A target-based discovery from a parasitic helminth as a novel therapeutic approach for autoimmune diseases.

BACKGROUND: Regulatory T cells (Tregs) can alleviate the development of autoimmune and inflammatory diseases, thereby proposing their role as a new therapeutic strategy. Parasitic helminths have co-evolved with hosts to generate immunological privilege and immune tolerance through inducing Tregs. Thus, constructing a "Tregs-induction"-based discovery pipeline from parasitic helminth is a promising strategy to control autoimmune and inflammatory diseases. METHODS: The gel filtration chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC) were used to isolate immunomodulatory components from the egg extracts of Schistosoma japonicum. The extracted peptides were evaluated for their effects on Tregs suppressive functions using flow cytometry, ELISA and T cell suppression assay. Finally, we carried out colitis and psoriasis models to evaluate the function of Tregs induced by helminth-derived peptide in vivo. FINDINGS: Here, based on target-driven discovery strategy, we successfully identified a small 3 kDa peptide (SjDX5-53) from egg extracts of schistosome, which promoted both human and murine Tregs production. SjDX5-53 presented immunosuppressive function by arresting dendritic cells (DCs) at an immature state and augmenting the proportion and suppressive capacity of Tregs. In mouse models, SjDX5-53 protected mice against autoimmune-related colitis and psoriasis through inducing Tregs and inhibiting inflammatory T-helper (Th) 1 and Th17 responses. INTERPRETATION: SjDX5-53 exhibited the promising therapeutic effects in alleviating the phenotype of immune-related colitis and psoriasis. This study displayed a screening and validation pipeline of the inducer of Tregs from helminth eggs, highlighting the discovery of new biologics inspired by co-evolution of hosts and their parasites. FUNDING: This study was supported by the Natural Science Foundation of China (82272368) and Natural Science Foundation of Jiangsu Province (BK20211586).

Maternal BPAF exposure impaired synaptic development and caused behavior abnormality in offspring.

Bisphenol A (BPA) has been widely restricted, leading to a significant increase in the production of bisphenol AF (BPAF), one of the most common bisphenol analogs use as a substitute for BPA. However, there is limit evidence on the neurotoxicity of BPAF, especially the potential effects of maternal exposed to BPAF on offspring. A maternal BPAF exposure model was used to evaluate its effects on long-term neurobehaviors in offspring. We found that maternal BPAF exposure resulted in immune disorders, characterized by abnormal CD4+T cell subsets, and their offspring exhibited anxiety- and depression-like behaviors, as well as impairments in learning-memory, sociability and social novelty. Further, brain bulk RNA-sequencing (RNA-seq) and hippocampus single-nucleus RNA-sequencing (snRNA-seq) of offspring showed that differentially expressed genes (DEGs) were enriched in pathways related to synaptic and neurodevelopment. Synaptic ultra-structure of offspring was damaged after maternal BPAF exposure. In conclusion, maternal BPAF exposure induced behavior abnormality in adult offspring, together with synaptic and neurodevelopment defects, which might be related to maternal immune dysfunction. Our results provide a comprehensive insight into the neurotoxicity mechanism of maternal BPAF exposure during gestation. Given the increasing and ubiquitous exposure to BPAF, especially during sensitive periods of growth and development, the safety of BPAF requires urgent attention.

Early-life bisphenol AP exposure impacted neurobehaviors in adulthood through microglial activation in mice.

Bisphenol AP (BPAP), a structural analog of bisphenol A (BPA), has been widely detected in environment and biota. BPAP was reported to interfere with hormone and metabolism, while limited data were available about its effects on neurobehavior, especially exposure to it during early-life time. A mouse model of early-life BPAP exposure was established to evaluate the long-term neurobehaviors in offspring. Collectively, early-life BPAP exposure caused anxiety-like behaviors and impaired learning and memory in adult offspring. Through brain bulk RNA-sequencing (RNA-seq), we found differential expressed genes were enriched in pathways related to behaviors and neurodevelopment, which were consistent with the observed phenotype. Besides, single-nucleus RNA-sequencing (snRNA-seq) showed BPAP exposure altered the transcriptome of microglia in hippocampus. Mechanistically, BPAP exposure induced inflammations in hippocampus through upregulating Iba-1 and activating the microglia. In addition, we observed that BPAP exposure could activate peripheral immunity and promote proportion of macrophages and activation of dendritic cells in the offspring. In conclusion, early-life exposure to BPAP impaired neurobehaviors in adult offspring accompanied with excessive activation of hippocampal microglia. Our findings provide new clues to the underlying mechanisms of BPAP's neurotoxic effects and therefore more cautions should be taken about BPAP.

Identification and Characterization of Antigenic Properties of Schistosoma japonicum Heat Shock Protein 90α Derived Peptides.

It is known that schistosome-derived antigens induce innate and adaptive immune responses that are essential for the formation of hepatic immunopathology. Here, we screened and synthesized four peptides derived from Schistosoma japonicum (S. japonicum) heat shock protein 90α (Sjp90α-1, -2, -3, and -4), which is widely expressed in adults and eggs of the genus S. japonicum and induces remarkable immune reactions. To define the antigenicity of these peptides, we stimulated splenocytes with peptides, and the results showed that only the Sjp90α-1 peptide could predominately induce the activation of dendritic cells (DCs) and macrophages as well as alter the proportion of follicular helper T (Tfh) cells. Next, CD4+ T cells were purified and cocultured with mouse bone-marrow-derived DCs (BMDCs) with or without Sjp90α-1 peptide stimulation in vitro, and the results showed that Sjp90α-1-stimulated BMDCs can significantly induce CD4+ T-cell differentiation into Tfh cells, while the direct stimulation of CD4+ T cells with Sjp90α-1 did not induce Tfh cells, indicating that the Sjp90α-1 peptide promotes Tfh cell differentiation depending on the presence of DCs. Furthermore, we selected and prepared an Sjp90α-1-peptide-based antibody and illustrated that it has excellent reactivity with the immunizing peptide and detects a single band of 29 kDa corresponding to the Sjp90α protein. The immunolocalization results showed that the protein recognized by this Sjp90α-1-peptide-based antibody is present in the mature eggs and the tegument of adults, implying that the parasite-derived peptide has a potential interaction with the host immune system. Finally, we evaluated antipeptide IgG antibodies and revealed a significantly higher level of anti-Sjp90α-1 peptide IgG antibodies in mice 3 weeks after S. japonicum infection. In conclusion, we illustrate that these synthetic peptides warrant further investigation by evaluating their antigen-specific immune response and their ability to efficiently induce Tfh cells. Moreover, they may constitute a potentially helpful method for the laboratory diagnosis of schistosomiasis japonica.

Oral berberine ameliorates high-fat diet-induced obesity by activating TAS2Rs in tuft and endocrine cells in the gut.

BACKGROUND AND AIMS: Although oral berberine, a natural compound extracted from the Chinese herbal medicine curcumin, has low bioavailability, it is still effective in suppressing obesity; however, the underlying mechanism is unclear. Berberine can bind to bitter-taste receptors (TAS2Rs) in intestinal endocrine secretin tumor (STC-1) cells to promote glucagon-like peptide-1 (GLP-1) secretion. Notably, TAS2Rs also exist in the tuft cells of the gut. Therefore, this study aimed to explore whether the beneficial effect of oral berberine on obesity is dependent on bitter-taste signaling in the tuft cells of the gut. METHODS AND RESULTS: Standard chow diet (SCD) or high-fat diet (HFD) was administered to C57BL/6 mice, with or without berberine (100 mg/kg, 200 mg/kg, p. o.). The PLCß2 inhibitor U73122 was used to verify whether the anti-obesity effect of berberine was dependent on the bitter-taste signaling pathway. In this study, we observed that the oral administration of berberine alleviated HFD-induced obesity in mice that U73122 partially inhibited. Both in vivo and ex vivo, berberine upregulated the release of GLP-1, promoted the proliferation of tuft cells and secretion of IL-25 in obesity via the TAS2R signaling pathway. CONCLUSIONS: Oral berberine ameliorated HFD-induced obesity through the TAS2R-IL-25 signaling pathway in tuft cells in the gut. SIGNIFICANCE: We identified and functionally characterized the TAS2Rs and Gα-gustducin/Gß1γ13 signaling pathway utilized by tuft cells in response to oral berberine in obese mice and proposed a new mechanism underlying the anti-obesity effect of berberine.

Tripartite motif 25 ameliorates doxorubicin-induced cardiotoxicity by degrading p85α.

Doxorubicin (DOX)-based chemotherapy is widely used to treat malignant tumors; however, the cardiotoxicity induced by DOX restricts its clinical usage. A therapeutic dose of DOX can activate ubiquitin-proteasome system. However, whether and how ubiquitin-proteasome system brings out DOX-induced cardiotoxicity remains to be investigated. Here we conducted a proteomics analysis of a DOX-induced cardiotoxicity model to screen the potentially ubiquitination-related molecules. Dysregulated TRIM25 was found to contribute to the cardiotoxicity. In vivo and in vitro cardiotoxicity experiments revealed that TRIM25 ameliorated DOX-induced cardiotoxicity. Electron microscopy and endoplasmic reticulum stress markers revealed that TRIM25 mitigated endoplasmic reticulum stress and apoptosis in DOX-induced cardiomyocytes. Mechanistically, the Co-immunoprecipitation assays and CHX pulse-chase experiment determined that TRIM25 affected p85α stability and promoted its ubiquitination and degradation. This leads to increase of nuclear translocation of XBP-1s, which mitigates endoplasmic reticulum stress. These findings reveal that TRIM25 may have a therapeutic role for DOX-induced cardiotoxicity.

Peritoneal GATA6+ macrophage drives hepatic immunopathogenesis and maintains the Treg cell niche in the liver.

The source of macrophages that contribute to human liver disease remains poorly understood. The purpose of this study is to investigate the functional mechanism of peritoneal macrophages in the development of hepatic immunopathology. By performing the natural infection with the blood fluke Schistosoma japonicum (S. japonicum) and the chemically carbon tetrachloride (CCl4 )-induced liver injured mouse model, we identified the peritoneal cavity as an essential source of hepatic macrophages. Here, we show that a large number of F4/80+ macrophages was accumulated in the peritoneal cavity during liver injury. An unknown source population of macrophages, which highly expressed GATA6 that is specific to peritoneal macrophages, was found to exist in the injured livers. Peritoneal macrophage deletion by injection with clodronate-containing liposomes led to an attenuated hepatic pathology and the inflammatory microenvironment, while adoptive transfer of macrophages into the abdominal cavity, by contrast, results in restoring liver pathology. Importantly, there are set genes of monocyte chemoattractant protein (MCP)-1, -2, and -3 that are highly related to recruit GATA6+ macrophages during S. japonicum infection, while administration of bindarit, a selective inhibitor of MCPs synthesis, dramatically decreased the hepatic expression of GATA6+ macrophages and thus attenuated hepatic pathology. Furthermore, in vivo study showed that peritoneal macrophages promote hepatic immunopathology is dependent on the accumulation of regulatory T cells (Tregs) in the liver. Altogether, these data provide the first clear evidence that GATA6+ peritoneal macrophages play critical roles in both the formation of hepatic immunopathology and the accumulation of Tregs cells.

Right Ventricular Ejection Fraction Assessed by Three-Dimensional Echocardiography Is Associated with Long-Term Adverse Clinical Cardiac Events in Patients with Anthracycline-Induced Cardiotoxicity.

BACKGROUND: Patients with cancer treated with chemotherapy are at risk for cardiovascular toxicity. Global longitudinal strain has been reported to play important roles in predicting cardiovascular adverse events (CAEs) in patients treated with anthracycline. In addition to various left ventricular indicators, the authors hypothesized that right ventricular (RV) parameters might be associated with CAEs related to anthracycline treatment. METHODS: In this retrospective study, 96 patients diagnosed with diffuse large B-cell lymphoma who received chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab) were studied using three-dimensional transthoracic echocardiography. Baseline demographic data and oncologic and echocardiographic parameters were analyzed. The main outcome was the proportion of patients with grade 3 to 5 CAEs. The association of all three-dimensional transthoracic echocardiographic parameters with long-term CAEs was analyzed using Cox proportional-hazard analysis. RESULTS: Over a median follow-up period of 6.1 years (range, 4.9-7.6 years) after the completion of anthracycline chemotherapy, 18 of 96 patients (19%) experienced CAEs. Percentage changes (%Δ) in left ventricular global longitudinal strain (LVGLS), global circumferential strain, RV ejection fraction (RVEF), and RV end-systolic volume were associated with CAEs (P < .05). A relative reduction of RVEF (hazard ratio, 0.847; 95% CI, 0.785-0.915; P < .001) was the strongest associated factor for CAEs. An increase in CAEs was also observed in patients with impaired %ΔLVGLS > 15% and impaired %ΔRVEF > 12.7% compared with those with impaired %ΔLVGLS > 15% and impaired %ΔRVEF < 12.7% (P = .032). CONCLUSIONS: Three-dimensional echocardiography-based assessments of %ΔRVEF and %Δ in RV end-systolic volume were significantly associated with CAEs in patients with lymphoma treated with anthracycline chemotherapy.

Helminth-induced CD9+ B-cell subset alleviates obesity-associated inflammation via IL-10 production.

It has been shown that helminth infection can protect against obesity and improve insulin sensitivity to a certain extent, based on epidemiological investigations and animal experiments. Meanwhile, helminths induce a network of regulatory immune cells, including regulatory B cells (Bregs). However, the molecule characteristics and function of these Bregs in improving whole-body metabolic homeostasis remains largely unclear. We established a mouse model with chronic Schistosoma japonicum infection, and compared the differences in B10 cells (CD19+CD5+CD1dhi) and B10- cells (CD19+CD5-CD1d-) from splenic B cells of infected mice using RNA-seq. A unique Breg population was identified. Furthermore, these Bregs were evaluated for their ability to produce inhibitory cytokines in vitro and suppress obesity when adoptively transferred into mice on a high-fat diet. We found that schistosome infection could expand Breg cell populations in mice. CD9 was demonstrated to be a key surface marker for most murine IL-10+ B cells in spleen. CD19+CD9+ B cells produced more IL-10 than conventional B10 cells. Adoptive transfer of CD9+ B cells had the capacity to alleviate obesity-associated inflammation via promoting Tregs, Th2 cells and decreasing Th1, Th17 cells in high-fat diet mice. In conclusion, schistosome infection can induce regulatory CD9+ B cell production, which plays a critical role in the regulation of metabolic disorders through IL-10 production.

Predictive Modeling of MAFLD Based on Hsp90α and the Therapeutic Application of Teprenone in a Diet-Induced Mouse Model.

Background and Aims: The heat shock protein (Hsp) 90α is induced by stress and regulates inflammation through multiple pathways. Elevated serum Hsp90α had been found in nonalcoholic steatohepatitis (NASH). Geranylgeranylacetone (GGA, also called teprenone) is a terpenoid derivative. It was reported to induce Hsp and alleviate insulin resistance. We aimed to evaluate the Hsp90α as a biomarker in predicting metabolic-associated fatty liver disease (MAFLD) and define the therapeutic effects of geranylgeranylacetone for the disease. Methods: A clinical study was conducted to analyze the elements associated with Hsp90α, and a predictive model of MAFLD was developed based on Hsp90α. The histopathological correlation between Hsp90α and MAFLD was investigated through a diet-induced mouse model. Furthermore, GGA was applied to the mouse model. Results: Serum Hsp90α was increased in patients with MAFLD. A positive linear relationship was found between age, glycosylated hemoglobin (HbA1c), MAFLD, and serum Hsp90α. Meanwhile, a negative linear relationship with body mass index (BMI) was found. A model using Hsp90α, BMI, HbA1c, and ALT was established for predicting MAFLD. The area under the receiver operating characteristic (ROC) curves was 0.94 (95% CI 0.909-0.971, p = 0.000). The sensitivity was 84.1%, and the specificity was 93.1%. In vitro experiments, GGA induced Hsp90α in steatosis cells. In the mice model, Hsp90α decreased in the GGA treatment group. Hepatic steatosis, inflammation, insulin resistance, and glucose intolerance were improved in the GGA-treated group. Serum Hsp90α was positively correlated with steatohepatitis activity according to hepatic histopathology. Conclusions: Serum Hsp90α was elevated in MAFLD, and a positive correlation between serum Hsp90α and the grade of activity of steatohepatitis was observed. The model using BMI, HbA1c, and alanine aminotransferase (ALT) had a good value to predict MAFLD. The findings also revealed the effectiveness of GGA in the treatment of MAFLD.

Rescue of maternal immune activation-induced behavioral abnormalities in adult mouse offspring by pathogen-activated maternal Treg cells.

Maternal immune activation (MIA) induced by lipopolysaccharides or polyinosinic:polycytidylic acid injections can induce behavioral abnormalities in adult mouse offspring. Here, we used the soluble tachyzoite antigen from Toxoplasma gondii, a parasite that infects approximately two billion people, to induce MIA in mice. The adult male offspring showed autism-relevant behaviors and abnormal brain microstructure, along with a pro-inflammatory T-cell immune profile in the periphery and upregulation of interleukin-6 in brain astrocytes. We show that adoptive transfer of regulatory T (Treg) cells largely reversed these MIA-induced phenotypes. Notably, pathogen-activated maternal Treg cells showed greater rescue efficacy than those from control donors. Single-cell RNA sequencing identified and characterized a unique group of pathogen-activated Treg cells that constitute 32.6% of the pathogen-activated maternal Treg population. Our study establishes a new preclinical parasite-mimicking MIA model and suggests therapeutic potential of adoptive Treg cell transfer in neuropsychiatric disorders associated with immune alterations.

Therapeutic inhibition of miR-802 protects against obesity through AMPK-mediated regulation of hepatic lipid metabolism.

Background: The host-parasite relationship is based on subtle interplay between parasite survival strategies and host defense mechanisms. It is well known that helminth infection, which afflicts more than one billion people globally, correlates with a decreased prevalence of obesity. Dissecting the underlying mechanisms can provide new targets for treating obesity from the host-parasite interaction perspective. Methods: C57BL/6 mice received a normal or high-fat diet (HFD) with or without Sjp40 (one main component of schistosome-derived soluble egg antigens) treatment. Both the loss and gain-of-function experiments by the inhibitor suppression and lentivirus treatment of miR-802 were utilized to elucidate the role of miR-802/AMPK axis in host lipid metabolism. Hepatocyte lipogenesis assay and metabolic parameters were assessed both in vivo and in vitro. The potential interactions among Sjp40, CD36, miR-802, Prkab1, and AMPK were clarified by pull-down, miRNA expression microarray, quantitative RT-PCR, dual-luciferase reporter assay, and western blotting analysis. Results: We showed a link between decreased miR-802 and impaired lipid metabolism in Schistosoma japonicum infected mice. The decreased miR-802 promotes murine Prkab1 or human Prkaa1 expression, respectively, which increases levels of phosphorylated AMPK, resulting in a decrease in hepatic lipogenesis. Also, injection with schistosome-derived soluble egg antigens (SEA) attenuated metabolism. We demonstrated that Sjp40 as a main component of SEA interacted with CD36 on hepatocytes to inhibit miR-802, resulting in the activation of AMPK pathway and subsequent attenuation of lipogenesis. Collectively: Our study reveals the significant role of miR-802/AMPK axis in hepatic lipid metabolism and identifies the therapeutic potential of Sjp40 in treating obesity-related fatty liver.

P21 activated kinase-1 (PAK1) in macrophages is required for promotion of Th17 cell response during helminth infection.

CD4+ T cells differentiate into distinct functional effector and inhibitory subsets are facilitated by distinct cytokine cues present at the time of antigen recognition. Maintaining a balance between T helper 17 (Th17) and regulatory T (Treg) cells are critical for the control of the immunopathogenesis of liver diseases. Here, by using the mouse model of helminth Schistosoma japonicum (S japonicum) infection, we show that the hepatic mRNA levels of P21-activated kinase 1 (PAK1), a key regulator of the actin cytoskeleton, adhesion and cell motility, are significantly increased and associated with the development of liver pathology during S japonicum infection. In addition, PAK1-deficient mice are prone to suppression of Th17 cell responses but increased Treg cells. Furthermore, PAK1 enhances macrophage activation through promoting IRF1 nuclear translocation in an NF-κB-dependent pathway, resulting in promoting Th17 cell differentiation through inducing IL-6 production. These findings highlight the importance of PAK1 in macrophages fate determination and suggest that PAK1/IRF1 axis-dependent immunomodulation can ameliorate certain T cell-based immune pathologies.

Therapeutic potential of fucoidan in the reduction of hepatic pathology in murine schistosomiasis japonica.

BACKGROUND: Hepatic granuloma formation and fibrosis as the consequence of tissue entrapped eggs produced by female schistosomes characterize the pathology of Schistosoma japonicum infection. It has been proposed that fucoidan, a sulfated polysaccharide existing naturally in brown seaweed Fucus vesiculosus, plays a diversified role to perform immunomodulatory activities. However, whether fucoidan functions in the host hepatic pathology is unknown and identifying the potential mechanism that is responsible for hepatic improvement is still necessary. METHODS: We evaluated the hepatic pathology from S. japonicum-infected mice after treatment with fucoidan. qRT-PCR and immunofluorescence were used to detect the pro- or anti-inflammatory factors and the phosphorylated p65 in the livers. In addition, flow cytometry was also performed to investigate the T cell subsets in the S. japonicum-infected mice after treatment with fucoidan, and functional molecules relatively specific to Treg cells were detected in vitro. Furthermore, macrophages were treated with fucoidan in vitro and to detect the inflammatory cytokines. RESULTS: Treatment with fucoidan significantly reduced the hepatic granuloma size and fibrosis response during S. japonicum infection. The attenuated phospho-p65 protein levels and the mRNA levels of pro-inflammatory cytokines (IL-6, IL-12 and TNF-α) were observed in the livers from fucoidan-treated S. japonicum-infected mice; however, the mRNA levels of anti-inflammatory cytokines (IL-4 and IL-13) were increased. In addition, the infiltration of Treg cells was significantly enhanced both in the livers and spleens from fucoidan-treated S. japonicum-infected mice. Consistent with this, the mRNA levels of IL-10 and TGF-ß were dramatically increased in the livers from S. japonicum-infected mice after fucoidan treatment. Furthermore, in vitro stimulated splenocytes with fucoidan resulted in increasing Treg cells in splenocytes as well as the functional expression of CC chemokine receptor type 4 (CCR4) and CXC chemokine receptor type 5 (CXCR5) in Treg cells. Additionally, fucoidan promoted the mRNA levels of IL-4 and IL-13 in macrophages. CONCLUSIONS: These findings suggest an important role of natural fucoidan in reducing hepatic pathology in the progress of S. japonicum infection with a stronger Treg response, which may reveal a new potential therapeutic strategy for hepatic disease caused by parasitic chronic infection.

Protective Role of Fecal Microbiota Transplantation on Colitis and Colitis-Associated Colon Cancer in Mice Is Associated With Treg Cells.

Colitis-associated cancer (CAC) is the most serious outcome of inflammatory bowel disease, which has an alteration of commensal intestinal microbiota. However, the role of intestinal microbiota on CAC progression is not well-understood. Fecal microbiota transplantation (FMT) was used for treating murine azoxymethane-dextran sodium sulfate (AOM-DSS) model of CAC. Composition of gut microbiota during FMT treatment was analyzed. RT-PCR and ELISA were used to detect the inflammatory factors, and immunofluorescence was applied to examine the phospho-nuclear factor (NF)-κB p65/p100 and Ki67-positive cells in the colons. In addition, flow cytometry was performed to analyze the immune cell after FMT treatment. Rehabilitation of the intestinal microbiota by FMT restored both the ratio and diversity of microbiota during CAC progression. Remarkably, a favorable morphometric outcome characterized by decreased tumor load and size was observed in CAC mice with FMT treatment. In addition, an anti-inflammatory function of FMT was demonstrated by decreasing pro-inflammatory factors but increasing anti-inflammatory factors through inhibiting canonical NF-κB activity and cellular proliferation in colons of CAC mice. The expression of CD4+CD25+Foxp3+ regulatory T cells (Tregs) was significantly increased after FMT treatment in CAC mice, but not T helper (Th)1/2/17 cells. Our study aids in the understanding of CAC pathogenesis and reveals a previously unrecognized role for FMT in the treatment of CAC through restoring the intestinal microbiota and inducing regulatory T cells.

Schistosoma japonicum infection causes a reprogramming of glycolipid metabolism in the liver.

BACKGROUND: Recent investigations indicate that schistosome infection is closely associated with aberrant glycolipid metabolism. However, the actual glycolipid metabolism gene expression, as well as the possible pathways that regulate glycolipid metabolism in the schistosome-infected liver, has not been extensively explored. METHODS: In this study, we evaluated the dynamic expression of glycolipid metabolism-associated genes and proteins in the livers from mice infected with Schistosoma japonicum at the indicated time points using real-time PCR and immunofluorescence. Then, cultures of macrophages were treated with schistosome soluble egg antigen (SEA) to detect the expression levels of genes associated with glucose and lipid metabolism in order to identify macrophages metabolic characteristics in response to these antigens. Furthermore, SEA-stimulated macrophages were co-cultures with hepatocytes and detected the effects of macrophages on the gene expression of hepatocytes metabolism. RESULTS: The expression of glycolysis-related genes (Ldha, Glut4, Pkm2, Glut1, Pfkfb3, Aldoc, HK2, Pfk) in the liver were upregulated but the gluconeogenesis gene (G6pc) was downregulated during S. japonicum infection. In addition, the mRNA levels of fatty acid (FA) oxidation-related genes (Ucp2, Atp5b, Pparg) in the liver were significantly upregulated; however, the FA synthesis genes (Fas, Acc, Scd1, Srebp1c) and lipid uptake gene (Cd36) were downregulated post-S. japonicum-infection. In consistence with these data, stimulation with SEA in vitro significantly enhanced the gene expression that involved in glycolysis and FA oxidation, but decreased genes related to gluconeogenesis, FA synthesis and lipid uptake in macrophages. The levels of phosphorylated AMPK, AKT and mTORC1 were increased in macrophages after SEA stimulation. Inhibition of phosphorylated AMPK, AKT and mTORC1 promoted SEA-treated macrophages to produce glucose. In addition, suppression of phosphorylated-AMPK, but not phosphorylated-AKT and phosphorylated-mTOR, induced the lipid accumulation in SEA-stimulated macrophages. Furthermore, SEA-treated macrophages significantly reduced the expression of Acc mRNA in hepatocytes in vitro. CONCLUSIONS: These findings reveal S. japonicum infection induces dynamic changes in the expression levels of genes involved in catabolism (glucose uptake, glycolysis and fatty acid oxidation) and suppressing anabolism (glycogen synthesis) in the liver, which could occur via macrophages' metabolic states, particularly those involved in the AMPK, AKT and mTORC1 pathways.

Fucoidan from seaweed Fucus vesiculosus inhibits 2,4-dinitrochlorobenzene-induced atopic dermatitis.

Fucoidan, one activator of scavenger receptor class A (SR-A), plays important roles in a variety of biological activities, including anti-inflammatory, antioxidant, and antitumor actions. However, the effects of fucoidan on atopic dermatitis (AD) have not been elucidated. To assess this, 2,4-dinitrofluorobenzene (DNFB)-treated BALB/c mice were painted with fucoidan. Results showed that fucoidan significantly ameliorated ear swelling, improved abdomen skin lesions, and decreased inflammatory cell infiltration. In addition, fucoidan significantly suppressed the serum levels of IgE and IL-4 in DNFB-induced AD mice. The infiltration of CD4+ T cells in skin lesions and spleen was also reduced in fucoidan-treated AD mice. Furthermore, treatment with fucoidan promoted Treg cells but attenuated Th1/17 response in the spleens from DNFB-induced AD mice. Together, these results suggest that fucoidan, a natural seaweed-rich polysaccharide, has a potential therapeutic efficacy in the treatment of AD, correlates with the induction of higher anti-inflammatory response through inducing Treg cells.

Research on the effect and mechanism of antimicrobial peptides HPRP-A1/A2 work against Toxoplasma gondii infection.

With increasing antibiotic resistance and drug safety concerns, novel therapeutics are urgently needed. Antimicrobial peptides are promising candidates that could address the spread of multidrug-resistant pathogens. HPRP-A1/A2 are known to display antimicrobial activity against gram-negative bacteria, gram-positive bacteria and some pathogenic fungi, but whether HPRP-A1/A2 work on Toxoplasma gondii (T gondii) is unknown. In this study, we found that the viability of tachyzoites that received HPRP-A1/A2 treatment was significantly decreased, and there was a reduction in the adhesion to and invasion of macrophages by tachyzoites after HPRP-A1/A2 treatment. HPRP-A1/A2 damaged the integrity of tachyzoite membranes, as characterized by membrane disorganization in and cytoplasm outflow from tachyzoites. In addition, in vivo injection with HPRP-A1/A2 resulted in a significantly decreased number of tachyzoites and an accelerated Th1/Tc1 response, and elicited pro-inflammatory cytokines in T gondii-infected mice. Furthermore, HPRP-A1/A2-treated splenocytes exhibited a significantly increased Tc1/Th1 response, and HPRP-A1/A2-stimulated macrophages inhibited the growth of carboxyfluorescein succinimidyl amino ester (CFSE)-labelled tachyzoites, which had higher TNF-α/IL-12 mRNA levels. Altogether, these results imply that HPRP-A1/A2 are effective against T gondii through damaging the structure of tachyzoites and inducing a protective immune response, which could offer an alternative approach against T gondii infection.

PPAR-γ Agonist Alleviates Liver and Spleen Pathology via Inducing Treg Cells during Schistosoma japonicum Infection.

BACKGROUND: Peroxisome proliferator-activated receptor- (PPAR-) γ plays critical roles in human metabolic disorders and has recently been implicated as a regulator of cellular proliferation and inflammatory responses. Regulatory T cells (Tregs), which express high levels of PPAR-γ protein, have the ability to maintain immune tolerance to self-antigens and regulate immune response to Schistosoma infection. However, mechanisms involved in the resolution of these responses are elusive. METHODS: Liver and spleen tissue samples in Schistosoma japonicum-infected mice after administration of pioglitazone (a PPAR-γ agonist) were collected. The hepatic and splenic pathologies were detected by H&E and Masson staining. The percentages of Th1/2 and Treg cells in the liver and spleen of each mouse were determined using flow cytometry. Levels of gene expression of PPAR-γ and Foxp3 in tissues or cells were determined using real-time PCR (RT-PCR). Macrophages were treated with pioglitazone in vitro or cocultured with normal purified CD4+ T cells for detecting Treg cells by flow cytometry. The interactions of PPAR-γ with Foxp3 in CD4+ T cells were detected by coimmunoprecipitation. RESULTS: Administration of pioglitazone resulted in the prevention of the development of hepatic and splenic pathologies. Activation of PPAR-γ by pioglitazone resulted in increased percentages of CD4+CD25+Foxp3+ Treg cells and decreased percentages of CD3+CD4+IFN-γ+ and CD3+CD4+IL-4+ cells in the liver and spleen of Schistosoma japonicum-infected mice. In addition, the PPAR-γ agonist can induce Treg cells in vitro directly or by modulating the macrophage's function indirectly. Furthermore, through interaction with Foxp3 in CD4+ T cells, the PPAR-γ agonist can promote the expression of Foxp3; however, the inhibitor of PPAR-γ weakened the expression of Foxp3 by modifying the coexpression of Foxp3 and PPAR-γ. CONCLUSIONS: Our study reveals a previously unrecognized role for PPAR-γ/Foxp3 signaling in regulating the immunopathology that occurs during Schistosoma infection through induction of Treg cells.

PPAR-γ agonist ameliorates liver pathology accompanied by increasing regulatory B and T cells in high-fat-diet mice.

OBJECTIVE: Peroxisome proliferator-activated receptor (PPAR)-γ plays critical roles in human metabolic disorders. However, the mechanism remains incompletely understood. Regulatory cells contribute to these metabolic improvements; therefore, whether PPAR-γ agonist regulates regulatory cells was investigated. METHODS: C57BL/6J mice received a normal or high-fat diet (HFD) with or without pioglitazone treatment. Mice were sacrificed for detecting the metabolic parameters. Lymphocytes from spleen and visceral adipose tissue (VAT) were collected and analyzed for ST2+ Tregs and Bregs by flow cytometry. IL-10 in the liver or VAT was detected by immunofluorescence and ELISA. Correlation analysis between IL-10 and liver weight or serum total cholesterol was made by Pearson correlation analysis. RESULTS: Pioglitazone increased VAT weight but reduced serum total cholesterol, hepatic steatosis, and cholesterol crystallization formation. Pioglitazone treatment enhanced ST2+ Tregs and Bregs in the VAT and spleen of HFD-fed mice (all P < 0.05). Pioglitazone treatment increased IL-10 in the livers or VAT of HFD-fed mice (all P < 0.05). The expression of IL-10 in the liver was significantly negatively correlated with liver weight or serum total cholesterol in pioglitazone-treated HFD-fed mice (r2 = 0.74, P < 0.05; r2 = 0.58, P < 0.05). CONCLUSIONS: PPAR-γ signaling plays a critical role in the regulation of metabolic disorders through promoting regulatory cell response.