Autophagy plays an important role in cellular response to pathogens. However, the impact of the autophagy machinery on bovine ephemeral fever virus (BEFV) infection is not yet determined. A recent study in our laboratory demonstrated that BEFV triggers simultaneously the PI3K/Akt/NF-κB and Src/JNK-AP1 pathways in the stage of virus binding to enhance virus entry. In this work, we report that BEFV induces autophagy via upregulation of the PI3K/Akt/NF-κB and Src/JNK/AP1 pathways in the early to middle stages of infection and suppresses the PI3K/Akt/mTOR pathway at the late stage of infection. To activate NF-κB, BEFV promotes degradation of IκBα and activates Akt to stimulate NF-κB translocation into the nucleus. Immunoprecipitation assays revealed that BEFV disrupts Beclin 1 and Bcl-2 interaction by JNK-mediated Bcl-2 phosphorylation, thereby activating autophagy. Overexpression of Bcl-2 reversed the BEFV-induced increase in the LC3 II levels. Suppression of autophagy either by knockdown of autophagy-related genes with shRNAs or treatment with a pharmacological inhibitor 3-MA reduced BEFV replication, suggesting that BEFV-induced autophagy benefits virus replication. Our results revealed that the BEFV M protein is one of the viral proteins involved in inducing autophagy via suppression of the PI3K/Akt/mTORC1 pathway. Furthermore, degradation of p62 was observed by immunoblotting, suggesting that BEFV infection triggers a complete autophagic response. Disruption of autophagosome-lysosome fusion by depleting LAMP2 resulted in reduction of virus yield, suggesting that formation of autolysosome benefits virus production.

Tumor metastasis is the most important cause of cancer death and various treatment strategies have targeted at preventing the occurrence of metastasis. Phyllanthus urinaria L is a popular folk medicine and has several proven biological properties, including antioxidant, antihypertension, and anti-inflammatory. This study provides molecular evidence associated with the antimetastatic effects of P urinaria L extracts (PUE), which contained polyphenols including gallic acid, methyl gallate, epicatechin, epigallocatechin-3-gallate, gallocatechin-3-gallate, rutin, epicatechin-3-gallate, and naringin, by showing a marked inhibition on the invasion (P < .001) and migration (P < .001) of highly metastatic A549 and Lewis lung carcinoma (LLC) cells. To further investigate the precise involvement of PUE in tumor metastasis, A549 and LLC cells were treated with PUE at various concentrations and results from zymography and Western blotting showed that a PUE treatment may decrease the expressions of matrix metalloproteinase-2 (MMP-2; P < .001), MMP-9 (P < .001), urokinase plasminogen activator (P < .001), and their endogenous inhibitors, that is, tissue inhibitor of metalloproteinase-2 and plasminogen activator inhibitor-1, in a concentration-dependent manner. Reverse transcription-polymerase chain reaction and MMP-2 promoter luciferase analysis (P < .001) revealed that PUE inhibits the transcription of MMP-2 mRNA. PUE also exerted an inhibitory effect on the DNA-binding activity and the nuclear translocation of NF-κB and AP-1. Furthermore, the inhibitory effects of PUE on the metastasis and growth of LLC cells in vivo were proven. These results indicate that PUE could be applied to be a potential antimetastatic agent.

Recent study in our laboratory has demonstrated that BEFV-induced autophagy via activation of the PI3K/Akt/NF-κB and Src/JNK pathways and suppression of the PI3K-AKt-mTORC1 pathway is beneficial for virus replication. In the current study, we found that both aspirin and 5-aminoimidazole-4-carboxamide-1-β-riboside (AICAR) siginificantly attenuated virus replication by inhibiting BEFV-induced autophagy via suppressing the BEFV-activated PI3K/Akt/NF-κB and Src/JNK pathways as well as inducing reversion of the BEFV-suppressed PI3K-Akt-mTORC1 pathway. AICAR reversed the BEFV-activated PI3K/Akt/NF-κB and Src/JNK pathways at the early to late stages of infection and induced reversion of the BEFV-suppressed PI3K-AKt-mTORC1 pathway at the late stage of infection. Our findings reveal that inhibition of BEFV-induced autophagy by AICAR is independent of AMPK. Furthermore, we found that AICAR transcriptionally downregulates the ATG related genes ULK1, Beclin 1, and LC3 and enhances Atg7 degradation by the proteasome pathway. Aspirin suppresses virus replication by inhibiting BEFV-induced autophagy. It directly suppressed the NF-κB pathway and reversed the BEFV-activated Src/JNK pathway at the early stage of infection and reversed the BEFV-suppressed PI3K/Akt/mTOR pathway at the late stage of infection. The current study provides mechanistic insights into the effects of aspirin and AICAR on BEFV replication through suppression of BEFV-induced autophagy.