Myeloid deficiency of the intrinsic clock protein BMAL1 accelerates cognitive aging by disrupting microglial synaptic pruning

Chinyere Agbaegbu Iweka, Erica Seigneur, Amira Latif Hernandez, Sur Herrera Paredes, Mica Cabrera, Eran Blacher, Connie Tsai Pasternak, Frank M. Longo, Luis de Lecea, Katrin I. Andreasson

Research output: Contribution to journalArticlepeer-review

Abstract

Aging is associated with loss of circadian immune responses and circadian gene transcription in peripheral macrophages. Microglia, the resident macrophages of the brain, also show diurnal rhythmicity in regulating local immune responses and synaptic remodeling. To investigate the interaction between aging and microglial circadian rhythmicity, we examined mice deficient in the core clock transcription factor, BMAL1. Aging Cd11bcre;Bmallox/lox mice demonstrated accelerated cognitive decline in association with suppressed hippocampal long-term potentiation and increases in immature dendritic spines. C1q deposition at synapses and synaptic engulfment were significantly decreased in aging Bmal1-deficient microglia, suggesting that BMAL1 plays a role in regulating synaptic pruning in aging. In addition to accelerated age-associated hippocampal deficits, Cd11bcre;Bmallox/lox mice also showed deficits in the sleep–wake cycle with increased wakefulness across light and dark phases. These results highlight an essential role of microglial BMAL1 in maintenance of synapse homeostasis in the aging brain.

Original languageEnglish
Article number48
JournalJournal of Neuroinflammation
Volume20
Issue number1
DOIs
StatePublished - Dec 2023

Keywords

  • BMAL1
  • Circadian clock
  • Microglia
  • Sleep–wake cycle
  • Synaptic plasticity

All Science Journal Classification (ASJC) codes

  • General Neuroscience
  • Immunology
  • Neurology
  • Cellular and Molecular Neuroscience

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