A Yersinia ruckeri TIR Domain-Containing Protein (STIR-2) Mediates Immune Evasion by Targeting the MyD88 Adaptor

TIR domain-containing proteins are essential for bacterial pathogens to subvert host defenses. This study describes a fish pathogen, Yersinia ruckeri SC09 strain, with a novel TIR domain-containing protein (STIR-2) that affects Toll-like receptor (TLR) function. STIR-2 was identified in Y. ruckeri by bioinformatics analysis. The toxic effects of this gene on fish were determined by in vivo challenge experiments in knockout mutants and complement mutants of the stir-2 gene. In vitro, STIR-2 downregulated the expression and secretion of IL-6, IL-1β, and TNF-α. Furthermore, the results of NF-κB-dependent luciferase reporter system, co-immunoprecipitation, GST pull-down assays, and yeast two-hybrid assay indicated that STIR-2 inhibited the TLR signaling pathway by interacting with myeloid differentiation factor 88 (MyD88). In addition, STIR-2 promoted the intracellular survival of pathogenic Yersinia ruckeri SC09 strain by binding to the TIR adaptor protein MyD88 and inhibiting the pre-inflammatory signal of immune cells. These results showed that STIR-2 increased virulence in Y. ruckeri and suppressed the innate immune response by inhibiting TLR and MyD88-mediated signaling, serving as a novel strategy for innate immune evasion.

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The Transcriptional Regulator CpsY Is Important for Innate Immune Evasion in Streptococcus pyogenes

Infection and Immunity ◽

10.1128/iai.00925-16 ◽

2016 ◽

Vol 85 (3) ◽

Cited By ~ 2

Author(s):

Luis A. Vega ◽

Kayla M. Valdes ◽

Ganesh S. Sundar ◽

Ashton T. Belew ◽

Emrul Islam ◽

...

Keyword(s):

Streptococcus Pyogenes ◽

Immune Evasion ◽

Immune Cell ◽

Group A Streptococcus ◽

Transcriptional Regulator ◽

Innate Immune ◽

Content Type ◽

Human Host

ABSTRACTAs an exclusively human pathogen,Streptococcus pyogenes(the group A streptococcus [GAS]) has specifically adapted to evade host innate immunity and survive in multiple tissue niches, including blood. GAS can overcome the metabolic constraints of the blood environment and expresses various immunomodulatory factors necessary for survival and immune cell resistance. Here we present our investigation of one such factor, the predicted LysR family transcriptional regulator CpsY. The encoding gene,cpsY, was initially identified as being required for GAS survival in a transposon-site hybridization (TraSH) screen in whole human blood. CpsY is homologous with transcriptional regulators ofStreptococcus mutans(MetR),Streptococcus iniae(CpsY), andStreptococcus agalactiae(MtaR) that regulate methionine transport, amino acid metabolism, resistance to neutrophil-mediated killing, and survivalin vivo. Our investigation indicated that CpsY is involved in GAS resistance to innate immune cells of its human host. However, GAS CpsY does not manifest thein vitrophenotypes of its homologs in other streptococcal species. GAS CpsY appears to regulate a small set of genes that is markedly different from the regulons of its homologs. The differential expression of these genes depends on the growth medium, and CpsY modestly influences their expression. The GAS CpsY regulon includes known virulence factors (mntE,speB,spd,nga[spn],prtS[SpyCEP], andsse) and cell surface-associated factors of GAS (emm1,mur1.2,sibA[cdhA], andM5005_Spy0500). Intriguingly, the loss of CpsY in GAS does not result in virulence defects in murine models of infection, suggesting that CpsY function in immune evasion is specific to the human host.

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Coxsackievirus B3 Responds to Polyamine Depletion via Enhancement of 2A and 3C Protease Activity

Viruses ◽

10.3390/v11050403 ◽

2019 ◽

Vol 11 (5) ◽

pp. 403 ◽

Cited By ~ 8

Author(s):

Courtney N. Dial ◽

Patrick M. Tate ◽

Thomas M. Kicmal ◽

Bryan C. Mounce

Keyword(s):

Protease Activity ◽

Rna Virus ◽

Coxsackievirus B3 ◽

Eukaryotic Cells ◽

Luciferase Reporter ◽

Reporter System ◽

3C Protease ◽

Picornavirus Infection

Polyamines are small positively-charged molecules abundant in eukaryotic cells that are crucial to RNA virus replication. In eukaryotic cells, polyamines facilitate processes such as transcription, translation, and DNA replication, and viruses similarly rely on polyamines to facilitate transcription and translation. Whether polyamines function at additional stages in viral replication remains poorly understood. Picornaviruses, including Coxsackievirus B3 (CVB3), are sensitive to polyamine depletion both in vitro and in vivo; however, precisely how polyamine function in picornavirus infection has not been described. Here, we describe CVB3 mutants that arise with passage in polyamine-depleted conditions. We observe mutations in the 2A and 3C proteases, and we find that these mutant proteases confer resistance to polyamine depletion. Using a split luciferase reporter system to measure protease activity, we determined that polyamines facilitate viral protease activity. We further observe that the 2A and 3C protease mutations enhance reporter protease activity in polyamine-depleted conditions. Finally, we find that these mutations promote cleavage of cellular eIF4G during infection of polyamine-depleted cells. In sum, our results suggest that polyamines are crucial to protease function during picornavirus infection. Further, these data highlight viral proteases as potential antiviral targets and highlight how CVB3 may overcome polyamine-depleting antiviral therapies.

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microRNA-27b inhibits cell proliferation and invasion in bladder cancer by targeting engrailed-2

Bioscience Reports ◽

10.1042/bsr20201000 ◽

2020 ◽

Author(s):

Yunfei Li ◽

Qilin Duan ◽

Lu Gan ◽

Wei Li ◽

Jianggen Yang ◽

...

Keyword(s):

Bladder Cancer ◽

Malignant Tumour ◽

Expression Level ◽

Luciferase Reporter ◽

Reporter System ◽

Invasion And Migration ◽

Great Heterogeneity ◽

And Migration

Background: Bladder cancer is considered a malignant tumour characterised by great heterogeneity. Engrailed-2 may be a gene implicated in bladder cancer. Bioinformatics analysis found base pair complementation between microRNA-27b and engrailed-2. This study aimed to investigate the reciprocal association between microRNA-27b and engrailed-2 in bladder cancer. Methods: The microRNA-27b and the proteins of engrailed-2 in the tissues and cells of the bladder were detected. The processes of apoptosis, proliferation, invasion, and migration of tumour cells were evaluated. The co-action between microRNA-27b and engrailed-2 was detected by a luciferase reporter system. Finally, the interaction between microRNA-27b and engrailed-2 was further verified in vivo. Results: The study found that the expression level of microRNA-27b is lower in bladder cancer tissues and cells than that in neighbouring ordinary tissues, whereas the opposite outcome was observed regarding the expression level of engrailed-2. Furthermore, microRNA-27b expression level is not significantly linked to the age of patients with bladder cancer; however, it is significantly associated with the clinicopathological grade of bladder cancer. Notably, engrailed-2 is negatively regulated by microRNA-27b. Transfection with microRNA-27b was associated with a significant reduction in the activity of bladder cancer cells and promoted apoptosis, while engrailed-2 restoration effectively reversed the above effects of microRNA-27b on bladder cancer in vitro and in vivo. Conclusions: In conclusion, engrailed-2 is engaged in the development and process of bladder cancer through the negative mediation of microRNA-27b; additionally, microRNA-27b/engrailed-2 could form a signalling pathway with a significant effect on the process of bladder cancer.

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Long Non-Coding RNA AC022306.2 Promotes Cell Proliferation, Migration, and Invasion by Mediating GALK2 in Epithelial Ovarian Cancer

10.21203/rs.3.rs-1083813/v1 ◽

2021 ◽

Author(s):

Xin Liu ◽

Zhenghao Huang ◽

Honglei Qin ◽

Jingwen Chen ◽

Yang Zhao

Keyword(s):

Ovarian Cancer ◽

Figo Stage ◽

Luciferase Reporter ◽

Migration And Invasion ◽

Reporter System ◽

Non Coding Rna ◽

Tumor Tissues ◽

Long Non Coding Rna

Abstract BackgroundLong non-coding RNA (LncRNA) has been exhibited to exert significant function among human cancers. AC022306.2, as a newly discovered lncRNA, has an unclear function in ovarian cancer (OC). This study aims to uncover the functional role of AC022306.2 in OC and discover its possible mechanism. MethodsThe expression of AC022306.2 and Galactokinase 2 (GALK2) in OC tissues and adjacent non-tumor tissues was detected via qRT-PCR. The CCK-8 assay, cell clonogenesis assay, scratch healing assay and trans-well assay were used to reveal the function of AC022306.2 and GALK2 in ovarian cancer cell lines. Mice xenografts experiment was performed. Bioinformatics predicted the microRNA (miRNA) that bond with AC022306.2 and GALK2, and dual luciferase reporter system confirmed it. Rescue experiments of miRNA mimics and siGALK2 transfection on the basis of AC022306.2 over-expression were carried out to uncover the mechanism by which AC022306.2 played cancer-promoting roles in ovarian cancer.ResultsIt was found that AC022306.2 was up-regulated in EOC tissues compared with adjacent non-tumor tissues. The elevated expression of AC022306.2 was related to the FIGO stage of OC. Functional experiments showed that AC022306.2 overexpression accelerated proliferation and aggression of OC cells in vitro and accelerated tumor growth in vivo. We also found that GALK2 was up-regulated in OC tissues. The expression of GALK2 mRNA in OC tissue was positively associated with the expression of AC022306.2. After AC022306.2 was knocked down, the expression of GALK2 was down-regulated. In addition, GALK2 depletion restored the proliferation and aggression capabilities of OC cells after AC022306.2 overexpression. Mechanically, AC022306.2 acted as a competitive endogenous RNA (ceRNA) of miR-369-3p to modulate the expression of GALK2. The up-regulating of miR-369-3p or the down-regulating of GALK2 partially reversed the effect of AC022306.2 overexpressed on cell propagation and aggression in OC. ConclusionsAC022306.2 is a new oncogene in the carcinogenesis and development of OC. AC022306.2 improves the development of OC by regulating the miR-369-3p / GALK2 axis, indicating that AC022306.2 may have the potential to become a new molecular target for the treatment of OC.

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CircCRIM1 promotes ovarian cancer progression by working as ceRNAs of CRIM1 and targeting miR-383-5p/ZEB2 axis

Reproductive Biology and Endocrinology ◽

10.1186/s12958-021-00857-3 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Yuping Du ◽

Xin Liu ◽

Song Zhang ◽

Shuo Chen ◽

Xue Guan ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Progression ◽

Gynecologic Cancer ◽

Luciferase Assay ◽

Luciferase Reporter ◽

Circular Rnas ◽

Reporter System ◽

Correlation Relationship

Abstract Background Ovarian cancer is the leading cause of death in patients with gynecologic cancer, and circular RNAs (circRNAs) are involved in cancer progression. However, there are limited studies on the roles of circRNAs in ovarian cancer. Methods We designed divergent and convergent primers, used sanger sequencing and RNase R digestion to verify the source of circCRIM1. We detected the expression of circCRIM1 and its parental gene cysteine rich transmembrane BMP regulator 1 (CRIM1) in ovarian cancer and normal ovarian samples via qRT-PCR. MTT viability assay, apoptosis assay, wound healing assay and invasion assay were used to investigate the function of circCRIM1 and CRIM1 in ovarian cancer cell lines OVCAR3 and CAOV3. Mice xenografts experiment was performed. Bioinformatics predicted the microRNAs that bond with circCRIM1 and CRIM1, and dual luciferase reporter system confirmed it. Rescue experiments of microRNAs mimics transfection on the basis of circCRIM1 over-expression were carried out to uncover the mechanism by which circCRIM1 played cancer-promoting roles in ovarian cancer. Results CircCRIM1 was derived from CRIM1 by back-splicing. CircCRIM1 and CRIM1 had higher expression in ovarian cancer than in normal ovarian tissues, and both of them promoted ovarian cancer progression in vitro. In vivo circCRIM1 promoted the growth of tumors. CircCRIM1 and CRIM1 had a positive correlation relationship in the same cohort of ovarian cancer tissues. Bioinformatics predicted and dual luciferase assay confirmed circCRIM1 and CRIM1 bond with miR-145-5p, and circCRIM1 bond with miR-383-5p additionally. CircCRIM1 positively affected the expression of CRIM1. After circCRIM1 was over-expressed, miR-145-5p mimics transfection reversed the expression of CRIM1. Western blot discovered circCRIM1 positively affected the expression of zinc finger E-box binding homeobox 2 (ZEB2). Rescue experiments found miR-383-5p mimics reversed ZEB2 expression and the cancer-promoting effects of circCRIM1. Conclusions CircCRIM1 bond with miR-145-5p to work as competing endogenous RNA (ceRNA) of CRIM1, and circCRIM1 bond with miR-383-5p to improve the expression of ZEB2 in ovarian cancer. CircCRIM1 and CRIM1 promoted the ovarian cancer progression and supplied a novel insight into the researches of ovarian cancer.

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MiR-218 inhibits malignant phenotypes of glioma by targeting TNC/AKT/AP-1/TGFβ1 feedback signaling loop

10.21203/rs.3.rs-16349/v1 ◽

2020 ◽

Author(s):

Siwen Dang ◽

Rui Zhang ◽

Sijia Tian ◽

Banjun Ruan ◽

Peng Hou ◽

...

Keyword(s):

Tumor Suppressor ◽

Malignant Tumors ◽

Glioma Cells ◽

Luciferase Reporter ◽

Normal Brain ◽

Reporter System ◽

Control Subjects ◽

Luciferase Reporter System

Abstract Background: Gliomas are the most common and malignant tumors in the brain of humans, and the prognosis of glioma patient is very poor. MicroRNAs (miRNAs) play critical roles in different types of cancer by regulating gene expression at the posttranscriptional levels. Although miR-218 has been reported to be downregulated in gliomas, its role in gliomas still remains largely unknown. Methods: MiR-218 expression in gliomas and normal brain tissues (control subjects) were analyzed using TCGA dataset. The biological roles of miR-218 in glioma cells were determined by a series of in vitro and in vivo studies. The dual-luciferase reporter system was performed to identify potential targets of miR-218. The regulatory effect of miR-218 on TNC/AKT/AP-1/TGFβ1 pathway was evaluated by dual-luciferase reporter system and western blot.Results: We demonstrated miR-218 was significantly downregulated in gliomas compared to control subjects, and exerted a potent tumor suppressor in glioma cells by inhibiting cell proliferation, colony formation, migration, invasion and tumorigenic potential in nude mice, as well as inducing cell cycle arrest and apoptosis.Mechanistically, miR-218 inhibited malignant phenotypes of glioma cells by binding to the 3’ UTR of its target TNC and subsequently repressing its expression. As a result, it could reduce AKT phosphorylation and subsequently inhibit transcriptional activity of AP-1 by reducing JNK phosphorylation, downregulating the expression of TGFβ1, while TGFβ1 is able to, in turn, activate the TNC/AKT/AP-1 signaling axis.Conclusions: Our data uncover a previously unknown tumor suppressor role of miR-218 in glioma by blocking the TNC/AKT/AP-1/TGFβ1 positive feedback loop.

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An Ebola Virus-Like Particle-Based Reporter System Enables Evaluation of Antiviral DrugsIn Vivounder Non-Biosafety Level 4 Conditions

Journal of Virology ◽

10.1128/jvi.01239-16 ◽

2016 ◽

Vol 90 (19) ◽

pp. 8720-8728 ◽

Cited By ~ 9

Author(s):

Dapeng Li ◽

Tan Chen ◽

Yang Hu ◽

Yu Zhou ◽

Qingwei Liu ◽

...

Keyword(s):

Monoclonal Antibody ◽

Viral Entry ◽

Ebola Virus ◽

Firefly Luciferase ◽

Luciferase Reporter ◽

Target Cells ◽

Reporter System ◽

Biosafety Level

ABSTRACTEbola virus (EBOV) is a highly contagious lethal pathogen. As a biosafety level 4 (BSL-4) agent, however, EBOV is restricted to costly BSL-4 laboratories for experimentation, thus significantly impeding the evaluation of EBOV vaccines and drugs. Here, we report an EBOV-like particle (EBOVLP)-based luciferase reporter system that enables the evaluation of anti-EBOV agentsin vitroandin vivooutside BSL-4 facilities. Cotransfection of HEK293T cells with four plasmids encoding the proteins VP40, NP, and GP of EBOV and firefly luciferase (Fluc) resulted in the production of Fluc-containing filamentous particles that morphologically resemble authentic EBOV. The reporter EBOVLP was capable of delivering Fluc into various cultured cells in a GP-dependent manner and was recognized by a conformation-dependent anti-EBOV monoclonal antibody (MAb). Significantly, inoculation of mice with the reporter EBOVLP led to the delivery of Fluc protein into target cells and rapid generation of intense bioluminescence signals that could be blocked by the administration of EBOV neutralizing MAbs. This BSL-4-free reporter system should facilitate high-throughput screening for anti-EBOV drugs targeting viral entry and efficacy testing of candidate vaccines.IMPORTANCEEbola virus (EBOV) researches have been limited to costly biosafety level 4 (BSL-4) facilities due to the lack of animal models independent of BSL-4 laboratories. In this study, we reveal that a firefly luciferase-bearing EBOV-like particle (EBOVLP) with typical filamentous EBOV morphology is capable of delivering the reporter protein into murine target cells bothin vitroandin vivo. Moreover, we demonstrate that the reporter delivery can be inhibited bothin vitroandin vivoby a known anti-EBOV protective monoclonal antibody, 13C6. Our work provides a BSL-4-free system that can facilitate thein vivoevaluation of anti-EBOV antibodies, drugs, and vaccines. The system may also be useful for mechanistic study of the viral entry process.

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Ectopic Methylation of a Single Persistently Unmethylated CpG in the Promoter of the Vitellogenin Gene Abolishes Its Inducibility by Estrogen through Attenuation of Upstream Stimulating Factor Binding

Molecular and Cellular Biology ◽

10.1128/mcb.00436-19 ◽

2019 ◽

Vol 39 (23) ◽

Author(s):

Lia Kallenberger ◽

Rachel Erb ◽

Lucie Kralickova ◽

Andrea Patrignani ◽

Esther Stöckli ◽

...

Keyword(s):

Dna Methyltransferase ◽

Transcriptional Control ◽

Dna Demethylation ◽

Luciferase Reporter ◽

Luciferase Reporter Gene ◽

Reporter System ◽

E Box ◽

Stimulating Factor

ABSTRACT The enhancer/promoter of the vitellogenin II gene (VTG) has been extensively studied as a model system of vertebrate transcriptional control. While deletion mutagenesis and in vivo footprinting identified the transcription factor (TF) binding sites governing its tissue specificity, DNase hypersensitivity and DNA methylation studies revealed the epigenetic changes accompanying its hormone-dependent activation. Moreover, upon induction with estrogen (E2), the region flanking the estrogen-responsive element (ERE) was reported to undergo active DNA demethylation. We now show that although the VTG ERE is methylated in embryonic chicken liver and in LMH/2A hepatocytes, its induction by E2 was not accompanied by extensive demethylation. In contrast, E2 failed to activate a VTG enhancer/promoter-controlled luciferase reporter gene methylated by SssI. Surprisingly, this inducibility difference could be traced not to the ERE but rather to a single CpG in an E-box (CACGTG) sequence upstream of the VTG TATA box, which is unmethylated in vivo but methylated by SssI. We demonstrate that this E-box binds the upstream stimulating factor USF1/2. Selective methylation of the CpG within this binding site with an E-box-specific DNA methyltransferase, Eco72IM, was sufficient to attenuate USF1/2 binding in vitro and abolish the hormone-induced transcription of the VTG gene in the reporter system.

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Ectopic methylation of a single persistently-unmethylated CpG in the promoter of the vitellogenin gene abolishes its inducibility by estrogen through attenuation of USF binding

10.1101/768697 ◽

2019 ◽

Author(s):

Lia Kallenberger ◽

Rachel Erb ◽

Lucie Kralickova ◽

Andrea Patrignani ◽

Esther Stöckli ◽

...

Keyword(s):

Transcriptional Control ◽

Dna Demethylation ◽

Luciferase Reporter ◽

Luciferase Reporter Gene ◽

Reporter System ◽

Active Dna Demethylation ◽

E Box ◽

Vitellogenin Gene

ABSTRACTThe enhancer/promoter of the vitellogenin II (VTG) gene has been extensively studied as a model system of vertebrate transcriptional control. While deletion mutagenesis and in vivo footprinting identified the transcription factor (TF) binding sites governing its tissue specificity, DNase hypersensitivity- and DNA methylation studies revealed the epigenetic changes accompanying its hormone-dependent activation. Moreover, upon induction with estrogen (E2), the region flanking the estrogen-responsive element (ERE) was reported to undergo active DNA demethylation. We now show that although the VTG ERE is methylated in embryonic chicken liver and in LMH/2A hepatocytes, its induction by E2 was not accompanied by extensive demethylation. In contrast, E2 failed to activate a VTG enhancer/promoter-controlled luciferase reporter gene methylated by SssI. Surprisingly, this inducibility difference could be traced not to the ERE, but rather to a single CpG in an E-box (CACGTG) sequence upstream of the VTG TATA box, which is unmethylated in vivo, but methylated by SssI. We demonstrate that this E-box binds the upstream stimulating factor USF1/2. Selective methylation of the CpG within this binding site with an E-box-specific DNA methyltranferase Eco72IM was sufficient to attenuate USF1/2 binding in vitro and abolish the hormone-induced transcription of the VTG gene in the reporter system.

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MiR-218 inhibits malignant phenotypes of glioma by targeting TNC/AKT/AP-1/TGFβ1 feedback signaling loop

10.21203/rs.3.rs-16349/v2 ◽

2020 ◽

Author(s):

Siwen Dang ◽

Rui Zhang ◽

Sijia Tian ◽

Banjun Ruan ◽

Peng Hou ◽

...

Keyword(s):

Tumor Suppressor ◽

Regulation Of Gene Expression ◽

Glioma Cells ◽

Luciferase Reporter ◽

Normal Brain ◽

Reporter System ◽

Control Subjects ◽

Luciferase Reporter System

Abstract Background: Gliomas are the most malignant and common tumors in human brains, and the prognosis of glioma patient is very poor. MicroRNAs (miRNAs) play critical roles in different types of cancer by performing posttranscriptional regulation of gene expression. Although miR-218 has been demonstrated decreased in gliomas, its role in gliomas still remains largely unknown. Methods: MiR-218 expression were analyzed in gliomas and normal brain tissues (control subjects) using TCGA dataset. A series of in vitro and in vivo studies was performed to determine the biological roles of miR-218 in glioma cells. Potential targets of miR-218 were identified using dual-luciferase reporter system. Western blot and dual-luciferase reporter system were performed to evaluate the regulatory effect of miR-218 on TNC/AKT/AP-1/TGFβ1 pathway.Results: We demonstrated miR-218 was significantly downregulated in gliomas compared to control subjects, and played potent tumor suppressor roles in glioma cells by inhibited cell proliferation, colony formation, migration, invasion and tumorigenic potential in nude mice, as well as inducing cell cycle arrest and apoptosis.Mechanistically, miR-218 inhibited malignant phenotypes of glioma cells by binding to the 3’ UTR of its target TNC and subsequently repressing its expression. As a result, it could reduce AKT phosphorylation and subsequently inhibit transcriptional activity of AP-1 by reducing JNK phosphorylation, downregulating the expression of TGFβ1, while TGFβ1 is able to, in turn, activate the TNC/AKT/AP-1 signaling axis.Conclusions: Our data uncover a previously unknown tumor suppressor role of miR-218 by blocking the TNC/AKT/AP-1/TGFβ1 positive feedback loop in glioma.

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