Antiviral Activities of Carbazole Derivatives against Porcine Epidemic Diarrhea Virus In Vitro

Porcine epidemic diarrhea virus (PEDV), an enteric coronavirus, causes neonatal pig acute gastrointestinal infection with a characterization of severe diarrhea, vomiting, high morbidity, and high mortality, resulting in tremendous damages to the swine industry. Neither specific antiviral drugs nor effective vaccines are available, posing a high priority to screen antiviral drugs. The aim of this study is to investigate anti-PEDV effects of carbazole alkaloid derivatives. Eighteen carbazole derivatives (No.1 to No.18) were synthesized, and No.5, No.7, and No.18 were identified to markedly reduce the replication of enhanced green fluorescent protein (EGFP) inserted-PEDV, and the mRNA level of PEDV N. Flow cytometry assay, coupled with CCK8 assay, confirmed No.7 and No.18 carbazole derivatives displayed high inhibition effects with low cell toxicity. Furthermore, time course analysis indicated No.7 and No.18 carbazole derivatives exerted inhibition at the early stage of the viral life cycle. Collectively, the analysis underlines the benefit of carbazole derivatives as potential inhibitors of PEDV, and provides candidates for the development of novel therapeutic agents.

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Analysis of Intestinal Mucosa Integrity and GLP-2 Gene Functions upon Porcine Epidemic Diarrhea Virus Infection in Pigs

Animals ◽

10.3390/ani11030644 ◽

2021 ◽

Vol 11 (3) ◽

pp. 644

Author(s):

Yajing Zhou ◽

Zhanshi Ren ◽

Shuai Zhang ◽

Haifei Wang ◽

Shenglong Wu ◽

...

Keyword(s):

Epithelial Cells ◽

Intestinal Mucosa ◽

Porcine Epidemic Diarrhea Virus ◽

Intestinal Epithelial Cells ◽

Mrna Level ◽

Mucosal Barrier ◽

Intestinal Epithelial ◽

Intestinal Mucosal Barrier ◽

Diarrhea Virus ◽

Porcine Epidemic Diarrhea

Porcine epidemic diarrhea virus (PEDV) infects intestinal epithelial cells, destroys the intestinal mucosal barrier and then causes diarrhea in piglets. Glucagon-like peptide-2 (GLP-2) is a specific intestinal growth hormone that promotes the repair of damaged intestinal mucosa and improves the intestinal barrier. In this study, we investigated the functions of porcine GLP-2 gene in regulating PEDV infection. The intestinal tissues with damaged intestinal structures caused by PEDV infection were first confirmed and collected. Expression analysis indicated that the GLP-2 gene was expressed in the duodenum, jejunum and ileum tissues, and the mRNA level was significantly down-regulated in jejunum and ileum of piglets with damaged intestinal mucosa. Infection of PEDV to porcine small intestinal epithelial cells in vitro showed that GLP-2 gene was significantly decreased, which was consistent with the expression pattern in intestinal tissues. In addition, we silenced the GLP-2 gene by shRNA interfering and found that the copy numbers of PEDV were remarkably increased in the GLP-2 gene silencing cells. Our findings suggest that the GLP-2 gene was potentially involved in regulating PEDV infection and in maintaining the integrity of the intestinal mucosal barrier structure, which could contribute to our understanding of the mechanisms of PEDV pathogenesis and provide a theoretical basis for the identification and application of resistant genes in pig selective breeding for porcine epidemic diarrhea.

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Porcine Epidemic Diarrhea Virus Deficient in RNA Cap Guanine-N-7 Methylation Is Attenuated and Induces Higher Type I and III Interferon Responses

Journal of Virology ◽

10.1128/jvi.00447-20 ◽

2020 ◽

Vol 94 (16) ◽

Cited By ~ 2

Author(s):

Yunjian Lu ◽

Hui Cai ◽

Mijia Lu ◽

Yuanmei Ma ◽

Anzhong Li ◽

...

Keyword(s):

Viral Replication ◽

Porcine Epidemic Diarrhea Virus ◽

Antiviral Drugs ◽

Type I ◽

Single Mutation ◽

Live Attenuated Vaccines ◽

Diarrhea Virus ◽

Mtase Activity ◽

Animal Pathogens ◽

Porcine Epidemic Diarrhea

ABSTRACT The 5′ cap methylation of viral RNA plays important roles in RNA stability, efficient translation, and immune evasion. Thus, RNA cap methylation is an attractive target for antiviral discovery and development of new live attenuated vaccines. For coronaviruses, RNA cap structure is first methylated at the guanine-N-7 (G-N-7) position by nonstructural protein 14 (nsp14), which facilitates and precedes the subsequent ribose 2′-O methylation by the nsp16-nsp10 complex. Using porcine epidemic diarrhea virus (PEDV), an Alphacoronavirus, as a model, we showed that G-N-7 methyltransferase (G-N-7 MTase) of PEDV nsp14 methylated RNA substrates in a sequence-unspecific manner. PEDV nsp14 can efficiently methylate RNA substrates with various lengths in both neutral and alkaline pH environments and can methylate cap analogs (GpppA and GpppG) and single-nucleotide GTP but not ATP, CTP, or UTP. Mutations to the S-adenosyl-l-methionine (SAM) binding motif in the nsp14 abolished the G-N-7 MTase activity and were lethal to PEDV. However, recombinant rPEDV-D350A with a single mutation (D350A) in nsp14, which retained 29.0% of G-N-7 MTase activity, was viable. Recombinant rPEDV-D350A formed a significantly smaller plaque and had significant defects in viral protein synthesis and viral replication in Vero CCL-81 cells and intestinal porcine epithelial cells (IPEC-DQ). Notably, rPEDV-D350A induced significantly higher expression of both type I and III interferons in IPEC-DQ cells than the parental rPEDV. Collectively, our results demonstrate that G-N-7 MTase activity of PEDV modulates viral replication, gene expression, and innate immune responses. IMPORTANCE Coronaviruses (CoVs) include a wide range of important human and animal pathogens. Examples of human CoVs include severe acute respiratory syndrome coronavirus (SARS-CoV-1), Middle East respiratory syndrome coronavirus (MERS-CoV), and the most recently emerged SARS-CoV-2. Examples of pig CoVs include porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine enteric alphacoronavirus (SeACoV). There are no vaccines or antiviral drugs for most of these viruses. All known CoVs encode a bifunctional nsp14 protein which possesses ExoN and guanine-N-7 methyltransferase (G-N-7 MTase) activities, responsible for replication fidelity and RNA cap G-N-7 methylation, respectively. Here, we biochemically characterized G-N-7 MTase of PEDV nsp14 and found that G-N-7 MTase-deficient PEDV was defective in replication and induced greater responses of type I and III interferons. These findings highlight that CoV G-N-7 MTase may be a novel target for rational design of live attenuated vaccines and antiviral drugs.

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Evaluation of methods for inactivating porcine epidemic diarrhea virus (PEDV) in livestock trailers

10.31274/etd-180810-4014 ◽

2015 ◽

Author(s):

Paul Richard Thomas

Keyword(s):

Porcine Epidemic Diarrhea Virus ◽

Diarrhea Virus ◽

Porcine Epidemic Diarrhea ◽

Evaluation Of Methods

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Identifying outbreaks of Porcine Epidemic Diarrhea virus through animal movements and spatial neighborhoods

Scientific Reports ◽

10.1038/s41598-018-36934-8 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 18

Author(s):

Gustavo Machado ◽

Carles Vilalta ◽

Mariana Recamonde-Mendoza ◽

Cesar Corzo ◽

Montserrat Torremorell ◽

...

Keyword(s):

Porcine Epidemic Diarrhea Virus ◽

Animal Movements ◽

Diarrhea Virus ◽

Porcine Epidemic Diarrhea

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PSVI-4 Efficacy of Medium Chain Fatty Acids and Fatty Acid-based Feed Additives as a Mitigation Strategy Against Porcine Epidemic Diarrhea Virus and Porcine Reproductive and Respiratory Syndrome Virus

Journal of Animal Science ◽

10.1093/jas/skab054.354 ◽

2021 ◽

Vol 99 (Supplement_1) ◽

pp. 216-217

Author(s):

O L Harrison ◽

G E Nichols ◽

J T Gebhardt ◽

Cassandra K Jones ◽

Jason C Woodworth ◽

...

Keyword(s):

Fatty Acid ◽

Porcine Epidemic Diarrhea Virus ◽

Positive Control ◽

Feed Additives ◽

Feed Additive ◽

Respiratory Syndrome Virus ◽

Post Inoculation ◽

Diarrhea Virus ◽

Medium Chain ◽

Porcine Epidemic Diarrhea

Abstract Recent research has demonstrated that swine viruses can be transmitted via feed. Chemical feed additives have been suggested for the mitigation of these viruses in complete feed. Therefore, the objective of this study was to evaluate the efficacy of a commercially available formaldehyde-based feed additive, medium chain fatty acid blend (MCFA), and commercially available fatty acid-based products for mitigation of porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) in a feed matrix. Treatments consisted of: 1) non-treated positive control, 2) 0.33% commercial formaldehyde-based product (Sal Curb; Kemin Industries, Inc.; Des Moines, IA), 3) 0.5% MCFA blend (1:1:1 ratio of C6:0, C8:0, and C10:0, Sigma Aldrich, St. Louis, MO), 4) 0.25%, 5) 0.5%, or 6) 1% of commercial dry mono and diglyceride-based product (Furst Strike; Furst-McNess Company, Freeport, IL), 7) 0.25%, 8) 0.5%, or 9) 1% of commercial dry mono and diglyceride-based product (Furst Protect; Furst-McNess Company, Freeport, IL), 10) 0.25%, 11) 0.5%, or 12) 1% dry mono and diglyceride-based experimental product (Furst-McNess Company, Freeport, IL) with 3 replications/treatment. Treatments were applied to complete swine feed before inoculation with 106 TCID50/g of feed with PEDV or PRRSV. Post inoculation feed was held at ambient temperature for 24 h before being analyzed via qRT-PCR. The analyzed values represent the cycle threshold. Formaldehyde and MCFA decreased (P < 0.05) the detectable RNA of PEDV and PRRSV compared to all other treatments. Furst Strike, Furst Protect, and the experimental product did not significantly impact detectability of PEDV or PRRSV RNA. In conclusion, MCFA and formaldehyde treatments are effective at reducing detection of RNA from PEDV and PRRSV in feed.

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Differential expression and correlation analysis of miRNA–mRNA profiles in swine testicular cells infected with porcine epidemic diarrhea virus

Scientific Reports ◽

10.1038/s41598-021-81189-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xiaoqian Zhang ◽

Chang Li ◽

Bingzhou Zhang ◽

Zhonghua Li ◽

Wei Zeng ◽

...

Keyword(s):

Differential Expression ◽

Porcine Epidemic Diarrhea Virus ◽

Expression Profiles ◽

Expression Patterns ◽

Bacterial Invasion ◽

Sequencing Data ◽

Diarrhea Virus ◽

Comparison Groups ◽

Porcine Epidemic Diarrhea

AbstractThe variant virulent porcine epidemic diarrhea virus (PEDV) strain (YN15) can cause severe porcine epidemic diarrhea (PED); however, the attenuated vaccine-like PEDV strain (YN144) can induce immunity in piglets. To investigate the differences in pathogenesis and epigenetic mechanisms between the two strains, differential expression and correlation analyses of the microRNA (miRNA) and mRNA in swine testicular (ST) cells infected with YN15, YN144, and mock were performed on three comparison groups (YN15 vs Control, YN144 vs Control, and YN15 vs YN144). The mRNA and miRNA expression profiles were obtained using next-generation sequencing (NGS), and the differentially expressed (DE) (p-value < 0.05) mRNA and miRNA were obtained using DESeq R package. mRNAs targeted by DE miRNAs were predicted using the miRanda algortithm. 8039, 8631 and 3310 DE mRNAs, and 36, 36, and 22 DE miRNAs were identified in the three comparison groups, respectively. 14,140, 15,367 and 3771 DE miRNA–mRNA (targeted by DE miRNAs) interaction pairs with negatively correlated expression patterns were identified, and interaction networks were constructed using Cytoscape. Six DE miRNAs and six DE mRNAs were randomly selected to verify the sequencing data by real-time relative quantitative reverse transcription polymerase chain reaction (qRT-PCR). Based on bioinformatics analysis, we discovered the differences were mostly involved in host immune responses and viral pathogenicity, including NF-κB signaling pathway and bacterial invasion of epithelial cells, etc. This is the first comprehensive comparison of DE miRNA–mRNA pairs in YN15 and YN144 infection in vitro, which could provide novel strategies for the prevention and control of PED.

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