Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Aging Cells, Aging Body: Fresh Evidence for a Connection

03.02.2006


When cells age and stop dividing, how much do they contribute to whole-body aging? Brown University research strengthens the case for a strong connection by providing evidence that non-dividing or “replicatively senescent” cells can be found in large numbers in old animals. The research, led by John Sedivy, is the first to quantify the presence of these cells in any species. Results are published by Science.


Markers for replicative senescence - The presence of biomarkers, or biological “red flags,” for old, non-dividing cells in baboons increases dramatically with age. This finding, from the lab of Brown biologist John Sedivy, bolsters the theory that replicative aging on a cellular level contributes to aging in whole organisms – including humans.



Brown University biologists have uncovered intriguing evidence to support the theory that old cells help make old bodies. In a study of baboons, scientists showed that as these animals age, the number of aging cells in their skin significantly increases.

Over time, cells lose their ability to divide, a state known as replicative senescence. The new research, published in an advanced online edition of Science, is the first to quantify the presence of replicatively senescent cells in any species.


“For 40 years, we’ve known about replicative senescence,” said John Sedivy, a Brown professor of medical science and the senior scientist on the project. “Whether it promotes the aging of our bodies, however, is highly controversial. While it may make intuitive sense, skeptics say ‘Show us the evidence.’ The first solid evidence is in this study. These initial findings won’t settle the debate, but they make a strong case.”

Human cells replicate anywhere from 60 to 90 times before senescence sets in, a phenomenon scientists believe is a safeguard against disease. While senescent cells still function, they don’t behave the way young cells do – and are associated with skin wrinkles, delayed wound healing, weakened immune system response and age-related diseases such as cancer.

“There is good evidence that senescent cells are not benign,” Sedivy said. “But until now, no one has been able to confirm that they exist in appreciable numbers in old animals.”

So the Brown team began to study aging animals – baboons living on a research preserve that ranged in age from 5 to 30. In human years, that age range is roughly 15 to 90.

Veterinarians took small skin samples from the monkeys’ forearms. Scientists in the Sedivy lab tested the connective tissue for the presence of six biomarkers, or biological “red flags,” that signal cellular aging. For replicative senescence, the most important biomarker is telomere dysfunction-induced foci, or TIFs. Presence of these structures signals that the protective chromosome caps called telomeres have dwindled enough to halt cell division.

Scientists painstakingly counted the cells with aging biomarkers. What they found: The number of senescent cells increased exponentially with age. TIF-positive cells made up about 4 percent of the connective tissue cell population in 5-year-olds. In 30-year-olds, that number rose as high as 20 percent.

Director of the Center for Genomics and Proteomics at Brown, Sedivy now plans to track the presence of TIFs in muscle and blood vessels.

“This research confirms that telomeres are important in aging,” he said. “But we’ve only scratched the surface. Now that we’ve come up with the tools and methods for further TIF research, I am eager to see if the same patterns play out in other tissue.”

Brown post-doctoral research fellow Utz Herbig is the lead author of the article. Brown undergraduate Mark Ferreira rounds out the Brown research team. Laura Condel and Dee Carey from the Southwest Foundation for Biomedical Research also contributed.

The National Institute on Aging funded the work.

Wendy Lawton | EurekAlert!
Further information:
http://www.brown.edu

More articles from Life Sciences:

nachricht New way to look at cell membranes could change the way we study disease
19.11.2018 | University of Oxford

nachricht Controlling organ growth with light
19.11.2018 | European Molecular Biology Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

New materials: Growing polymer pelts

19.11.2018 | Materials Sciences

Earthquake researchers finalists for supercomputing prize

19.11.2018 | Information Technology

Controlling organ growth with light

19.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>