Featured Research

from universities, journals, and other organizations

Why Starving Cells Prolong Life

Date:
October 14, 2008
Source:
Ruhr-Universitaet-Bochum
Summary:
Cellular damage due to stress is an important factor in aging processes. It is, thus, amazing that starving, which is a stress factor per se, decelerates ageing processes and extends the lifespan of organisms. It has long been known that proteins from the sirtuin family contribute to this mechanism.

Cellular damage due to stress is an important factor in ageing processes. It is, thus, amazing that starving, which is a stress factor per se, decelerates ageing processes and extends the lifespan of organisms. It has long been known that proteins from the sirtuin family contribute to this mechanism. To date, the exact function of the seven members of the sirtuin family in mammals has, however, not yet been clarified.

Results obtained in studies performed by protein research scientists in Bochum and Dortmund under the auspices of Assistant Professor Dr. Clemens Steegborn (Institute for Physiological Chemistry at RUB) have supplied first insights into this phenomenon. The scientists identified initial functions of the two human sirtuins Sirt3 and Sirt5 that reside in mitochondria, the energy supplying “cellular power stations.”

Influence on the cellular self-destruction program

The mitochondria within the cell are responsible for the provision of energy by utilizing food molecules. This fact suggests that sirtuins located at this site should be involved in the life-prolonging effect of nutritional deficiency. The scientists did, however, discover that Sirt5 is not only located within the mitochondria, but also within the so-called intermembrane space between the exterior and interior membrane of the mitochondria. At this site, Sirt5 can modify the protein cytochrome c, which plays a major role in both, energy generation and the cellular self-destruction program, i.e. apoptosis, the reaction to extreme cellular stress. Dr. Steegborn states “that malfunctioning of apoptosis could be an explanation for the presumed role of Sirt 5 in some forms of cancer, but that the precise function of Sirt5 and the modification of cytochrome c have not yet been finally clarified.”

Use of alternative sources of energy

The scientists were, however, able to identify a precisely defined function for Sirt3. They were able to show that two central metabolic enzymes are altered and thereby activated. This activation enables the cells, if subject to a lack of food, to make use of other sources of energy and to use these effectively. More specifically, Sirt3 activates special forms of these enzymes that simultaneously form NADPH, which is required for the regeneration of cellular anti-stress systems. This explains how increased Sirt3 activity during starvation can contribute to a prolonged lifespan.

Long-term target: healthy aging

Diverse research groups have been able to show that increased sirtuin activity can increase the lifespan of model organisms. The situation is, however, more complex in human beings because different sirtuins are located at diverse sites in the cell and all have specific functions. The current research work, performed by the scientists in Bochum and Dortmund, are a first step towards the comprehension of these processes. Exact understanding of the specific functions is however a prerequisite to enable utilization of the correct sirtuin as target molecule for the desired therapeutic effect. Dr. Steegborn assumes that this will probably not lead to a life-prolonging elixir. The scientists do, however, hope to be able to identify agents that enable the treatment of age-related diseases. This in turn would enable “healthy aging.”


Story Source:

The above story is based on materials provided by Ruhr-Universitaet-Bochum. Note: Materials may be edited for content and length.


Journal Reference:

  1. Schlicker et al. Substrates and Regulation Mechanisms for the Human Mitochondrial Sirtuins Sirt3 and Sirt5. Journal of Molecular Biology, 2008; 382 (3): 790 DOI: 10.1016/j.jmb.2008.07.048

Cite This Page:

Ruhr-Universitaet-Bochum. "Why Starving Cells Prolong Life." ScienceDaily. ScienceDaily, 14 October 2008. <www.sciencedaily.com/releases/2008/10/081013111940.htm>.
Ruhr-Universitaet-Bochum. (2008, October 14). Why Starving Cells Prolong Life. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2008/10/081013111940.htm
Ruhr-Universitaet-Bochum. "Why Starving Cells Prolong Life." ScienceDaily. www.sciencedaily.com/releases/2008/10/081013111940.htm (accessed August 22, 2014).

Share This




More Health & Medicine News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Two US Ebola Patients Leave Hospital Free of the Disease

Two US Ebola Patients Leave Hospital Free of the Disease

AFP (Aug. 21, 2014) Two American missionaries who were sickened with Ebola while working in Liberia and were treated with an experimental drug are doing better and have left the hospital, doctors say on August 21, 2014. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
American Ebola Patients Released: What Cured Them?

American Ebola Patients Released: What Cured Them?

Newsy (Aug. 21, 2014) It's unclear whether the American Ebola patients' recoveries can be attributed to an experimental drug or early detection and good medical care. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins