Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Whether in mice or men, all cells age the same

21.07.2006
We can dye gray hair, lift sagging skin or boost lost hearing, but no visit to the day spa would be able to hide a newly discovered genetic marker for the toll that time takes on our cells. "We've found something that is at the core of aging," said Stuart Kim, PhD, professor of developmental biology and of genetics at the Stanford University School of Medicine.

In a study to be published in the July 21 issue of Public Library of Science-Genetics, Kim and colleagues report finding a group of genes that are consistently less active in older animals across a variety of species. The activity of these genes proved to be a consistent indicator of how far a cell had progressed toward its eventual demise.

Until now, researchers have studied genes that underlie aging in a single animal, such as flies or mice, or in different human tissues. However, a protein associated with aging in one species may not be relevant to the aging function in a different animal. This limitation had made it difficult to study the universal processes involved in aging.

Kim's work overturns a commonly held view that all animals, including humans, age like an abandoned home. Slowly but surely the windows break, the shingles fall off and floorboards rot, but there's no master plan for the decay.

That theory has left open questions about why tortoises and rockfish are still partying like 20-somethings at an age when humans are considered relics. At the other end of the spectrum, flies die off before young humans can even focus their eyes. Clearly, not all cells fall apart at the same rate.

"Aging isn't like the speed of light; it's not a constant," said Kim. Why animals and even people age at different rates prompted Kim to look deeper into the processes that control aging.

His new study suggests that the cell has a molecular homeowner that keeps up repairs until a predetermined time, when the owner picks up the welcome mat and moves out. Once that process kicks off, the decay happens as a matter of course. The homeowners in tortoise cells stick around for hundreds of years delaying the decay, while those in fly cells move out within weeks.

Although Kim's work doesn't identify what triggers that process, it does provide a way of detecting the point a cell has reached in its life span.

In the study, Kim and his colleagues looked at which genes were actively producing protein and at what level in flies and mice in a range of ages and in tissue taken from the muscle, brain and kidney of 81 people ranging in age from 20 to 80. The group used a microarray, which can detect the activity level of all genes in a cell or tissue. Genes that are more active are thought to be making more proteins.

One group of genes consistently made less protein as cells aged in all of the animals and tissues the group examined. These genes make up the cellular machinery called the electron transport chain, which generates energy in the cell's mitochondria.

Kim said the gene activity is a better indicator of a cell's relative maturity than a person's birthday. One 41-year-old participant had gene activity similar to that of people 10 to 20 years older; muscle tissue from the participant also appeared similar to that of older people. Likewise, the sample from a 64-year-old participant, whose muscles looked like those of a person 30 years younger, also showed gene activity patterns similar to a younger person.

These results confirm Kim's assumption that the rate of aging is at least in part genetically determined. Those study participants whose tissues appeared younger than their true age had something - something dearly sought by aging researchers - that made their cells keep activating genes in a more youthful pattern.

The question is: What causes the electron transport chain genes to slow their protein production and why? And why, if tortoises can live hundreds of years, do flies self-destruct in a matter of weeks?

Kim thinks there must be some reason behind when an animal's cells are programmed to begin falling apart. He points out that most animals begin to grow old at around the age when they would normally meet their demise in the wild. It's no coincidence, Kim noted, that 90 percent of mice get eaten in the first year and that mice start growing old in the lab at around that age.

Kim suggests that aging wouldn't have to happen if cells weren't programmed to fail. With a marker for aging in hand, he thinks future research will reveal what drives the process. "People think of aging and taxes as unavoidable," Kim said, "but in the case of aging, that's not true."

Amy Adams | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Life Sciences:

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht New antbird species discovered in Peru by LSU ornithologists
15.12.2017 | Louisiana State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>