Parenchymal border macrophages regulate CSF flow dynamics [CLO depletion]

ABSTRACT: Microglial cells are the resident macrophages of the brain. Perivascular macrophages (PVM) are also myeloid resident cells that are located at the interface between blood, CSF and brain in the perivascular space. Due to their strategic location and their ability to sample CSF content, we hypothesized that PVM might play a role in CSF flow. Using different fluorescent tracers injected either into the CSF (influx) or the brain parenchyma (efflux) we assessed their spatio-temporal distribution and found that ablation (using clodronate liposomes) or dysfunction (using genetic tools) of PVM alters CSF dynamics and patterns. Using single cell RNA sequencing, we found that PBMs can be divided in two sub-populations, and that one population of PBMs could interact with vascular smooth muscle cells, which allow arterial pulsations and subsequently CSF flow. Interestingly, aging results in altered PVM phenotype, and reversing this phenotype using macrophage specific grown factors reversed some of aging-associated dysfunctions of CSF flow. In summary, our results identify a new role of PVM in CSF flow and open new avenues for therapeutical applications targeting PVM in neurodegenerative diseases such as Alzheimer’s disease.

ORGANISM(S): Mus musculus

PROVIDER: GSE206115 | GEO | 2022/08/31

REPOSITORIES: GEO