AUTHOR=Calero Macarena , Moleiro Lara H. , Sayd Aline , Dorca Yeray , Miquel-Rio Lluis , Paz Verónica , Robledo-Montaña Javier , Enciso Eduardo , Acción Fernando , Herráez-Aguilar Diego , Hellweg Thomas , Sánchez Luis , Bortolozzi Analía , Leza Juan C. , García-Bueno Borja , Monroy Francisco 

TITLE=Lipid nanoparticles for antisense oligonucleotide gene interference into brain border-associated macrophages

JOURNAL=Frontiers in Molecular Biosciences

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2022.887678

DOI=10.3389/fmolb.2022.887678

ISSN=2296-889X

ABSTRACT=A novel colloidal synthesis based on the Bligh-Dyer emulsion inversion method was designed for integrating into lipid nanoparticles (LNPs) cell- permeating antisense single-stranded DNAs –also known as GapmeRs (GRs) for mRNA interference. The GR@LNPs were formulated as an interferential therapeutic platform targeted towards brain perivascular and meningeal macrophages for silencing inflammation-related genes. We aim at inhibiting the expression of the gene encoding for lipocalin-type prostaglandin D synthase (L-PGDS), an anti-inflammatory enzyme expressed in the border central nervous system macrophages whose level of expression is altered in inflammatory -related neuropsychopathologies such as depression and schizophrenia. We synthetized GR@LNPs functionalized with mannosylated lipid as a specific ligand for the macrophage surface receptors to facilitate its selective phagocytosis. The novel nanoobjects show a high GR-packing density in a compact multilamellar configuration as evaluated by light-scattering, zeta-potential and transmission electronic microscopy. In the preclinical setting, the GR@LNPs were tested in vivo by intracerebroventricular injection in Wistar rats. Immunofluorescence studies revealed the localization of GR@LNPs in perivascular and meningeal macrophages. Their ability to inhibit L-PGDS gene expression was verified by in situ hybridization performed in rat prefrontal cortex. Compared to conventional GapmeR-delivery systems, a reduction of L-PGDS mRNA expression was found in the cortical brain areas of rats receiving GR@LNPs. The novel GR@LNPs are expected with a bioorthogonal activity as reacting with L-PGDS gene transcripts inside the living system without interfering other genetic or biochemical circuitries. The results pave the way in novel gene therapy platforms for advanced treatments of neuroinflammation-related pathologies.