Glucosamine promotes hepatitis B virus replication through its dual effects in suppressing autophagic degradation and inhibiting MTORC1 signaling
Creators: name: Lin, Yong
name: Wu, Chunchen
name: Wang, Xueyu
name: Liu, Shi
name: Zhao, Kaitao
name: Kemper, Thekla
name: Yu, Haisheng
name: Li, Mengqi
name: Zhang, Jiming
name: Chen, Mingzhou
name: Zhu, Ying
name: Chen, Xinwen
name: Lu, Mengji
Publisher: name: Taylor & Francis
Year: 2019
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Molecular Biology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Science Policy
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified
subject: Cancer
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Glucosamine (GlcN), a dietary supplement widely utilized to promote joint health and effective in the treatment of osteoarthritis, is an effective macroautophagy/autophagy activator <i>in vitro</i> and <i>in vivo</i>. Previous studies have shown that autophagy is required for hepatitis B virus (HBV) replication and envelopment. The objective of this study was to determine whether and how GlcN affects HBV replication, using <i>in vitro</i> and <i>in vivo</i> experiments. Our data demonstrated that HBsAg production and HBV replication were significantly increased by GlcN treatment. Confocal microscopy and western blot analysis showed that the amount of autophagosomes and the levels of autophagic markers MAP1LC3/LC3-II and SQSTM1 were clearly elevated by GlcN treatment. GlcN strongly blocked autophagic degradation of HBV virions and proteins by inhibiting lysosomal acidification through its amino group. Moreover, GlcN further promoted HBV replication by inducing autophagosome formation via feedback inhibition of mechanistic target of rapamycin kinase complex 1 (MTORC1) signaling in an RRAGA (Ras related GTP binding A) GTPase-dependent manner. <i>In vivo</i>, GlcN application promoted HBV replication and blocked autophagic degradation in an HBV hydrodynamic injection mouse model. In addition, GlcN promoted influenza A virus, enterovirus 71, and vesicular stomatitis virus replication <i>in vitro</i>. In conclusion, GlcN efficiently promotes virus replication by inducing autophagic stress through its dual effects in suppressing autophagic degradation and inhibiting MTORC1 signaling. Thus, there is a potential risk of enhanced viral replication by oral GlcN intake in chronically virally infected patients. ACTB: actin beta; ATG: autophagy-related; CMIA: chemiluminescence immunoassay; ConA: concanavalin A; CQ: chloroquine; CTSD: cathepsin D; DAPI: 4ʹ,6-diamidino-2-phenylindole; EV71: enterovirus 71; GalN: galactosamine; GFP: green fluorescence protein; GlcN: glucosamine; GNPNAT1: glucosamine-phosphate N-acetyltransferase 1; HBP: hexosamine biosynthesis pathway; HBV: hepatitis B virus; HBcAg: hepatitis B core antigen; HBsAg: hepatitis B surface antigen; HBeAg: hepatitis B e antigen; HBV RI: hepatitis B replicative intermediate; IAV: influenza A virus; LAMP1: lysosomal associated membrane protein 1; LAMTOR: late endosomal/lysosomal adaptor, MAPK and MTOR activator; ManN: mannosamine; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTORC1: mechanistic target of rapamycin kinase complex 1; PHH: primary human hepatocyte; RAB7: RAB7A, member RAS oncogene family; RPS6KB1: ribosomal protein S6 kinase B1; RRAGA: Ras related GTP binding A; RT-PCR: reverse transcriptase polymerase chain reaction; SEM: standard error of the mean; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; UAP1: UDP-N-acetylglucosamine pyrophosphorylase 1; VSV: vesicular stomatitis virus.