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 Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Will Earth still exist 5 billion years from now?

08.12.2016 | Physics and Astronomy

Oxygen can wake up dormant bacteria for antibiotic attacks

08.12.2016 | Health and Medicine

Newly discovered bacteria-binding protein in the intestine

08.12.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>