Telomere, telomeraza in prezgodnja odpoved jajčnikov
Telomeres, telomerase and premature ovarian failure

slovenski

2011

letnik 80, številka 11

ginekologija   jajčniki   molekulrna genetika   staranje   telomeraza

Slovensko zdravniško društvo
(Obvezni izvod spletne publikacije)

Telomeres are specialized structures at the ends of chromosomes, consisting ofsix repeated nucleotides in TTAGGG sequence. Genome stability is partly maintained by the architecture of telomeres and is gradually lost as telomeresprogressively shorten with each cell replication. Critically shortened telomeres are recognized by DNA repair mechanisms as DNA damage and the cell replication cycle stops. The cell eventually dies or undergoes cell apoptosis. Telomere represents a cellular marker of biological age and are therefore also called cell mitotic clock. The enzyme that counteracts telomereshortening by adding nucleotides to the 3ć end of DNA strand is calledtelomerase. It is composed of the RNA subunit (TR), which is special type of messenger RNA (mRNA), the catalytic protein subunit (TERT), which works as a reverse transcriptase and numerous additional proteins. Telomerase is active in some germline, epithelial and haemopoietic cells, but in most somatic cells the activity is undetectable. In literature, the length of telomeres is closely connected with premature ovarian failure (POF). POF is generally defined as the onset of menopause before the age of 40. The causes of disease are genetical, autoimmune, iatrogenic or if we cannot establish thecause - idiopathic. A lot of studies examined correlation between idiopathic POF, length of telomeres and telomerase activity. The studies mostly show that women with POF have shortened telomeres and decreased activity of telomerase as compared to healthy women.

17.08.2012