An efficient, non-viral arrayed CRISPR screening platform for iPSC-derived myeloid and microglia models.

Here, we developed a CRISPR-Cas9 arrayed screen to investigate lipid handling pathways in human induced pluripotent stem cell (iPSC)-derived microglia. We established a robust method for the nucleofection of CRISPR-Cas9 ribonucleoprotein complexes into iPSC-derived myeloid cells, enabling genetic perturbations. Using this approach, we performed a targeted screen to identify key regulators of lipid droplet formation dependent on Apolipoprotein E (APOE). We identify the Mammalian Target of Rapamycin Complex 1 (mTORC1) signaling pathway as a critical modulator of lipid storage in both APOE3 and APOE knockout microglia. This study is a proof of concept underscoring the utility of CRISPR-Cas9 technology in elucidating the molecular pathways of lipid dysregulation associated with Alzheimer's disease and neuroinflammation.