Involvement of miR-15a in G0/G1 Phase Cell Cycle Arrest Induced by Porcine Circovirus Type 2 Replication

Amisulbrom induces mitochondrial dysfunction, leading apoptosis and cell cycle arrest in human trophoblast and endometrial cells

Amisulbrom, a triazole-based fungicide, is utilized in agriculture to increase agricultural production by controlling fungal infections. The long disappearance time of 50 % (DT50) and potential toxic effects of amisulbrom on nontarget organisms have been reported. However, the toxic effects on the pregnancy process remain unclear. This study aims to determine the cytotoxic responses of human trophoblast cells (HTR-8/SVneo) and human endometrial cells (T HESCs), which are associated with implantation upon amisulbrom exposure. Mitochondrial dysfunction and intracellular Ca2+ overload were determined in both cells that are exposed to amisulbrom. Additionally, amisulbrom arrested the cell cycle progression in the G2/M phase, causing apoptosis and reduced survival. Excessive reactive oxygen species (ROS) accumulation and dephosphorylation of PI3K/AKT signaling proteins by amisulbrom exposure mediated these toxic effects. Additionally, spheroid formation was inhibited by amisulbrom treatment in the three-dimensional hanging drop culture model. These results indicate that amisulbrom may pose an adverse effect on the implantation process. Further research is required to identify the toxicity of amisulbrom in vivo. This is the first study to raise concerns about possible toxicity mechanisms of amisulbrom in the implantation process.

Bombyx mori nucleopolyhedrovirus LEF-2 disrupts the cell cycle in the G2/M phase by triggering a host cell DNA damage response

It is a common strategy for viruses to block the host cell cycle to favour their DNA replication. Baculovirus, being a double-stranded DNA virus, can arrest the cell cycle in the G2/M phase to facilitate its replication. However, the key viral genes and mechanisms crucial for inducing cell cycle arrest remain poorly understood. Here, we initially examined the impacts of several Bombyx mori nucleopolyhedrovirus (BmNPV) DNA replication-associated genes: ie1, lef-1, lef-2, lef-3, lef-4, odv-ec27 and dbp. We assessed their effects on both the host cells' DNA replication and cell cycle. Our findings reveal that when the lef-2 gene was overexpressed, it led to a significant increase in the number of cells in the G2/M phase and a reduction in the number of cells in the S phase. Furthermore, we discovered that the LEF-2 protein is located in the virogenic stroma and confirmed its involvement in viral DNA replication. Additionally, by employing interference and overexpression experiments, we found that LEF-2 influences host cell DNA replication and blocks the cell cycle in the G2/M phase by regulating the expression of CyclinB and CDK1. Finally, we found that BmNPV lef-2 triggered a DNA damage response in the host cell, and inhibiting this response removed the cell cycle block caused by BmNPV LEF-2. Thus, our findings indicate that the BmNPV lef-2 gene plays a crucial role in viral DNA replication and can regulate host cell cycle processes. This study furthers our understanding of baculovirus-host cell interactions and provides new insight into the molecular mechanisms of antiviral research.

G3BP1 Regulates the Cell Cycle by Promoting IFNβ Production to Promote PCV2 Replication and Promotes Nuclear Transfer of Viral Proteins by Direct Binding

Porcine circovirus type 2 (PCV2) is a significant pathogen responsible for porcine circovirus-associated diseases (PCVAD), and it is widely prevalent in pig farms, leading to huge economic losses for the pig industry. Currently, the ability of PCV2 to enhance its own replication by using the antiviral inflammatory factors IFNα, IFNβ, and IL-2 and its complex immune escape mechanism remain unclear, which has attracted wide attention. Research has indicated that GTPase-activating protein (SH3 domain)-binding protein 1 (G3BP1) is involved in the innate immune response to a variety of viruses, primarily by regulating and composing stress granules (SGs) to inhibit viral replication. Our initial studies identified elevated G3BP1 expression during PCV2 infection, paradoxically promoting PCV2 replication. In light of this phenomenon, this study aims to elucidate how PCV2 regulates G3BP1 to enhance its replication. Our findings demonstrate that G3BP1 overexpression further activates PCV2-induced expression of RIG-I, MDA5, cGAS and STING, thereby promoting IFNβ production and affecting cell cycle arrest in the S phase, facilitating PCV2 replication. Moreover, interactions were observed between PCV2 Cap protein and G3BP1's RGG domain, and between PCV2 Rep protein and G3BP1's NTF2 and RRM domains, potentially promoting viral protein nuclear transfer. In summary, PCV2 enhances its replication by modulating G3BP1 to induce IFNβ production and directly binds viral proteins to promote viral protein nuclear transfer. This research provides a foundation for further investigation into the immune evasion mechanisms of PCV2.

miR-155 facilitates the synergistic replication between avian leukosis virus subgroup J and reticuloendotheliosis virus by targeting a dual pathway

IMPORTANCE

The synergy of two oncogenic retroviruses is an essential phenomenon in nature. The synergistic replication of ALV-J and REV in poultry flocks increases immunosuppression and pathogenicity, extends the tumor spectrum, and accelerates viral evolution, causing substantial economic losses to the poultry industry. However, the mechanism of synergistic replication between ALV-J and REV is still incompletely elusive. We observed that microRNA-155 targets a dual pathway, PRKCI-MAPK8 and TIMP3-MMP2, interacting with the U3 region of ALV-J and REV, enabling synergistic replication. This work gives us new targets to modulate ALV-J and REV's synergistic replication, guiding future research on the mechanism.

Advances in Crosstalk between Porcine Circoviruses and Host

Porcine circoviruses (PCVs), including PCV1 to PCV4, are non-enveloped DNA viruses with a diameter of about 20 nm, belonging to the genus Circovirus in the family Circoviridae. PCV2 is an important causative agent of porcine circovirus disease or porcine circovirus-associated disease (PCVD/PCVAD), which is highly prevalent in pigs and seriously affects the swine industry globally. Furthermore, PCV2 mainly causes subclinical symptoms and immunosuppression, and PCV3 and PCV4 were detected in healthy pigs, sick pigs, and other animals. Although the pathogenicity of PCV3 and PCV4 in the field is still controversial, the infection rates of PCV3 and PCV4 in pigs are increasing. Moreover, PCV3 and PCV4 rescued from infected clones were pathogenic in vivo. It is worth noting that the interaction between virus and host is crucial to the infection and pathogenicity of the virus. This review discusses the latest research progress on the molecular mechanism of PCVs–host interaction, which may provide a scientific basis for disease prevention and control.

RETRACTED: Role of microRNA-15a-5p/Sox9/NF-κB axis in inflammatory factors and apoptosis of murine nucleus pulposus cells in intervertebral disc degeneration

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concerns were raised over the provenance of the flow cytometry plots in Figures 6G and 7F, as detailed here: https://pubpeer.com/publications/A46066C72A3E518DD6CA192362E0DC; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. In addition, a portion of Figure 2G, ‘miR-15a-5p antagomir’ group appeared to contain image similarities with Figure 2G, ‘Oe-NC’ group. The journal requested that the corresponding author comment on these concerns and provide the raw data. The authors did not respond to this request and therefore the Editor-in-Chief decided to retract the article.

Cure lies in nature: medicinal plants and endophytic fungi in curbing cancer

Success of targeted cancer treatment modalities has generated an ambience of plausible cure for cancer. However, cancer remains to be the major cause of mortality across the globe. The emergence of chemoresistance, relapse after treatment and associated adverse effects has posed challenges to the present therapeutic regimes. Thus, investigating new therapeutic agents of natural origin and delineating the underlying mechanism of action is necessary. Since ages and still in continuum, the phytochemicals have been the prime source of identifying bioactive agents against cancer. They have been exploited for isolating targeted specific compounds to modulate the key regulating signaling pathways of cancer pathogenesis and progression. Capsaicin (alkaloid compound in chilli), catechin, epicatechin, epigallocatechin and epigallocatechin-3-gallate (phytochemicals in green tea), lutein (carotenoid found in yellow fruits), Garcinol (phenolic compound present in kokum tree) and many other naturally available compounds are also very valuable to develop the drugs to treat the cancer. An alternate repository of similar chemical diversity exists in the form of endophytic fungi inhabiting the medicinal plants. There is a high diversity of plant associated endophytic fungi in nature which are potent producers of anti-cancer compounds and offers even stronger hope for the discovery of an efficient anti-cancer drug. These fungi provide various bioactive molecules, such as terpenoids, flavonoids, alkaloids, phenolic compounds, quinines, steroids etc. exhibiting anti-cancerous property. The review discusses the relevance of phytochemicals in chemoprevention and as modulators of miRNA. The perspective advocates the imperative role of anti-cancerous secondary metabolites containing repository of endophytic fungi, as an alternative route of drug discovery.

Proteome Analysis in a Mammalian Cell line Reveals that PLK2 is Involved in Avian Metapneumovirus Type C (aMPV/C)-Induced Apoptosis

Avian metapneumovirus subtype C (aMPV/C) causes an acute respiratory disease that has caused serious economic losses in the Chinese poultry industry. In the present study, we first explored the protein profile in aMPV/C-infected Vero cells using iTRAQ quantitative proteomics. A total of 921 of 7034 proteins were identified as significantly altered by aMPV/C infection. Three selected proteins were confirmed by Western blot analysis. Bioinformatics GO analysis revealed multiple signaling pathways involving cell cycle, endocytosis, and PI3K-Akt, mTOR, MAPK and p53 signaling pathways, which might participate in viral infection. In this analysis, we found that PLK2 expression was upregulated by aMPV/C infection and investigated whether it contributed to aMPV/C-mediated cellular dysfunction. Suppressing PLK2 attenuated aMPV/C-induced reactive oxygen species (ROS) production and p53-dependent apoptosis and reduced virus release. These results in a mammalian cell line suggest that high PLK2 expression correlates with aMPV/C-induced apoptosis and viral replication, providing new insight into the potential avian host cellular response to aMPV/C infection and antiviral targets.

Regulatory mechanism of microRNA-155 in chicken embryo fibroblasts in response to reticuloendotheliosis virus infection

Reticuloendotheliosis virus (REV) infection of multiple avian species can lead to a number of diseases such as runting syndrome, immunosuppression and oncogenesis, causing major economic losses. MicroRNAs play important roles in post-transcriptional regulation, effectively inhibiting protein synthesis, and participating in many biological processes in cells, including proliferation, differentiation, apoptosis, lipometabolism, virus infection and replication, and tumorigenesis. Based on our previous high-throughput sequencing results, we explore the regulatory mechanisms of microRNA-155(miR-155) in chicken embryo fibroblasts (CEFs) in response to REV infection. Our results revealed expression of miR-155 in CEFs after REV infection upregulated in a time- and dose-dependent manner, indicating miR-155 plays a role in REV infection in CEFs indeed. After transfected with miR-155-mimic and miR-155-inhibitor, we found overexpression of miR-155 targeted caspase-6 and FOXO3a to inhibit apoptosis and accelerate cell cycle, thus improving viability of REV-infected CEFs. This result also verified the protective role of miR-155 in the viability of CEFs in the presence of REV. Knockdown of miR-155 also supported these above conclusions. Our findings uncover a new mechanism of REV pathogenesis in CEFs, and also provide a theoretical basis for uncovering new effective treatment and prevention methods for RE based on miR-155.

Evaluation of the combinatorial effect of Tinospora cordifolia and Zingiber officinale on human breast cancer cells

The present study was aimed to investigate the anticancer potential of the combination treatment of Tinospora cordifolia (TC) and Zingiber officinale (ZO) using network pharmacology approach. In silico analysis of the anticancer activity of TC + ZO was carried out using Cytoscape 3.2.0 software to elucidate the mechanism. The MTT assay confirms the combination of TC and ZO is more active (IC₅₀; 2 μg ml^-1) as compared to TC (509 μg ml^-1) and ZO (1 mg ml^-1) alone in MCF-7 cells. The TC + ZO combination treatment inhibits DNA synthesis, migration, and induces apoptosis in MCF-7 cells as compared to TC and ZO alone at a concentration of 1 µg ml^-1. TC + ZO combination treatment arrested cell cycle significantly at the G₀/G₁ phase. The proposed synergistic activity of the two herbs in the treatment of several cancers was correlated with an appropriate associated target/s, based on the pharmacological network. Interestingly, when both the plants used in combination, were found to regulate a total of 16 genes in 27 types of cancers. Further, ALOX5, MMP2, and MMP9 genes were identified as major targets which are responsible for the TC + ZO anticancer activity. According to merged and sub-networks of source-bioactive, bioactive-target, target-disease of TC, ZO alone and their combination; MMP9 was selected for validation purpose. The real-time PCR analysis confirmed that the TC + ZO combination treatment significantly down-regulated MMP9 mRNA expression by fivefold via up-regulation of its downstream target ER-α by 3.5-fold. In conclusion, the network analysis and in vitro validation confirmed the potent synergistic activity of TC + ZO combination treatment in breast cancer.

A radical form of nitric oxide inhibits porcine circovirus type 2 replication in vitro

Background

Porcine circovirus type 2 (PCV2) is the causal agent of postweaning multisystemic wasting syndrome (PMWS), causing large economical losses of the global swine industry. Nitric oxide (NO), as an important signaling molecule, has antiviral activity on some viruses. To date, there is little information on the role of NO during PCV2 infection.

Results

We used indirect fluorescence assay (IFA), TCID₅₀, real-time RT-qPCR and western blot assay to reveal the role of NO in restricting PCV2 replication. PCV2 replication was inhibited by a form of NO, NO^•, whereas PCV2 was not susceptible to another form of NO, NO⁺.

Conclusion

Our findings indicate that the form of NO^• has a potential role in the fight against PCV2 infection.

MicroRNA-30a-5p promotes replication of porcine circovirus type 2 through enhancing autophagy by targeting 14-3-3

Accumulating evidence demonstrates that autophagy and microRNAs (miRNAs) play key roles in regulating virus-host interactions and can restrict or facilitate viral replication. In the present study we examined whether a functional relationship exists between autophagy, miRNA and porcine circovirus type 2 (PCV2) infection, using several approaches. We demonstrated that there was a positive correlation between PCV2 infection and autophagy in 3D4/21 cells and autophagy induced by PCV2 infection triggered PCV2 replication. Four miRNA were selected by real-time PCR and further studied, but only miR-30a-5p mimic had a significant effect on PCV2 replication. Overexpression of miR-30a-5p significantly enhanced PCV2 infection and autophagy in a dose-dependent manner. Blockage of miR-30a-5p significantly decreased PCV2 replication. We provided further evidence that miR-30a-5p regulate the link between PCV2 infection and host immune system. Furthermore, miR-30a-5p targeted and regulated 14-3-3 gene, which is a regulator of autophagy. Flow cytometry data demonstrated that miR-30a-5p promotes cell cycle arrest at the G2 phase to regulate PCV2 replication and autophagy by interacting directly with 14-3-3, but not with the PCV2 genome. These data not only provide new insights into virus-host interactions during PCV2 infection but also suggest a potential new antiviral therapeutic strategy against PCV2 infection.

Transcriptome profiling of influenza A virus-infected lung epithelial (A549) cells with lariciresinol-4-β-D-glucopyranoside treatment

The influenza A virus is an acute contagious pathogen that affects the human respiratory system and can cause severe lung disease and even death. Lariciresinol-4-β-D-glucopyranoside is a lignan that is extracted from Isatis indigotica, which is a medicinal herb plant that was commonly applied to treat infections, the common cold, fever and inflammatory diseases. Our previous study demonstrated that lariciresinol-4-β-D-glucopyranoside possesses anti-viral and anti-inflammatory properties. However, the comprehensive and detailed mechanisms that underlie the effect of lariciresinol-4-β-D-glucopyranoside interventions against influenza virus infection remain to be elucidated. In this study, we employed high-throughput RNA sequencing (RNA-seq) to investigate the transcriptomic responses of influenza A virus-infected lung epithelial (A549) cells with lariciresinol-4-β-D-glucopyranoside treatment. The transcriptome data show that infection with influenza A virus prompted the activation of 368 genes involved in RIG-I signalling, the inflammatory response, interferon α/β signalling and gene expression that was not affected by lariciresinol-4-β-D-glucopyranoside treatment. Lariciresinol-4-β-D-glucopyranoside exerted its pharmacological actions on the immune system, signal transduction, cell cycle and metabolism, which may be an underlying defense mechanism against influenza virus infection. In addition, 166 differentially expressed genes (DEGs) were uniquely expressed in lariciresinol-4-β-D-glucopyranoside-treated cells, which were concentrated in the cell cycle, DNA repair, chromatin organization, gene expression and biosynthesis domains. Among them, six telomere-associated genes were up-regulated by lariciresinol-4-β-D-glucopyranoside treatment, which have been implicated in telomere regulation and stability. Collectively, we employed RNA-seq analysis to provide comprehensive insight into the mechanism of lariciresinol-4-β-D-glucopyranoside against influenza virus infection.