Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Why do certain diseases go into remission during pregnancy?

17.06.2010
University of Michigan and NIH scientists find a biological mechanism to explain the phenomenon

During pregnancy, many women experience remission of autoimmune diseases like multiple sclerosis and uveitis. Now, scientists have described a biological mechanism responsible for changes in the immune system that helps to explain the remission.

The expression of an enzyme known as pyruvate kinase is reduced in immune cells in pregnant women compared to non-pregnant women, according to Howard R. Petty, Ph.D., biophysicist at the University of Michigan Kellogg Eye Center and Roberto Romero, M.D., of the National Institutes for Health.

The study, which appears online ahead of print in the August issue of the American Journal of Reproductive Immunology, also reports that expression of the enzyme is lower in pregnant women compared to those with pre-eclampsia, a condition with inflammatory components.

The study is significant because the newly discovered mechanism points to a pathway that could be targeted for treatment. “It may be possible to design drugs that mildly suppress pyruvate kinase activity as a means of replicating the immune status of normal pregnancy,” says Petty.

In addition to pre-eclampsia, he believes that rheumatoid arthritis, type 1 diabetes, and uveitis may eventually yield to similarly designed drugs.

In his search to explain the phenomenon, Petty knew to look for a metabolic pathway or mechanism with two characteristics. It had to “dial down” the intensity of the normal immune response, an action needed so that a pregnant woman does not reject the fetus, which has proteins from the father that are “foreign” to the mother. At the same time, such a mechanism must support cell growth needed by the developing fetus.

The activity of the enzyme pyruvate kinase—and and its product, pyruvate—fills both roles: promoting cell growth while modifying the immune response. Because pyruvate kinase activity is depressed during pregnancy, cell metabolism supports an increased production of lipids, carbohydrates, amino acids, and other substances that support cell growth.

Petty explains that our normal robust immune response depends upon pyruvate to promote calcium signaling, which, in turn, stimulates the production of messenger molecules called cytokines. When pyruvate is decreased during pregnancy, calcium signaling is also reduced, and the immune response is different than that in non-pregnant individuals. Says Petty, “Modification of signaling along this pathway allows the pregnant woman to maintain an immune response, but at a level that will not harm the fetus.”

The study included 21 women in their third trimester of a normal pregnancy, 25 women with pre-eclampsia, and a control group of non-pregnant women. Petty and colleagues used a variety of methods to confirm their findings, including fluorescence microscopy and flow cytometry, which are used to study cell signaling.

The higher levels of the enzyme seen in women with pre-eclampsia bolster the study’s findings, says Petty. “Pre-eclampsia has features of inflammatory disease. If you don’t reduce these pyruvate levels, you heighten inflammatory disease,” he adds. Petty wonders whether one day enzyme levels could be tested early in pregnancy to predict the likelihood of developing pre-eclampsia or other complications.

It is possible, says Petty, that the general mechanisms described in the current study may apply to more than one complication of pregnancy. This possibility—and that of designing drugs to suppress pyruvate kinase activity—is the focus of future research. “I have a long list of things I’d like to see developed for the clinic in the next five years,” adds Petty.

Romero is chief of the Perinatology Research Branch (PRB) of the National Institute of Child Health and Human Development/National Institutes of Health (NICHD/NIH)

Reference: Leukocyte Pyruvate Kinase Expression Is Reduced in Normal Human Pregnancy but Not in Pre-eclampsia. Amer J Reprod Immunol, online 6.15.10 at http://www3.interscience.wiley.com/cgi-bin/fulltext/123525215/HTMLSTART

Research support: Division of Intramural Research of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, DHHS, contract number N01-HD-2-3342 and subcontract WSU04055.

Other U-M authors: Megan Elfline, Aiping Zhu

Additional authors: Roberto Romero (Perinatology Research Branch, National Institute of Child Health and Human Development, National Institutes of Health; Wayne State University); Yi Xu, Sonia Hassan, Pooja Mittal (Wayne State University); Sally A. Madsen-Bouterse (NICHD, NIH)

Betsy Nisbet | EurekAlert!
Further information:
http://www.umich.edu

More articles from Health and Medicine:

nachricht Neutrons produce first direct 3D maps of water during cell membrane fusion
21.09.2018 | DOE/Oak Ridge National Laboratory

nachricht Narcolepsy, scientists unmask the culprit of an enigmatic disease
20.09.2018 | Universitätsspital Bern

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Astrophysicists measure precise rotation pattern of sun-like stars for the first time

21.09.2018 | Physics and Astronomy

Brought to light – chromobodies reveal changes in endogenous protein concentration in living cells

21.09.2018 | Life Sciences

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

VideoLinks
Science & Research
Overview of more VideoLinks >>>