TELOMERES

Study of telomeres concerns clinical  and scientist research.

Are Telomere tests ready for Prime Time ? Download pdf.

A telomere is a particular area constituting the end of a chromosome.

With each time a chromosome is duplicated, at  replication's time, telomeres are shortened. Telomeres become too short do not protect any more the cell resulting in its death.

An enzyme, the telomerase, makes it possible the telomere to be reconstituted. This enzyme is the object of many researchs.

Telomeres shorten with age, inflamation and stress. Studies showed that short telomeres are associated with a higher risk of  aging diseases. The shortest telomeres were observed in octogenarians. In some 60 year old  people, the probability of dying of an infectious disease or a heart attack appears to be much more important at those having the shortest telomeres. Studies showed that by stimulating telomerase it is possible to increase  the cells' lifetime in a very important way. 

In 1971, the Russian biologist Alekseï Olovnikov expressed for the first time the hypothesis that the maximum lifetime of  cells in culture (limit of Hayflick) is correlated with the progressive loss of telomeric sequences.The telomeres act like a biological clock governing the cells' lifetime. This theory is known under the name of telomeric theory of aging.

In 1985, identification of telomerase is made by Elizabeth Blackburn and Carol Greide.

In 2009 Elizabeth Blackburn et Carol Greide receive the Nobel Prize of physiology or medicine. 

In 2009 a publication shows the lengthening of lymphocytes' telomeres under the influence of androgens (1) (Download pdf)

Protective action of androgens on white blood cells of HIV positive men (reduction of cellular destruction from 34 to 52%) was already shown in 1997. download pdf.

Bibliography  WEB

1.Sex hormones, acting on the TERT gene, increase telomerase activity in human primary hematopoietic cells. Donwload pdf.

Constantine A. Stratakis and Neal S. Young, Rodrigo T. Calado, William T. Yewdell, Keisha L. Wilkerson, Joshua A. Regal, Sachiko Kajigaya,

From bloodjournal.hematologylibrary.org by guest on October 22, 2012. For personal use only.