CRISPR targeting of SNPs associated with age-related macular degeneration in ARPE-19 cells: a potential model for manipulating the complement system

Age-related Macular degeneration (AMD) is a major cause of vision loss and is linked to several predisposing single nucleotide polymorphisms (SNPs). CRISPR-mediated genome editing offers the potential to target negatively associated SNPs in an allele-specific manner, necessitating the need for a relevant cell model. The ARPE-19 cell line, with its stable monolayer growth and retinal pigment epithelium (RPE) characteristics, serves as an ideal model for AMD studies. Chronic inflammation and complement system dysregulation are implicated in AMD pathogenesis. Most genetic variations associated with AMD are in complement genes, suggesting their regulatory role. In this study, we conducted targeted PCRs to identify AMD-related SNPs in ARPE-19 cells and used CRISPR constructs to assess allele-specific activity. Guide RNA sequences were cloned into an EF-1-driven SpCas9 vector and packaged into lentivirus. Targeting efficiencies were evaluated with TIDE analysis, and allele-specificity was measured with NGS analysis 30 days post-transduction. Our results showed varying targeting efficiencies depending on guide RNA efficacy. For example, TIDE analysis of CFH SNPs rs1061170 and rs1410996 revealed efficiencies of 35.5% and 33.8%, respectively. CFB SNP rs4541862 showed efficiencies from 3% to 36.7%, and rs641153 ranged from 3.4% to 23.8%. Additionally, allele-specific targeting of AMD-related SNPs rs1061170, rs1410996, rs4541862, and rs641153 ranged from 48% to 52% in heterozygous differentiated ARPE-19 cells. These findings demonstrate the potential to manipulate the complement system in an AMD model by targeting disease-associated SNPs in an allele-specific manner, offering a promising therapeutic approach.