Disruption of the IL-33-ST2-AKT signaling axis impairs neurodevelopment by inhibiting microglial metabolic adaptation and phagocytic function

Using single-cell RNA-Seq coupled with pharmacological and genetic perturbation to indentify a range of microglial states and uncover novel pathways that regulate microglial function and activation during postnatal development. Overall design: 1, To define the transcriptional landscape of developing microglia in postnatal cortex, we profiled 9,391 CD45int CD11bint cells from postnatal (postnatal day 9, P9) and young adult (postnatal day 28, P28) cortices by massively parallel droplet-based 3' scRNA-seq. 2. To explore the role of IL33-ST2 signaling in regulating the microglial activation gene program and the microglia heterogeneity, we performed scRNA-seq of cortical microglia from ST2-/- mice and littermate controls at P9. 3, To analyze the molecular signature induced by IL-33 in primary microglia, we profiled low-input bulk RNA Sequencing of primary mouse microglia stimulated with IL-33 and unstimulated control cells. 4, To analyze transcriptional features of pro-phagocytic microglia from developing brain, Tau-GFP positive and negative microglia were sorted from postnatal day 9 cortex for low-input bulk RNA Seq by SmartSeq2. 5, To analyze transcriptional signature of metabolically active microglia in developing brain, TMRM staining high and low microglia subsets were sorted from postnatal day 9 cortex for low-input bulk RNA Seq by SmartSeq2