Longevity gene may lead to 'molecular fountain of youth'

Washington, Feb 1 (ANI): A new study has made a major advance in the understanding of the molecular mechanisms behind aging, providing new hope for the development of targeted treatments for age-related degenerative diseases.

Researchers were able to turn back the molecular clock by infusing the blood stem cells of old mice with a longevity gene and rejuvenating the aged stem cells' regenerative potential.

The biologists found that SIRT3, one among a class of proteins known as sirtuins, plays an important role in helping aged blood stem cells cope with stress. When they infused the blood stem cells of old mice with SIRT3, the treatment boosted the formation of new blood cells, evidence of a reversal in the age-related decline in the old stem cells' function.

"We already know that sirtuins regulate aging, but our study is really the first one demonstrating that sirtuins can reverse aging-associated degeneration, and I think that's very exciting," said study principal investigator Danica Chen, UC Berkeley assistant professor of nutritional science and toxicology.

"This opens the door to potential treatments for age-related degenerative diseases," Chen noted.

Notably, SIRT3 is found in a cell's mitochondria, a cell compartment that helps control growth and death, and previous studies have shown that the SIRT3 gene is activated during calorie restriction, which has been shown to extend lifespan in various species.

To gauge the effects of aging, the researchers studied the function of adult stem cells, which are responsible for maintaining and repairing tissue; it is a function that breaks down with age. They focused on hematopoietic, or blood, stem cells because of their ability to completely reconstitute the blood system, the capability that underlies successful bone marrow transplantation.

The researchers first observed the blood system of mice that had the gene for SIRT3 disabled. Surprisingly, among young mice, the absence of SIRT3 made no difference. It was only when time crept up on the mice that things changed. By the ripe old age of two, the SIRT3-deficient mice had significantly fewer blood stem cells and decreased ability to regenerate new blood cells compared with regular mice of the same age.

What is behind the age gap? It appears that in young cells, the blood stem cells are functioning well and have relatively low levels of oxidative stress, which is the burden on the body that results from the harmful byproducts of metabolism. At this youthful stage, the body's normal antioxidant defenses can easily deal with the low stress levels, so differences in SIRT3 are less important.

"When we get older, our system doesn't work as well, and we either generate more oxidative stress or we can't remove it as well, so levels build up. Under this condition, our normal antioxidative system can't take care of us, so that's when we need SIRT3 to kick in to boost the antioxidant system. However, SIRT3 levels also drop with age, so over time, the system is overwhelmed," said Chen.

To see if boosting SIRT3 levels could make a difference, the researchers increased the levels of SIRT3 in the blood stem cells of aged mice. That experiment rejuvenated the aged blood stem cells, leading to improved production of blood cells.

It remains to be seen whether over-expression of SIRT3 can actually prolong life, but Chen pointed out that extending lifespan is not the only goal for this area of research.

"A major goal of the aging field is to utilize knowledge of genetic regulation to treat age-related diseases," she said.

The findings will be published online in the journal Cell Reports. (ANI)

Matches

MORE TOP STORIES TODAY

Pietersen may play against Hyderabad

Pietersen may play against Hyderabad

As much as Pietersen's availability is a boost, the loss of a potent death bowler might sting Delhi badly. More »

Struggling Mumbai need batting fuel

Struggling Mumbai need batting fuel

Mumbai have explosive hitters down the order in the form of Corey Anderson and Kieron Pollard, but the lack of contributions from them has compounded their… More »

Boycotting IPL will not save cricket

Boycotting IPL will not save cricket

Boycotting the IPL as a means of protest against the grime in the game may not yield the desired results. More »

Srinivasan's ICC presence to be challenged

Srinivasan's ICC presence to be challenged

Srinivasan, who has been replaced by the court as board president, was named the BCCI's representative to the ICC last September. However, that position… More »

Brilliant Maxwell powers Punjab’s renaissance

Brilliant Maxwell powers Punjab’s renaissance

Maxwell has easily been the best player on display in the first nine days, with scores of 95, 89 and 95 helping Punjab shed their image of also-rans and… More »

Indian cricket is now dope-free

Indian cricket is now dope-free

The BCCI conducted over 200 dope tests during senior domestic tournaments in the just-ended 2013-14 season – the largest number of tests done by an ICC… More »

Bangalore lose nerve, lose game

Bangalore lose nerve, lose game

IPL 7, GAME 11—Vinay's over, Lynn's catch turns last-over finish in KKR's favour. More »

Couldn't turn down ECB offer: Farbrace

Couldn't turn down ECB offer: Farbrace

England's new assistant coach Paul Farbrace admitted that it was impossible turn down the job even though he will have mixed feelings when he faces… More »

Atapattu likely to be SL interim coach

Atapattu likely to be SL interim coach

Sri Lanka's chief selector Sanath Jayasuriya issued the strongest indication yet that Marvan Atapattu would be appointed coach for the tour of Ireland… More »

T20 is all about the little things: Balaji

T20 is all about the little things: Balaji

Balaji acknowledged Maxwell’s role in Punjab’s great start to season seven, but he insists that the efforts of other players like Virender Sehwag, among… More »

Cleaning up the game starts with fans

Cleaning up the game starts with fans

... because, as recent events reveal, the BCCI has little intention of doing it. More »

Jadeja spins out Rajasthan in close chase

Jadeja spins out Rajasthan in close chase

IPL 7, GAME 10—Chennai beat Rajasthan by 7 runs after last-over scare. More »

Is Srini group delaying BCCI meeting?

Is Srini group delaying BCCI meeting?

The group opposed to Srinivasan alleged that since BCCI secretary Sanjay Patel belongs to the president’s group, he was intentionally delaying the SGM… More »

'BCCI should have picked panel with care'

'BCCI should have picked panel with care'

Dalmiya said that it was the first time that the BCCI had been faced with a situation where the apex court had hauled up the Board and it should have acted… More »

Vithanage, Priyanjan get T20 call-ups

Vithanage, Priyanjan get T20 call-ups

Herath has been rested, while the team will be without the veteran pair of Mahela Jayawardene and Kumar Sangakkara, who retired from T20 internationals… More »

'Gambhir will strike form soon'

'Gambhir will strike form soon'

Gautam made an eight-ball duck in the opening game against Mumbai and in the second game against Delhi, he lasted only half those balls. More »

SL in 'difficult place' after Farbrace exit

SL in 'difficult place' after Farbrace exit

Sri Lanka depart for assignments in Ireland and England in two weeks, and Sanath Jayasuriya suggested Marvan Atapattu would be interim head coach for those… More »

Chandimal axed as T20 captain

Chandimal axed as T20 captain

Sri Lanka's cricket selectors on Wednesday sacked Dinesh Chandimal as Twenty20 captain and replaced him with Lasith Malinga, while Angelo Mathews was… More »

Farbrace is England's assistant coach

Farbrace is England's assistant coach

The ECB continued the restructuring of the England coaching set-up on Wednesday by announcing the appointment of Paul Farbrace as assistant coach. More »

SC asks Mudgal committee to continue

SC asks Mudgal committee to continue

Mukul Mudgal has communicated to the court his willingness to take up the investigation and has been asked to specify the terms and modalities on April… More »

Sri Lanka players resolve pay dispute

Sri Lanka players resolve pay dispute

The pay dispute between Sri Lanka Cricket and its 13 contracted players ended on Wednesday when the latter agreed to accept 10 percent of the participation… More »

Hope to be fit for next game - Pietersen

Hope to be fit for next game - Pietersen

With two heavy defeats at the hands of Bangalore and Chennai, Daredevils currently languish near the bottom of the table. More »

'SC decision could hurt BCCI's status'

'SC decision could hurt BCCI's status'

The Supreme Court prefers that the Justice Mudgal panel further investigate the IPL corruption scandal. More »

Mudgal panel drops bombshell in court

Mudgal panel drops bombshell in court

The Mukul Mudgal probe committee dropped a bombshell in the Supreme Court on Tuesday by making a sensational claim that it was forced to stop audio recording… More »