In a new study from Polytechnic Institute, researchers found the brain’s ability to clear a protein closely linked to Alzheimer’s disease is tied to our circadian cycle (body clock).
The finding underscores the importance of healthy sleep habits in preventing the protein Amyloid-Beta 42 (AB42) from forming clumps in the brain, and opens a path to new Alzheimer’s therapies.
Circadian regulation of immune cells plays a role in the link between the circadian clock and Alzheimer’s disease.
This shows a healthy sleep pattern might be important to alleviate some of the symptoms in Alzheimer’s disease, and this beneficial effect might be imparted by an immune cell type called macrophages/microglia.
The circadian system is comprised of a core set of clock proteins that anticipate the day/night cycle by causing daily oscillations in the levels of enzymes and hormones.
It ultimately affects physiological parameters such as body temperature and the immune response. Disruption of the circadian system is increasingly associated with diseases like diabetes, cancer, and Alzheimer’s.
A telltale sign of Alzheimer’s disease is plaques, extracellular clumps of AB42 in the brain.
Macrophages, which are immune cells that seek and destroy unwanted material, clear AB42 from the brain.
In earlier research, the researchers noticed oscillations in enzymes that help to make two proteins on the macrophage cell surface—heparan sulfate proteoglycan and chondroitin sulfate proteoglycan– both of which are known to play a role in regulating clearance of AB42.
Could these cell surface proteoglycans be a link between the circadian system and Alzheimer’s?
In this study, the team established that the amount of AB42 ingested by healthy macrophages oscillates with a daily circadian rhythm.
Peak AB42 clearance occurred as the production of surface cell proteoglycans was at its lowest level, and removal of these proteoglycans increased ingestion, which suggests that the proteoglycans inhibit AB42 clearance.
The team says what’s clear is that this is all timed by the circadian clock.
That link could be used to develop therapies that would encourage greater AB42 clearance, perhaps by boosting the amplitude of daily oscillations, which tend to diminish as we age.
The team says in theory if doctors could boost that rhythm, perhaps they could increase the clearance of AB42 and prevent damage to the brain.
If you care about Alzheimer’s, please read studies about anti-seizure drug that could improve cognitive function in Alzheimer’s, and antioxidants that could help prevent Alzheimer’s disease.
For more information about brain health, please see recent studies about common cancer drug that could help reverse Alzheimer’s symptoms, and results showing this stuff in basil may protect against Alzheimer’s disease.
The study is published in PLOS Genetics and was conducted by Jennifer Hurley et al.
Copyright © 2022 Knowridge Science Report. All rights reserved.
