Multiplexed CRISPR gene editing in primary human islet cells with Cas9 ribonucleoprotein

Abstract

SummarySuccessful genome editing in primary human islets could reveal features of the genetic regulatory landscape underlying β cell function and diabetes risk. Here, we describe a CRISPR-based strategy to interrogate functions of predicted regulatory DNA elements using electroporation of a complex of Cas9 ribonucleoprotein (Cas9 RNP) and guide RNAs into primary human islet cells. We successfully targeted coding regions including thePDX1exon 1, and non-coding DNA linked to diabetes susceptibility. CRISPR/Cas9 RNP approaches revealed genetic targets of regulation by DNA elements containing candidate diabetes risk SNPs, including anin vivoenhancer of theMPHOSPH9gene. CRISPR/Cas9 RNP multiplexed targeting of twocis-regulatory elements linked to diabetes risk inPCSK1, which encodes an endoprotease crucial for insulin processing, also demonstrated efficient simultaneous editing ofPCSK1regulatory elements, resulting in impaired β cellPCSK1regulation and insulin secretion. Multiplex CRISPR/Cas9 RNP provides powerful approaches to investigate and elucidate human islet cell gene regulation in health and diabetes.