Diminished circadian rhythms in hippocampal microglia may contribute to age-related neuroinflammatory sensitization.

ABSTRACT: Aged animals exhibit diminished circadian rhythms, and both aging and circadian disruption sensitize neuroinflammatory responses. Microglia-the innate immune cell of the central nervous system-possess endogenous timekeeping mechanisms that regulate immune responses. Here, we explored whether aging is associated with disrupted diurnal rhythms in microglia and neuroinflammatory processes. First, hippocampal microglia isolated from young rats (4 months F344XBN) rhythmically expressed circadian clock genes, whereas microglia isolated from the hippocampus of aged rats (25 months) had aberrant Per1 and Per2 rhythms. Unstimulated microglia from young rats exhibited robust rhythms of TNFα and IL-1β mRNA expression, whereas those from aged rats had flattened and tonically elevated cytokine expressi

SUBMITTER: Fonken LK 

PROVIDER: S-EPMC5813798 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature