Cookie Settings

We use cookies to optimize our website. These include cookies that are necessary for the operation of the site, as well as those that are only used for anonymous statistic. You can decide for yourself which categories you want to allow. Further information can be found in our data privacy protection .

Essential

These cookies are necessary to run the core functionalities of this website and cannot be disabled.

Name Webedition CMS
Purpose This cookie is required by the CMS (Content Management System) Webedition for the system to function correctly. Typically, this cookie is deleted when the browser is closed.
Name econda
Purpose Session cookie emos_jcsid for the web analysis software econda. This runs in the “anonymized measurement” mode. There is no personal reference. As soon as the user leaves the site, tracking is ended and all data in the browser are automatically deleted.
Statistics

These cookies help us understand how visitors interact with our website by collecting and analyzing information anonymously. Depending on the tool, one or more cookies are set by the provider.

Name econda
Purpose Statistics
External media

Content from external media platforms is blocked by default. If cookies from external media are accepted, access to this content no longer requires manual consent.

Name YouTube
Purpose Show YouTube content
Name Twitter
Purpose activate Twitter Feeds

Biosensor for Measuring Stress in Cells

No. 29 | 16/05/2008 | by (Koh)

Reactive oxygen compounds, including the well-known "free radicals", have an oxidation effect and, thereby, damage cells. However, at low levels, they also regulate key life processes. Scientists at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) have developed a highly sensitive biological measuring system for determining the oxidation state of living cells in real time. It is the first system that enables researchers to directly observe oxidation state variations accompanying biological processes. The biosensor can also be used for studying the oxidation effect of food constituents and pharmaceutical substances. These results have been published in Nature Methods by a group of researchers headed by Dr. Tobias Dick.

Human cancer cells with biosensor show different fluorescence before (left) and after (right) the development of "Oxidative stress"
© dkfz.de

Cancer, nervous system disorders such as Parkinson’s disease, cardiovascular disorders and old age have one thing in common: Both in afflicted tissue and in aging cells, scientists have observed oxidative changes in important biomolecules. These are caused by reactive oxygen molecules, including the notorious "free radicals" that are formed as a by-product of cellular respiration and attack cellular proteins, nucleic and fatty acids.

Today, reactive oxygen molecules are no longer regarded by and large as culprits, since it has turned out that they are also involved in regulating major life processes such as growth and cell death. The right balance between oxidation and the reverse reaction, reduction, makes the difference between health and disease. "Oxidative stress" arises when this balance shifts towards oxidation-promoting processes.

So far, it has hardly been possible for scientists to measure the level of oxidation and, thus, the stress status of living cells. This will now be feasible thanks to a highly sensitive biomarker presented in the journal Nature Methods by Dr. Tobias Dick and co-workers of the German Cancer Research Center, jointly with colleagues from the University of Heidelberg.

The biosensor specifically measures the oxidation state of glutathione. This is an important protection molecule that captures a large portion of reactive oxygen molecules within a cell by oxidation. If much of a cell’s glutathione is present in an oxidized state, this is an important indicator of the cell’s overall oxidation level. The investigators equipped test cells with a fluorescent protein that reacts to changes in oxidation level by releasing light signals. Since the fluorescent protein on its own is not sensitive enough, it was coupled with an enzyme called glutaredoxin. This enzyme "measures" the oxidation state of glutathione and transmits the value to the fluorescent protein.

The stress biosensor developed by Dick and colleagues measures the slightest changes in the oxidation state of glutathione without destroying the cell. Even more relevant, however, is its precise time resolution, as Tobias Dick explains: "In order to measure short-term variations of oxidation state, the systems needs to react instantly and dynamically. This is guaranteed with our biosensor, which works down to the scale of seconds." The measuring system allows researchers to determine those short-term variations that occur when reactive oxygen compounds are released as signaling molecules. However, the biosensor is equally suitable for use in pharmaceutical research, for example, to determine the effect of new substances or plant food constituents on oxidative processes and, thus, on the stress status of cells.

Marcus Gutscher, Anne-Laure Pauleau, Laurent Marty, Thorsten Brach, Guido H. Wabnitz, Yvonne Samstag, Andreas J. Meyer and Tobias P. Dick: Real-time imaging of the intracellular glutathione redox potential. Nature Methods 2008, DOI: 10.1038/nmeth.1212

The German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) with its more than 3,000 employees is the largest biomedical research institution in Germany. More than 1,300 scientists at the DKFZ investigate how cancer develops, identify cancer risk factors and search for new strategies to prevent people from developing cancer. They are developing new methods to diagnose tumors more precisely and treat cancer patients more successfully. The DKFZ's Cancer Information Service (KID) provides patients, interested citizens and experts with individual answers to all questions on cancer.

Jointly with partners from the university hospitals, the DKFZ operates the National Center for Tumor Diseases (NCT) in Heidelberg and Dresden, and the Hopp Children's Cancer Center KiTZ in Heidelberg. In the German Consortium for Translational Cancer Research (DKTK), one of the six German Centers for Health Research, the DKFZ maintains translational centers at seven university partner locations. NCT and DKTK sites combine excellent university medicine with the high-profile research of the DKFZ. They contribute to the endeavor of transferring promising approaches from cancer research to the clinic and thus improving the chances of cancer patients.

The DKFZ is 90 percent financed by the Federal Ministry of Education and Research and 10 percent by the state of Baden-Württemberg. The DKFZ is a member of the Helmholtz Association of German Research Centers.

RSS-Feed

Subscribe to our RSS-Feed.

to top
powered by webEdition CMS