A high-content RNAi-screening assay to identify modulators of cholesterol accumulation in Niemann-Pick type C cells.

Abstract Niemann–Pick disease type C (NPC) is an inherited lipid storage disorder characterized by a defect in intracellular trafficking of exogenous cholesterol and glycosphingolipids. A goal for therapeutic treatment of NPC is to decrease/normalize cholesterol accumulation. We developed a functional genomics-based assay, combining high-throughput RNA interference (HT-RNAi) screening with high-content fluorescence imaging to identify specific genes in NPC cells that will result in more normal cholesterol levels in the diseased cells. Conditions for siRNA tranfections were optimized for 2 NPC fibroblast cell lines (GM03123, GM18453) and a normal fibroblast cell line (GM05659). RNAi screening was done using a focused-set siRNA library targeting 40 cholesterol trafficking-associated genes, knowledge mined from the existing literature on NPC disease, and/or their association with NPC1/NPC2 genes. We utilized filipin staining as a measure of cholesterol accumulation in fixed NPC cells. Data analysis of these ...