Mechanism of Aging, Death Unveiled

South Koreans scientists reported a breakthrough in studies on the genetic secrets behind death, shedding light on the regulatory mechanism of how aging induces massive cell death in living organisms.

In a study published by peer-review journal, Science, a team of researchers led by Pohang University of Science and Technology's (POSTECH) Nam Hong-gil suggested death was a result ensured by genetic programming.

Nam's team demonstrated that a gene, named ORE1 (``oresara1'') regulates aging-induced cell death in arabidopsis leaves by interacting with other genes such as EIN2 and miR164.

Although aging gradually induces massive cell death in higher organisms, such as plants, there has been limited knowledge about the underlying mechanism of the process.

``We provided the scientific evidence to show that aging and death in plants were an inevitable, pre-determined process that is regulated by a system of genetic programming,'' Nam told The Korea Times.

``The discovery could also provide new insight in studies on the genetic mechanism of aging and death in other life forms, including animals and humans,'' he said.

According to the study by Nam's team, the expression of EIN2 increases with leaf aging, which also induces an up-regulation in ORE1 mutant transcript. The elimination of ORE1 in the leaves delayed the aging process by about 20 percent, Nam said.

In younger leaves, the expression of ORE1 was found to be significantly lower, as the gene was negatively regulated by miR164. However, the expression of ORE1 increased with the advancement in age, with the expression of miR164 suppressed by EIN2. The scientist also found that EIN2 still contributes to aging-induced cell death in the absence of ORE1.


Courtesy : http://www.globalaging.org/health/world/2009/aging.htm