Navigation Links
UF scientists reveal how dietary restriction cleans cells
Date:8/23/2007

GAINESVILLE, Fla. Reduce, recycle and rebuild is as important to the most basic component of the human body, the cell, as it is to the environment.

And a University of Florida study shows just how much the body benefits when it goes green, at least if youre a rat: Cutting calories helps rodents live longer by boosting cells ability to recycle damaged parts so they can maintain efficient energy production.

Caloric restriction is a way to extend life in animals. If you give them less food, the stress of this healthy habit actually makes them live longer, said Christiaan Leeuwenburgh, Ph.D., chief of the division of biology of aging in UFs Institute on Aging.

Understanding how the process works at the cellular level in rodents could help scientists develop drugs that mimic the process in humans, Leeuwenburgh added.

How does it work? During the aging process, free radicals highly reactive byproducts of our cells respiration wreak havoc on our cellular machinery. Mitochondria, the tiny power plants that keep a cell functioning, are especially vulnerable to this type of damage.

The effects can be disastrous if malfunctioning mitochondria arent removed, they begin to spew out suicidal proteins that prompt the entire cell to die. Cell death, on a whole-body scale, is what aging is all about.

Fortunately, younger cells are adept at reducing, recycling and rebuilding.

In this process, damaged mitochondria are quickly swallowed up and degraded. The broken down pieces are then recycled and used to build new mitochondria. However, older cells are less adept at this process, so damaged mitochondria tend to accumulate and contribute to aging.

Cell survival is dependent upon the ability of the cell to reduce and recycle by a mechanism called autophagy, said William Dunn Jr., Ph.D., a professor of anatomy and cell biology in UFs College of Medicine and senior author of the study, which was published online this month in the journal Rejuvenation Research. When a cell is under stress, autophagy is turned on to clean up the cell by removing damaged cellular components, while recycling building blocks necessary to rebuild the cell. Its there to protect the cell. But in aged cells, theyre basically not able to adjust to stress as well.

UF scientists studied 22 young and old rats, comparing those allowed to eat freely with those fed a low-calorie, nutritious diet.

The stress of a low-calorie diet was enough to boost cellular cleaning in the hearts of older rats by 120 percent over levels seen in rats that were allowed to eat what they wanted. The diet had little or no effect on younger rats.

Autophagy is a housekeeping mechanism that keeps cells free of damaged and thereby detrimental mitochondria and other toxic materials while recycling their building blocks nutrients needed by the cell, said Stephanie Wohlgemuth, Ph.D., a lecturer in UFs department of aging and geriatrics and the studys lead author. So if that process is maintained with age or even increased that can only be beneficial.

To determine how dietary restriction boosted cells ability to reduce the toxic trash, the scientists studied how the amount of certain proteins changed with the rats age and diet. They found that some proteins responsible for degrading the damaged parts of the cell by autophagy were more abundant in older, calorie-restricted mice.

Boosting autophagy is especially important in the heart, a vital organ packed with mitochondria, Wohlgemuth said. Swift disposal of damaged cellular components is essential to maintaining an abundance of healthy heart cells as we age.

Cardiac cells have lost the capability to divide readily to replace dying cells. So the maintenance of the cells survival mechanisms is crucial for the heart, said Wohlgemuth.

Now that some of these proteins have been identified, UF researchers say the next step is to figure out how the proteins can be activated without inflicting dietary stress.

What if we bypass the caloric restriction and find a way of increasing autophagy" asked Dunn. That is, instead of starving yourself you can find another way of enhancing autophagy that will allow the enhanced removal of various damaged organelles that accumulate in aged cells.

Ulf Brunk, M.D., Ph.D., a professor emeritus of experimental pathology at Linkping University in Sweden, said the study builds on past research showing that removal of toxic mitochondria may extend life in a variety of mammals.

The paper is a further step in the direction of showing that the stimulation of autophagy may be beneficial, Brunk said.


'/>"/>
Contact: Ann Griswold
anngriswold@gmail.com
352-273-5819
University of Florida
Source:Eurekalert

Related biology news :

1. Wisconsin scientists grow critical nerve cells
2. Scientists ID molecular switch in liver that triggers harmful effects of saturated and trans fats
3. UCSB scientists probe sea floor venting to gain understanding of early life on Earth
4. UAB scientists discover the origin of a mysterious physical force
5. Fox Chase Cancer Center scientists identify immune-system mutation
6. Scientists Replicate Hepatitis C Virus in Laboratory
7. Scientists detect probable genetic cause of some Parkinsons disease cases
8. Scientists find missing enzyme for tuberculosis iron scavenging pathway
9. Scientists seek answers on what activates deadly anthrax spores
10. Yale Scientists Find MicroRNA Regulates Ras Cancer Gene
11. Scientists collaborate to assess health of global environment
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/5/2017)... April 5, 2017  The Allen Institute for Cell ... Explorer: a one-of-a-kind portal and dynamic digital window into ... data, the first application of deep learning to create ... cell lines and a growing suite of powerful tools. ... these and future publicly available resources created and shared ...
(Date:4/4/2017)... YORK , April 4, 2017   EyeLock ... today announced that the United States Patent and Trademark ... patent broadly covers the linking of an iris image ... same transaction) and represents the company,s 45 th ... latest patent is very timely given the multi-modal biometric ...
(Date:3/30/2017)... The research team of The Hong Kong Polytechnic University (PolyU) ... ground breaking 3D fingerprint minutiae recovery and matching technology, pushing contactless ... use in identification, crime investigation, immigration control, security of access and ... ... A research team led by Dr Ajay Kumar ...
Breaking Biology News(10 mins):
(Date:4/20/2017)... /PRNewswire/ - Prometic Life Sciences Inc. (TSX: PLI) (OTCQX: PFSCF) ("Prometic" ... Liver Congress ("ILC") 2017 of the European Association for the ... on the positive effects of PBI-4050 on reduction of ... metabolic syndrome. ... Dr. Lyne Gagnon, Vice-President of R&D Pre-clinical of Prometic "This ...
(Date:4/20/2017)... ... April 20, 2017 , ... Open Therapeutics and the ... sharing and commercialization model. , The Center for Advancing Innovation helps institutions maximize ... effort is bringing the IP to the attention of the entrepreneurial community and ...
(Date:4/20/2017)... April 20, 2017 For today, Stock-Callers.com ... novel drug development and clinical research aimed at treating diseases ... (NASDAQ: BSTG), Keryx Biopharmaceuticals Inc. (NASDAQ: KERX), Kite Pharma Inc. ... ). You can access our complimentary research reports on these ... ...
(Date:4/19/2017)... ... April 18, 2017 , ... Alisa Wright, founder and CEO ... from the Purdue College of Pharmacy in Lafayette, Indiana. , The Distinguished Alumni ... achievements in their careers and other scientific endeavors. , Wright began her career ...
Breaking Biology Technology: