Role of the PI3K‑AKT‑mTOR pathway in hepatitis B virus infection and replication

Mol Med Rep. 2018 Mar;17(3):4713-4719. doi: 10.3892/mmr.2018.8395. Epub 2018 Jan 8.

Abstract

The replication of hepatitis B virus (HBV) may be modulated by a variety of cell signaling pathways, including the phosphatidylinositol 3‑kinase (PI3K)‑RAC‑α serine/threonine‑protein kinase (AKT)‑serine/threonine‑protein kinase mTOR (mTOR) pathway. The aim of the present study was to determine the regulatory effects of this pathway on the infection and replication of HBV. The results indicated that the HBV entry process may activate the AKT pathway, as demonstrated by AKT phosphorylation in HBV natural infection. However, inhibition of AKT phosphorylation by short‑term treatment with AKT inhibitors was unable to block HBV entry, which suggested that AKT activation induced by HBV infection is not essential for viral entry process. Prolonged treatment with PI3K‑AKT‑mTOR pathway inhibitors markedly promoted HBV replication in HBV replicating and natural infection models. The PI3K‑AKT‑mTOR pathway was therefore identified to be a negative regulator of HBV replication. These inhibitors enhanced the replication and transcription of HBV in an HBx‑dependent way. The results additionally indicated that a PI3K inhibitor, Ly294002, inhibited the secretion of the small surface antigen of HBV in a PI3K‑AKT‑independent manner. The inhibitor Ly294002 may be used as a tool for the drug development of surface antigen secretion inhibitors.

Keywords: hepatitis B virus; entry; transcription; phosphatidylinositol 3-kinase-RAC-α serine/threonine-protein kinase-serine/threonine-protein kinase mTOR; hepatitis B virus surface antigen.

MeSH terms

  • Chromones / pharmacology
  • DNA, Viral / metabolism
  • Hep G2 Cells
  • Hepatitis B / pathology
  • Hepatitis B / virology
  • Hepatitis B Surface Antigens / metabolism
  • Hepatitis B virus / physiology*
  • Humans
  • Morpholines / pharmacology
  • Phosphatidylinositol 3-Kinase / metabolism*
  • Phosphorylation
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction / drug effects
  • Sirolimus / pharmacology
  • TOR Serine-Threonine Kinases / antagonists & inhibitors
  • TOR Serine-Threonine Kinases / metabolism*
  • Virus Internalization / drug effects
  • Virus Replication

Substances

  • Chromones
  • DNA, Viral
  • Hepatitis B Surface Antigens
  • Morpholines
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • MTOR protein, human
  • Phosphatidylinositol 3-Kinase
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases
  • Sirolimus