The research, published online in PLoS ONE on January 25, 2012, suggests that childhood adversity may lead to epigenetic changes in the human glucocorticoid receptor gene, an important regulator of the biological stress response that may increase risk for psychiatric disorders.
The association between childhood adversity, including parental loss and childhood maltreatment, and risk for psychiatric disorders such as depression and anxiety has been established in multiple studies. However, researchers have yet to define how and why this association exists in humans. "We need to understand the biology of this effect in order to develop better treatment and prevention programs," said Audrey Tyrka, MD, PhD, director of the Laboratory for Clinical and Translational Neuroscience at Butler Hospital and associate professor of Psychiatry and Human Behavior at Brown University. "Our research group turned to the field of epigenetics to determine how environmental conditions in childhood can influence the biological stress response."
Epigenetics is the study of changes to the genome that do not alter the DNA sequence, but influence whether genes will be expressed, or "turned on," versus whether they will be silenced. Knowing that the connection between childhood maltreatment and psychiatric disorders has been linked to the hormone system that coordinates biological stress responses, the researchers sought to identify the root cause at a genetic level.
The glucocorticoid receptor is an important regulator of the stress response, and methylation is a particularly stable type of epigenetic modification. "We knew that epigenetic changes to this gene could be affected by childhood parenting experiences because previous animal research showed that rodents with low levels of maternal care had increased methylation of this gene, and consequently, as adults these animals had greater stress sensitivity and fear in stressful situations," said Tyrka.
The researchers looked at 99 healthy adults, some of whom had a history of parental loss or childhood maltreatment. DNA was extracted from each of the participants using a blood sample, then analyzed to identify epigenetic changes to the glucocorticoid receptor. The researchers then performed a standardized hormone provocation test to measure the stress hormone, cortisol.
The researchers found that adults with a history of childhood adversity—maltreatment or parental loss—had increased methylation of the glucocorticoid receptor (GR) gene, which is thought to change the way this gene is expressed on a long-term basis. They also found that greater methylation was linked to blunted cortisol responses to the hormone provocation test. "Our results suggest that exposure to stressful experiences during childhood may actually alter the programming of an individual's genome. This concept may have broad public health implications, as it could be a mechanism for the association of childhood trauma with poor health outcomes, including psychiatric disorders as well as medical conditions such as cardiovascular disease," said Tyrka.
In early studies of animals, researchers have identified drugs that can reverse methylation effects. "More research is needed to better understand the epigenetic mechanism behind this association," said Tyrka, noting a larger scale study currently underway at Butler and a study of this association in children. "This line of research may allow us to better understand who is most at risk and why, and may allow for the development of treatments that could reverse epigenetic effects of childhood adversity."
Butler Hospital is the only private, nonprofit psychiatric and substance abuse hospital serving adults, adolescents and children in Rhode Island and southeastern New England. Founded in 1844, it was the first hospital in Rhode Island and has earned a reputation as the leading provider of innovative psychiatric treatments in the region. The flagship hospital for the Department of Psychiatry and Human Behavior at the Warren Alpert Medical School of Brown University, Butler is recognized worldwide as a pioneer in conducting cutting-edge research.
Holly Brown-Ayers | EurekAlert!
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences