The looming specter of 13.8 million Americans with Alzheimer's disease (AD) by the year 2050 motivates us to expand our biomedical research paradigm outside of the typical "cell line to rodent to human trials" model. The disappointing performance of all AD drugs that have come to Phase III clinical trials to date also forces us to think more creatively about how to study the mechanisms that underlie neurodegeneration. The advent of human induced pluripotent stem cells (iPSCs) allows us to create disease models from patients with sporadic AD as well as from those with defined familial mutations. In addition, we can use cutting-edge genome editing techniques, such as the Crispr/Cas system, to introduce disease-associated mutations into the genome of otherwise healthy human derived pluripotent cells. In the past five years, neuroscientists have made incredible advances in the creation of different brain cell types, such as neurons, astrocytes, and oligodendrocytes, from human-derived pluripotent cells. What is lacking, however, is a human cellular model of neuroinflammation, a critical component of all neurodegenerative disorders, including AD. In the current application, we describe the creation of human microglia, the brain's "immune" cell, from patient-derived and control pluripotent cells. We propose a comprehensive set of experiments that will determine the role that known and novel AD-associated genes play in these cells using cutting-edge genome editing techniques combined with high-throughput functional assays, transcriptomic profiling, and high-resolution proteomics.
Recent genome-wide association (GWAS) and gene expression studies in human Alzheimer's disease (AD) have revealed a striking preponderance of microglial and immune-associated genes. In the current proposal, we describe the creation of a novel human cellular model that will examine the role of AD-associated genes in microglia derived from control and patient-derived induced human pluripotent stem cells (iPSCs). In addition, we will use genome-editing techniques to create isogenic human pluripotent stem cell lines with defined mutations in AD risk genes, and will differentiate these into multiple neural cel types that include microglia and various neuronal subtypes that will be used for functional and genomic studies.