Neural progenitor cells mediated by H2A.Z.2 regulate microglial development via Cxcl14 in the embryonic brain

Microglia, the resident immune cells of the central nervous system, play an important role in the brain. Microglia have a special spatiotemporal distribution during the development of the cerebral cortex. Neural progenitor cells (NPCs) are the main source of neural-specific cells in the early brain. It is unclear whether NPCs affect microglial development and what molecular mechanisms control early microglial localization. H2A.Z.2, a histone variant of H2A, has a key role in gene expression regulation, genomic stability, and chromatin remodeling, but its function in brain development is not fully understood. Here, we found that the specific deletion of H2A.Z.2 in neural progenitor cells led to an abnormal increase in microglia in the ventricular zone/subventricular zone (VZ/SVZ) of the embryonic cortex. Mechanistically, H2A.Z.2 regulated microglial development by incorporating G9a into the promoter region of Cxcl14 and promoted H3k9me2 modification to inhibit the transcription of Cxcl14 in neural progenitor cells. Meanwhile, we found that the deletion of H2A.Z.2 in microglia itself had no significant effect on microglial development in the early cerebral cortex. Our findings demonstrate a key role of H2A.Z.2 in neural progenitor cells in controlling microglial development and broaden our knowledge of 2 different types of cells that may affect each other through crosstalk in the central nervous system.