Identification and characterization of protein 14-3-3 in carcinogenic liver fluke Opisthorchis viverrini

EgSeverin and Eg14-3-3zeta from Echinococcus granulosus are potential antigens for serological diagnosis of echinococcosis in dogs and sheep

Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by the metacestode larva of Echinococcus granulosus. In this study, two-dimensional gel electrophoresis (2-DE) coupled with immunoblot analysis revealed that E. granulosus severin and 14-3-3zeta proteins (named EgSeverin and Eg14-3-3zeta, respectively) might be two potential biomarkers for serological diagnosis of echinococcosis. The recombinant EgSeverin (rEgSeverin, 45 kDa) and Eg14-3-3zeta (rEg14-3-3zeta, 35 kDa) were administered subcutaneously to BALB/c mice to obtain polyclonal antibodies for immunofluorescence analyses (IFAs). And IFAs showed that both proteins were located on the surface of protoscoleces (PSCs). Western blotting showed that both proteins could react with sera from E. granulosus-infected sheep, dog, and mice. Indirect ELISAs (rEgSeverin- and rEg14-3-3zeta-iELISA) were developed, respectively, with sensitivities and specificities ranging from 83.33% to 100% and a coefficient of variation (CV %) of less than 10%. The rEgSeverin-iELISA showed cross-reaction with both E. granulosus and E. multilocularis, while the rEg14-3-3zeta-iELISA showed no cross-reaction with other sera except for the E. granulosus-infected ones. The field sheep sera from Xinjiang and Qinghai were analyzed using rEgSeverin-iELISA, rEg14-3-3zeta-iELISA, and a commercial kit respectively, and no significant differences were found among the three methods (p > 0.05). However, the CE positive rates in sheep sera from Qinghai were significantly higher than those from Xinjiang (p < 0.01). Overall, the results suggest that EgSeverin and Eg14-3-3zeta could be promising diagnostic antigens for E. granulosus infection.

Proteomic and Immunological Identification of Diagnostic Antigens from Spirometra erinaceieuropaei Plerocercoid

Human sparganosis is a food-borne parasitic disease caused by the plerocercoids of Spirometra species. Clinical diagnosis of sparganosis is crucial for effective treatment, thus it is important to identify sensitive and specific antigens of plerocercoids. The aim of the current study was to identify and characterize the immunogenic proteins of Spirometra erinaceieuropaei plerocercoids that were recognized by patient sera. Crude soluble extract of the plerocercoids were separated using 2-dimensional gel electrophoresis coupled with immunoblot and mass spectrometry analysis. Based on immunoblotting patterns and mass spectrometry results, 8 antigenic proteins were identified from the plerocercoid. Among the proteins, cysteine protease protein might be developed as an antigen for diagnosis of sparganosis.

YWHAE as an HE4 interacting protein can influence the malignant behaviour of ovarian cancer by regulating the PI3K/AKT and MAPK pathways

Background

Malignant tumours of the female reproductive system threaten the lives and health of women worldwide, with ovarian cancer having the highest mortality rate. Based on previous work, this study analysed the expression and role of YWHAE in ovarian epithelial tumours.

Methods

The interaction between YWHAE and HE4 was evaluated via immunoprecipitation, western blot analysis, and cellular immunofluorescence. Immunohistochemistry was used to address the relationship between YWHAE expression, clinicopathological parameters, and patient prognosis. Changes in cell invasion, epithelial–mesenchymal transition, migration, proliferation, apoptosis, and cell cycle before and after differential expression of YWHAE were also explored in ovarian cancer cell lines and via in vivo experiments.

Results

YWHAE was found to interact with HE4, and its expression was positively correlated with HE4 expression. Moreover, YWHAE upregulation was associated with advanced stages of ovarian cancer and poor patient prognosis. In addition, YWHAE enhanced invasion, migration, and proliferation, but inhibited the apoptosis of ovarian cancer cells. These biological effects were found to be mediated by the AKT and MAPK signalling pathways.

Conclusions

Altogether, this study demonstrates that YWHAE is substantially upregulated in ovarian cancer tissues, representing a risk factor for the prognosis of ovarian cancer that is positively correlated with HE4 expression. Furthermore, YWHAE and its downstream pathways may represent new therapeutic targets for ovarian cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01989-7.

Prospecting Biomarkers for Diagnostic and Therapeutic Approaches in Pythiosis

Pythiosis, whose etiological agent is the oomycete Pythium insidiosum, is a life-threatening disease that occurs mainly in tropical and subtropical countries, affecting several animal species. It is frequently found in horses in Brazil and humans in Thailand. The disease is difficult to diagnose because the pathogen's hyphae are often misdiagnosed as mucoromycete fungi in histological sections. Additionally, there is no specific antigen to use for rapid diagnosis, the availability of which could improve the prognosis in different animal species. In this scenario, we investigated which P. insidiosum antigens are recognized by circulating antibodies in horses and humans with pythiosis from Brazil and Thailand, respectively, using 2D immunoblotting followed by mass spectrometry for the identification of antigens. We identified 23 protein spots, 14 recognized by pooled serum from horses and humans. Seven antigens were commonly recognized by both species, such as the heat-shock cognate 70 KDa protein, the heat-shock 70 KDa protein, glucan 1,3-beta-glucosidase, fructose-bisphosphate aldolase, serine/threonine-protein phosphatase, aconitate hydratase, and 14-3-3 protein epsilon. These results demonstrate that there are common antigens recognized by the immune responses of horses and humans, and these antigens may be studied as biomarkers for improving diagnosis and treatment.

Immunization with a Recombinant Protein of Trichinella britovi 14-3-3 Triggers an Immune Response but No Protection in Mice

14-3-3 proteins are present in all eukaryotic organisms and are ubiquitously expressed in a broad range of tissues and cellular compartments. They are regulatory adapter proteins that play key roles in a variety of signaling pathways, and have been proposed as suitable targets for the control and detection of certain parasites. Trichinella britovi is a widely-distributed parasitic nematode, transmitted through ingestion of meat products containing invasive larvae. The present study describes the cloning and expression of Tb14-3-3, and investigates the immunological and protective potential of the recombinant protein. Immunization of mice with rTb14-3-3 triggered an IgG response, and significant differences, in the profiles of secreted cytokines observed in vitro, between experimental groups. Nonetheless, neither specific antibodies, nor increased secretion of IFNγ, IL-4, and IL-10 cytokines, conferred greater protection against infection. No reduction in larval burden was observed during recovery at 48 dpi. Additionally, rTb14-3-3 was not recognized by sera from the infected control mice, except for one, suggesting some mismatch between native and recombinant Tb14-3-3 antigenic sites. Therefore, before 14-3-3 can be considered a potential tool for Trichinella detection and vaccination, more research regarding its target proteins, and actual specific function, is needed.

Overexpression of 14-3-3δ Predicts Poor Prognosis in Extrahepatic Cholangiocarcinoma Patients

The protein 14-3-3δ interacts with Trp53 to maintain G2 arrest and thus regulates the cell cycle. Though dysfunction of 14-3-3δ caused by hyper-methylation of CpG islands was reported in several carcinomas, the exact role of this protein in the development of extrahepatic cholangiocarcinoma has not been fully elucidated. Here, we aim at investigating the clinical relevance between 14-3-3δ and human extrahepatic cholangiocarcinoma. We collected extrahepatic cholangiocarcinoma specimens of 65 patients in Beijing Chao Yang Hospital and evaluated their 14-3-3δ expression using immunohistochemistry. We categorized the patients into different subgroups according to clinic pathological factors, such as sex, age, tumor size, pathological classification, lymph node metastasis status, tumor stage, and serum markers including CEA, CA-242, or CA19-9, and further evaluated the correlation between 14-3-3δ expression and these potential prognostic factors. As a result, we detected 14-3-3δ expression in 53 out of 65 specimens (81.5%), and the expression was positively correlated with TNM stage, lymph node metastasis, and overall survival. Our results suggest that 14-3-3δ serves as an oncogenic driver in extrahepatic cholangiocarcinoma tumorigenesis rather than a cell cycle regulator; the overexpression of 14-3-3δ might be frequently acquired by tumor cells to escape appropriate cell cycle regulation. Thus, 14-3-3δ could be a potential target for extrahepatic cholangiocarcinoma diagnosis and therapy.

Identification, recombinant protein production, and functional analysis of a M60-like metallopeptidase, secreted by the liver fluke Opisthorchis viverrini

The carcinogenic liver fluke Opisthorchis viverrini (O. viverrini) is endemic in Thailand and neighboring countries including Laos PDR, Vietnam and Cambodia. Infections with O. viverrini lead to hepatobiliary abnormalities including bile duct cancer-cholangiocarcinoma (CCA). Despite decades of extensive studies, the underlying mechanisms of how this parasite survives in the bile duct and causes disease are still unclear. Therefore, this study aims to identify and characterize the most abundant protein secreted by the parasite. Proteomics and bioinformatics analysis revealed that the most abundant secretory protein is a metallopeptidase, named Ov-M60-like-1. This protein contains an N-terminal carbohydrate-binding domain and a C-terminal M60-like domain with a zinc metallopeptidase HEXXH motif. Further analysis by mass spectrometry revealed that Ov-M60-like-1 is N-glycosylated. Recombinant Ov-M60-like-1 (rOv-M60-like-1) expressed in Escherichia coli (E. coli) was able to digest bovine submaxillary mucin (BSM). The mucinase activity was inhibited by the ion chelating agent EDTA, confirming its metallopeptidase identity. The enzyme was active at temperatures ranging 25-37 °C in a broad pH range (pH 2-10). The identification of Ov-M60-like-1 mucinase as the major secretory protein of O. viverrini worms warrants further research into the role of this glycoprotein in the pathology induced by this carcinogenic worm.

Identification and molecular characterization of exosome-like vesicles derived from the Taenia asiatica adult worm

Taenia asiatica is an important food-borne parasite that poses a threat to food-safety and animal husbandry hygine, yet little is known about its specific infection and immune escape mechanisms. Exosome-like vesicles have recently emerged as a regulator in the interactions between parasites and hosts, providing a new direction for research on infection of T. asiatica. In this experiment, exosome-like vesicles were collected from the excretory/secretory products of cultured T. asiatica and isolated by differential centrifugation. The purified vesicles, ranging from 30 to 150 nm in size, were identified as exosome-like vesicles by transmission electron microscope and Nanoparticle tracking analysis. Proteomics analysis identified 455 proteins in the exosome-like vesicles. Of these proteins, enzymes involved in metabolic processes were identified, including glyceraldehyde 3 phosphate dehydrogenase, fructose-1, 6-bisphosphate aldolase, cytosolic malate dehydrogenase, and enolase. The two most abundant proteins from proteomic analysis, 14-3-3 and enolase, were shown to be present in the exosome-like vesicles by immunogold labeling. High-throughput RNA sequencing yielded twenty known miRNAs present in exosome-like vesicle sRNA libraries. Nine of the miRNAs, including six known miRNAs (tas-miR-71, tas-miR-1, tas-miR-7, tas-miR-9, tas-miR-10, and tas-let-7) and three newly discovered miRNAs (tas-m0022-3p, tas-m0816-3p, tas-m0082-5p), were confirmed by RT-qPCR as present in T. asiatica adult worm extracts and secreted exosome-like vesicles in T. asiatica. Additionally, we demonstrated that exosome-like vesicles experimentally labeled with PKH67 were internalized by LoVo cells in vitro. These findings provide new insights into the interaction between tapeworms and hosts mediated by exosome-like vesicles.

Identification of MicroRNAs and Their Target Genes Associated with Ovarian Development in Black Tiger Shrimp (Penaeus monodon) Using High-Throughput Sequencing

Plenty of evidence showing that microRNAs (miRNAs) post-transcriptionally regulate gene expression and are involved in a wide range of biological processes. However, the roles of miRNAs in ovarian development process remain largely unknown in shrimp. In the present study, high-throughput sequencing of small RNAs was performed to find specific miRNAs that are involved in ovarian development process in Penaeus monodon. Two small RNA libraries were constructed from undeveloped (UNDEV group) and developed (DEV group) ovarian tissues in P. monodon. In total, 43 differentially expressed miRNAs were identified between the two groups (P ≤ 0.05, |log2 ratio| ≥1), and their expression profiles were validated by qRT-PCR. In order to further clarify the functional roles of these differentially expressed miRNAs during ovarian development process, target gene prediction was performed. In total, 4,102 target genes of 43 miRNAs were predicted, then clustered by the Kyoto Encyclopedia of Genes and Genomes (KEGG) database; only four specific pathways related to ovarian development were obtained (P < 0.05). Dual-luciferase reporter assays and integrated expression analysis were also conducted to further clarify the interaction between the miRNAs and their target mRNAs. This study provides important information about the function of miRNAs involved in ovarian developmental stages in P. monodon.

Molecular Cloning and Effects of Tm14-3-3ζ-Silencing on Larval Survivability Against E. coli and C. albicans in Tenebrio molitor

The 14-3-3 family of proteins performs key regulatory functions in phosphorylation-dependent signaling pathways including cell survival and proliferation, apoptosis, regulation of chromatin structure and autophagy. In this study, the zeta isoform of 14-3-3 proteins (designated as Tm14-3-3ζ) was identified from the expressed sequence tags (ESTs) and RNA sequencing (RNA-Seq) database of the coleopteran pest, Tenebrio molitor. Tm14-3-3ζ messenger RNA (mRNA) is expressed at higher levels in the immune organs of the larval and adult stages of the insect and exhibit almost five-fold induction within 3 h post-infection of the larvae with Escherichia coli and Candida albicans. To investigate the biological function of Tm14-3-3ζ, a peptide-based Tm14-3-3ζ polyclonal antibody was generated in rabbit and the specificity was confirmed using Western blot analysis. Immunostaining and confocal microscopic analyses indicate that Tm14-3-3ζ is mainly expressed in the membranes of midgut epithelial cells, the nuclei of fat body and the cytosol of hemocytes. Gene silencing of Tm14-3-3ζ increases mortality of the larvae at 7 days post-infection with E. coli and C. albicans. Our findings demonstrate that 14-3-3ζ in T. molitor is essential in the host defense mechanisms against bacteria and fungi.

Opisthorchis viverrini Proteome and Host-Parasite Interactions

The omics technologies have improved our understanding of the molecular events that underpin host-parasite interactions and the pathogenesis of parasitic diseases. In the last decade, proteomics and genomics in particular have been used to characterize the surface and secreted products of the carcinogenic liver fluke Opisthorchis viverrini and revealed important roles for proteins at the host-parasite interface to ensure that the flukes can migrate, feed and reproduce in a hostile environment. This review summarizes the advances made in this area, primarily focusing on discoveries enabled by the publication of the fluke secreted proteomes over the last decade. Protein families that will be covered include proteases, antioxidants, oncogenic proteins and the secretion of exosome-like extracellular vesicles. Roles of these proteins in host-parasite interactions and pathogenesis of fluke-induced hepatobiliary diseases, including cholangiocarcinogenesis, are discussed. Future directions for the application of this knowledge to control infection and disease will also be discussed.