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Biomarker of Alzheimer's found to be regulated by sleep cycles

newatlas.com

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Re: Biomarker of Alzheimer's found to be regulated by sleep cycles

#32
From the paper Chi3l1/YKL-40 is controlled by the astrocyte circadian clock and regulates neuroinflammation and Alzheimer’s disease pathogenesis [1]:

> Regulation of glial activation and neuroinflammation are critical factors in the pathogenesis of Alzheimer’s disease (AD). YKL-40, a primarily astrocytic protein encoded by the gene Chi3l1, is a widely studied cerebrospinal fluid biomarker that increases with aging and early in AD.

> Accordingly, Chi3l1 knockdown increased phagocytosis of zymosan particles and of β-amyloid peptide in both astrocytes and microglia in vitro. We further observed that expression of Chi3l1 is regulated by the circadian clock, as deletion of the core clock proteins BMAL1 or CLOCK/NPAS2 strongly suppresses basal Chi3l1 expression, whereas deletion of the negative clock regulators PER1/PER2 increased Chi3l1 expression. Basal Chi3l1 mRNA was nonrhythmic because of a long mRNA half-life in astrocytes. However, inflammatory induction of Chi3l1 was gated by the clock. Our findings reveal Chi3l1/YKL-40 as a modulator of glial phagocytic activation and AD pathogenesis in both mice and humans and suggest that the astrocyte circadian clock regulates inflammatory Chi3l1 induction.

The New Atlas title conflates "sleep cycles" with "circadian rhythm". The Washington University news release gets it right [2].

[1] https://stm.sciencemag.org/content/12/574/eaax3519

[2] https://medicine.wustl.edu/news/protein-involved-in-removing...

Re: Biomarker of Alzheimer's found to be regulated by sleep cycles

#33

I'm currently reading the book, "Why We Sleep (Unlocking the Power of Sleep and Dreams)" right now and I'm stunned by all the new things we ignored when it comes to sleep. There are so many fascinating aspects of our life and body, all governed by Sleep. I highly suggest reading the book to explore more about your sleep.

It's a great book for emphasizing the importance of sleep. The author's desired outcome is to get people interested in healthy sleep habits, and he hits a home run in that regard. However, take some of the science positions in the book with a grain of salt. The author is notorious for being directionally correct in his opinions, but exaggerating a lot of the science for dramatic effect. This doesn't matter at all if…

> However, take some of the science positions in the book with a grain of salt. The author is notorious for being directionally correct in his opinions,

I've read it and I agree. Although he does admit in the beginning that there basically is not much conclusive facts about sleep, hence his motivation for writing the book. It's implied that what he is saying is fact, and its a lot more correlation than I think panacea.

> It's also commonly known that people get less sleep than they think they do.

A few things IIRC from the book:

- The specific number is irrelevant as long as its "around 7~9"

- If you're lying down / resting this still "counts" (its not as impactful, but still beneficial)

If people don't want to read the book, the JRE podcast is actually pretty good at summarizing whats in the book: https://www.youtube.com/watch?v=pwaWilO_Pig

Good high level points about what to do to get to sleep (5 things):

https://youtu.be/pwaWilO_Pig?t=3011

Re: Biomarker of Alzheimer's found to be regulated by sleep cycles

#34

Earlier quoted context omitted.

It's a great book for emphasizing the importance of sleep. The author's desired outcome is to get people interested in healthy sleep habits, and he hits a home run in that regard. However, take some of the science positions in the book with a grain of salt. The author is notorious for being directionally correct in his opinions, but exaggerating a lot of the science for dramatic effect. This doesn't matter at all if…

I have a weird relationship with sleep. If I sleep LESS (5, 6 hours) I feel better. More energy, lighter on my feet, less depressed. That lack of sleep always catches up with me though, and after 4-5 days of that I'll have a day where I just feel EXHAUSTED and end up sleeping like 10 hours that night.

> and end up sleeping like 10 hours that night

Paraphrased from the book - basically once you get passed the number of REM cycles needed all of the sleep after that is worthless and ends up just making you groggy. In other words the idea of "catching up on sleep" is BS.

Re: Biomarker of Alzheimer's found to be regulated by sleep cycles

#35
Am I starting to understand that people with Alzheimer were all part of "hustle culture" when they were younger?

Guess we should teach discipline in a different way, or just acknowledge that our socioeconomic circumstances will never materially change - or at least have a real ceiling - outside of complete luck.

Re: Biomarker of Alzheimer's found to be regulated by sleep cycles

#37
post #32

From the paper Chi3l1/YKL-40 is controlled by the astrocyte circadian clock and regulates neuroinflammation and Alzheimer’s disease pathogenesis [1]: > Regulation of glial activation and neuroinflammation are critical factors in the pathogenesis of Alzheimer’s disease (AD). YKL-40, a primarily astrocytic protein encoded by the gene Chi3l1, is a widely studied cerebrospinal fluid biomarker that increases with aging an…

Thanks for posting this. Helps me springboard into the paper faster.

Re: Biomarker of Alzheimer's found to be regulated by sleep cycles

#38

I'm curious if sleep aids, whether it's OTC like melatonin or Rx like trazodone and Ambien, can help this situation. Is it just the sleep that's beneficial or is it "natural" sleep (that term doesn't mean anything, but you get the point of it)? In other words, should people who have difficulty sleeping look to aids as a way of staving off dementia later in life.

The first line of treatment is CBT-I.

Re: Biomarker of Alzheimer's found to be regulated by sleep cycles

#39
post #34

Earlier quoted context omitted.

I have a weird relationship with sleep. If I sleep LESS (5, 6 hours) I feel better. More energy, lighter on my feet, less depressed. That lack of sleep always catches up with me though, and after 4-5 days of that I'll have a day where I just feel EXHAUSTED and end up sleeping like 10 hours that night.

> and end up sleeping like 10 hours that night Paraphrased from the book - basically once you get passed the number of REM cycles needed all of the sleep after that is worthless and ends up just making you groggy. In other words the idea of "catching up on sleep" is BS.

I do find it curious that the body seems to need to sleep longer after long bouts of insomnia (or a week of 18hr work days). I think the hypothesis "You need an extra hour of sleep for every hour missed" is disproven, but the body clearly needs a single dose of extra recovery time after exhaustion.

Re: Biomarker of Alzheimer's found to be regulated by sleep cycles

#40

I'm curious if sleep aids, whether it's OTC like melatonin or Rx like trazodone and Ambien, can help this situation. Is it just the sleep that's beneficial or is it "natural" sleep (that term doesn't mean anything, but you get the point of it)? In other words, should people who have difficulty sleeping look to aids as a way of staving off dementia later in life.

The first line of treatment is CBT-I.

I wouldn't start CBT-I without first getting a sleep test, particulary for sleep apnea which can be present without obvious symptoms beyond insomnia or a delayed sleep phase. It's also much more common in young fit people than is often thought.
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