An isogenic cell line panel identifies major regulators of aberrant astrocyte proliferation in Down syndrome

Abstract Astrocytes exert adverse effects on the brains of individuals with Down syndrome (DS). Although a neurogenic-to-gliogenic shift in the fate-specification step has been reported, the mechanisms and key regulators underlying the accelerated proliferation of astrocyte precursor cells (APCs) in DS remain elusive. Here, we established an isogenic cell line panel, based on DS-specific induced pluripotent stem cells, the XIST-mediated transcriptional silencing system in trisomic chromosome 21, and genome/chromosome-editing technologies to eliminate phenotypic fluctuations caused by genetic variation. The transcriptional responses of genes observed upon XIST induction and/or downregulation were not uniform, and only a small subset of genes showed a characteristic expression pattern, which is consistent with the proliferative phenotypes of DS APCs. Comparative analysis and experimental verification using gene modification revealed dose-dependent proliferation-promoting activity of DYRK1A and PIGP on DS APCs. Our collection of isogenic cell lines provides a comprehensive set of cellular models for DS investigations.