Lipid-based nanoparticles deliver mRNA to reverse the pathogenesis of lysosomal acid lipase deficiency in a preclinical model

Lysosomal acid lipase (LAL) is the only known enzyme that degrades cholesteryl esters (CEs) and triglycerides (TGs) in the lysosomes. LAL deficiency (LAL-D) results in hepatosplenomegaly with extensive accumulation of CEs and TGs, and can in the most severe cases be a life-threatening condition in early infancy. Using messenger ribonucleic acid (mRNA) for protein replacement is an innovative approach for the treatment of genetic disorders, but is challenged by a safe and efficient mRNA delivery. Here, we generated a combinatorial library of lipid-based nanoparticles (LNPs) for mRNA delivery and screened it in vitro and in vivo, which yielded a new formulation with a superior potency than an FDA-approved nanoformulation. This formulation efficiently delivered LAL mRNA and restored LAL activity in liver and spleen, mediating significant reversal of the pathological progression in an aggressive preclinical model of LAL-D. In vivo, the new formulation also promoted a more sustained and quantitatively higher LAL expression. In addition, repeated administration regimen mitigated hepatosplenomegaly, and targeted lipidomic analysis revealed strong diminution of CEs and TGs and of toxic lipid species in the liver and spleen. Transcriptomic analysis showed significant attenuation of inflammatory processes, fibrosis and several pathological pathways associated to LAL-D. These findings provide strong evidence that the intracellular production of LAL via mRNA-LNP is a very promising approach for the chronic treatment of LAL-D and support the clinical translation of mRNA therapy to overcome the challenges associated with traditional enzyme replacement therapies.