL-6 from 1490 to 590 pg/ml, TNF-α from 260 to 150 pg/ml) and increased regulatory cytokines (IL-10 from360 to 550 pg/ml, and TGF-ß from 220 to 410 pg/ml) in both sera (proteins) and affected lung tissue (proteins and mRNAs). The polarization of macrophages from M1to M2 type was found to be involved in the therapeutic effect of rSj-Cys on the PQ-induced acute lung injury, possibly through inhibiting TLR2/MyD88 signaling pathway. CONCLUSIONS: Our study demonstrated the therapeutic effect of rSj-Cys on PQ poisoning caused acute lung injury by inducing M2 macrophage polarization through inhibiting TLR2/MyD88 signaling pathway. The finding in this study provides an alternative approach for the treatment of PQ poisoning and other inflammatory diseases.

Feasibility of ultrasound radiomics based models for classification of liver fibrosis due to Schistosoma japonicum infection.

BACKGROUND: Schistosomiasis japonica represents a significant public health concern in South Asia. There is an urgent need to optimize existing schistosomiasis diagnostic techniques. This study aims to develop models for the different stages of liver fibrosis caused by Schistosoma infection utilizing ultrasound radiomics and machine learning techniques. METHODS: From 2018 to 2022, we retrospectively collected data on 1,531 patients and 5,671 B-mode ultrasound images from the Second People's Hospital of Duchang City, Jiangxi Province, China. The datasets were screened based on inclusion and exclusion criteria suitable for radiomics models. Liver fibrosis due to Schistosoma infection (LFSI) was categorized into four stages: grade 0, grade 1, grade 2, and grade 3. The data were divided into six binary classification problems, such as group 1 (grade 0 vs. grade 1) and group 2 (grade 0 vs. grade 2). Key radiomic features were extracted using Pyradiomics, the Mann-Whitney U test, and the Least Absolute Shrinkage and Selection Operator (LASSO). Machine learning models were constructed using Support Vector Machine (SVM), and the contribution of different features in the model was described by applying Shapley Additive Explanations (SHAP). RESULTS: This study ultimately included 1,388 patients and their corresponding images. A total of 851 radiomics features were extracted for each binary classification problems. Following feature selection, 18 to 76 features were retained from each groups. The area under the receiver operating characteristic curve (AUC) for the validation cohorts was 0.834 (95% CI: 0.779-0.885) for the LFSI grade 0 vs. LFSI grade 1, 0.771 (95% CI: 0.713-0.835) for LFSI grade 1 vs. LFSI grade 2, and 0.830 (95% CI: 0.762-0.885) for LFSI grade 2 vs. LFSI grade 3. CONCLUSION: Machine learning models based on ultrasound radiomics are feasible for classifying different stages of liver fibrosis caused by Schistosoma infection.

An insight into the gut microbiota after Schistosoma japonicum eggs immunization in an experimental ulcerative colitis model.

Schistosome infection and schistosome-derived products have been implicated in the prevention and alleviation of inflammatory bowel disease by manipulating the host immune response, whereas the role of gut microbiota in this protective effect remains poorly understood. In this study, we found that the intraperitoneal immunization with Schistosoma japonicum eggs prior to dextran sulfate sodium (DSS) application significantly ameliorated the symptoms of DSS-induced acute colitis, which was characterized by higher body weight, lower disease activity index score and macroscopic inflammatory scores. We demonstrated that the immunomodulatory effects of S. japonicum eggs were accompanied by an influence on gut microbiota composition, abundance, and diversity, which increased the abundance of genus Turicibacter, family Erysipelotrichaceae, phylum Firmicutes, and decreased the abundance of genus Odoribacter, family Marinifilaceae, order Bacteroidales, class Bacteroidia, phylum Bacteroidota. In addition, Lactobacillus was identified as a biomarker that distinguishes healthy control mice from DSS-induced colitis mice. The present study revealed the importance of the gut microbiota in S. japonicum eggs exerting protective effects in an experimental ulcerative colitis (UC) model, providing an alternative strategy for the discovery of UC prevention and treatment drugs.

[Screening and functional analysis of differentially expressed long non-coding RNA in the liver of mice infected with Schistosoma japonicum during the chronic pathogenic stage].

OBJECTIVE: To screen differentially expressed long non-coding RNAs (lncRNAs) in the liver of mice infected with Schistosoma japonicum during the chronic pathogenic stage and identify their functions, so as to provide insights into unravelling the role of lncRNAs in S. japonicum infection-induced liver disorders. METHODS: Twenty 6-week-old C57BL/6 mice were randomly divided into two groups, of 10 animals each group. Each mouse in the experimental group was infected with (15 ± 2) S. japonicum cercariae via the abdomen for modeling chronic S. japonicum infection in mice, and distilled water served as controls. All mice were sacrificed 70 days post-infection, and mouse liver specimens were sampled for RNA extraction and library construction. All libraries were sequenced on the Illumina NovaSeq 6000 sequencing platform. Data cleaning was performed using the fastp software, and reference genome alignment and gene expression (FPKM) calculation were performed using the HISAT2 software. Potential lncRNA sequences were predicted using the software CNIC, CPC, Pfam, and PLEK, and potential lncRNAs were screened. Differentially expressed lncRNAs were screened with the DESeq2 software and subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses to identify biological processes and metabolic pathways involved in target genes of differentially expressed lncRNAs. RESULTS: A total of 333 potential lncRNAs were screened, and 67 were identified as differentially expressed lncRNAs, including 49 up-regulated and 18 down-regulated lncRNAs. A total of 53 target genes were predicted for differentially expressed lncRNAs. GO enrichment analysis showed that these target genes were mainly enriched in biological process and molecular function, among which Sema7a, Arrb1, and Ccl21b genes may be hub target genes for positive regulation of extracellular regulated protein kinase 1 (ERK1) and ERK2 cascades and may participate in the regulation of collagen expression. KEGG enrichment analysis showed that the target genes of differentially expressed lncRNAs were mainly enriched in cytokine-cytokine receptor interaction, viral protein interactions with cytokines and cytokine receptors, chemokine signaling pathway, and nuclear factor kappa-B (NF-κB) signaling pathway. CONCLUSIONS: This study identifies differentially expressed lncRNAs and functional enrichment of their target genes in the liver of mice during the chronic pathogenic stage of S. japonicum infection. Up-regulated lncRNAs may affect biological processes of ERK1/2 cascades and chemokine signaling pathways via target genes Sema7a, Arrb1, and Ccl21b, thereby affecting collagen expression and inflammatory signal pathways, ultimately affecting the development of liver disorders.

Effect of hepatocyte damage in hepatic fibrogenesis of patients infected with Schistosoma japonicum.

Schistosomiasis is a serious public health problem, and previous studies found that liver function and hepatic cells are damaged. To evaluate the serum parameters of liver function and fibrosis in schistosomiasis patients infected with Schistosoma japonicum (Schistosoma J.) and analyze the correlations between liver function and serum fibrosis markers in patients infected with Schistosoma J., this retrospective study enrolled 133 patients. The study population was divided into four groups: healthy people control group (n = 20), chronic schistosomiasis without liver cirrhosis (CS) group (n = 21), schistosomiasis cirrhosis without hypoalbuminemia (SC-HA) group (n = 68), and schistosomiasis cirrhosis with hypoalbuminemia (SC +HA) group (n = 24). Clinical and laboratory data were collected for analysis. In the multiple comparison of abnormal rates of aspartate aminotransferase (AST) and total bilirubin (TBIL), the abnormal rate of the SC +HA group was significantly higher than that of the other three groups (P < 0.05), and the abnormal rate of γ-GT in the SC +HA group was significantly higher than that in the control group (P < 0.05). Multiple comparison results of serum levels of fibrosis markers showed that the SC group had a significantly higher level of indexes than other groups (P < 0.05). The levels of TGF-ß1 in the CS group, SC-HA group and SC +HA group were significantly higher than those in the control group (P < 0.001). Our study demonstrated that the liver function and hepatic cells were damaged with the progression of liver disease in patients infected with Schistosoma J., and they played an important role in the occurrence and development of liver fibrosis.

Development of a Gaussia luciferase immunoprecipitation assay for detecting Schistosoma japonicum infection.

Timely and accurate diagnosis of Schistosoma infection is important to adopt effective strategies for schistosomiasis control. Previously, we demonstrated that Schistosoma japonicum can secret extracellular vesicles and their cargos may serve as a novel type of biomarkers for diagnosing schistosomiasis. Here, we developed a Gaussia luciferase immunoprecipitation assay combined with S. japonicum extracellular vesicle (SjEV) protein to evaluate its potential for diagnosing schistosomiasis. A saposin-like protein (SjSLP) identified from SjEVs was fused to the Gaussia luciferase as the diagnostic antigen. The developed method showed good capability for detecting S. japonicum infection in mice and human patients. We also observed that the method could detect Schistosoma infection in mice as early as 7 days of post-infection, which showed better sensitivity than that of indirect ELISA method. Overall, the developed method showed a good potential for detecting Schistosoma infection particularly for early stage, which may provide an alternative strategy for identify Schistosoma infection for disease control.