Genetic editing of primary human dorsal root ganglion neurons using CRISPR-Cas9

CRISPR-Cas9 is now the leading method for genome editing and is advancing for the treatment of human disease. CRISPR has promise in treating neurological diseases, but traditional viral-vector-delivery approaches have neurotoxicity, limiting their use. Here, we describe a simple method for non-viral transfection of primary human DRG (hDRG) neurons for CRISPR-Cas9 editing. We edited TRPV1, NTSR2, and CACNA1E using a lipofection method with CRISPR-Cas9 plasmids containing reporter tags (GFP or mCherry). Transfection was successfully demonstrated by the expression of the reporter two days post-administration. CRISPR-Cas9 editing was confirmed at the genome level with a T7-endonuclease-I assay; protein level with immunocytochemistry and Western blot; and functional level through capsaicin-induced Ca2+ accumulation in a high-throughput compatible fluorescent imaging plate reader (FLIPR) system. This work establishes a reliable, target-specific, non-viral CRISPR-Cas9-mediated genetic editing in primary human neurons with potential for future clinical application for sensory diseases.