To sleep, perchance to heal: Newly discovered gene governs need for slumber when sick

A True Open Forum; Share/Discuss whatever you like
User avatar
Edge Guerrero
Posts: 8287
Joined: Tue Oct 22, 2013 7:14 am
Reputation: 3064
Location: Smackdown Hotel at "the corner of Know Your Role Blvd

To sleep, perchance to heal: Newly discovered gene governs need for slumber when sick

Postby Edge Guerrero » Fri Feb 01, 2019 10:59 am

Direct link between illness and the need for more sleep

Date: January 31, 2019
Source: University of Pennsylvania School of Medicine

Summary: Humans spend nearly one-third of their lives in slumber, yet sleep is still one of biology's most enduring mysteries. Little is known about what genetic or molecular forces drive the need to sleep -- until now. In a study of over 12,000 lines of fruit flies, researchers have found a single gene, called nemuri, that increases the need for sleep.

Image
This is an image of a fruit that fly has been infected with bacteria, showing nemuri expression (green) in the brain -- a single neuron and its projections on either side of the brain.
Credit: Amita Sehgal, Perelman School of Medicine, University of Pennsylvania; Science


The NEMURI protein fights germs with its inherent antimicrobial activity and it is secreted by cells in the brain to drive prolonged, deep sleep after an infection.

"While it's a common notion that sleep and healing are tightly related, our study directly links sleep to the immune system and provides a potential explanation for how sleep increases during sickness," said senior author Amita Sehgal, PhD, a professor of Neuroscience and director of Penn's Chronobiology Program.

Without the nemuri gene, flies were more easily aroused during daily sleep, and their acute need for an increase in sleep -- induced by sleep deprivation or infection -- was reduced. On the other hand, sleep deprivation, which increases the need for sleep, and to some extent infection, stimulated nemuri to be expressed in a small set of fly neurons nestled close to a known sleep-promoting structure in the brain. Overexpression of nemuri increased sleep in bacteria-infected flies and led to their increased survival compared to non-infected control flies.

In response to infection, NEMURI appears to kill microbes, most likely in the peripheral parts of the fruit fly body, and increases sleep through its action in the brain. Several molecules like NEMURI, which is an antimicrobial peptide (AMP), have multiple functions that help combat infection, but its sleep-promoting role may be just as important for host defense, the researchers suggest, given that increased sleep during sickness promotes survival in the flies.

What's more, the authors note that cytokines such as interleukin-1 (IL-1), an immune cell molecule, are implicated in human sleep. IL-1 can function in the same pathway as AMPs, and it accumulates after prolonged wakefulness and appears to promote sleep. In mammals, cytokines can induce production of AMPs, but AMPS may also affect the expression of cytokines. Given this interwoven relationship, the researchers conclude that NEMURI is a working link between immune function and sleep.

"The NEMURI protein is a genuine driver of keeping sleep on track under conditions of high sleep need like when we're sick," said first author Hirofumi Toda, PhD, a postdoctoral fellow in Sehgal's lab. "In the next phase of our work, we plan to investigate the mechanism by which NEMURI drives sleep."

Julie Williams and Michael Gulledge, both from Sehgal's lab, are also co-authors on this paper. This work was funded by the Howard Hughes Medical Institute and the National Institutes of Health (R01GM123783 402).

Source: https://www.sciencedaily.com/releases/2019/01/190131143335.htm
- I rent this space for advertising

Don't be selfish, preserve this world for the next generations.

I'll never long for what might have been
Regret won't waste my life again
I won't look back I'll fight to remain

Return to “Anarchy Zone”

Who is online

Users browsing this forum: No registered users and 93 guests