Integrative analysis of transcriptome and proteome in primary Sjögren syndrome.

OBJECTIVE: Primary Sjögren's syndrome (pSS) is a intricate autoimmune disease mainly characterized of immune-mediated destruction of exocrine tissues, such as salivary and lacrimal glands, occurring dry mouth and eyes. Although some breakthroughs in understanding pSS have been uncovered, many questions remain about its pathogenesis, especially the internal relations between exocrine glands and secretions. METHOD: Transcriptomic and proteomic analyses were conducted on salivary tissues and saliva in experimental Sjögren syndrome (ESS). The ESS model was established by immunization with salivary gland protein. The expression of mRNAs and proteins in salivary tissues and saliva were determined by high-throughput sequencing transcriptomic analysis and LC-MS/MS-based proteome, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to recognize dysregulated genes and proteins. The association between RNA and protein abundance was investigated to provides a comprehensive understanding of RNA-protein correlations in the pathogenesis of pSS. RESULTS: As a result, we successfully established the ESS model. We recognized 3221 differentially expressed genes (DEGs) and 253 differentially expressed proteins (DEPs). The sample analysis showed that 61 proteins overlapped through the integrative analysis of transcriptomics and proteomics data. The enrichment pathway analysis of DEGs and DEPs in samples showed alterations in renin-angiotensin-system (RAS), lysosome, and apoptosis. Notably, we found that some genes, such as AGT, FN1, Klk1b26, Klk1, Klk1b5, Klk1b3 had a consistent trend in the regulation at the RNA and protein levels and might be potential diagnostic biomarkers of pSS. CONCLUSION: Herein, we found critical processes and potential biomakers that may contribute to pSS pathogenesis by analyzing dysregulated genes and pathways. Additionally, the integrative multi-omics datasets provided additional insight into understanding complicated disease mechanisms.

Compound shougong powder inhibits the malignant phenotype of hepatocellular carcinoma cells by targeting the DNA damage repair pathway.

OBJECTIVES: Compound Shougong Powder (SGS), a traditional Chinese medicine formulation, has been used to treat cancer for many years with remarkable efficacy. However, the mechanisms underlying the therapeutic effect of SGS in Hepatocellular carcinoma (HCC) are not completely clear. METHODS: The survival and metastasis of HCC cells were examined by CCK-8 assay, EdU assay, Wound-healing and Transwell assay. The anti-tumour effect of SGS was studied using hoechst 33258 staining and flow cytometry. RNA sequencing was applied to detect the underlying mechanism. Comet DNA, qRT-PCR and WB experiments were performed for validation. In addition, HCC nude mouse model was constructed to detect SGS effect in vivo. KEY FINDINGS: SGS inhibited the proliferation, migration and invasion of HCC cells and induced apoptosis in vitro. In addition, SGS also suppressed tumour growth in a nude mouse model of HCC in a dose-dependent manner. RNA sequencing of the suitably treated HCC cells revealed significant changes in the expression levels of genes involved in the DNA damage repair pathway. The sequencing results were verified by Comet DNA, qRT-PCR, WB assays and molecular docking. CONCLUSIONS: Taken together, SGS inhibits the malignant phenotype of HCC cells by down-regulating DNA repair genes and consequently inducing DNA damage.

Immune infiltration analysis reveals immune cell signatures in salivary gland tissue of primary Sjögren's syndrome.

Introduction: Mouse models are the basis for primary Sjögren's syndrome (pSS) research. However, the depth of comparisons between mice and humans in salivary gland (SG) immune cells remains limited. Methods: The gene expression profiles of SGs from normal subjects and pSS patients were downloaded from the Gene Expression Comprehensive Database. The proportion of infiltrating immune cell subsets was then assessed by cell type identification by estimating relative subsets of RNA transcripts (CIBERSORT). An experimental Sjögren's syndrome (ESS) mouse model was successfully constructed using SG protein. Based on mouse SG tissue RNA-Seq data, the seq-ImmuCC model was used to quantitatively analyze the compositional ratios of 10 immune cells in pSS patients and mouse model SG tissues. Results: Computed and obtained 31 human data samples using the CIBERSORT deconvolution method. The immune cell infiltration results showed that, compared to normal human SG tissue, the content of gamma delta T cells was significantly different from naive CD4+ T cells and significantly increased, while the plasma cell content decreased. Principal component analysis indicated differences in immune cell infiltration between pSS patients and normal subjects. Meanwhile, for ESS model mouse data analysis, we found that the proportion of macrophages increased, while the proportion of CD4+ T cells, B cells, and monocytes decreased. Furthermore, we found that the proportion of monocytes was decreased, while the proportion of macrophages was increased in the SG tissues of pSS patients and model mice. The infiltration of CD4+ T, CD8+ T, and B cells also showed some differences. Discussion: We comprehensively analyzed SG immune infiltration in pSS patients and model mice. We demonstrated conserved and nonconserved aspects of the immune system in mice and humans at the level of immune cells to help explain the primary regulation of immune mechanisms during the development of Sjögren's syndrome.

Integrated Bioinformatic Analysis and Experimental Validation to Reveal the Mechanisms of Xinfeng Capsule against Rheumatoid Arthritis.

BACKGROUND: Xinfeng capsule (XFC) is a well-known drug against rheumatoid arthritis (RA). However, the combination mechanisms of XFC on RA remain unclear. OBJECTIVE: The purpose of this study is to explore the mechanisms of XFC against RA in terms of compounds, targets, and signaling pathways via network pharmacology. METHODS: The bioactive compounds and potential targets of XFC were extracted from TCMSP and BATMAN-TCM database, and the putative RA-related targets were determined from the DisGeNET, PHGKB, PharmGKB, and CTD database. The approach of protein-protein interaction, gene ontology analysis, and kyoto encyclopedia of genes and genomes pathway enrichment analysis were constructed, respectively. In animal experiments, we evaluated the expression of core targets. RESULTS: We found that XFC handled 30 active compounds and 131 common target genes. Among them, mairin, folic acid, cholesterol, and triptolide in XFC were selected as the central active compounds against RA. The mechanisms of XFC on RA which concerned critical targets were protein kinase B (AKT1) and tumor necrosis factor (TNF). In vivo, we found that the expression levels of AKT1 and TNF in the modeling group were significantly increased but reversed by XFC. CONCLUSION: The combination mechanisms of XFC were elucidated in terms of components and targets and signaling pathways, which may be related to inhibiting the proliferation of synovial cells and inflammation.

The role and potential mechanism of O-Glycosylation in gastrointestinal tumors.

Glycosylation is a critical post-translational modification (PTM) that affects the function of proteins and regulates cell signaling, thereby regulating various biological processes. Protein oxygen-N-acetylglucosamine (O-GlcNAc) glycosylation modifications are glycochemical modifications that occur within cells in the signal transduction and are frequently found in the cytoplasm and nucleus. Due to the rapid and reversible addition and removal, O-GlcNAc modifications are able to reversibly compete with certain phosphorylation modifications, immediately regulate the activity of proteins, and participate in kinds of cellular metabolic and signal transduction pathways, playing a pivotal role in the regulation of tumors, diabetes, and other diseases. This article provided a brief overview of O-GlcNAc glycosylation modification, introduced its role in altering the progression and immune response regulation of gastrointestinal tumors, and discussed its potential use as a marker of tumor neogenesis.

[Research progress in B10 cells and autoimmune diseases].

Regulatory B cells (Bregs) are a group of B cells with negative immune regulation, which produce negative regulatory cytokines, such as interleukin-10 (IL-10), transform growth factor ß (TGF- ß), or participate in immune regulation and inhibit inflammatory response by intercellular activities. B10 cells are a kind of Bregs that generates IL-10. In recent years, a large number of studies have reported that B10 cells are involved in the development of a variety of autoimmune diseases. Here, we make a systematic review of the origin and immune mechanism of B10 cells, their roles in autoimmune diseases (rheumatoid arthritis, inflammatory bowel disease and Sjogren's syndrome, etc.) and regulations, coupled with its applications in the treatment of autoimmune diseases.We also discussed the B10 cells as a potential method feasible for treating autoimmune diseases.

Effects of N6-Methyladenosine Modification on Cancer Progression: Molecular Mechanisms and Cancer Therapy.

N6-methyladenosine (m6A) is a major internal epigenetic modification in eukaryotic mRNA, which is dynamic and reversible. m6A is regulated by methylases ("writers") and demethylases ("erasers") and is recognized and processed by m6A-binding proteins ("readers"), which further regulate RNA transport, localization, translation, and degradation. It plays a role in promoting or suppressing tumors and has the potential to become a therapeutic target for malignant tumors. In this review, we focus on the mutual regulation of m6A and coding and non-coding RNAs and introduce the molecular mechanism of m6A methylation involved in regulation and its role in cancer treatment by taking common female malignant tumors as an example.

Roles of Major RNA Adenosine Modifications in Head and Neck Squamous Cell Carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer malignancy worldwide and is known to have poor prognosis. The pathogenesis behind the development of HNSCC is not fully understood. Modifications on RNA are involved in many pathophysiological processes, such as tumor development and inflammation. Adenosine-related RNA modifications have shown to be linked to cancer and may play a role in cancer occurrence and development. To date, there are at least 170 different chemical RNA modifications that modify coding and non-coding RNAs (ncRNAs). These modifications affect RNA stability and transcription efficiency. In this review, we focus on the current understanding of the four major RNA adenosine modifications (N6-Methyladenosine, N1-Methyladenosine, Alternative Polyadenylation Modification and A-to-I RNA editing) and their potential molecular mechanisms related to HNSCC development and progression. We also touch on how these RNA modifications affect treatment of HNSCCs.

Proteomic profiling of saliva reveals association of complement system with primary Sjögren's syndrome.

INTRODUCTION: To compare the saliva proteomes of experimental Sjögren's syndrome (ESS) model mice and healthy controls to identify potential diagnostic biomarkers for primary Sjögren's syndrome (pSS). METHODS: Proteins were extracted from the saliva of three ESS and three normal control mice using the data-independent acquisition technique. R language was used to identify the differentially expressed proteins (DEPs). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed to functionally annotate the DEPs. The protein-protein interaction (PPI) network was constructed and the core proteins were identified with the STRING website and Cytoscape software. The concentrations of Serpin family G member 1 (SERPING1), C3, complement factor H (CFH), fibrinogen alpha (FGA), and fibrinogen gamma (FGG) in saliva were determined by ELISA. RESULTS: A total of 1722 DEPs were identified in the saliva of the ESS mice relative to the controls, of which 50 showed significantly different expression levels between the two groups. SERPING1, C3, CFH, FGA, and FGG were significantly downregulated, and keratin 4 (Krt4) and transglutaminase 3 (TGM3) were upregulated in the saliva of ESS mice. The PPI network showed that SERPING1, C3, FGG, FGA, TGM3, and hemopexin (HPX) were the core proteins. ELISA results showed that the expression of C3, CFH, FGA, and SERPING1 were significantly downregulated in the saliva of ESS mice. However, the expression of FGG was a little downregulated but with no significant difference. SERPING1, FGG, and FGA may downregulate the complement C3 by inhibiting immune complement system, thereby promoting pSS progression. CONCLUSIONS: The salivary proteome of ESS mice was markedly different from that of healthy controls, suggesting that salivary proteomics is a promising noninvasive diagnostic tool for pSS. SERPING1, C3, CFH, FGA, and FGG are potential biomarkers of pSS.

Two new inflammatory markers related to the CURB-65 score for disease severity in patients with community-acquired pneumonia: The hypersensitive C-reactive protein to albumin ratio and fibrinogen to albumin ratio.

BACKGROUND: The objective of this study was to investigate the relationship among hypersensitive C-reactive protein to albumin ratio (CAR), fibrinogen to albumin ratio (FAR), and the CURB-65 score for community-acquired pneumonia (CAP) severity. METHODS: Clinical data and laboratory indicators of 82 patients with CAP and 40 healthy subjects were retrospectively analysed. The relationship among CAR, FAR, and the severity of CAP was then analysed. RESULTS: CAR and FAR in patients with low-risk CAP were significantly higher than those in the normal control group (P < 0.05). CAR and FAR in patients with medium-high-risk CAP were further increased compared with those in patients with low-risk CAP (P < 0.05). CAR and FAR were positively correlated with hypersensitive C-reactive protein, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and CURB-65 scores (P < 0.05). In the receiver operating characteristic curve for predicting severe CAP, the area under the curve of combining four biomarkers (CAR + FAR + NLR + PLR) was the largest. CAR was also an independent risk factor for severe CAP (OR = 8.789, 95% CI: 1.543-50.064, P = 0.014). CONCLUSIONS: CAR and FAR may be used as the inflammatory markers for CAP severity evaluation.

Prevalence and risk factor analysis for the nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus.

ABSTRACT: Although non-alcoholic fatty liver disease (NAFLD) is strongly associated with type 2 diabetes mellitus (T2DM), the diagnosis of NAFLD for T2DM patients remains a challenge.This study aimed to investigate the prevalence and risk factors for the NAFLD in T2DM outpatients.This is a retrospective, cross-sectional study that included 2405 T2DM patients treated and admitted for glucose control into the Endocrinology Department of our hospital from April 2017 to March 2019. Using strict exclusion criteria, the target patients were screened and divided into two groups: NAFLD patients (study group) and non-NAFLD patients (control group). Subsequently, 34 factors were compared between the two groups. Furthermore, multivariate analysis of the NAFLD risk factors was performed using logistic regression. Finally, the diagnostic significance of individual biochemical predictors, as well as the combined predictive indicator (CPI), for NAFLD was estimated using receiver operating characteristic (ROC) curve analysis.In this study, the overall prevalence of NAFLD in T2DM patients was 58.67%. Of the target patients, 17 factors were identified by univariate analysis to be associated with NAFLD, and 8 factors were found to be significant predictors for NAFLD using binary logistic regression modeling. Furthermore, the CPI and C-Peptide represent high diagnostic value for NAFLD in T2DM patients.This study provides a more comprehensive risk factor analysis for NAFLD in T2DM patients. These data can be used to provide timely diagnosis and effective management of NAFLD.

Identification of an autophagy-related gene signature that can improve prognosis of hepatocellular carcinoma patients.

BACKGROUND: Autophagy is a programmed cell degradation mechanism that has been associated with several physiological and pathophysiological processes, including malignancy. Improper induction of autophagy has been proposed to play a pivotal role in the progression of hepatocellular carcinoma (HCC). METHODS: Univariate Cox regression analysis of overall survival (OS) was performed to identify risk-associated autophagy-related genes (ARGs) in HCC data set from The Cancer Genome Atlas (TCGA). Multivariate cox regression was then performed to develop a risk prediction model for the prognosis of 370 HCC patients. The multi-target receiver operating characteristic (ROC) curve was used to determine the model's accuracy. Besides, the relationship between drug sensitivity and ARGs expression was also examined. RESULTS: A total of 62 differentially expressed ARGs were identified in HCC patients. Univariate and multivariate regression identified five risk-associated ARGs (HDAC1, RHEB, ATIC, SPNS1 and SQSTM1) that were correlated with OS in HCC patients. Of importance, the risk-associated ARGs were independent risk factors in the multivariate risk model including clinical parameters such as malignant stage (HR = 1.433, 95% CI = 1.293-1.589, P < 0.001). In addition, the area under curve for the prognostic risk model was 0.747, which indicates the high accuracy of the model in prediction of HCC outcomes. Interestingly, the risk-associated ARGs were also correlated with drug sensitivity in HCC cell lines. CONCLUSION: We developed a novel prognostic risk model by integrating the molecular signature and clinical parameters of HCC, which can effectively predict the outcomes of HCC patients.

Epithelial-mesenchymal transition classification of circulating tumor cells in lung and colon cancer patients: potential role in clinical practice.

BACKGROUND: Tumor cells undergoing epithelial-mesenchymal transition (EMT) display enhanced ability to enter the circulation, thereby being major source of circulating tumor cells (CTCs). In this study, we aimed to better understand the roles of CTC undergoing EMT in monitoring cancer progression. METHODS: We analyzed gene expression profiling of epithelial and mesenchymal markers in lung or colon tumor samples by mining TCGA database. We detected CTCs and classify their EMT phenotypes of 31 patients with lung or colon cancer by using a CanPatrol CTC-enrichment technique. RESULTS: The bioinformatic analysis indicated that mesenchymal markers were expressed in a subset of lung tumor samples, and its high expression was associated with poor survival of lung cancer patients. However, in colon cancer, majority of tumor samples expressed hybrid epithelial/mesenchymal markers. CTC analysis with EMT classification showed that the number of CTCs with mesenchymal phenotype was high in lung cancer patients with the advanced stage. Dynamic CTC analysis in a lung cancer patient indicated that CTC with mesenchymal phenotype was effective to monitor tumor progression. In a colon cancer patient, dynamic CTC analysis indicated that CTC with hybrid epithelial/mesenchymal phenotypes was an effective biomarker to guide therapy. CONCLUSIONS: Encouraging results from this proof-of-concept study show that CTC with mesenchymal phenotype or hybrid epithelial/mesenchymal phenotypes could be a potential biomarker for monitoring tumor progression in lung or colon cancer respectively.

Preventive effect of pidotimod on reactivated toxoplasmosis in mice.

As one of food-borne parasitic diseases, toxoplasmosis entails the risk of developing reactivation in immunocompromised patients. The synthetic dipeptide pidotimod is a potent immunostimulating agent that improves the immunodefenses in immunodepression. To investigate the efficacy of pidotimod as a preventive treatment, we used a murine model of reactivated toxoplasmosis with cyclophosphamide (CY)-induced immunosuppression. Pidotimod administration significantly restored the body weight and spleen organ index, increased survival time (from 70 to 90%), and decreased the parasitemia (from 80 to 35%) of CY-induced mice with reactivated toxoplasmosis. Cytokine profiles and CD4(+) T cells subpopulation analyses by Cytometric Bead Array and flow cytometry demonstrated that pidotimod treatment resulted in a significant upregulation of pro-inflammatory cytokines (IFN-γ, TNF-α, and IL-2) and Th1 cells (from 3.73 ± 0.39 to 5.88 ± 0.46%) after CY induction in infected mice. Additionally, histological findings and parasite DNA quantification revealed that mice administered with pidotimod had a remarkable reduction of parasite burden (two-log) and amelioration of histopathology in the brains. The in vitro studies showed that pidotimod significantly restored concanavalin A-induced splenocyte proliferation and pro-inflammatory cytokines in the supernatants of splenocyte culture. It could be concluded that the administration of pidotimod in immunocompromised mice significantly increases the Th1-biased immune response, prolongs survival time, and ameliorates the load of parasites in the blood. This is the first report of the preventive effect of pidotimod on reactivated toxoplasmosis.

LukS-PV induces mitochondrial-mediated apoptosis and G0/G1 cell cycle arrest in human acute myeloid leukemia THP-1 cells.

The S component (LukS-PV) is one of the two components of Panton-Valentine leukocidin (PVL), which is a pore-forming cytotoxin secreted by Staphylococcus aureus, with the ability to lyse leukocytes. In this study, LukS-PV had the ability to induce apoptosis in the human acute myeloid leukemia (AML) cell line THP-1. Therefore, we investigated the mechanisms of LukS-PV-induced apoptosis in THP-1 cells. THP-1 cells treated with LukS-PV, resulted in a significant inhibition of proliferation in a dose- and time-dependent manner, and induced G0/G1 arrest associated with an inhibition of cell cycle arrest regulatory protein (cyclin D1) in a dose- and time-dependent manner, as measured by flow cytometry (FCM). After 12h exposure to LukS-PV (1.00 µM), annexin V-EGFP/propidium iodide (PI) FCM revealed that 19.5±3.6% of THP-1 cells were apoptotic, and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) staining also revealed THP-1 cells were apoptotic. Chip analysis of 84 apoptosis-related genes demonstrated that 9 genes were up-regulated at least 2-fold and that 5 genes were down-regulated at least 2-fold in the treatment group when compared with levels in the control group. Western blotting reveled that the expression of caspase-8 increased significantly (approximately 4-fold). The levels of caspase-9, -3 and Bax increased significantly, and levels of Bcl-2 decreased rapidly with LukS-PV treatment. These data suggest that LukS-PV acts as an anti-leukemia agent and activates AML cell apoptosis via the mitochondrial pathway. Therefore, LukS-PV may be a multi-targeting drug candidate for the prevention and therapy of AML.

Genotypes and mouse virulence of Toxoplasma gondii isolates from animals and humans in China.

BACKGROUND: Recent population structure studies of T. gondii revealed that a few major clonal lineages predominated in different geographical regions. T. gondii in South America is genetically and biologically divergent, whereas this parasite is remarkably clonal in North America and Europe with a few major lineages including Types I, II and III. Information on genotypes and mouse virulence of T. gondii isolates from China is scarce and insufficient to investigate its population structure, evolution, and transmission. METHODOLOGY/PRINCIPAL FINDINGS: Genotyping of 23 T. gondii isolates from different hosts using 10 markers for PCR-restriction fragment length polymorphism analyses (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) revealed five genotypes; among them three genotypes were atypical and two were archetypal. Fifteen strains belong to the Chinese 1 lineage, which has been previously reported as a widespread lineage from swine, cats, and humans in China. Two human isolates fall into the type I and II lineages and the remaining isolates belong to two new atypical genotypes (ToxoDB#204 and #205) which has never been reported in China. Our results show that these genotypes of T. gondii isolates are intermediately or highly virulent in mice except for the strain TgCtwh6, which maintained parasitemia in mice for 35 days post infection although it possesses the uniform genotype of Chinese 1. Additionally, phylogenetic network analyses of all isolates of genotype Chinese 1 are identical, and there is no variation based on the sequence data generated for four introns (EF1, HP2, UPRT1 and UPRT7) and two dense granule proteins (GRA6 and GRA7). CONCLUSION/SIGNIFICANCE: A limited genetic diversity was found and genotype Chinese 1 (ToxoDB#9) is dominantly circulating in mainland China. The results will provide a useful profile for deep insight to the population structure, epidemiology and biological characteristics of T. gondii in China.

[Pidotimod inhibits activation of latent Toxoplasma gondii infection induced by dexamethasone in mice].

OBJECTIVE: To study the inhibition effect of pidotimod (PT) on dexamethasone (Dem)-induced reactivated toxoplasmosis in mice. METHODS: A total of 96 female BALB/C mice were infected orally with 30 cysts of Toxoplasma gondii TgCtwh6 strain (genotype Chinese 1). 4 weeks later the mice were divided into three groups (A, B, and C). Mice of group A (Dem+NS) were given Dem [6 mg/(kg x d)] intraperitoneally and 200 microl normal saline given orally. Mice of group B (Dem+PT) were orally given pidotimod [100 mg/(kg x d)] and intraperitoneally injected with Dem[6 mg/(kg x d)] simultaneously. Each mouse in group C received 200 microl normal saline intraperitoneally. The mice were injected and given by gavage for 5 weeks. After treatment, three mice in each group were scarified weekly, and the survival time of the mice was recorded in days. Brain parasite burden and T. gondii DNA copies in serum were detected by quantitative real-time PCR. T cell subsets, cytokine profiles in each group were analyzed by flow cytometry, and CBA kit, respectively. RESULTS: On the second week after Dem administration, parasitemia appeared in group A; in 5 weeks 50% mice had parasitemia again, and 17 mice died. Comparatively, in group B parasitemia appeared on the third week after PT and Dem administration, in 5 weeks 25% mice had parasitemia again, and 7 mice died. Parasitemia did not appear in Group C. On the 21st day after Dem administration, T. gondii DNA copies in brain tissues of group A was (209 +/- 12) x 10(9), significantly higher than (62 +/- 10) x 10(9) in group B treated with PT (n = 3, P < 0.01). Flow cytometry test showed that on the 21st day after Dem administration, the proportions of Th1, Th2 and Treg cells in groups A and B were (4.0 +/- .5)% and (6.1 +/- 1.0)%, (0.6 +/- 0.1)% and (0.5 +/- 0.2)%, and (5.0 +/- 0.9)% and (7.0 +/- 1.2)%, respectively. There was significant difference in the percentages of Th1 and Treg between group B and A (P < 0.01). The levels of IFN-gamma, TNF-alpha in group A were (2.2 +/- 0.7) pg/ml and (20.1 +/- 5.0) pg/ml, respectively, lower than that of group B [(3.6 +/- 0.6) pg/ml and (32.0 +/- 8.0) pg/ml] (P < 0.01). No statistical significance was found in the levels of IL-4 and IL-10 between group A [(2.6 +/- 0.4) pg/ml, (39.0 +/- 6.0) pg/ml] and group B [(2.7 +/- 0.7) pg/ml, (40.0 +/- 8.0) pg/ml] (P > 0.05). CONCLUSION: Pidotimod can inhibit activation of latent Toxoplasma gondii infection induced by dexamethasone in mice. Th1 and Treg cells may contribute to the pidotimod/dexamethasone-induced immunoregulation.

[Kinetic distribution of cyst-forming Chinese isolate of Toxoplasma gondii in mice].

OBJECTIVE: To determine the kinetics of infection and cyst formation in CD1 mice following oral infection with cyst-forming Chinese isolate of Toxoplasma gondii TgCtwh1(genotype China 1, ToxoDB#9). METHODS: 50 CD1 female mice were obtained from specific pathogen-free (SPF) mouse colony in the Vital River Laboratories (VRL), Beijing. Mice were randomly divided into 10 groups each with 5 mice. All mice but control were peroral gavage infected with 50 cysts (1x10(4) bradyzoites) of TgCtwh1 isolate of T. gondii isolated from Wuhan, China. Cysts were isolated from the entire brain of mice infected with TgCtwh1 by density gradient centrifugation over Fycoll-paque plus. Animals were orally inoculated with cysts on day zero, and peripheral blood, lymph nodes, heart, liver, and brain of infected mice were collected on days 2, 4, 7, 10, 14, 21, 35, 50, and 72 post infection. Five mice were sacrificed by cervical dislocation under anesthesia at each time of collection, and the kinetic distribution was detected by fluorescence quantitative PCR and tissue inoculation into fresh mice. The cyst formation at various intervals after infection was also observed, as was the number of the cysts in brains and the cyst-forming rate. RESULTS: The body weight of the mice lessened (3.650 +/- 0.252)g post oral infection on day 7, and the weight was progressively decreased between day 10 [(1.730 +/- 0.017)g] and day 14 [(-0.390 +/- 0.554) g] after infection (P<0.05). In the brain tissue, cysts were first observed on day 21 post oral infection and the cyst-forming rate was 80%, and the average diameter of cysts was 20-40 microm. While on day 35 after infection, the cysts were formed in all infected mice(cyst-forming rate was 100%) and the average diameter was 50-60 microm. In chronic infection, DNA copies of parasites were first detected in blood, heart, liver and lymph node at 3.51 +/- 0.152, 4.100 +/- 0.198, 4.220 +/- 0.209 and 4.960 +/- 0.052 respectively on day 2, then in the brain on day 4 (3.800 +/- 0.154). During the early days of infection, the parasite burden in blood was progressively increased until days 7 (5.240 +/- 0.115) then gradually decreased and become undetectable on day 35. The burden of T. gondii in the heart and brain tissues increased significantly and reached their maximum on day 14 (5.640 +/- 0.214) and day 10 (5.790 +/- 0.060), respectively, and remained a stable level thereafter. Liver and lymph tissues reached their maximum on day 7 (5.310 +/- 0.038) and day 10 (6.200 +/- 0.152), then gradually decreased and become undetectable on day 50. CONCLUSION: The parasitemia in mice infected with T. gondii cyst-forming isolate lasts for 21 d at least, and cysts are detected in brain on day 21.

Prevalence and genotypes of Toxoplasma gondii in pork from retail meat stores in Eastern China.

Pork is known as one of the most important sources of Toxoplasma gondii infection in China. In the present study, 416 fresh pork samples were collected from different locations of Anhui province, Eastern China. Tissue fluid ELISA was conducted to detect the antibodies to T. gondii. Real-time PCR and bioassay were performed to identify the presence of T. gondii DNA and viable parasites, respectively. Seventy-five out of 416 samples (18.03%) demonstrated real-time PCR positive reaction and 42 out of 416 samples (10.1%) showed tissue fluid ELISA positive reaction. One isolate (Tgpkfx171) was obtained through bioassay in mice from 14 samples that demonstrated both PCR and ELISA positive reaction. The isolate and seven positive DNA samples were genotyped using 9 PCR-RFLP markers including SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico. Among these, only the isolate and two positive DNA samples were genotyped with complete data for all loci, belonging to ToxoDB#9 (Chinese 1) and ToxoDB#213, respectively. This is the first report of the prevalence and genetic typing of T. gondii from pork in retail meat stores in China. The present results provide an accurate picture of the risk of exposure to T. gondii in retail pork in China.

Reactive oxygen species-triggered trophoblast apoptosis is initiated by endoplasmic reticulum stress via activation of caspase-12, CHOP, and the JNK pathway in Toxoplasma gondii infection in mice.

Toxoplasma gondii infection in pregnant women may result in abortion or in fetal teratogenesis; however, the underlying mechanisms are still unclear. In this paper, based on a murine model, we showed that maternal infection with RH strain T. gondii tachyzoites induced elevated production of reactive oxygen species (ROS), local oxidative stress, and subsequent apoptosis of placental trophoblasts. PCR array analysis of 84 oxidative stress-related genes demonstrated that 27 genes were upregulated at least 2-fold and that 9 genes were downregulated at least 2-fold in the T. gondii infection group compared with levels in the control group. The expression of NADPH oxidase 1 (Nox1) and glutathione peroxidase 6 (Gpx6) increased significantly, about 25-fold. The levels of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) increased significantly with T. gondii infection, and levels of glutathione (GSH) decreased rapidly. T. gondii infection increased the early expression of endoplasmic reticulum stress (ERS) markers, followed by cleavage of caspase-12, activation of ASK1/JNK, and increased apoptosis of trophoblasts, both in vivo and in vitro. The apoptosis of trophoblasts, the activation of caspase-12 and the ASK1/JNK pathway, and the production of peroxides were dramatically inhibited by pretreatment with N-acetylcysteine (NAC). The upregulation of Nox1 was contact dependent and preceded the increase in levels of ERS markers and the activation of the proapoptosis cascade. Thus, we concluded that apoptosis in placental trophoblasts was initiated predominantly by ROS-mediated ERS via activation of caspase-12, CHOP, and the JNK pathway in acute T. gondii infection. Elevated ROS production is the central event in T. gondii-induced apoptosis of placental trophoblasts.