Single-Nucleus Transcriptomics Reveals Cell-Type-Specific Dysregulation in the TRN and Cerebellum of an Akap11 Loss-of-Function Mouse Model

Abstract

Bipolar disorder (BD) is a complex psychiatric condition characterized by recurrent mood episodes and disruptions in sleep, cognition, and emotional regulation. Recent genetic studies have identified loss-of-function mutations in Akap11 as a significant risk factor for BD, yet the cellular and molecular consequences of Akap11 dysfunction remain poorly understood. This project investigates what cell-type-specific molecular effects loss-of-function in Akap11 has in two BD-relevant brain regions: the thalamic reticular nucleus (TRN) and deep cerebellar nuclei (DCN) in the cerebellum. We developed and applied region-specific nuclei isolation workflows that utilized antibody-based fluorescence-activated sorting to enrich neuronal and subtype-specific nuclei in wild-type (WT) and knockout (KO) mice. Single-nucleus RNA sequencing was performed using the 10x Genomics Chromium platform to quantify transcriptional alterations and changes in cell-type composition. Processed datasets were integrated with spatial and reference transcriptomic atlases to refine cell-type annotations and localize gene expression changes. Together, these approaches aim to define how Akap11 loss broadly reshapes the cellular and molecular landscape by disrupting cell-type specific gene regulation in BD-relevant circuits. While this work is done in mice, it provides a foundational mechanistic model and is a portion of a broader project dedicated to understanding cell-type-specific perturbations in human circuits implicated in the disorder to engineer alternative therapeutic opportunities.