Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Apr;30(4):327-334.
doi: 10.1111/jvh.13799. Epub 2023 Jan 11.

DDX3-mediated miR-34 expression inhibits autophagy and HBV replication in hepatic cells

Affiliations

DDX3-mediated miR-34 expression inhibits autophagy and HBV replication in hepatic cells

Amit Kumar Mishra et al. J Viral Hepat. 2023 Apr.

Abstract

HBV entry to the host cells and its successful infection depends on its ability to modulate the host restriction factors. DEAD box RNA helicase, DDX3, is shown to inhibit HBV replication. However, the exact mechanism of inhibition still remains unclear. DDX3 is involved in multitude or RNA metabolism processes including biogenesis of miRNAs. In this study, we sought to determine the mechanism involved in DDX3-mediated HBV inhibition. First, we observed that HBx protein of HBV downregulated DDX3 expression in HBV-infected cells. Overexpression of DDX3 inhibited HBx, HBsAg and total viral load, while its knockdown reversed the result in Hep G2.2.15 cells. Expression of miR-34 was downregulated in HBV-infected cells. Overexpression of pHBV1.3 further confirmed that HBV downregulates miR-34 expression. Consistent with the previous finding that DDX3 is involved in miRNA biogenesis, we observed that expression of miR-34 positively corelated with DDX3 expression. miRNA target prediction tools showed that miR-34 can target autophagy pathway which is hijacked by HBV for the benefit of its own replication. Indeed, transfection with miR-34 oligos downregulated the expression of autophagy marker proteins in HBV-expressing cells. Overexpression of DDX3 in HBV-expressing cells, downregulated expression of autophagy proteins while silencing of DDX3 reversed the results. These results led us to conclude that DDX3 upregulates miR-34 expression and thus inhibits autophagy in HBV-expressing cells while HBx helps HBV evade DDX3-mediated inhibition by downregulating DDX3 expression in HBV-infected cells.

Keywords: DEAD box RNA helicase; HBV; autophagy; host restriction factor; miR-34.

PubMed Disclaimer

References

REFERENCES

    1. Decorsière A, Mueller H, van Breugel PC, et al. Hepatitis B virus X protein identifies the Smc5/6 complex as a host restriction factor. Nature. 2016;531(7594):386-389. doi:10.1038/nature17170
    1. van de Klundert MAA, van den Biggelaar M, Kootstra NA, Zaaijer HL. Hepatitis B virus protein X induces degradation of Talin-1. Viruses. 2016;8(10):281. doi:10.3390/v8100281
    1. Mu T, Zhao X, Zhu Y, Fan H, Tang H. The E3 ubiquitin ligase TRIM21 promotes HBV DNA polymerase degradation. Viruses. 2020;12(3):346. doi:10.3390/v12030346
    1. Lv M, Zhang B, Shi Y, et al. Identification of BST-2/tetherin-induced hepatitis B virus restriction and hepatocyte-specific BST-2 inactivation. Sci Rep. 2015;5:11736. doi:10.1038/srep11736
    1. Ko C, Lee S, Windisch MP, Ryu WS. DDX3 DEAD-box RNA helicase is a host factor that restricts hepatitis B virus replication at the transcriptional level. J Virol. 2014;88(23):13689-13698. doi:10.1128/JVI.02035-14

Publication types

LinkOut - more resources