Navigation Links
Study identifies key player in the body's immune response to chronic stress
Date:9/3/2007

HOUSTON (Sept. 3, 2007) Osteopontin (OPN), a protein molecule involved in many different cellular processes, plays a significant role in immune deficiency and organ atrophy following chronic physiological stress, resulting in increased susceptibility to illness. These findings appear in the September 4th issue of the Proceedings of the National Academy of Sciences.

The study is supported by the National Space Biomedical Research Institute (NSBRI), the Busch Biomedical Research Grant, National Multiple Sclerosis Society, and Rutgers Technology Commercialization Fund. Authors on the paper include Dr. Yufang Shi, investigator on NSBRIs Radiation Effects Team and professor of molecular genetics, microbiology and immunology at the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Dr. David T. Denhardt, one of the discoverers of OPN, professor of cell biology and neuroscience at Rutgers, the State University of New Jersey, and Kathryn X. Wang, graduate student in the Rutgers Graduate Program in Cell and Developmental Biology.

Following periods of prolonged physical stress such as when astronauts live in microgravity, white blood cells that fight disease, called lymphocytes, die at an increased rate and immune system organs like the thymus and spleen lose mass and begin to atrophy, said Dr. Shi.

Immune system organs include the thymus, spleen, lymph nodes and bone marrow.

By determining the role of lymphocyte death in a stressed immune system, we may be able to develop therapies to maintain a healthy immune system, which can help in space and in clinical settings to prevent and treat malignancy and infections, Shi said.

It is known that spaceflight and long periods of physiological stress cause changes in the immune system. Until now, the role of OPN in the stress response of immune organs has never been examined, Shi said.

Evidence suggests that astronauts may suffer increased rates of infection after flight. Through an animal study, Shi and colleagues simulated spaceflight conditions to investigate its effects on the immune system. They found that infection-fighting white blood cells inappropriately die off in large numbers, leading to immune-organ atrophy and the decreased ability of the immune system to protect the body from illness.

The team studied two types of mice, one group with the normal OPN gene and another group lacking this gene. The mice experienced three days of hindlimb unloading, a widely used technique to simulate the physiologic changes that astronauts experience during spaceflight. With this technique, body fluids shift similarly to how they do in microgravity (toward the head instead of toward the extremities) and immune system changes occur.

Mice of both types made up the control groups, which did not undergo unloading.

After three days, the researchers compared the mice with normal OPN and the OPN-lacking mice. The normal OPN mice experienced weight loss, spleen and thymus atrophy, and a reduced number of white blood cells. In addition, increased levels of corticosterone, a steroid that contributes to the death of white blood cells, were found only in the normal OPN mice studied.

By contrast, the mice lacking the OPN gene showed statistically insignificant changes in weight and the levels of corticosterone, and were more similar to the control group.

White blood cell death in the spleen and thymus was evident only in the mice with normal OPN, Shi said. Since white blood cells were dying rather than increasing, that indicates partly why immune system organs atrophy during prolonged physical stress.

The team concluded that under chronic physical stress, OPN must be present for the increase in corticosterone, which leads to atrophy and white blood cell death.

Shi hopes that this finding will lead to preventative treatments in the future.

Already were researching an antibody that can remove OPN from blood serum. Perhaps one day, we can turn this research into a therapy to counteract white blood cell death in immune system organs and keep humans healthier during times of prolonged physical stress, Shi said.

Shi and colleagues want to better understand the mechanisms through which stress affects the immune system, so they can prevent illness in space and help those who suffer from illness following physiological stress here on Earth.


'/>"/>
Contact: Lauren Hammit
lhammit@bcm.edu
713-798-7595
National Space Biomedical Research Institute
Source:Eurekalert

Related medicine news :

1. Gene study links endometriosis, infertility
2. Study reveals how stress can make you sick
3. Study points out that HIV vaccine may not be accepted easily
4. A new study surpasses Gene Therapy Hurdle
5. Tomato Sauce reduces Cancer Risk- Study
6. A question on study of Adult Stem Cell
7. Study on obesity and heart failure
8. National Lung Study in the process
9. Marijuana gateway theory strengthened by study of twins
10. Old theory of adaptation confirmed by new study
11. Study casts doubt on keyboard ills
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/9/2016)... ... February 09, 2016 , ... METTLER TOLEDO has ... personnel have a basic understanding of the techniques they use so they can ... help them reduce waste and rework to create a leaner overall lab experience. ...
(Date:2/9/2016)... ... 09, 2016 , ... United Methodist Communications collaborated with Chocolate ... animated video designed to prevent the next widespread Ebola outbreak from ... being distributed throughout Togo, Liberia, Sierra Leone, Nigeria, Côte d’Ivoire and other African ...
(Date:2/9/2016)... ... 09, 2016 , ... Shark Finds and Kevin Harrington, and the Product Managers of ... GRIP-DRY is a newly patented product that has solved some of the basic problems golfers ... early morning dew or right after a rain shower, might understand the struggle of placing ...
(Date:2/8/2016)... ... February 08, 2016 , ... The Federal ... federallabs.org . The site houses a wealth of federal resources that businesses ... the process called technology transfer (T2). As a network of over 300 federal ...
(Date:2/8/2016)... ... February 08, 2016 , ... ... Houma, LA, celebrates the beginning of a new charity campaign. As part of ... Appointed Special Advocates (CASA). In the belief that children deserve a voice, and ...
Breaking Medicine News(10 mins):
(Date:2/9/2016)... GLENWOOD, Ill., Feb. 9, 2016  Landauer, Inc. (NYSE: ... environmental radiation measurement and monitoring, outsourced medical physics services ... results for its fiscal 2016 first quarter ended December ... --> Fiscal 2016 First Quarter Highlights , ... the first quarter of 2015 , Domestic Radiation Measurement ...
(Date:2/9/2016)...  Jazz Pharmaceuticals plc (Nasdaq: JAZZ ) today ... and full year financial results on Tuesday, February 23, ... management will host a live audio webcast immediately following ... discuss fourth quarter and full year 2015 financial results ... for 2016 financial results. www.jazzpharmaceuticals.com .  Please ...
(Date:2/9/2016)... Amarantus BioScience Holdings, Inc. ... for Regenerative Medicine, Neurology and Orphan Diseases, today announced ... Source Capital Group,s 2016 Disruptive Growth & Healthcare Conference ... New York City . The Company,s presentation ... 12:30 pm by Gerald E. Commissiong , President ...
Breaking Medicine Technology: