CRISPR/dCas9-Mediated Upregulation of Reelin and Neuronal Excitability

Reelin is an extracellular matrix protein involved in brain development, synaptic plasticity, and long-term potentiation. The specific mechanisms by which Reelin regulates these processes is currently unclear. Previous strategies to upregulate Reln and other genes relied on genetic manipulations such as global overexpression or knockout. Here, we employ a CRISPR-dCas9 strategy to alter gene expression through recruitment of transcription activators to understand how manipulating the endogenous Reln locus will impact gene expression and neuronal function. Using a specific guide RNA targeting the promoter of Reln in cultured hippocampal neurons, we found that recruitment of the transcriptional activator VPR to the Reln promoter induced robust and selective upregulation of Reln mRNA. To explore whether Reln upregulation altered neuronal physiology, hippocampal neurons expressing CRISPR components were plated on multi-electrode arrays to record neuronal activity, bursting, and network synchrony. Hippocampal neurons overexpressing Reln appear to exhibit increased spontaneous activity, suggesting that Reln manipulation may globally alter neuronal excitability. Faculty Mentor: Jeremy J. Day