Karima Abounouh1,2, Mohammad Enamul Hoque Kayesh3,4, Haya Altawalah5,6, Bouchra Kitab3, Shuko Murakami7, Shintaro Ogawa7, Yasuhito Tanaka7,8, Hind Dehbi2, Pascal Pineau9, Michinori Kohara10, Soumaya Benjelloun1, Kyoko Tsukiyama-Kohara3, Sayeh Ezzikouri11. 1. Virology Unit, Viral Hepatitis Laboratory, Institut Pasteur du Maroc, 1 Place Louis Pasteur, Casablanca, 20360, Morocco. 2. Laboratory of Genetics and Molecular Pathology, Medical School, University Hassan II, Casablanca, Morocco. 3. Transboundary Animal Diseases Centre, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan. 4. Department of Microbiology and Public Health, Faculty of Animal Science and Veterinary Medicine, Patuakhali Science and Technology University, Barishal, 8210, Bangladesh. 5. Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait. 6. Virology Unit, Yacoub Behbehani Center, Sabah Hospital, Ministry of Health, Safat, Kuwait. 7. Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. 8. Department of Gastroenterology and Hepatology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan. 9. Unité "Organisation Nucléaire et Oncogenèse", INSERM U993, Institut Pasteur, Paris, France. 10. Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan. 11. Virology Unit, Viral Hepatitis Laboratory, Institut Pasteur du Maroc, 1 Place Louis Pasteur, Casablanca, 20360, Morocco. sayeh.ezzikouri@pasteur.ma.
Abstract
BACKGROUND: Hepatitis B Virus (HBV) is the most common cause of chronic liver disease worldwide. The mechanisms that regulate HBV viral replication remain poorly defined. Here, we show that blocking of the neddylation elicits antiviral effect against HBV replication, indicating that NEDD8 supports viral production. METHODS AND RESULTS: To explore role of neddylation, HBV-replicating HepG2.2.15.7 cells and HBV-infected HepG2-hNTCP-30 cells were treated with siNEDD8 and MLN4924, a potent and selective NEDD8-activating enzyme inhibitor. Cell viability, intracellular and extracellular HBV DNA, covalently closed circular DNA (cccDNA), HBsAg, HBeAg, and HBcrAg were measured to assess the consequences of the various treatments on viral replication. Our data showed that HBV infection increased NEDD8 expression in human liver cell lines. Symmetrically, NEDD8 knockdown by siRNA or MLN4924 treatments decreased HBV replication in HepG2.2.15.7 and HepG2-hNTCP-30 cells. Notably, HBsAg, and HBeAg secretions were strongly suppressed in the culture supernatants, but not the HBcrAg. These results indicate that the suppression of NEDD8 decreases HBV replication. However, cccDNA steady level confirms once again its persistence and longevity in chronic infection. CONCLUSION: The manipulation of the neddylation pathway can thus provide new tools interfering with HBV persistence as well as novel therapeutic strategies against chronic hepatitis B.
BACKGROUND: Hepatitis B Virus (HBV) is the most common cause of chronic liver disease worldwide. The mechanisms that regulate HBV viral replication remain poorly defined. Here, we show that blocking of the neddylation elicits antiviral effect against HBV replication, indicating that NEDD8 supports viral production. METHODS AND RESULTS: To explore role of neddylation, HBV-replicating HepG2.2.15.7 cells and HBV-infected HepG2-hNTCP-30 cells were treated with siNEDD8 and MLN4924, a potent and selective NEDD8-activating enzyme inhibitor. Cell viability, intracellular and extracellular HBV DNA, covalently closed circular DNA (cccDNA), HBsAg, HBeAg, and HBcrAg were measured to assess the consequences of the various treatments on viral replication. Our data showed that HBV infection increased NEDD8 expression in human liver cell lines. Symmetrically, NEDD8 knockdown by siRNA or MLN4924 treatments decreased HBV replication in HepG2.2.15.7 and HepG2-hNTCP-30 cells. Notably, HBsAg, and HBeAg secretions were strongly suppressed in the culture supernatants, but not the HBcrAg. These results indicate that the suppression of NEDD8 decreases HBV replication. However, cccDNA steady level confirms once again its persistence and longevity in chronic infection. CONCLUSION: The manipulation of the neddylation pathway can thus provide new tools interfering with HBV persistence as well as novel therapeutic strategies against chronic hepatitis B.