mRNA-based in vivo induction of ETV2 to restore blood flow in a preclinical mouse hindlimb ischemia model.

Regenerative medicine aims to repair tissue defects and functional abnormalities by enhancing endogenous cellular processes. Additional to cell-based therapy, viral and nonviral gene therapies have raised substantial interest as promising approaches that allow the direct modulation of key signaling pathways for tissue regeneration in the body. E26 transformation-specific (ETS) variant transcription factor 2 (ETV2) is a well-validated transcription factor which enables vascular regeneration. The therapeutic efficacy of this factor was demonstrated using lentiviral-based in vivo transduction of ETV2 in a murine model of hindlimb ischemia (HLI). However, given the theoretical safety risks inherent to the clinical use of lentivirus, alternative approaches are considered desirable. Here, we investigated the use of a messenger RNA (mRNA)-based approach to in vivo induction of ETV2. Consistent with previous reports using ETV2 lentivirus, we show that ETV2 translated from synthetic mRNA promotes the upregulation of key endothelial genes in vitro. Furthermore, we demonstrate that the intramuscular injection of ETV2 mRNA encapsulated in lipid nanoparticle (LNP) induces local expression of ETV2 protein in skeletal muscle stromal cells and accelerates blood flow recovery in a murine HLI model. These results provide the first demonstration of ETV2 mRNA with LNP as a potential therapeutic tool for targeting peripheral artery disease.