Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New NIST method evaluates response to oxidation in live cells

13.02.2014
Researchers at the National Institute of Standards and Technology (NIST) have developed a new method for accurately measuring a key process governing a wide variety of cellular functions that may become the basis for a "health checkup" for living cells.

The NIST technique measures changes in a living cell's internal redox (reduction-oxidation) potential, a chemistry concept that expresses the favorability of reactions in which molecules or atoms either gain or lose electrons.


NMR data showing the levels of reduced glutathione (GSH) and oxidized glutathione (GSSG) over time in yeast cells at rest (top) and under oxidative stress (bottom). The cells at rest have almost no GSSG (dark blue shades) but it spikes briefly when they are stressed, while GSH declines. This type of analysis may one day help to measure cell health.

Credit: Reipa/NIST

Redox reactions are important to cell chemistry because they regulate many genes and the proteins they produce. An accurate measure of redox potential can provide insight into how well these genes are working, and in turn, whether or not the activities they control—such as differentiation and growth—are functioning normally.

To assess this, scientists customarily measure the levels of both the reduced (electrons added) and oxidized (electrons lost) forms of glutathione, a peptide the cell uses as an antioxidant. Glutathione in cells is found predominately in the reduced state, known as GSH, but some gets converted to the oxidized form, known as GSSG. A high amount of GSSG indicates a cell has suffered oxidative stress, a process believed to contribute to cell aging, breakdown, malfunction (such as cancer) and eventual death.

Unfortunately, traditional methods of obtaining this data are akin to an autopsy. The only way to measure the relative amounts of GSH and GSSG within a cell has been to rupture its membrane—killing it—and then examine the released contents.

The NIST team developed a way to measure GSH and GSSG levels in living cells in real time using nuclear magnetic resonance (NMR)spectroscopy, a technique that images individual molecules similar to how doctors use magnetic resonance imaging (MRI) to noninvasively view organs. "NMR has been shown in recent years to be a powerful tool for studying metabolites as they operate in living cells, so we felt it could work well as a noninvasive way to do the same for GSH and GSSG," says NIST research chemist Vytas Reipa.

In their proof-of-concept experiment,* the NIST researchers grew a mutant strain of yeast cells that could not manufacture their own glutathione in a medium containing the peptide tagged with a nitrogen isotope. This ensured that the only glutathione available in the cells would be detectable using NMR during its conversion from GSH to GSSG.

GSH and GSSG levels were measured by NMR for both cells at rest and under oxidative stress, and then used to calculate the changing intracellular redox potentials over time. The results showed, for the first time ever, that redox potential can serve as an indicator of how cells perform in response to oxidation in real time.

"We know that when oxidation tips the balance toward too much GSSG, we get a redox potential shifted more to the positive than it should be," Reipa explains. "A healthy cell compensates by reversing the process and when that happens, the redox potential shifts back to its original value. A sick cell, on the other hand, does not compensate and the value stays positive. Therefore, an accurate in-cell measurement of redox potential could one day help us determine how well cells can recover from oxidative stress and, as a result, give us a picture of the cell's overall health."

Currently, the NIST researchers are exploring other NMR-detectable peptides involved in reduction and oxidation processes to conduct studies with mammalian cells.

The NMR spectroscopy in this experiment was conducted at NIST's Gaithersburg, Md., facility in collaboration with NIST scientists at the Hollings Marine Laboratory (HML) in Charleston, S.C., and the Institute for Bioscience and Biotechnology Research (IBBR) in Rockville, Md.

*S.Y. Rhieu, A.A. Urbas, D.W. Bearden, J.P. Marino, K.A. Lippa and V. Reipa. Probing the intracellular glutathione redox potential by in-cell NMR spectroscopy. Angewandte Chemie, 126: 457-460 (2014). DOI: http://dx.doi.org/10.1002/anie.201308004.

Michael E. Newman | EurekAlert!
Further information:
http://www.nist.gov

More articles from Life Sciences:

nachricht Speech dynamics are coded in the left motor cortex
31.03.2015 | Universitätsmedizin Göttingen - Georg-August-Universität

nachricht Discovery of two new species of primitive fishes discovered
31.03.2015 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

Speech dynamics are coded in the left motor cortex

31.03.2015 | Life Sciences

100-million-year-old scale insect practiced brood care

31.03.2015 | Life Sciences

Discovery of two new species of primitive fishes discovered

31.03.2015 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>