A gene IRAK1 blocks insulin signaling in muscle which reduces the ability of insulin to metabolize glucose causing insulin resistance.
A new molecule has been identified to be involved in the development of insulin resistance. Normally, the hormone insulin breaks down glucose. But in some people this process becomes increasingly inefficient, a phenomenon known as insulin resistance. Until now, researchers had not understood how insulin resistance turns into full-blown diabetes, in which the body is unable to metabolize sugar properly.
‘A gene called IRAK1 (Interleukin-1 receptor-associated kinase 1) induces insulin resistance and increases risk of diabetes.’
The findings were published recently in the Journal of Biological Chemistry. The study is the first to identify a new molecular link between inflammation and the disease. "Until now, we didn't really understand how insulin resistance occurred," said Xiao-Jian Sun, an assistant professor in the Department of Medicine at UM SOM. "Our study has done something new: it has identified a new molecule involved in the development of insulin resistance."
Surprisingly, the underlying molecular mechanism for insulin resistance and type 2 diabetes remains mysterious. Diabetes occurs when the body cannot metabolize glucose properly.
Dr. Sun's previous research began by focusing on two molecules, Insulin Receptor Substrate-1 and Insulin Receptor Substrate-2, known as IRS-1 and IRS-2. They are key signaling molecules that allow insulin to do its work.
In the body, insulin has many jobs: it synthesizes fat, it promotes muscle growth and it breaks down glucose. This is why, in diabetes, patients have multiple problems: the hormone plays many roles.
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It appears that a gene called IRAK1 (Interleukin-1 receptor-associated kinase 1) plays a key role in this process. For years, researchers have known that inflammation activates IRAK1. Dr. Sun' team discovered that this enzyme blocks insulin signaling in muscle by blocking IRS-1. This blocks insulin signaling, and as a result, significantly reduces the ability of insulin to metabolize glucose in muscle.
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"It increases insulin resistance, particularly in muscle. This gives us insight into how to improve insulin resistance in patients with diabetes."
Dr. Sun says that in the future it may be possible to test diabetes patients to see what version of IRAK1 they have. Some people have a more active version of the gene, while others have a less active version.
With this test, it may be possible to predict how much insulin resistance might be possible with weight loss or other preventive measures. In addition, in the future he hopes to look for drugs that can inhibit IRAK1 activity.
Source-Eurekalert