Just one week of sleep deprivation alters the expression of at least 711 different genes.
Sleep loss affects gene function. I’m Bob Hirshon and this is Science Update.
Just one week of mild sleep deprivation affects the function of 711 different genes. This according to researchers at the University of Surrey in the U.K., including chronobiologist Simon Archer. His team took blood samples from volunteers over the course of a week. One group slept eight hours a night; the other, six.
The changes are quite large, and they’re comparable to the kinds of differences that you would see if you were to compare, for example, a normal tissue with a diseased tissue.
Genes linked to inflammation and stress increased their activity in sleep-deprived people, while master control switches that regulate the whole body became sluggish. Since long-term sleep deprivation is already linked to a wide range of problems, from cognitive impairments to heart disease, the study may help scientists unravel the root causes. I’m Bob Hirshon for AAAS, the Science Society.
Making Sense of the Research
It's well known that sleep deprivation can have a wide range of effects, including irritability and depression, memory and cognitive deficits, impaired driving skills, and a higher risk of obesity, cardiovascular disease, and possibly even some kinds of cancer. This research may help explain why all these risks elevate when we lose sleep.
This study also looked at an increasingly important area of medical research: gene expression. We each have a unique genetic code, written in the sequence of molecules called nucleotides that make up our DNA. That sequence is basically a set of instructions for making one or more proteins that make up and affect our bodies. It goes a long way toward determining who we are and how our bodies uniquely function.
But those instructions aren't always carried out in the exact same way. Different biological factors determine when genes are turned “on” or “off”—in other words, whether or not the genes are actively triggering protein production. They also can determine the rate at which these proteins are produced. And those factors, in turn, can be influenced by illness, environmental toxins, or stresses like sleep deprivation.
This study found that just one week of mild sleep deprivation altered the expression of 711 genes. Although researchers are learning that many, many things can influence gene expression in some way, the number of genes affected and the extent of the changes is quite large. As you heard, it's comparable to the difference between healthy and diseased tissue.
Researchers don't yet know enough to look at all 711 changes and determine exactly how they impact our bodies and our health. However, they can say that in general, sleep deprivation increases activity in genes associated with stress and inflammation, and decreases activity in genes that act as master control switches. Inflammation, in particular, is beginning to look like an underlying cause of many different diseases. It's not hard to imagine that having a body that's more stressed and inflamed, but less well-regulated, can trigger many other problems.
What's more, the participants in this study shortchanged their sleep for only a week. Many people don't get enough sleep for months or years, because of hectic schedules, night shift jobs, insomnia, or other reasons. Looking deeper into the consequences of these changes in gene expression may make it clearer how that lifestyle poses a direct threat to health.
Now try and answer these questions:
- What is gene expression? How is it different from our genetic code?
- What is the effect of sleep deprivation on gene expression?
- Why is it reasonable to conclude that many people may suffer even more extensive changes in gene expression than the participants in this study?
- What factors in modern life contribute to sleep deprivation? How do you think these can be addressed? Are some of them unavoidable?
In the Science Netlinks lesson Adolescent Sleep students discuss, summarize, and express alternative positions regarding a study on adolescent sleep.
In the lesson DNA Chips, from the National Institutes of Health Snapshot Series, students learn about the functions of a DNA microarray, also known as a DNA chip, including aspects of gene expression.