Molecular signatures of immune cells and neuroblasts in the aged brain

Normal aging is accompanied by escalating systemic inflammation. To comprehensively characterize the impact of aging on immune cells in the brain and periphery, we harvested immune cells from mouse spleen and brain tissues. Single cell sequencing was performed to compare the genetic signatures in these isolated immune cell subsets from spleen and brain tissues in young and aged mice. Our results demonstrate increased accumulations of immune cells such as natural killer (NK) cells in the aged brain as compared to the young brain. In addition, NK cells in the aged brain display augmented proliferation activity and cytotoxicity.  RNA-sequencing of neuroblasts isolated from the aged brain revealed that aging induces dysregulated expression of genes related to DNA damage response and upregulation of senescence signatures.