Researchers at Washington University School of Medicine in St. Louis have discovered a protein that links the amyloid-removal process to the circadian clock.
The findings suggest that YKL-40 is a possible link between circadian rhythm dysfunction and Alzheimer’s, and that therapies targeting the protein may slow the course of the disease.
“If your circadian clock is not quite right for years and years — you routinely suffer from disrupted sleep at night and napping during the day — the cumulative effect of chronic dysregulation could influence inflammatory pathways such that you accumulate more amyloid plaques,” said senior author Erik Musiek, MD, PhD, an associate professor of neurology. Amyloid plaques in the brain are one of the early hallmarks of Alzheimer’s disease. “We hope that a better understanding of how the circadian clock affects YKL-40 could lead to a new strategy for reducing amyloid in the brain.”
Our daily rhythms are set by a master clock in the brain that is driven by the day and night cycle. Each cell also maintains its own internal clock, pegged to the master clock. A surprisingly broad array of biological processes — from sugar absorption to body temperature to immune and inflammatory responses — vary by time of day.