(DEAD)-box RNA helicase 3 modulates NF-κB signal pathway by controlling the phosphorylation of PP2A-C subunit.

Asp-Glu-Ala-Asp (DEAD)-box RNA helicase 3 (DDX3), an ATP-dependent RNA helicase, is associated with RNA splicing, mRNA export, transcription, translation, and RNA decay. Recent studies revealed that DDX3 participates in innate immune response during virus infection by interacting with TBK1 and regulating the production of IFN-β. In our studies, we demonstrated that DDX3 regulated NF-κB signal pathway.

Glycyrrhizin inhibits porcine epidemic diarrhea virus infection and attenuates the proinflammatory responses by inhibition of high mobility group box-1 protein.

Porcine epidemic diarrhea (PED), caused by porcine epidemic diarrhea virus (PEDV) infection, leads to significant economic losses in the swine industry worldwide. In our studies, we found that glycyrrhizin, the major component of licorice root extracts, could moderately inhibit PEDV infection in Vero cells, when analyzed by western blot, qRT-PCR and a plaque formation assay. We also revealed that glycyrrhizin inhibited the entry and replication of PEDV.

Porcine epidemic diarrhea virus nucleoprotein contributes to HMGB1 transcription and release by interacting with C/EBP-β.

Porcine epidemic diarrhea is a devastating swine enteric disease, which is caused by porcine epidemic diarrhea virus (PEDV) infection. Our studies demonstrated that PEDV infection resulted in the up-regulation of proinflammatory cytokines. Meanwhile, PEDV infection and overexpression of viral nucleoprotein resulted in the acetylation and release of high mobility group box 1 proteins in vitro, an important proinflammatory response mediator, which contributes to the pathogenesis of various inflammatory diseases.

Syndecan-4, a PRRSV attachment factor, mediates PRRSV entry through its interaction with EGFR.

The causative agent of porcine reproductive and respiratory syndrome is the PRRS virus (PRRSV), an enveloped, single-stranded and positive-sense RNA virus. The host factors and mechanisms that are involved in PRRSV entry are still largely unknown. In our present studies, we found that syndecan-4, one of the heparan sulfate proteoglycans, plays a critical role in PRRSV entry, especially in PRRSV attachment.

Porcine epidemic diarrhea virus uses cell-surface heparan sulfate as an attachment factor.

It is well known that many viruses use heparan sulfate as the initial attachment factor. In the present study, we determined whether porcine epidemic diarrhea virus (PEDV), an emerging veterinary virus, infects Vero cells by attaching to heparan sulfate. Western blot analysis, real-time PCR, and plaque formation assay revealed that PEDV infection was inhibited when the virus was pretreated with heparin (an analogue of heparan sulfate).

The involvement of FAK-PI3K-AKT-Rac1 pathway in porcine reproductive and respiratory syndrome virus entry.

CD163 and sialoadhesin had been reported as the two receptors for porcine reproductive and respiratory syndrome virus (PRRSV) infection. The signaling pathway activated by PRRSV entry was seldom reported. In our studies, we demonstrated that PRRSV entry triggers FAK, PI3K, AKT and Rac1 activation.