Schistosoma Japonicum Research Articles

Impact of water physicochemical properties on the survival of Oncomelania hupensis snails, the intermediate host of Schistosoma japonicum.

Schistosoma japonicum, the causative agent of schistosomiasis, heavily relies on its single intermediate host, the Oncomelania hupensis snail, for its life cycle. Controlling these snails effectively plays a pivotal role in curbing the transmission and prevalence of this disease. While prior research has extensively investigated the impact of environmental factors such as temperature and vegetation on snail survival, growth, and reproduction, the contribution of water physicochemical properties has been notably underexplored. This study presents laboratory experiments designed to comprehensively explore the influence of water physicochemical properties on snail survival, offering valuable insights into environmental factors for more precise predictions of snail distribution. We meticulously conducted laboratory snail survival experiments using water from different sources (river water/tap water), and employed a statistical approach amalgamating principal component analysis with Cox regression to preliminarily investigate the effects of different water physicochemical properties on the survival of snails. Our analysis indicates that after a 6-month laboratory snail survival experiment, the survival rate in the tap water group was significantly higher than that in the river water group for infected snails (χ2 = 7.74, p = 0.005), while the difference in survival rates for non-infected snails was not statistically significant (χ2 = 0.61, p = 0.434). The Principal Component-Cox regression analysis revealed that in the infected snail group, total phosphorus, pH value, five-day biochemical oxygen demand, conductivity, and nitrite were protective factors for snail survival, while phosphate and total nitrogen were risk factors. In the non-infected snail group, total phosphorus, pH value, five-day biochemical oxygen demand, conductivity, and nitrite were protective factors for snail survival, and total nitrogen, ammonia nitrogen, phosphate, and nitrate were risk factors. This study underscores the substantial impact of water quality's physicochemical properties on snail survival. The effects of water quality on snails are complex, and maintaining an appropriate level of organic matter content and controlling the pH value at a weak alkalescency level prove beneficial for snail survival. These findings hold significant promise for advancing our understanding of snail-borne diseases and optimizing control strategies.

Identification of optimum scopes of environmental drivers for schistosome-transmitting Oncomelania hupensis using agent-based model in Dongting Lake Region, China.

Oncomelania hupensis (O. hupensis), the sole intermediate host of Schistosoma japonicum, greatly influence the prevalence and distribution of schistosomiasis japonica. The distribution area of O. hupensis has remained extensive for numerous years. This study aimed to establish a valid agent-based model of snail density and further explore the environmental conditions suitable for snail breeding. A marshland with O. hupensis was selected as a study site in Dongting Lake Region, and snail surveys were monthly conducted from 2007 to 2016. Combined with the data from historical literature, an agent-based model of snail density was constructed in NetLogo 6.2.0 and validated with the collected survey data. BehaviorSpace was used to identify the optimal ranges of soil temperature, pH, soil water content, and vegetation coverage for snail growth, development and reproduction. An agent-based model of snail density was constructed and showed a strong agreement with the monthly average snail density from the field surveys. As soil temperature increased, the snail density initially rose before declining, reaching its peak at around 21°C. There were similar variation patterns for other environmental factors. The findings from the model suggested that the optimum ranges of soil temperature, pH, soil water content and vegetation coverage were 19°C to 23 °C, 6.4 to 7.6, 42% to 75%, and 70% to 93%, respectively. A valid agent-based model of snail density was constructed, providing more objective information about the optimum ranges of environmental factors for snail growth, development and reproduction.

Risk factors for schistosomiasis

ABSTRACT In this review, I describe the progress in a study that focused on the risk factors for schistosomiasis around the globe for the purposes of the review. Human schistosomiasis affects 229 million people; at least 90% are in sub-Saharan Africa, and 54% are school-aged children. Schistosoma haematobium infects 112 million people, Schistosoma japonicum infects 3.1 million people, and Schistosoma mansoni infects 54 million people. Schistosomiasis can occur in endemic and non-endemic areas. A high risk of schistosomiasis can occur in, for example, preschool-aged children, school-aged children, and workers in endemic schistosomiasis areas. These people make contact with infested freshwater day by day. In addition, environmental factors and socioeconomic factors can affect the transmission of schistosomiasis. Various factors can cause the transmission of schistosomiasis, for example, climate changes and proximity to infested freshwater bodies. People with high risks for schistosomiasis need great attention for treatment and/or prevention programs. Risk factors for schistosomiasis, for example, human behavior and socioeconomic status, can affect the transmission of schistosomiasis. Many developing countries in Africa, Asia, and South America are at risk of this disease. High-risk people need special attention in programs for schistosomiasis elimination.

Multi-omics analyses of Bacillus amyloliquefaciens treated mice infected with Schistosoma japonicum reveal dynamics change of intestinal microbiome and its associations with host metabolism.

Schistosomiasis japonica is a serious threat to human health. It causes damage to the intestine and liver. Probiotic therapy has been shown to be effective in alleviating intestinal diseases and improving host health. Previous studies have found that Bacillus amyloliquefaciens could alleviate the pathological symptoms of schistosomiasis japonica, but the regulatory mechanism of alleviating schistosomiasis japonica is still unknown. This study analyzed the dynamic changes of intestinal microbiome in mice infected with Schistosoma japonicum after the intervention of B. amyloliquefaciens and its connection to host metabolism by multi-omics sequencing technology. B. amyloliquefaciens was found to significantly regulate the homeostasis of intestinal microbiota by promoting the growth of beneficial bacteria and inhibiting potential pathogenic bacteria and protect the number of core microbes. Meanwhile, the genes related to the metabolism of glycerophospholipids and amino acid from intestinal microbiome changed significantly, and were shown to be significantly positively correlated with the associated metabolites of microbial origin. Moreover, host metabolism (lipid metabolism and steroid hormone biosynthesis) was also found to be significantly regulated. The recovery of intestinal microbial homeostasis and the regulation of host metabolism revealed the potential probiotic properties of B. amyloliquefaciens, which also provided new ideas for the prevention and adjuvant treatment of schistosomiasis japonica.

Single-Cell Analysis Reveals the Cellular and Molecular Changes of Liver Injury and Fibrosis in Mice During the Progression of Schistosoma japonicum Infection

Schistosomiasis is a parasitic disease that poses a serious threat to human health. However, the pathogenic mechanism during the progression of Schistosoma japonicum infection remains unclear. In order to elucidate this mechanism, we used single-cell RNA sequencing (scRNA-seq) to investigate the transcriptome characteristics of the cellular (single-cell) landscape in the livers of mice infected with Schistosoma japonicum, which were divided into three groups: uninfected mice (0 week (w)), infected mice at 6 w post-infection (the acute phase), and infected mice at 10 w post-infection (the chronic phase). A total of 31,847 liver cells were included and clustered into 21 groups. The cells and T-cells had high heterogeneity in the liver during the progression of schistosome infection. The number and intensity of the intercellular interactions significantly increased at 6 w after infection but decreased at 10 w. The inflammatory signaling pathways chemoattractant cytokine ligand (CCL)5-chemokine C-C-motif receptor (CCR)5 between macrophages and T-cells were predominant at 6 w post-infection; the CCL6-CCR2 signaling pathway between macrophages was predominant at 10 w. The CD80 signaling pathway related to T-cell activation was increased at 6 w after infection, and increased expression of its receptor CD28 on the surfaces of CD4+ and CD8+ T-cells was confirmed by flow cytometry, suggesting an increase in their activation. In addition, scRNA-seq and quantitative reverse transcription polymerase chain reaction (qRT-PCR) confirmed that the intercellular communication between secretory phosphoprotein 1 (SPP1)-cluster of differentiation (CD44), insulin-like growth factor (IGF)-1-IGF1r and visfatin-insulin receptor (Insr) associated with bone metabolism and insulin metabolism was increased and enhanced in the liver at 6 w post-infection. Overall, we provide the comprehensive single-cell transcriptome landscape of the liver in mice during the progression of schistosome infection and delineate the key cellular and molecular events involved in schistosome infection-induced liver injury and fibrosis. The elevated CCL5-CCR5 and CCL6-CCR2 signaling pathways in the liver may be a drug target for liver injury and fibrosis caused by schistosome infection, respectively.

Depression in the schistosomiasis japonica population based on the PHQ-9 scale: a cross-sectional survey from Jiangxi Province, China

Depression is the second leading-cause of disability in China. Although studies have shown that more than 80% of patients with advanced schistosomiasis (AS) suffer from anxiety and depression, these study groups are all hospitalized patients with AS and do not represent the extent of the disease in the whole group. To our knowledge, there are no studies assessing the severity of depression in patients with other forms of schistosomiasis japonicum. Therefore, it is necessary to evaluate the occurrence and potential risk factors of depression in the schistosomiasis endemic population. This cross-sectional study was conducted in Jiangxi Province, where schistosomiasis is relatively common in China, as the investigation site. The Patient Health Questionnaire-9 (PHQ-9) scale was selected to assess the depressive symptoms in the study population. At the same time, basic personal information of the research subjects and relevant socio-economics and schistosomiasis endemic area indicators were collected. The survey results show that AS has the highest incidence of depression (34.35%), while non-advanced schistosomiasis (N-AS) and control group (CG) have 22.35% and 22.24% respectively; the incidence of depression in AS is significantly higher than in N-AS and CG, while there is no statistical significance in the comparison between N-AS and CG; the incidence of mild depressive symptoms accounts for 61.08%-75.54% of the total incidence of depression in different groups; multivariate analysis shows that the occurrence of moderate/severe depressive symptoms in the AS group was significantly related to above 60 years old, male, the combination of other serious diseases, personal financial difficulties, and marshland and lake endemic areas. In the N-AS group, the occurrence of moderate/severe depressive symptoms was significantly related to the combination of other serious diseases, personal financial difficulties, significant correlation between marshland and lake endemic areas and the level of control of schistosomiasis epidemics. In conclusion, depression is still relatively common among patients with schistosomiasis patients, especially those with AS. It is recommended that the government and relevant departments consider mental health care when developing prevention and control work in schistosomiasis-endemic areas, in order to effectively protect the physical and mental health of schistosomiasis patients and residents in endemic areas.

Rectal Schistosomiasis and Adenocarcinoma

Abstract Introduction/Objective Schistosoma infestation has been implicated by the International Agency for Research on Cancer as an etiology for several cancers such as colon, liver, and bladder. S. japonicum is classified as a probable carcinogen in humans (class 2B). These trematodes may cause chronic infection in the affected organ leading to the trend of “inflammation-adenoma-carcinoma”. There is rising evidence that infection with Schistosoma japonicum is correlated with the liver and colorectal carcinoma in endemic Asian countries. We herein present a case of rectal adenocarcinoma associated with Schistosoma as a possible causal factor. Methods/Case Report An 88-year-old-woman from China, currently living in United States for past six years, presented with rectal bleeding. Colonoscopy showed evidence of a rectosigmoid mass 2.2 x 1.0 x 0.3 cm. She underwent trans-anal excision of the tumor. Microscopic examination showed moderately differentiated adenocarcinoma with tumor invading the muscularis propria (pT2). There were numerous oval / round calcified eggs (30 - 46 microns) with minute subterminal or no spine morphologically consistent with Schistosoma japonicum associated with granulomatous and foreign body giant cell reaction, fibrosis, and tissue eosinophilia. She was treated with Praziquantel and is currently undergoing endoscopic surveillance for recurrence. Results (if a Case Study enter NA) N/A Conclusion Patients with chronic Schistosoma japonicum infection have 3 times increased risk of developing colorectal cancer than those with no previous exposure to schistosomal infection. We believe that chronic S. japonicum infection is the likely etiology of rectal cancer in our patient. Physicians should be aware of such associations, especially for immigrants from endemic areas, to facilitate accurate diagnosis and management.

Schistosoma japonicum infection-mediated downregulation of lncRNA Malat1 contributes to schistosomiasis hepatic fibrosis by the Malat1/miR-96/Smad7 pathway

BackgroundSchistosoma japonicum infection causes hepatic fibrosis, a primary cause of morbidity and mortality associated with the disease, and effective treatments are still lacking. Long non-coding RNAs (lncRNAs) have been implicated in the pathogenic process of various tissue fibroses. However, the role of lncRNAs in schistosomiasis hepatic fibrosis (HF) is poorly understood. Understanding the role of lncRNAs in schistosomiasis HF will enhance knowledge of disease processes and aid in the discovery of therapeutic targets and diagnostic biomarkers.MethodsDifferentially expressed lncRNA profiles in primary hepatic stellate cells (HSCs) of mice infected with S. japonicum were identified using high-throughput lncRNA sequencing. Primary HSCs were isolated from infected mice using collagenase digestion and density-gradient centrifugation, cultured in DMEM with 10% fetal bovine serum. Dual-luciferase reporter assays, nuclear cytoplasm fractionation and RIP assays were employed to assess the relationship between Malat1 and miRNA-96. Malat1 lentivirus and ASO-Malat1 were constructed for forced expression and downregulated expression of Malat1. The Malat1-KO mouse was constructed by CRISPR/Cas9 technology. Pathological features of the liver were evaluated by hematoxylin-eosin (HE), Masson’s trichrome staining and immunohistochemistry (IHC). The expression levels of fibrosis-related genes were determined by quantitative real-time PCR (qRT-PCR) and Western blot.ResultsA total of 1561 differentially expressed lncRNAs were identified between infected and uninfected primary HSCs. Among the top altered lncRNAs, the downregulated Malat1 was observed in infected HSCs and verified by qPCR. Treatment of infected mice with praziquantel (PZQ) significantly increased the Malat1 expression. Elevated Malat1 expression in infected primary HSC reduced the expressions of profibrogenic genes, whereas Malat1 knockdown had the opposite effect. Moreover, Malat1 was found to interact with miR-96, a profibrotic miRNA, by targeting Smad7. Forced Malat1 expression reduced miR-96 levels in infected primary HSCs, attenuating fibrogenesis and showing negative correlation between Malat1 expression and the expression levels of miR-96 and profibrogenic genes α-SMA and Col1α1. Notably, in Malat1-KO mice, knockout of Malat1 aggravates schistosomiasis HF, while restored Malat1 expression in the infected HSCs reduced the expression of profibrogenic genes.ConclusionsWe demonstrate that lncRNA is involved in regulation of schistosomiasis HF. Elevated lncRNA Malat1 expression in infected HSCs reduces fibrosis via the Malat1/miR-96/Smad7 pathway, thus providing a novel therapeutic target for schistosomiasis HF. Furthermore, Malat1 expression is sensitive to PZQ treatment, thus offering a potential biomarker for assessing the response to chemotherapy.Graphical abstract

Schistosoma japonicumsja-let-7 Inhibits the Growth of Hepatocellular Carcinoma Cells via Cross-Species Regulation of Col1α2.

Liver fibrosis, a critical precursor to hepatocellular carcinoma (HCC), results from chronic liver injury and significantly contributes to HCC progression. Schistosomiasis, a neglected tropical disease, is known to cause liver fibrosis; however, this process can be modulated by schistosome-derived miRNAs. Previous studies from our laboratory have demonstrated that Schistosoma japonicum extracellular vesicles (EVs) deliver sja-let-7 to hepatic stellate cells, leading to the inhibition of Col1α2 expression and alleviation of liver fibrosis. Given the well-documented antifibrotic and antiproliferative properties of the let-7 miRNA family, this study aims to preliminarily investigate the effects of the sja-let-7/Col1α2 axis on BALB/c mice and HCC cell line SNU387, providing a basis for the potential application of parasite-derived molecules in HCC therapy. In the present study, schistosome-induced fibrosis datasets were analyzed to identify the role of Col1α2 in extracellular matrix organization. Pan-cancer analysis revealed that Col1α2 is upregulated in various cancers, including HCC, with significant associations with immune cell infiltration and clinical parameters, highlighting its diagnostic importance. Functional assays demonstrated that transfection with sja-let-7 mimics significantly reduced Col1α2 expression, inhibited HCC cell proliferation, migration, and colony formation. These findings suggest that sja-let-7, by targeting Col1α2, has the potential to serve as a therapeutic agent in HCC treatment. This study indicates the pivotal role of Col1α2 in liver fibrosis and HCC, and the promising therapeutic application of helminth-derived miRNAs.

Colorectal Cancer Complicated with Chronic Schistosoma Japonicum Infected: A Case Report.

Colonic schistosomiasis is a significant health issue in endemic areas, presenting diagnostic challenges due to its nonspecific clinical symptoms and radiographic features. This case report highlights a patient with concomitant colorectal cancer and chronic Schistosoma japonicum infection, emphasizing the need for a comprehensive diagnostic approach. A 67-year-old male from an endemic region presented with a six-month history of intermittent hematochezia. Initial colonoscopy revealed multiple mucosal elevations in the sigmoid colon and rectum. Subsequent investigations, including CT scans and endoscopic ultrasonography, indicated high echogenic changes and multiple lesions. The patient underwent endoscopic submucosal dissection (ESD), revealing adenocarcinoma of the rectal mucosa and tubular adenoma in the sigmoid colon, both with extensive deposition of Schistosoma japonicum eggs. Postoperative pathology confirmed the diagnosis of moderately differentiated adenocarcinoma with chronic schistosomiasis. This case underscores the diagnostic complexity of colonic schistosomiasis, particularly when coexisting with malignancy. The integration of colonoscopy, histopathology, and auxiliary tests is crucial for accurate diagnosis. Clinicians should maintain a high index of suspicion for schistosomiasis in patients from endemic areas presenting with gastrointestinal symptoms. Regular screening and detailed medical histories are essential for early detection and treatment, improving patient outcomes and reducing the risk of misdiagnosis.

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

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. 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. 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. 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.

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.

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

BackgroundSchistosomiasis 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.MethodsThe 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).ResultsWe 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.ConclusionsThis 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.Graphical

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

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. 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. 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.

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.

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

BackgroundArtemisinin (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, β-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.MethodsWe 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.ResultsATT 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.ConclusionATT, as a novel preventive strategy for schistosomiasis japonica in mice, significantly outperforms ART.Graphical

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.

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-1β (IL-1β), 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-β1 (TGF-β1) 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.

Precision mapping of snail habitat in lake and marshland areas: Integrating environmental and textural indicators using Random Forest modeling

Schistosomiasis japonica continues to pose a significant public health challenge in China, primarily due to the widespread distribution of Oncomelania hupensis, the sole intermediate host of Schistosoma. This study aims to address the constraints of existing remote sensing analyses for identifying snail habitats, which frequently neglect spatial scale and seasonal variations. To this end, we adopt a multi-source data-driven Random Forest approach that integrates bottomland and ground-surface texture data with traditional environmental variables, enhancing the accuracy of snail habitat assessments. We developed four distinct models for the lake and marshland areas of Guichi, China: a baseline model incorporating ground-surface texture, bottomland variables, and environmental variables; Model 1 with only environmental variables; Model 2 adding ground-surface texture and environmental variables; and Model 3 integrating bottomland with environmental variables. The baseline model outperformed the others, achieving a true skill statistic of 0.93, an accuracy of 0.97, a kappa statistic of 0.94, and an area under the curve of 0.99. Our analysis pinpointed critical high-risk snail habitats distributed in a belt-like pattern along major water bodies, near the Yangtze River, QiuPu River, and around Shengjin Lake, Jiuhua River, and Qingtong River. These insights can aid local health authorities in more efficiently allocating limited resources, developing effective snail surveillance and control strategies to combat schistosomiasis. Additionally, this approach can be adapted to localize other endemic hosts with similar ecological characteristics.

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

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. 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. 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. 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.