1
|
Tang L, Remiszewski S, Snedeker A, Chiang LW, Shenk T. An allosteric inhibitor of sirtuin 2 blocks hepatitis B virus covalently closed circular DNA establishment and its transcriptional activity. Antiviral Res 2024; 226:105888. [PMID: 38641024 DOI: 10.1016/j.antiviral.2024.105888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 04/21/2024]
Abstract
296 million people worldwide are predisposed to developing severe end-stage liver diseases due to chronic hepatitis B virus (HBV) infection. HBV forms covalently closed circular DNA (cccDNA) molecules that persist as episomal DNA in the nucleus of infected hepatocytes and drive viral replication. Occasionally, the HBV genome becomes integrated into host chromosomal DNA, a process that is believed to significantly contribute to circulating HBsAg levels and HCC development. Neither cccDNA accumulation nor expression from integrated HBV DNA are directly targeted by current antiviral treatments. In this study, we investigated the antiviral properties of a newly described allosteric modulator, FLS-359, that targets sirtuin 2 (SIRT2), an NAD+-dependent deacylase. Our results demonstrate that SIRT2 modulation by FLS-359 and by other tool compounds inhibits cccDNA synthesis following de novo infection of primary human hepatocytes and HepG2 (C3A)-NTCP cells, and FLS-359 substantially reduces cccDNA recycling in HepAD38 cells. While pre-existing cccDNA is not eradicated by short-term treatment with FLS-359, its transcriptional activity is substantially impaired, likely through inhibition of viral promoter activities. Consistent with the inhibition of viral transcription, HBsAg production by HepG2.2.15 cells, which contain integrated HBV genomes, is also suppressed by FLS-359. Our study provides further insights on SIRT2 regulation of HBV infection and supports the development of potent SIRT2 inhibitors as HBV antivirals.
Collapse
Affiliation(s)
- Liudi Tang
- Evrys Bio, LLC, Pennsylvania Biotechnology Center, Doylestown, PA, 18902, USA; Baruch S. Blumberg Institute, Doylestown, PA, 18902, USA.
| | - Stacy Remiszewski
- Evrys Bio, LLC, Pennsylvania Biotechnology Center, Doylestown, PA, 18902, USA
| | | | - Lillian W Chiang
- Evrys Bio, LLC, Pennsylvania Biotechnology Center, Doylestown, PA, 18902, USA
| | - Thomas Shenk
- Evrys Bio, LLC, Pennsylvania Biotechnology Center, Doylestown, PA, 18902, USA; Department of Molecular Biology, Princeton University, Princeton, NJ, 08540, USA
| |
Collapse
|
2
|
Wang J, Yuan X, Wang Y, Zhang Y, Han M, Lu H, Liu S, Zhang Y, Ge F, Liu Y, Cheng J. PreS1BP mediates inhibition of Hepatitis B virus replication by promoting HBx protein degradation. Virus Res 2024; 341:199326. [PMID: 38253259 PMCID: PMC10846407 DOI: 10.1016/j.virusres.2024.199326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/07/2024] [Accepted: 01/18/2024] [Indexed: 01/24/2024]
Abstract
BACKGROUND PreS1-binding protein (PreS1BP), recognized as a nucleolar protein and tumor suppressor, influences the replication of various viruses, including vesicular stomatitis virus (VSV) and herpes simplex virus type 1 (HSV-1). Its role in hepatitis B virus (HBV) replication and the underlying mechanisms, however, remain elusive. METHODS We investigated PreS1BP expression levels in an HBV-replicating cell and animal model and analyzed the impact of its overexpression on viral replication metrics. HBV DNA, covalently closed circular DNA (cccDNA), hepatitis B surface antigen (HBsAg), hepatitis B core antigen (HBcAg), and HBV RNA levels were assessed in HBV-expressing stable cell lines under varying PreS1BP conditions. Furthermore, co-immunoprecipitation and ubiquitination assays were used to detect PreS1BP- hepatitis B virus X protein (HBx) interactions and HBx stability modulated by PreS1BP. RESULTS Our study revealed a marked decrease in PreS1BP expression in the presence of active HBV replication. Functional assays showed that PreS1BP overexpression significantly inhibited HBV replication and transcription, evidenced by the reduction in HBV DNA, cccDNA, HBsAg, HBcAg, and HBV RNA levels. At the molecular level, PreS1BP facilitated the degradation of HBx in a dose-dependent fashion, whereas siRNA-mediated knockdown of PreS1BP led to an increase in HBx levels. Subsequent investigations uncovered that PreS1BP accelerated HBx protein degradation via K63-linked ubiquitination in a ubiquitin-proteasome system-dependent manner. Co-immunoprecipitation assays further established that PreS1BP enhances the recruitment of the proteasome 20S subunit alpha 3 (PSMA3) for interaction with HBx, thereby fostering its degradation. CONCLUSIONS These findings unveil a previously unidentified mechanism wherein PreS1BP mediates HBx protein degradation through the ubiquitin-proteasome system, consequentially inhibiting HBV replication. This insight positions PreS1BP as a promising therapeutic target for future HBV interventions. Further studies are warranted to explore the clinical applicability of modulating PreS1BP in HBV therapy.
Collapse
Affiliation(s)
- Jun Wang
- Peking University Ditan Teaching Hospital, Beijing 100015, China; Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Xiaoxue Yuan
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China; The Division of Liver Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Yun Wang
- The Division of Liver Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Yu Zhang
- The Division of Liver Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Ming Han
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China; The Division of Liver Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Hongping Lu
- Hebei Utu Pharmaceutical Company Ltd, Shijiazhuang, Hebei Province 052165, China
| | - Shunai Liu
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China; The Division of Liver Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Yang Zhang
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Feilin Ge
- Department of Chinese Medicine, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Yan Liu
- Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing 100039, China.
| | - Jun Cheng
- Peking University Ditan Teaching Hospital, Beijing 100015, China; Hebei Utu Pharmaceutical Company Ltd, Shijiazhuang, Hebei Province 052165, China.
| |
Collapse
|