17 June 2010

How to increase life expectancy by a third?

New protein molecules regulating life expectancy have been found
RIA NewsScientists have identified a new group of protein molecules that affect the lifespan of laboratory worms and are associated with the reproductive functions of the body, which is another evidence of the relationship between life expectancy and reproductive functions, according to an article by researchers published in the journal Nature (Eric L. Greer et al., Members of the H3K4 trimethylation complex regulate lifespan in a germline-dependent manner in C. elegans – VM).

The proteins identified by scientists take part in the so–called epigenetic modifications - changing the functions of individual sections of DNA by attaching to it or removing additional chemical groups, for example methyl – CH3. This modification changes the degree of "twisting" of DNA in the cell, which affects the activity of the genes located at this site.

Such epigenetic interference in DNA in both worms and humans is activated under the influence of external factors and allows you to "adjust" the work of an organism that does not have the ability to directly interfere with the genes inherited from parents.

The Caenorhabditis elegans worms involved in the work are a very convenient model organism for studying various biological processes, including aging, but most scientific groups try to work with sterilized animals for the sake of the purity of the experiment.

The authors of the new study showed that the group of proteins they identified is able to increase the life expectancy of worms by almost 30%, but only if their reproductive system is working properly.

In their work, a group of scientists led by Anne Brunet, a professor at the Stanford University School of Medicine, consistently carried out a methodical blocking of the genes in the DNA of worms that are responsible for the epigenetic status of cells – involved in the process of modifying a hereditary molecule. As a result of this work, scientists have identified a set of genes, the blocking of which allows to increase the lifespan of worms by almost 30%.

The most active gene in this regard, called Ash-2, is responsible for protein synthesis, which is involved in the process of attaching a methyl group to histone proteins responsible for DNA packaging. The addition of a methyl group causes DNA in a certain area to "unfold" and become more accessible to the cellular apparatus, which increases the activity of the genes located here.

Scientists have noticed that the Ash-2 gene is most active in primary or already mature germ cells. In addition, in sterilized worms deprived of these cells, the effect of increasing life expectancy when blocking this gene was not observed. Moreover, the researchers have shown that Ash-2, which affects the work of several other genes specific to primary germ cells, can only be blocked in them to increase life expectancy, whereas the work of this gene in the rest of the adult worm organism can not be blocked.

"We don't know exactly what the mechanism of this prolongation of life in worms is, but we have shown that for its operation it is absolutely necessary to have primary germ cells in the body," said Brunet, quoted by the university press service (Study identifies proteins that extend life span in worms – VM).

"This suggests that the reproductive system in some way has an impact on life expectancy, since it is the only truly "immortal" part of the body. In this sense, the rest of the body is just a mortal wrapper," the scientist summed up.

In the future, the authors intend to investigate more extensively the effect of histone methylation on the lifespan of worms and find out how natural processes affect it.

Portal "Eternal youth" http://vechnayamolodost.ru17.06.2010

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