Furanocoumarins promote proteasomal degradation of viral HBx protein and down-regulate cccDNA transcription and replication of hepatitis B virus

Purnima Tyagi; Ankita Singh; Jitendra Kumar; Belal Ahmad; Aparna Bahuguna; Perumal Vivekanandan; Shiv Kumar Sarin; Vijay Kumar

doi:10.1016/j.virol.2024.110065

Furanocoumarins promote proteasomal degradation of viral HBx protein and down-regulate cccDNA transcription and replication of hepatitis B virus

Virology. 2024 Mar 24:595:110065. doi: 10.1016/j.virol.2024.110065. Online ahead of print.

Authors

Purnima Tyagi¹, Ankita Singh¹, Jitendra Kumar¹, Belal Ahmad², Aparna Bahuguna³, Perumal Vivekanandan², Shiv Kumar Sarin⁴, Vijay Kumar⁵

Affiliations

¹ Department of Molecular and Cellular Medicine, Institute of Liver and Biliary Sciences, New Delhi, India.
² Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India.
³ Elsevier/ RELX India Pvt Ltd., DLF Cyber City, Gurgaon, 122002, India.
⁴ Department of Hepatology, Institute of Liver and Biliary Sciences, New Delhi, India.
⁵ Department of Molecular and Cellular Medicine, Institute of Liver and Biliary Sciences, New Delhi, India. Electronic address: vkumar@ilbs.in.

PMID: 38569227
DOI: 10.1016/j.virol.2024.110065

Abstract

Nucleot(s)ide analogues, the current antiviral treatments against chronic hepatitis B (CHB) infection, are non-curative due to their inability to eliminate covalently closed circular DNA (cccDNA) from the infected hepatocytes. Preclinical studies have shown that coumarin derivatives can effectively reduce the HBV DNA replication. We evaluated the antiviral efficacy of thirty new coumarin derivatives in cell culture models for studying HBV. Furanocoumarins Fc-20 and Fc-31 suppressed the levels of pre-genomic RNA as well as cccDNA, and reduced the secretion of virions, HBsAg and HBeAg. The antiviral efficacies of Fc-20 and Fc31 improved further when used in combination with the hepatitis B antiviral drug Entecavir. There was a marked reduction in the intracellular HBx level in the presence of these furanocoumarins due to proteasomal degradation resulting in the down-regulation of HBx-dependent viral genes. Importantly, both Fc-20 and Fc-31 were non-cytotoxic to cells even at high concentrations. Further, our molecular docking studies confirmed a moderate to high affinity interaction between furanocoumarins and viral HBx via residues Ala3, Arg26 and Lys140. These data suggest that furanocoumarins could be developed as a new therapeutic for CHB infection.

Keywords: 3.5 Kb RNA; CYEI mutant; Coumarin derivatives; Cyclin D1 promoter; Furanocoumarin; HBV replication; HBx protein; cccDNA.