CRISPRi Screening of Enhancers in Human Primary Astrocytes Identifies Regulatory Circuitry Disrupted in Alzheimer's Disease

We used CROP-seq to perform a high-throughput, parallel screen of 979 candidate enhancer perturbations in normal human astrocytes (NHAs), a primary cell-line. We identified the target gene(s) for 145 of these candidates, which were enriched for transcription with eRNA, transcription factor footprinting, and superenhancer annotation. Most regulatory interactions were <50kb, targeting the nearest gene in ~50% of cases, but were not typically captured by eQTL or in silico predictions. These data elucidate the regulatory network of an understudied-but-crucial brain cell-type. Overall design: To identify regions of open chromatin, ATAC-seq was performed on Normal Human Astrocytes (NHA; Lonza) stably expressing dCas9-KRAB-Blast