Hormone curbs depressive-like symptoms in stressed mice

Finding could open up new area of drug discovery for depression

2012-07-10

(Press-News.org) SAN ANTONIO, Texas, U.S.A. (July 9, 2012) — A hormone with anti-diabetic properties also reduces depression-like symptoms in mice, researchers from the School of Medicine at the UT Health Science Center San Antonio reported today.

All types of current antidepressants, including tricyclics and selective serotonin reuptake inhibitors, increase the risk for type 2 diabetes. "The finding offers a novel target for treating depression, and would be especially beneficial for those depressed individuals who have type 2 diabetes or who are at high risk for developing it," said the study's senior author, Xin-Yun Lu, Ph.D., associate professor of pharmacology and psychiatry and member of the Barshop Institute for Longevity and Aging Studies at the UT Health Science Center.

The hormone, called adiponectin, is secreted by adipose tissue and sensitizes the body to the action of insulin, a hormone that lowers blood sugar. "We showed that adiponectin levels in plasma are reduced in a chronic social defeat stress model of depression, which correlates with the degree of social aversion," Dr. Lu said.

Facing Goliath over and over

In the study mice were exposed to 14 days of repeated social defeat stress. Each male mouse was introduced to the home cage of an unfamiliar, aggressive resident mouse for 10 minutes and physically defeated. After the defeat, the resident mouse and the intruder mouse each were housed in half of the cage separated by a perforated plastic divider to allow visual, olfactory and auditory contact for the remainder of the 24-hour period. Mice were exposed to a new resident mouse cage and subjected to social defeat each day. Plasma adiponectin concentrations were determined after the last social defeat session. Defeated mice displayed lower plasma adiponectin levels.

Withdrawal, lost pleasure and helplessness

When adiponectin concentrations were reduced by deleting one allele of the adiponectin gene or by a neutralizing antibody, mice were more susceptible to stress-induced social withdrawal, anhedonia (lost capacity to experience pleasure) and learned helplessness.

Mice that were fed a high-fat diet (60 percent calories from fat) for 16 weeks developed obesity and type 2 diabetes. Administration of adiponectin to these mice and mice of normal weight produced antidepressant-like effects.

Possible innovative approach for depression

"These findings suggest a critical role of adiponectin in the development of depressive-like behaviors and may lead to an innovative therapeutic approach to fight depression," Dr. Lu said.

A novel approach would benefit thousands. "So far, only about half of the patients suffering from major depressive disorders are treated to the point of remission with antidepressant drugs," Dr. Lu said. "The prevalence of depression in the diabetic population is two to three times higher than in the non-diabetic population. Unfortunately, the use of current antidepressants can worsen the control of diabetic patients. Adiponectin, with its anti-diabetic activity, would serve as an innovative therapeutic target for depression treatments, especially for those individuals with diabetes or prediabetes and perhaps those who fail to respond to currently available antidepressants."

###The study is in this week's Proceedings of the National Academy of Sciences.

Funding from the National Alliance for Research on Schizophrenia and Depression (NARSAD) and the National Institutes of Health made this research possible.

On the Web and Twitter

For current news from the UT Health Science Center San Antonio, please visit our news release website or follow us on Twitter @uthscsa.

About the UT Health Science Center San Antonio

The University of Texas Health Science Center at San Antonio, one of the country's leading health sciences universities, ranks in the top 3 percent of all institutions worldwide receiving federal funding. Research and other sponsored program activity totaled $231 million in fiscal year 2011. The university's schools of medicine, nursing, dentistry, health professions and graduate biomedical sciences have produced approximately 28,000 graduates. The $736 million operating budget supports eight campuses in San Antonio, Laredo, Harlingen and Edinburg. For more information on the many ways "We make lives better®," visit www.uthscsa.edu.

ELSE PRESS RELEASES FROM THIS DATE:

Researchers offer new approach to track former prisoners' access to community HIV care

2012-07-10

PROVIDENCE, R.I. – A new monitoring approach developed by researchers from The Miriam Hospital could close a major gap by providing the ability to track whether HIV-positive prisoners are getting the community-based HIV care they need once they are released. Reporting in the journal Virulence, researchers say this new tool could play a major role in preventing the spread of the disease and could guide future strategies to improve the quality of care for prisoners, a population disproportionately affected by HIV. "Jails and prisons are an opportunity to diagnose and ...

Regulation by proteins outside cancer cells points to potential new drug target

2012-07-10

SAN ANTONIO (July 9, 2012) – Protein interactions outside breast cancer cells can send signals to the cancer cells to permanently stop proliferating, a new study showed in the School of Medicine at The University of Texas Health Science Center San Antonio. "Because this protein cascade is outside the cells, it is likely amenable to therapeutic manipulation," said lead author Yuzuru Shiio, M.D., Ph.D., assistant professor of biochemistry at the university's Greehey Children's Cancer Research Institute. "I hope our study will ultimately lead to a therapeutic strategy to ...

Iron supplements can reduce fatigue in nonanemic women

2012-07-10

Iron supplementation reduced fatigue by almost 50% in women who are low in iron but not anemic, according to the results of a clinical trial published July 9 in CMAJ (Canadian Medical Association Journal). "We found that iron supplementation for 12 weeks decreased fatigue by almost 50% from baseline, a significant difference of 19% compared with placebo, in menstruating iron-deficient nonanemic women with unexplained fatigue and ferritin levels below 50 μg/L," writes Dr. Bernard Favrat, Department of Ambulatory Care and Community Medicine, University of Lausanne, ...

Tiny bubbles snap carbon nanotubes like twigs

2012-07-10

HOUSTON – (July 9, 2012) -- What's 100 times stronger than steel, weighs one-sixth as much and can be snapped like a twig by a tiny air bubble? The answer is a carbon nanotube -- and a new study by Rice University scientists details exactly how the much-studied nanomaterials snap when subjected to ultrasonic vibrations in a liquid. "We find that the old saying 'I will break but not bend' does not hold at the micro- and nanoscale," said Rice engineering researcher Matteo Pasquali, the lead scientist on the study, which appears this month in the Proceedings of the National ...

University of Miami-led study finds winds played important role in keeping oil away from S. Fla.

2012-07-10

MIAMI – July 9, 21012 -- The Deepwater Horizon oil spill in spring 2010 is the largest oil spill in the history of the United States, with more than 200 million gallons of crude oil released at about 1,500 m. depth off the Mississippi Delta in the Gulf of Mexico. At the time of the accident, the proximity of the intense Loop Current, flowing from the Yucatan Channel to the Florida Straits, raised major concerns that the oil at the surface of the ocean would be headed toward the South Florida and East Atlantic coastal areas. However, the dominant transport of oil and oil ...

Lax gun ownership laws could impact ability of high-risk individuals to purchase firearms

2012-07-10

Sixty percent of persons incarcerated for gun crimes in the thirteen U.S. states with the most lax standards for legal firearm ownership were not legally prohibited from possessing firearms when they committed the crime that led to their incarceration. According to the study by researchers at the Johns Hopkins Bloomberg School of Public Health, 31 percent of these gun offenders were old enough to possess a firearm and had no prior disqualifying record. But 29 percent had criminal records or would have been too young to legally possess a firearm in states with the strictest ...

Turning off key piece of genetic coding eliminates toxic effect of statins, SLU research finds

2012-07-10

ST. LOUIS -- In research funded by the National Institutes of Health and the American Heart Association and published in EMBO Molecular Medicine, Saint Louis University investigator Ángel Baldán, Ph.D., found that the microRNA miR-33 plays a key role in regulating bile metabolism. Further, the research suggests that, in an animal model, the manipulation of this microRNA can improve the liver toxicity that can be caused by statins. "As we learn more about the way cholesterol is moved and metabolized through the body, we have more tools at our disposal to try to limit ...

Technique spots disease using immune cell DNA

2012-07-10

PROVIDENCE, R.I. [Brown University] — When a person is sick, there is a tell-tale sign in their blood: a different mix of the various types of immune cells called leukocytes. A group of scientists at several institutions including Brown University has discovered a way to determine that mix from the DNA in archival or fresh blood samples, potentially providing a practical new technology not only for medical research but also for clinical diagnosis and treatment monitoring of ailments including some cancers. The key to the new technique, described in two recent papers, ...

EARTH: Karakoram glaciers buck global, regional trends

2012-07-10

Alexandria, VA – Resting in the Karakoram Range between northern Pakistan and western China, the Karakoram glaciers are stumping scientists. Unlike most mountain glaciers, the Karakoram glaciers, which account for 3 percent of the total ice-covered area in the world, excluding Greenland and Antarctica, are not shrinking. On the contrary, a team of French glaciologists has recently confirmed that these glaciers on average have remained stable or may have even grown slightly in recent years. Although all glacial regions evolve in unique ways, why are these glaciers bucking ...

Study shows Islamist extremists emphasize self-defense, not world domination

2012-07-10

A common belief in the West is that al Qaeda wishes to impose Islam everywhere. This might be a pipe dream for the group, but a new study of their use of religious texts suggests that Islamists' goals are much more modest. Researchers with Arizona State University's Center for Strategic Communication (CSC) analyzed more than 2,000 items of propaganda from al Qaeda and related Islamist groups from 1998 to 2011. They catalogued more than 1,500 quotes from the Qur'an that extremists used to support their arguments, and identified the chapter (surah) and verse represented ...

Hormone curbs depressive-like symptoms in stressed mice

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: