[Seminar] A CRISPR/Cas9-based gene editing framework allows modeling early-onset Alzheimer’s disease in genetically defined human iPSC lines

Seminar

Title:  A CRISPR/Cas9-based gene editing framework allows modeling early-onset Alzheimer’s disease in genetically defined human iPSC lines

Speaker: Dominik Parquet

Affiliation: Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich

Host: Catarina Brito Lab - Advanced Cell Models

Abstract:

Our aging society is confronted with a dramatic increase in patients suffering from Alzheimer's disease (AD), for which no mechanism-based cure is available. Animal models, although very useful for understanding some the molecular mechanisms resulting in AD pathology, do not capture key disease aspects and have limited use in developing treatments. The development of induced pluripotent stem cells (iPSCs) and their differentiation into human brain neurons now allows generating human in vitro AD models that could enhance functional studies and improve drug screening. Although first studies have shown promising results, the field still lacks an efficient technology for generating genetically defined lines that faithfully display disease-relevant phenotypes. We developed a highly efficient CRISPR/Cas9-based genome-editing framework that allows selective introduction of homo- and heterozygous mutations into human iPSCs. By systemically interrogating gene editing events at the APP and PSEN1 loci, we identified experimental conditions that allow for efficient insertion of mutations at only one allele, which is crucial for direct replication of the mutation zygosity found in early-onset AD (EOAD) patients. Using this approach, we generated the first human iPSCs with heterozygous and homozygous dominant EOAD APPSwe or PSEN1M146V mutations. When differentiating iPSCs into disease-relevant cortical neurons we found genotype-dependent disease phenotypes, particularly in the pathological amyloidogenic processing of APP. Taken together, our findings will allow the field to apply a new generation of genetically defined human in vitro models for uniquely human neurodegenerative or other diseases, which can shed new light on underlying molecular mechanisms.