Manganese inhibits HBV transcription and promotes HBsAg degradation at non-toxic levels

Int J Biol Macromol. 2024 Nov;280(Pt 2):135764. doi: 10.1016/j.ijbiomac.2024.135764. Epub 2024 Sep 17.

Abstract

Chronic hepatitis B virus (HBV) infection continues to pose a significant global health challenge. However, therapeutic measures for a cure are lacking in clinical practice. Manganese, an essential trace element, has garnered attention due to its potential to activate innate immune pathways and its significant role in antiviral and antitumor immunity. Yet, the specific impact of manganese on chronic hepatitis B has been largely unexplored. Our research reveals that manganese substantially inhibits HBV replication in hepatocellular carcinoma cells at non-toxic levels. This suppression occurs independently of well-known anti-HBV innate immune pathways, such as the cGAS-STING pathway. Mechanistically, manganese decreases HBV transcription by diminishing the levels of liver-specific transcription factors. Furthermore, it activates the mTOR pathway, enhancing HBsAg ubiquitination through the upregulation of the ubiquitin ligase β-TrCP and increasing proteasome activity via the augmentation of its subunits, leading to a ubiquitin-dependent degradation of HBsAg. Significantly, our study also uncovers a notable clinical correlation between manganese levels and chronic hepatitis B infection. These findings position manganese as a critical element in diminishing HBV replication, offering a new direction in the management of chronic hepatitis B.

Keywords: HBV transcription; HBsAg; Manganese; Ubiquitin-proteasome system; mTOR.

MeSH terms

  • Cell Line, Tumor
  • Hep G2 Cells
  • Hepatitis B Surface Antigens* / metabolism
  • Hepatitis B virus* / drug effects
  • Hepatitis B virus* / physiology
  • Hepatitis B, Chronic / drug therapy
  • Hepatitis B, Chronic / virology
  • Humans
  • Manganese* / pharmacology
  • Proteolysis* / drug effects
  • Transcription, Genetic / drug effects
  • Ubiquitination / drug effects
  • Virus Replication* / drug effects

Substances

  • Manganese
  • Hepatitis B Surface Antigens