Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rapamycin makes mice live longer, but hardly slows down the aging process

26.07.2013
The drug rapamycin is known to increase lifespan in mice. Whether rapamycin slows down aging, however, remains unclear.

A team of researchers from the German Center for Neurodegenerative Diseases (DZNE) and the Helmholtz Zentrum München has now found that rapamycin extends lifespan - but its impact on aging itself is limited.

The life-extending effect seems to be related to rapamycin’s suppression of tumors, which represent the main causes of death in these mouse strains. The findings are reported in the current issue of the “Journal of Clinical Investigation” (published online on July 25, 2013).

The body’s repair mechanisms begin to fail with increasing age. As a result, signs of wear and tear appear and the risk for many diseases, including Alzheimer’s disease, diabetes, cardiovascular disorders and cancer, increases. “Current efforts to develop therapies against age-related diseases target these disorders one by one,” says Dr. Dan Ehninger, research group leader at the DZNE site in Bonn. “Influencing the aging process itself may be an alternative approach with the potential to yield broadly effective therapeutics against age-related diseases.”

In this context, the substance rapamycin is noteworthy. Rapamycin is used in recipients of organ transplants, as it keeps the immune system in check and can consequently prevent rejection of the foreign tissue. In 2009, US scientists discovered another effect: Mice treated with rapamycin lived longer than their untreated counterparts. “Rapamycin was the first drug shown to extend maximal lifespan in a mammalian species. This study has created quite a stir,” says Ehninger.

For Ehninger and his team, this finding motivated further studies: “We wanted to address if rapamycin slows down aging in mice or, alternatively, if it has an isolated effect on lifespan - without broadly modulating aging.”

Not a youth elixir

Together with scientists from the Helmholtz Zentrum München and other colleagues, Ehninger’s group investigated if rapamycin influences aging in mice. The results are sobering: “Our results indicate that rapamycin extends lifespan, but it has only limited effects on the aging process itself,” is Ehninger’s summary of the findings. “Most aging traits were not affected by rapamycin treatment. Although we did observe positive effects on some aging traits, such as memory impairments and reduced red blood cell counts, our studies showed that similar drug effects are also seen in young mice, indicating that rapamycin did not influence these measures by slowing aging, but rather via other, aging-independent, mechanisms.”

The researchers believe that such aging-independent drug effects also underlie rapamycin’s effect on lifespan. “We assume that the lifespan of mice is extended because rapamycin inhibits tumor formation. This is a well-known rapamycin effect, which we were able to confirm. Cancer is the leading cause of death in the relevant mouse strains” says the specialist in molecular medicine. “Rapamycin, therefore, seems to have isolated effects on specific life-limiting pathology, but lacks broad effects on aging in mice.”

A comprehensive assessment of aging

The research team assessed more than 150 traits, which typically change during the course of aging. These analyses included an assessment of vision, reflexes, cardiovascular function, learning and behavior, immune functions and the integrity of the arterial wall, to just name a few. “Aging is a complex process, which cannot be captured by assessing a single parameter. This is why we analysed a large number of structural and functional signs of aging,” explains Ehninger. “The present study is one of the most comprehensive assessments of a putative anti-aging intervention.”

The analysis comprised three different age cohorts, in which rapamycin treatment was either initiated in young adulthood, in midlife or late in life. “At the time, the US study showed that rapamycin extends lifespan irrespective of whether the treatment is given to young or aged animals,” says the Bonn-based researcher. “We, therefore, chose a study design, in the context of which we also investigated rapamycin’s effects on different age groups. This enabled us to examine whether the possible effects of rapamycin depend on the age at which treatment started.”

The animals were genetically identical twin mice. All of the animals received rapamycin regularly over a period of approximately one year. For each age cohort there was also a control group, which did not take the substance.

Need for comprehensive analyses

“Generally speaking, our studies show that a number of different parameters have to be considered when assessing the efficacy of possible anti-aging interventions. The interpretation of the data depends heavily on the overall picture of findings. Lifespan measures alone are not a reliable indicator of anti-aging effects,” emphasises Ehninger. “This makes the search for anti-aging medicines tedious, but it is also very promising, because such substances could open up new possibilities for medicine. However, this is still some way off.”

Original publication
”Rapamycin extends murine lifespan but has limited effects on aging “, Frauke Neff, Diana Flores-Dominguez etc., Journal of Clinical Investigation (published online on July 25, 2013), http://dx.doi.org/10.1172/JCI67674

The German Center for Neurodegenerative Diseases (DZNE) investigates the causes of diseases of the nervous system and develops strategies for prevention, treatment and care. It is an institution of the Helmholtz Association of German Research Centres with sites in Berlin, Bonn, Dresden, Göttingen, Magdeburg, Munich, Rostock/Greifswald, Tübingen and Witten. The DZNE cooperates closely with universities, their clinics and other research facilities. Website: http://www.dzne.de/en / Twitter: http://twitter.com/DZNE_en

Dr. Marcus Neitzert | idw
Further information:
http://www.dzne.de/en

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>