Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study identifies key player in the body’s immune response to chronic stress

05.09.2007
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 NSBRI’s 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 we’re 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.

NSBRI projects address space health concerns such as bone and muscle loss, cardiovascular changes, balance problems, sleep disturbances, radiation exposure, nutrition, physical fitness, rehabilitation, remote-treatment medical technologies, and neurobehavioral and psychosocial factors. Research findings will also impact the understanding and treatment of similar medical conditions experienced on Earth.

NSBRI, funded by NASA, is a consortium of institutions studying the health risks related to long-duration spaceflight. The Institute’s science, technology and education projects take place at more than 70 institutions across the United States.

Lauren Hammit | NSBRI
Further information:
http://www.nsbri.org/NewsPublicOut/Release.epl?r=105

More articles from Studies and Analyses:

nachricht Researchers simplify tiny structures' construction drip by drip
12.11.2018 | Princeton University, Engineering School

nachricht Mandibular movement monitoring may help improve oral sleep apnea devices
06.11.2018 | Elsevier

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Epoxy compound gets a graphene bump

14.11.2018 | Materials Sciences

Microgel powder fights infection and helps wounds heal

14.11.2018 | Health and Medicine

How algae and carbon fibers could sustainably reduce the athmospheric carbon dioxide concentration

14.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>