Hepatocyte-Derived Prostaglandin E2-Modulated Macrophage M1-Type Polarization via mTOR-NPC1 Axis-Regulated Cholesterol Transport from Lysosomes to the Endoplasmic Reticulum in Hepatitis B Virus x Protein-Related Nonalcoholic Steatohepatitis

• Published in: International journal of molecular sciences 2022-10, Vol.23 (19), p.11660
• Main Authors: Lan, You, Qian, Bo, Huang, Hai-Yan, Wang, Pan, Li, Ting, Yuan, Qi, Zhang, Han-Yu, Lin, Yu-Chun, Lin, Zhong-Ning
• Format: Article
• Language: English
• Subjects: Cholesterol; cholesterol transport; Endoplasmic reticulum; endoplasmic reticulum stress; Genes; Hepatitis B; hepatitis B virus x protein; Homeostasis; Lipids; Lipoproteins; Liver diseases; lysosomal mTOR-NPC1 signal axis; Lysosomes; macrophage M1-type polarization; Macrophages; Metabolism; Metabolites; Metabolomics; Npc1 protein; Oxidoreductase; Phenotypes; Polarization; Prostaglandin E2; Proteins; Rapamycin; Risk analysis; Risk factors; Signal transduction; TOR protein; Transcriptomics
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms231911660

Lipid metabolic dysregulation and liver inflammation have been reported to be associated with nonalcoholic steatohepatitis (NASH), but the underlying mechanisms remain unclear. Hepatitis B virus x protein (HBx) is a risk factor for NASH. Based on metabolomic and transcriptomic screens and public database analysis, we found that HBx-expressing hepatocyte-derived prostaglandin E2 (PGE2) induced macrophage polarization imbalance via prostaglandin E2 receptor 4 (EP4) through in vitro, ex vivo, and in vivo models. Here, we revealed that the M1-type polarization of macrophages induced by endoplasmic reticulum oxidoreductase-1-like protein α (ERO1α)-dependent endoplasmic reticulum stress was associated with the HBx-related hepatic NASH phenotype. Mechanistically, HBx promoted Niemann–Pick type C1 (NPC1)/oxysterol-binding protein-related protein 5 (ORP5)-mediated cholesterol transport from the lysosome to the endoplasmic reticulum via mammalian target of rapamycin (mTOR) activation. This study provides a novel basis for screening potential biomarkers in the macrophage mTOR–cholesterol homeostasis–polarization regulatory signaling pathway and evaluating targeted interventions for HBx-associated NASH.