Engineering of an Exosome-Based <i>GPIHBP1</i> mRNA Delivery System for Efficient Therapy of Familial Hypertriglyceridemia

Familial hypertriglyceridemia (FHTG), a severe subtype of primary hypertriglyceridemia caused by mutations in <i>GPIHBP1</i> and other related genes, is linked to life-threatening cardiovascular complications. Current therapies inadequately address the underlying genetic pathology. Here, we developed a novel exosome-based mRNA delivery platform to restore functional glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (<i>GPIHBP1</i>) expression, providing a targeted therapeutic strategy for FHTG. Using <i>GPIHBP1</i>^-/- mice as disease models, we engineered exosomes (Exo^GPIHBP1) encapsulating <i>GPIHBP1</i> mRNA via an optimized vector. These exosomes exhibited high biostability and preferential liver accumulation after systemic administration, enabling efficient protein translation. Consequently, treatment significantly reduced serum triglyceride (TG) levels, attenuated lipid accumulation, and ameliorated liver steatosis. Our study explores exosome-mediated <i>GPIHBP1</i> mRNA therapy as a precise, safe, and effective strategy for FHTG, highlighting a considerable translational potential for genetic dyslipidemias. The platform advances RNA-based therapeutics by bridging the gap between gene therapy and clinical applications.