Researchers find potential new predictor of stress-related illnesses

http://www.eurekalert.org/pub_releases/2014-08/uoth-rfp080114.php

PUBLIC RELEASE DATE: 3-Aug-2014

Contact: Rosanne Fohn
University of Texas Health Science Center at San Antonio
Researchers find potential new predictor of stress-related illnesses
University of Texas Health Science Center at San Antonio scientist leads study

SAN ANTONIO (Aug. 2, 2014) ― Scientists studying depression in teens have discovered that subtle changes in a gene can predict how the brain reacts to stress, which can cause such health issues as depression, post-traumatic stress disorder and obesity.

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Scientists have believed that the tendency to develop stress-related disorders is an inherited trait or is the result of exposure to traumatic events. In this paper, the researchers are also looking into another factor ― that genes may change over time, making some individuals with the same genetic makeup more susceptible to stress than others.

In these studies the researchers looked at the serotonin transporter, a gene that regulates the amount of serotonin signaling that occurs between brain cells and is frequently the target for antidepressant drugs. They proved the existence of a mechanism impacting the brain that also may play a role in an individual's reaction to stress, which may be a stronger predictor of stress than DNA sequencing.

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Attached to the serotonin transporter's DNA are chemical marks called methyl groups that help regulate when, where and how much of the gene is expressed. DNA methylation (the chemical marks) are one form of gene modification, which scientists are studying to understand how the same genetic code can produce a wide range of cellular responses in the body, as well as differences in individuals' reaction to stress.

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"The fact that methylation patterns were the same in saliva, blood and the brain suggests that these patterns, at least in the case of the serotonin transporter, may be passed down through generations. However, it is also possible that exposure to stress over time impacts changes in methylation systematically throughout the body," Dr. Williamson said.

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