[Comparison of pathogenicity and gene expression profiles between adult Schistosoma japonicum isolated from hilly and marshland and lake regions of Anhui Province].

OBJECTIVE: To compare the differences in pathogenicity and gene expression profiles between adult Schistosoma japonicum isolated from hilly and marshland and lake regions of Anhui Province, so as to provide the scientific evidence for formulating the precise schistosomiasis control strategy in different endemic foci. METHODS: C57BL/6 mice were infected with cercariae of S. japonicum isolates from Shitai County (hilly regions) and Susong County (marshland and lake regions) of Anhui Province in 2021, and all mice were sacrificed 44 days post-infection and dissected. The worm burdens, number of S. japonicum eggs deposited in the liver, and the area of egg granulomas in the liver were measured to compare the difference in the pathogenicity between the two isolates. In addition, female and male adult S. japonicum worms were collected and subjected to transcriptome sequencing, and the gene expression profiles were compared between Shitai and Susong isolates of S. japonicum. The differentially expressed genes (DEGs) were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. RESULTS: The total worm burdens [(14.50 ± 3.96) worms/mouse vs. (16.10 ± 3.78) worms/mouse; t = 0.877, P = 0.392], number of female and male paired worms [(4.50 ± 0.67) worms/mouse vs. (5.10 ± 1.45) worms/mouse; t = 1.129, P = 0.280], number of unpaired male worms [(5.50 ± 4.01) worms/mouse vs. (5.60 ± 1.69) worms/mouse; t = 0.069, P = 0.946], number of eggs deposited in per gram liver [(12 116.70 ± 6 508.83) eggs vs. (16 696.70 ± 4 571.56) eggs; t = 1.821, P = 0.085], and area of a single egg granuloma in the liver [(74 359.40 ± 11 766.34) µm2 vs. (74 836.90 ± 13 086.12) µm2; t = 0.081, P = 0.936] were comparable between Shitai and Susong isolates of S. japonicum. Transcriptome sequencing identified 584 DEGs between adult female worms and 1 598 DEGs between adult male worms of Shitai and Susong isolates of S. japonicum. GO enrichment analysis showed that the DEGs between female adults were predominantly enriched in biological processes of stimulus response, cytotoxicity, multiple cell biological processes, metabolic processes, cellular processes and signaling pathways, cellular components of cell, organelles and cell membranes and molecular functions of binding and catalytic ability, and KEGG enrichment analysis showed that these DEGs were significantly enriched in pathways of vascular endothelial growth factor signaling, glutathione metabolism, arginine and proline metabolism. In addition, the DEGs between male adults were predominantly enriched in biological processes of signaling transduction, multiple cell biological processes, regulation of biological processes, metabolic processes, development processes and stimulus responses, cellular components of extracellular matrix and cell junction and molecular functions of binding and catalytic ability, and these DEGs were significantly enriched in pathways of Wnt signaling, Ras signaling, natural killer cells-mediated cytotoxicity, extracellular matrix-receptor interactions and arginine biosynthesis. CONCLUSIONS: There is no significant difference in the pathogenicity between S. japonicum isolates from hilly and marshland and lake regions of Anhui Province; however, the gene expression profiles vary significantly between S. japonicum isolates.

JQ-1 ameliorates schistosomiasis liver fibrosis by suppressing JAK2 and STAT3 activation.

Schistosomiasis is a serious parasitic infection caused by Schistosoma. The parasite deposits eggs in the host liver, causing inflammation that activates hepatic stellate cells (HSCs), which leads to liver fibrosis. Currently, there is no effective therapy for liver fibrosis; thus, treatments are urgently needed. Therefore, in the present study, mice infected with Schistosoma japonicum were treated with JQ-1, a small-molecule bromodomain inhibitor with reliable anti-tumor and anti-inflammatory activities. The fibrotic area of the liver measured by computer-assisted morphometric analysis and the expression levels of the cytoskeletal protein alpha smooth muscle actin (α-SMA) and of collagen assessed by quantitative PCR, Western blot and immunohistochemistry were significantly decreased in the liver following JQ-1 treatment compared with vehicle-treated controls. Total RNA was extracted from the liver of JQ-1-treated Schistosoma-infected mice for RNA-sequencing analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated that JQ-1 affected biological processes and the expression of cellular components known to play key roles in the transdifferentiation of HSCs to myofibroblasts. In vitro treatment with JQ-1 of JS-1 cells, a mouse HSC line, indicated that JQ-1 significantly inhibited JS-1 proliferation but had no effect on JS-1 activity, senescence, or apoptosis. Western blot results showed that JQ-1 inhibited the expression levels of phosphorylated JAK2 and phosphorylated STAT3 without altering expression levels of these non-phosphorylated proteins. Taken together, these findings suggested that JQ-1 treatment ameliorated S. japonicum egg-induced liver fibrosis, at least in part, by suppressing HSC activation and proliferation through the inhibition of JAK2/STAT3 signaling. These results lay a foundation for the development of novel approaches to treat and control liver fibrosis caused by S. japonicum.

Ikzf2 Regulates the Development of ICOS+ Th Cells to Mediate Immune Response in the Spleen of S. japonicum-Infected C57BL/6 Mice.

Background: Th cells (helper T cells) have multiple functions in Schistosoma japonicum (S. japonicum) infection. Inducible co-stimulator (ICOS) is induced and expressed in activated T lymphocytes, which enhances the development of B cells and antibody production through the ICOS/ICOSL pathway. It remains unclear about the role and possible regulating mechanism of ICOS+ Th cells in the spleen of S. japonicum-infected C57BL/6 mice. Methods: C57BL/6 mice were infected with cercariae of S. japonicum through the abdomen. The expression of ICOS, activation markers, and the cytokine production on CD4+ ICOS+ Th cells were detected by flow cytometry (FCM) and quantitative real-time PCR (qRT-PCR). Moreover, the differentially expressed gene data of ICOS+ and ICOS- Th cells from the spleen of infected mice were obtained by mRNA sequencing. Besides, Western blot and chromatin immunoprecipitation (ChIP) were used to explore the role of Ikzf2 on ICOS expression. Results: After S. japonicum infection, the expression of ICOS molecules gradually increased in splenic lymphocytes, especially in Th cells (P < 0.01). Compared with ICOS- Th cells, more ICOS+ Th cells expressed CD69, CD25, CXCR5, and CD40L (P < 0.05), while less of them expressed CD62L (P < 0.05). Also, ICOS+ Th cells expressed more cytokines, such as IFN-γ, IL-4, IL-10, IL-2, and IL-21 (P < 0.05). RNA sequencing results showed that many transcription factors were increased significantly in ICOS+ Th cells, especially Ikzf2 (P < 0.05). And then, the expression of Ikzf2 was verified to be significantly increased and mainly located in the nuclear of ICOS+ Th cells. Finally, ChIP experiments and dual-luciferase reporter assay confirmed that Ikzf2 could directly bind to the ICOS promoter in Th cells. Conclusion: In this study, ICOS+ Th cells were found to play an important role in S. japonicum infection to induce immune response in the spleen of C57BL/6 mice. Additionally, Ikzf2 was found to be one important transcription factor that could regulate the expression of ICOS in the spleen of S. japonicum-infected C57BL/6 mice.

MiR-130a-3p Alleviates Liver Fibrosis by Suppressing HSCs Activation and Skewing Macrophage to Ly6Clo Phenotype.

Emerging evidences have highlighted the crucial role of microRNAs (miRNAs) in the liver cirrhosis, but the relationship between miR-130a-3p and liver cirrhosis is not entirely clear. As we all know, schistosomiasis, as one of the zoonoses, can lead to liver cirrhosis when it advances. In this study, we investigated the biological functions of miR-130a-3p on the liver fibrosis of schistosomiasis in vivo and in vitro. The mice infected with Schistosoma japonicum (S. japonicum) were treated with lentivirus vector (LV)-miR-130a-3p by hydrodynamic injection through the tail vein. Our findings showed significantly decreased expression of miR-130a-3p both in the serum of patients with cirrhosis and in the liver of mice infected with S. japonicum. The results showed that LV-miR-130a-3p could effectively enter into the liver and alleviate liver granulomatous inflammation and collagen deposition. Simultaneously, LV-miR-130a-3p-promoted macrophages presented the Ly6Clo phenotype, concomitant with the decreased expression of the tissue inhibitor of metalloproteinases (TIMP) 1, and increased the expression of matrix metalloproteinase (MMP) 2, which contributed to the dissolution of collagen. Furthermore, overexpression of miR-130a-3p not only inhibited the activation and proliferation of hepatic stellate cells (HSCs) but also induced the apoptosis of HSCs. In addition, we also confirmed that miR-130a-3p enables to bind with mitogen-activated protein kinase (MAPK) 1 and transforming growth factor-beta receptors (TGFBR) 1 and TGFBR2 genes and inhibit the expressions of these genes. Our findings suggested that miR-130a-3p might represent as the potential candidate biomarker and therapeutic target for the prognosis identification and treatment of schistosomiasis liver fibrosis.

Hepatocyte CD1d protects against liver immunopathology in mice with schistosomiasis japonica.

Schistosomiasis is a neglected tropical disease with over 250 million people infected worldwide. The main clinically important species Schistosoma mansoni (S. mansoni) and Schistosoma japonicum (S. japonicum) cause inflammatory responses against tissue-trapped eggs, resulting in formation of granulomas mainly in host liver. Persistent granulomatous response results in severe fibrosis in the liver, leading to irreversible impairment of the liver and even death of the host. CD1d, a highly conserved MHC class I-like molecule, is expressed by both haematopoietic and non-haematopoietic cells. CD1d on antigen-presenting cells (APCs) of haematopoietic origin presents pathogen-derived lipid antigens to natural killer T (NKT) cells, which enables them to rapidly produce large amounts of various cytokines and facilitate CD4+ T helper (Th) cell differentiation upon invading pathogens. Noteworthy, hepatocytes of non-haematopoietic origin have recently been shown to be involved in maintaining liver NKT cell homeostasis through a CD1d-dependent manner. However, whether hepatocyte CD1d-dependent regulation of NKT cell homeostasis also modulates CD4+ Th cell responses and liver immunopathology in murine schistosomiasis remains to be addressed. Here, we show in mice that CD1d expression on hepatocytes was decreased dramatically upon S. japonicum infection, accompanied by increased NKT cells, as well as upregulated Th1 and Th2 responses. Overexpression of CD1d in hepatocytes significantly decreased local NKT numbers and cytokines (IFN-γ, IL-4, IL-13), concomitantly with downregulation of both Th1 and Th2 responses and alleviation in pathological damage in livers of S. japonicum-infected mice. These findings highlight the potential of hepatocyte CD1d-targeted therapies for liver immunopathology control in schistosomiasis.

ApoE deficiency promotes hepatic pathology by aggravating Th17/Treg imbalance in murine schistosomiasis japonica.

AIMS: The Schistosoma japonicum (S japonicum)-infected ApoE gene deficiency (ApoE-/- ) mice were used to determine effect of ApoE on hepatic immunopathology. METHODS: Murine activities and appetite, body weight, and ratio of liver weight to its body weight (Hepatic mass index, HMI) were observed. Worm load and liver egg burden were evaluated as the infection intensity. Number and size of liver egg granulomas and serum levels of alanine aminotransferase (ALT) were investigated. We analysed hepatic fibrosis by markers of fibrosis in tissue, detected hepatic Th17 and Treg frequency by flow cytometry, and measured hepatic expressions of RORγt, Foxp3, IL-17A and TGF-ß1 via qPCR. Lipid metabolism was determined by serum levels of cholesterol (TC) and triglyceride (TG) as well as hepatic Oil red O staining. RESULTS: In the infected ApoE-/- mice, the increased infection intensity aggravated the hepatic immunopathology (evidenced by increased HMI, elevated egg granulomas and increased ALT levels) and fibrosis (increased hepatic collagen deposition). ApoE deficiency resulted in significantly elevated ratio of hepatic Th17/Treg and higher serum levels of TC and TG, along with higher level of hepatic Oil red O staining. CONCLUSIONS: ApoE deficiency promotes hepatic pathology and fibrosis by exacerbating Th17/Treg imbalance and altering lipid metabolism in murine schistosomiasis japonica.

Impact of continuous low water stage on the breeding environment of Oncomelania hupensis: a case study of Poyang Lake area in China.

BACKGROUND: Oncomelania hupensis is the only intermediate host of Schistosoma japonicum and plays a decisive role in its transmission. The variation of water level greatly affects the reproduction and growth of snails. Therefore, in this paper, we analyze the variations of water level in the Poyang Lake region from 1993 to 2016 combined with satellite imagery to elucidate the evolution of the snail breeding environment. METHODS: By employing remote sensing data from 1993 to 2016 (April-June and September-November), the vegetation area of Poyang Lake and the vegetation area at different elevations were extracted and calculated. Moreover, the average daily water level data from the four hydrological stations (Hukou station, Xingzi station, Tangyin station and Kangshan station) which represent the typical state of Poyang Lake were collected from 1993 to 2016. The variance of the monthly mean water level, inundation time and the average area were analyzed by variance to find a significance level of α = 0.05. RESULTS: According to hydrological data before and after 2003, the average water level after 2003 is significantly lower than that before 2003 in Poyang Lake. After 2003, the time of inundateing the snail breeding period was later in April to June than that before 2003, while the time of wate-falling stage in September to November moved forward after 2003 than before 2003. Of them, the lowest water level affecting the breeding and growing period of O. hupensis in the northern part of Poyang Lake decreased from 11 m to 9 m. After 2003, the expansion of meadow area in the north part of Poyang Lake was mainly concentrated in the elevation of 9-11 m, and the newly increased infested-meadow in the lake area was mainly concentrated in the north part of Poyang Lake. CONCLUSIONS: By comparing the change of water level characteristics in different parts of the Poyang Lake area as well as changes in meadow area before and after 2003, it is found that the water level changes mainly affect the snail breeding area in the northern part of Poyang Lake. The results are helpful for improving scientific measures for snail control in Jiangxi Province. This approach could also be applicible to Dongting Lake area and other lake areas affected by water level changes and can bring significant guidance for snail control in lake areas.

IL-17A-producing γδ T cells promote liver pathology in acute murine schistosomiasis.

BACKGROUND: The main symptoms of schistosomiasis are granuloma and fibrosis, caused by Schistosoma eggs. Numerous types of cells and cytokines are involved in the progression of Schistosoma infection. As a class of innate immune cells, γδ T cells play critical roles in the early immune response. However, their role in modulating granuloma and fibrosis remains to be clarified. METHODS: Liver fibrosis in wild-type (WT) mice and T cell receptor (TCR) δ knockout (KO) mice infected with Schistosoma japonicum was examined via Masson's trichrome staining of collagen deposition and quantitative reverse transcriptase-PCR (RT-PCR) of fibrosis-related genes. Granuloma was detected by hematoxylin-eosin (H&E) staining and quantified. Flow cytometry was used for immune cell profiling and for detecting cytokine secretion. The abundance of the related cytokines was measured using quantitative RT-PCR. RESULTS: The livers of S. japonicum-infected mice had significantly increased proportions of interleukin (IL)-17A producing γδ T cells and secreted IL-17A. Compared with the WT mice, TCR δ deficiency resulted in reduced pathological impairment and fibrosis in the liver and increased survival in infected mice. In addition, the profibrogenic effects of γδ T cells in infected mice were associated with enhanced CD11b+Gr-1+ cells, concurrent with increased expression of transforming growth factor (TGF)-ß in the liver. CONCLUSIONS: In this mouse model of Schistosoma infection, γδ T cells may promote liver fibrosis by recruiting CD11b+Gr-1+ cells. These findings shed new light on the pathogenesis of liver pathology in murine schistosomiasis.

Adjustments of γδ T Cells in the Lung of Schistosoma japonicum-Infected C56BL/6 Mice.

Many kinds of lymphocytes are involved in Schistosoma japonicum (S. japonicum) infection-induced disease. γδ T cells comprise a small number of innate lymphocytes that quickly respond to foreign materials. In this study, the role of γδ T cells in the lung of S. japonicum-infected C56BL/6 mice was investigated. The results demonstrated that S. japonicum infection induces γδ T cell accumulation in the lung, expressing higher levels of CD25, MHCII, CD80, and PDL1, and lower levels of CD127 and CD62L (P < 0.05). The intracellular cytokines staining results illustrated higher percentages of IL-4-, IL-10-, IL-21-, and IL-6-producing γδ T cells and lower percentages of IFN-γ-expressing γδ T cells in the lung of infected mice (P < 0.05). Moreover, the granuloma size in lung tissue was significantly increased in Vδ-/- mice (P < 0.05). In the lung of S. japonicum-infected Vδ-/- mice, both type 1 and type 2 immune responses were decreased significantly (P < 0.05). In addition, the expression of CD80 and CD69 on B cells was decreased significantly (P < 0.05), and the SEA-specific antibody was markedly decreased (P < 0.05) in the blood of infected Vδ-/- mice. In conclusion, this study indicates that γδ T cells could adjust the Th2 dominant immune response in the lung of S. japonicum-infected mice.

Oncomelania hupensis retains its ability to transmit Schistosoma japonicum 13 years after migration from permissive to non-permissive areas.

BACKGROUND: The East Route Project (ERP) of the South-to-North Water Diversion Project (SNWDP) stretches across schistosomiasis endemic and non-endemic areas in China, which may lead to the dispersal of Oncomelania hupensis, the intermediate host of Schistosoma japonicum, from permissive areas along the Yangtze River Basin to non-permissive areas in northern China. A previous survey demonstrated that O. hupensis could survive and breed for 13 years (12 generations) after being transferred to a non-permissive area, and could be infected by S. japonicum. However, it is not clear if the migrated snails will change their ability to transmit S. japonicum. METHODS: We infected mice with the cercariae released from the infected transferred snails bred in Jining city of Shandong Province (non-permissive areas) for 13 years. The mice in the control group were infected with cercariae derived from the snails collected in their original habitat (Jiangdu county of Jiangsu Province, permissive areas). Then, we explored the pathogenicity to mice including worm burden, liver egg count and pathology. Additionally, the gene expression profiles of the adult male and female worms recovered from the infected mice were analyzed by RNA sequencing. RESULTS: The worm burden, liver egg count and pathology of the mice infected with cercariae released from transferred snails bred in non-permissive areas for 13 years showed no significant differences, when compared with the control cercariae. Slight changes occurred at the transcription level between adult male and female worms recovered from mice infected with cercariae derived from snails bred in permissive and non-permissive areas. Only fourteen genes were significantly differentially expressed in the comparison of adult female worms, and no significantly differentially expressed gene was found in the comparison of adult male worms. CONCLUSIONS: Our findings strongly suggest that transferred snails did not change their schistosomiasis transmission ability and the worms derived from them retained the original pathogenicity, even after migrating from permissive to non-permissive areas for 13 years. Therefore, a long-term surveillance system of snails along the SNWDP is urgently needed to prevent the diffusion of O. hupensis and reduce the risk of transmission of schistosomiasis.

Upregulation of KSRP by miR-27b attenuates schistosomiasis-induced hepatic fibrosis by targeting TGF-ß1.

Hepatic stellate cells (HSCs) are the main effectors for various types of hepatic fibrosis, including Schistosome-induced hepatic fibrosis. Multiple inflammatory cytokines/chemokines, such as transforming growth factor-ß1 (TGF-ß1), activate HSCs, and contribute to the development of hepatic fibrosis. MicroRNAs regulate gene expression at the posttranscriptional level and are involved in regulation of inflammatory cytokine/chemokine synthesis. In this study, we showed that soluble egg antigen (SEA) stimulation and Schistosoma japonicum infection downregulate miR-27b expression and increase KH-type splicing regulatory protein (KSRP) mRNA and protein levels in vitro and in vivo. miR-27b regulates the stabilization of TGF-ß1 mRNA through targeting KSRP by interacting with their AU-rich elements in hepatocytes and non-parenchymal cells, which has an effect on the activation of HSCs. Importantly, our results have shown that either knockdown miR-27b or overexpression of KSRP attenuates S. japonicum-induced hepatic fibrosis in vivo. Therefore, our study highlights the crucial role of miR-27b and KSRP in the negative regulation of immune reactions in hepatocyte and non-parenchymal cells in response to SEA stimulation and S. japonicum infection. It reveals that manipulation of miR-27b or KSRP might be a useful strategy not only for treating Schistosome-induced hepatic fibrosis but also for curing hepatic fibrosis in general.

Process Development of Sj-p80: A Low-Cost Transmission-Blocking Veterinary Vaccine for Asiatic Schistosomiasis.

Asiatic schistosomiasis caused by Schistosoma japonicum is a neglected tropical disease resulting in significant morbidity to both humans and animals - particularly bovines - in endemic areas. Infection with this parasite leads to less healthy herds, causing problems in communities which rely on bovines for farming, milk and meat production. Additionally, excretion of parasite eggs in feces perpetuates the life cycle and can lead to human infection. We endeavored to develop a minimally purified, inexpensive, and effective vaccine based on the 80 kDa large subunit of the calcium activated neutral protease (calpain) from S. japonicum (Sj-p80). Here we describe the production of veterinary vaccine-grade Sj-p80 at four levels of purity and demonstrate in a pilot study that minimally purified antigen provides protection against infection in mice when paired with a low-cost veterinary adjuvant, Montanide™ ISA61 VG. Preliminary data demonstrate that the vaccine is immunogenic with robust antibody titers following immunization, and vaccination resulted in a reduction of parasite eggs being deposited in the liver (23.4-51.4%) and intestines (1.9-55.1%) depending on antigen purity as well as reducing the ability of these eggs to hatch into miracidia by up to 31.6%. We therefore present Sj-p80 as a candidate vaccine antigen for Asiatic schistosomiasis which is now primed for continued development and testing in bovines in endemic areas. A successful bovine vaccine could play a major role in reducing pathogen transmission to humans by interrupting the parasitic life cycle and improving quality of life for people living in endemic countries.

Genome assembly and transcriptome analysis provide insights into the antischistosome mechanism of Microtus fortis.

Microtus fortis is the only mammalian host that exhibits intrinsic resistance against Schistosoma japonicum infection. However, the underlying molecular mechanisms of this resistance are not yet known. Here, we perform the first de novo genome assembly of M. fortis, comprehensive gene annotation analysis, and evolution analysis. Furthermore, we compare the recovery rate of schistosomes, pathological changes, and liver transcriptomes between M. fortis and mice at different time points after infection. We observe that the time and type of immune response in M. fortis are different from those in mice. M. fortis activates immune and inflammatory responses on the 10th day post infection, such as leukocyte extravasation, antibody activation, Fc-gamma receptor-mediated phagocytosis, and the interferon signaling cascade, which play important roles in preventing the development of schistosomes. In contrast, an intense immune response occurrs in mice at the late stages of infection and could not eliminate schistosomes. Infected mice suffer severe pathological injury and continuous decreases in cell cycle, lipid metabolism, and other functions. Our findings offer new insights into the intrinsic resistance mechanism of M. fortis against schistosome infection. The genome sequence also provides the basis for future studies of other important traits in M. fortis.

Inhibition of Rho-Kinase Downregulates Th17 Cells and Ameliorates Hepatic Fibrosis by Schistosoma japonicum Infection.

BACKGROUND: Schistosomiasis is an immunopathogenic disease in which Th17 cells play vital roles. Hepatic granuloma formation and subsequent fibrosis are its main pathologic manifestations and the leading causes of hepatic cirrhosis, and effective therapeutic interventions are lacking. In this study, we explored the effects of fasudil, a selective RhoA-Rho-associated kinase (ROCK) inhibitor, on Th17 cells and the pathogenesis of schistosomiasis. METHODS: Mice were infected with Schistosoma japonicum and treated with fasudil. The worm burden, hepatic granuloma formation, and fibrosis were evaluated. The roles of fasudil on Th17, Treg, and hepatic stellate cells were analyzed. RESULTS: Fasudil therapy markedly reduced the granuloma size and collagen deposit in livers from mice infected with S. japonicum. However, fasudil therapy did not affect the worm burden in infected mice. The underlying cellular and molecular mechanisms were investigated. Fasudil suppressed the activation and induced the apoptosis of CD4+ T cells. Fasudil inhibited the differentiation and effector cytokine secretion of Th17 cells, whereas it upregulated Treg cells in vitro. It also restrained the in vivo interleukin (IL)-4 and IL-17 levels in infected mice. Fasudil directly induced the apoptosis of hepatic stellate cells and downregulated the expressions of hepatic fibrogenic genes, such as collagen type I (Col-I), Col-III, and transforming growth factor-1 (TGF-ß1). These effects may contribute to its anti-pathogenic roles in schistosomiasis. CONCLUSIONS: Fasudil inhibits hepatic granuloma formation and fibrosis with downregulation of Th17 cells. Fasudil might serve as a novel therapeutic agent for hepatic fibrosis due to schistosome infections and perhaps other disorders.

Schistosomiasis.

Schistosomiasis (bilharzia) is a neglected tropical disease caused by parasitic flatworms (blood flukes) of the genus Schistosoma, with considerable morbidity in parts of the Middle East, South America, Southeast Asia and, particularly, in sub-Saharan Africa. Infective larvae grow in an intermediate host (fresh-water snails) before penetrating the skin of the definitive human host. Mature adult worms reside in the mesenteric (Schistosoma mansoni and Schistosoma japonicum) or pelvic (Schistosoma haematobium) veins, where female worms lay eggs, which are secreted in stool or urine. Eggs trapped in the surrounding tissues and organs, such as the liver and bladder, cause inflammatory immune responses (including granulomas) that result in intestinal, hepato-splenic or urogenital disease. Diagnosis requires the detection of eggs in excreta or worm antigens in the serum, and sensitive, rapid, point-of-care tests for populations living in endemic areas are needed. The anti-schistosomal drug praziquantel is safe and efficacious against adult worms of all the six Schistosoma spp. infecting humans; however, it does not prevent reinfection and the emergence of drug resistance is a concern. Schistosomiasis elimination will require a multifaceted approach, including: treatment; snail control; information, education and communication; improved water, sanitation and hygiene; accurate diagnostics; and surveillance-response systems that are readily tailored to social-ecological settings.

rSjP40 suppresses hepatic stellate cell activation by promoting microRNA-155 expression and inhibiting STAT5 and FOXO3a expression.

Activation of hepatic stellate cells (HSCs) is the central event of the evolution of hepatic fibrosis. Schistosomiasis is one of the pathogenic factors which could induce hepatic fibrosis. Previous studies have shown that recombinant Schistosoma japonicum egg antigen P40 (rSjP40) can inhibit the activation and proliferation of HSCs. MicroRNA-155 is one of the multifunctional noncoding RNA, which is involved in a series of important biological processes including cell development, proliferation, differentiation and apoptosis. Here, we try to observe the role of microRNA-155 in rSjP40-inhibited HSC activation and explore its potential mechanisms. We found that microRNA-155 was raised in rSjP40-treated HSCs, and further studies have shown that rSjP40 enhanced microRNA-155 expression by inhibiting STAT5 transcription. Up-regulated microRNA-155 can down-regulate the expression of FOXO3a and then participate in rSjP40-inhibited expression of α-smooth muscle actin (α-SMA) and collagen I. Furthermore, we observed microRNA-155 inhibitor could partially restore the down-regulation of FOXO3a, α-SMA and collagen I expression in LX-2 cells induced by rSjP40. Therefore, our research provides further insight into the mechanism by which rSjP40 could inhibit HSC activation via miR-155.

IL-7 suppresses macrophage autophagy and promotes liver pathology in Schistosoma japonicum-infected mice.

In schistosomiasis japonica and mansoni, parasite eggs trapped in host liver elicit severe liver granulomatous inflammation that subsequently leads to periportal fibrosis, portal hypertension, haemorrhage or even death. Macrophages are critical for granuloma formation and the development of liver fibrosis during schistosomiasis. However, whether the aberrant regulation of macrophage autophagy has an effect on the development of liver immunopathology in schistosomiasis remains to be elucidated. In this study, we showed that Schistosoma japonicum (S. japonicum) egg antigen (SEA)-triggered macrophage autophagy limited the development of pathology in host liver. However, engagement of IL-7 receptor (IL-7R/CD127) on macrophages by S. japonicum infection-induced IL-7 significantly suppressed SEA-triggered macrophage autophagy, which led to an enhanced liver pathology. In addition, anti-IL-7 neutralizing antibody or anti-CD127 blocking antibody treatment increased macrophage autophagy and suppressed liver pathology. Finally, we demonstrated that IL-7 protects macrophage against SEA-induced autophagy through activation of AMP-activated protein kinase (AMPK). Our study reveals a novel role for IL-7 in macrophage autophagy and identifies AMPK as a novel downstream mediator of IL-7-IL-7R signalling and suggests that manipulation of macrophage autophagy by targeting IL-7-IL-7R signalling may have the potential to lead to improved treatment options for liver pathogenesis in schistosomiasis.

Effect of miR-182 on hepatic fibrosis induced by Schistosomiasis japonica by targeting FOXO1 through PI3K/AKT signaling pathway.

The study aimed to investigate the impact of miR-182 and FOXO1 on S. japonica-induced hepatic fibrosis. Microarray analysis was performed to screen out differential expressed miRNAs and mRNAs. Rat hepatic fibrosis model and human hepatocellular cell line LX-2 were used to study the effect of miR-182 and FOXO1. qRT-PCR and Western blot were used to detect the expression of miR-182, FOXO1 or other fibrosis markers. The targeting relationship between FOXO1 and miR-182 was verified by luciferase reporter assay. Immunohistochemistry or immunofluorescence staining was conducted to detect FOXO1 or α-SMA in rat hepatic tissues. Cell viability and apoptosis were detected by MTT assay and flow cytometry. The expression of PI3K/AKT pathway-related proteins was detected by Western blot. miR-182 was highly expressed in liver fibrosis samples, and FOXO1 expression was negatively correlated with miR-182 expression. After transfection of miR-182, FOXO1 expression was down-regulated, with the results of LX-2 cells proliferation inhibition and apoptosis induction, as well as the aggravation of rat hepatic fibrosis. The expression of p-AKT/AKT and p-S6/S6 was increased, meaning that the PI3K/AKT signal pathway was activated. The results were reversed when treated with Wortmannin (PI3K inhibitor). After transfection of miR-182 inhibitor, FOXO1 expression was up-regulated, LX-2 cell proliferation was inhibited, and apoptosis rate was increased. High-expressed miR-182 and low-expressed FOXO1 promoted proliferation and inhibiting apoptosis on liver fibrosis cells, stimulating the development of S. japonica-induced hepatic fibrosis through feeding back to PI3K/AKT signaling pathway.

Praziquantel Targets M1 Macrophages and Ameliorates Splenomegaly in Chronic Schistosomiasis.

Splenomegaly is a common feature of many infectious diseases, including schistosomiasis japonica. However, the immunopathogenesis and the treatment of splenomegaly due to schistosomiasis have been largely neglected. Praziquantel (PZQ), a classical schistosomicide, has been demonstrated by us and others to have antifibrotic and anti-inflammatory activities against schistosomiasis. In this study, we investigated the effect of PZQ on alleviating the splenomegaly caused by Schistosoma japonicum infection in mice. The results showed that the number of macrophages, especially the number of M1 macrophages, was significantly increased in the enlarged spleens of infected mice (P < 0.001). After PZQ treatment for 4 weeks, the number of splenic macrophages, especially the number of M1 macrophages, was significantly reduced (P < 0.001) by the way of apoptosis, and another schistosomicide, mefloquine, had no effect either on the splenomegaly or on reducing the number of macrophages. Furthermore, by using the murine macrophage line RAW 264.7, we found that PZQ could inhibit the formation of the NLRP3 inflammasome and attenuate phagocytic activity in M1 macrophages. Thus, our studies suggest that PZQ plays a powerful role in ameliorating the splenomegaly caused by S. japonicum infection, which presents a new strategy for the therapy of splenomegaly resulting from other pathological conditions.