Single-cell Sequencing of Microglia following Repopulation Reveals Distinct Clusters and Transcriptomic Signatures in the 3xTg Alzheimer's Disease Model

In this study, we aimed to deplete the aging microglia and investigate the impact of the newly-born microglia in Alzheimer's pathology using the 3xTg mouse model. Specifically, >24 mo male 3xTg mice were given chow containing 1200mg/kg PLX5622 (AIN-76A-D1001i, Research Diests, NJ, USA) for 2 weeks to deplete their microglia. Control diet with the same base formula were given to control group and to experimental groups during a 4-week repopulation phase immediately following PLX treatment. At the end of the repopulation, we pooled sorted, viable microglia (CD45int CD11b) from 3-5 mice/group and ran single-cell RNAseq analysis to determine the similarities and differences between the aged and repopulated cells in the context of Alzheimer's Disease. We also included non-transgenic controls as a separate group. Microglia (CD45int CD11b+) pooled from 3-5 mice/group were sorted from isolated hippocampi and processed for single-cell RNAseq.