Adipose-derived microRNA-518a drives hepatic cholesterol dysregulation and hypertension-related vascular remodeling in metabolic dysfunction-associated steatohepatitis via the MST1-AMPK-SREBP2 axis.

INTRODUCTION: Metabolic dysfunction-associated steatohepatitis (MASH) is characterized by disrupted hepatic lipid homeostasis and progressive liver injury, and frequently coexists with hypertension and systemic vascular remodeling, suggesting shared pathophysiological mechanisms. Although adipose tissue-derived microRNAs have emerged as important mediators of inter-organ communication, their roles in regulating hepatic cholesterol metabolism and vascular dysfunction during MASH remain incompletely understood.

OBJECTIVES: This study aimed to investigate whether microRNA-518a regulates hepatic cholesterol metabolism and MASH progression through the MST1-AMPK-SREBP2 signaling pathway and to explore its potential implications for vascular remodeling and hypertension.

METHODS: Integrative bioinformatic analyses, including Mendelian randomization and transcriptomic network analysis, were performed to identify candidate regulatory pathways associated with MASH. Functional validation was conducted using human clinical samples, in vitro cell models, exosome-mediated microRNA delivery, and a dietary mouse model of MASH.

RESULTS: MST1 was identified as a key regulatory target of microRNA-518a. Increased microRNA-518a expression suppressed MST1, resulting in reduced AMPK activation and enhanced SREBP2-mediated cholesterol biosynthesis. Functional experiments demonstrated that microRNA-518a promoted hepatic cholesterol accumulation, lipid deposition, inflammation, and fibrotic changes, whereas restoration of MST1 partially reversed these effects. Exosome-mediated delivery of microRNA-518a further supported its ability to modulate hepatic metabolic responses through intercellular communication.

CONCLUSIONS: MicroRNA-518a promotes hepatic cholesterol dysregulation and MASH progression by targeting the MST1-AMPK-SREBP2 signaling pathway. Notably, the convergence of this axis with vascular regulatory networks suggests broader implications for understanding the metabolic-vascular comorbidities frequently observed in MASH patients, including hypertension and arterial stiffness.