Authors: Hunt, Charleen; Hartford, Suzanne A.; White, Derek; Pefanis, Evangelos; Hanna, Timothy; Herman, Clarissa; Wiley, Jarrell; Brown, Heather; Su, Qi; Xin, Yurong; Voronin, Dennis; Nguyen, Hien; Altarejos, Judith; Crosby, Keith; Haines, Jeffery; Cancelarich, Sarah; Drummond, Meghan; Moller-Tank, Sven; Malpass, Ryan; Buckley, Jacqueline; del Pilar Molina-Portela, Maria; Droguett, Gustavo; Frendewey, David; Chiao, Eric; Zambrowicz, Brian; Gong, Guochun
Issue: Nat Commun. 2021 May 13;12(1):2770.
CRISPR-based transcriptional activation is a powerful tool for functional gene interrogation; however, delivery difficulties have limited its applications in vivo. Here, we created a mouse model expressing all components of the CRISPR-Cas9 guide RNA-directed Synergistic Activation Mediator (SAM) from a single transcript that is capable of activating target genes in a tissue-specific manner. We optimized Lipid Nanoparticles and Adeno-Associated Virus guide RNA delivery approaches to achieve expression modulation of one or more genes in vivo. We utilized the SAM mouse model to generate a hypercholesteremia disease state that we could bidirectionally modulate with various guide RNAs. Additionally, we applied SAM to optimize gene expression in a humanized Transthyretin mouse model to recapitulate human expression levels. These results demonstrate that the SAM gene activation platform can facilitate in vivo research and drug discovery.