Messenger RNA-based therapeutics for brain diseases: An animal study for augmenting clearance of beta-amyloid by intracerebral administration of neprilysin mRNA loaded in polyplex nanomicelles.
Alzheimer's disease (AD) pathogenesis is considered to be the metabolic imbalance between anabolism and clearance of amyloid-beta (Aβ), and the strategy of breaking the equilibrium between soluble and insoluble forms of Aβ is likely to help prevent the progression of AD. Neprilysin (NEP) plays a major role in the clearance of Aβ in the brain, and its supplementation using viral vectors has shown to decrease Aβ deposition and prevent pathogenic changes in the brain. In this study, we developed a new therapeutic strategy by mRNA-based gene introduction. mRNA has the advantages of negligible risk of random integration into genome and not needing to be transcribed precludes the need for nuclear entry. This allows efficient protein expression in slowly-dividing or non-dividing cells, such as neural cells. We constructed mRNA encoding the mouse NEP protein and evaluated its ability degrade Aβ. In vitro transfection of NEP mRNA to primary neurons exhibited Amyloid Precursor Protein (APP) degradation activity superior to that of NEP encoding plasmid DNA. We then evaluated the in vivo activity of NEP mRNA by intracerebroventricular (i.c.v.) infusion using a cationic polymer-based PEGylated nanocarrier to form polyplex nanomicelles, which have been shown to have a high potential to deliver mRNA to various target tissues and organs. Nanomicelles carrying a GFP-NEP fusion mRNA produced efficient protein expression in a diffuse manner surrounding the ventricular space. An ELISA evaluation revealed that the mRNA infusion significantly augmented NEP level and effectively reduced the concentration of Aβ that had been supplemented in the mouse brain. To the best of our knowledge, this is the first study to demonstrate the therapeutic potential of introducing exogenous mRNA for the treatment of brain diseases, opening the new era of mRNA-based therapeutics.
Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Chin-Yu
CY
Lin
Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Federico
F
Perche
Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Masaru
M
Ikegami
Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Satoshi
S
Uchida
Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. Electronic address: kataoka@bmw.t.u-tokyo.ac.jp.
Kazunori
K
Kataoka
Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. Electronic address: itaka-ort@umin.net.
Keiji
K
Itaka
D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism; D001927:Brain Diseases / Q000628:therapy; D002460:Cell Line; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004333:Drug Administration Routes; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008810:Mice, Inbred C57BL; D015260:Neprilysin / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D012333:RNA, Messenger / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use
D016229:Amyloid beta-Peptides; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins; D015260:Neprilysin
Amyloid; Gene therapy; Messenger RNA; Polyplex nanomicelle; mRNA-based therapeutics