GRIM-19 Restricts HCV Replication by Attenuating Intracellular Lipid Accumulation

Area of Science:

• Virology
• Molecular Biology
• Hepatology

Background:

• Gene-associated with retinoid-interferon-induced mortality 19 (GRIM-19) influences cell death and growth pathways.
• The role of GRIM-19 in hepatitis virus pathogenesis is currently unknown.

Purpose of the Study:

• To investigate the restrictive effects of GRIM-19 on hepatitis C virus (HCV) replication.
• To elucidate the mechanism by which GRIM-19 affects HCV pathogenesis.

Main Methods:

• Assessed GRIM-19 protein levels in HCV-infected cells and cells with HCV replicons.
• Evaluated the impact of GRIM-19 overexpression and siRNA knockdown on viral replication.
• Analyzed the effect of GRIM-19 on lipid metabolism and related transcription factors (SREBP-1c, FAS, ACC).

Main Results:

• GRIM-19 protein levels were decreased in HCV-infected cells.
• Overexpression of GRIM-19 reduced intracellular viral RNA and secreted viruses.
• GRIM-19 attenuated intracellular lipid droplet accumulation and SREBP-1c activity.
• Restoration of lipid accumulation or SREBP-1c expression rescued HCV replication in GRIM-19-expressing cells.

Conclusions:

• GRIM-19 acts as an antiviral host factor against HCV.
• GRIM-19 inhibits HCV replication by suppressing intracellular lipid accumulation via the SREBP-1c pathway.
• GRIM-19 represents a potential therapeutic target for HCV treatment.