Markers of cellular senescence. Telomere shortening as a marker of cellular senescence

Accelerated Telomere Shortening in Acromegaly; IGF-I Induces Telomere Shortening and Cellular Senescence

OBJECTIVE Patients with acromegaly exhibit reduced life expectancy and increased prevalence of age-related diseases, such as diabetes, hypertension, and cardiovascular disease. However, the underlying mechanism has not been fully elucidated. Telomere shortening is reportedly associated with reduced life expectancy and increased prevalence of these age-related diseases. METHODS We measured tel...

Nuclear accumulation of globular actin as a cellular senescence marker.

We evaluated the nuclear actin accumulation as a new marker of cellular senescence, using human diploid fibroblast (HDF), chondrocyte primary cultures, Mv1Lu epithelial cells, and Huh7 cancer cells. Nuclear accumulation of globular actin (G-actin) and dephosphorylated cofilin was highly significant in the senescent HDF cells, accompanied with inhibition of LIM kinase (LIMK) -1 activity. When nu...

Cellular Senescence and Its Relation with Telomere

Deregulated telomere transcription causes replication-dependent telomere shortening and promotes cellular senescence

Telomeres are transcribed into non-coding TElomeric Repeat containing RNAs (TERRA). We have employed a transcriptionally inducible telomere to investigate how telomere transcription affects telomere function in Saccharomyces cerevisiae. We report that telomere shortening resulting from high levels of telomere transcription stems from a DNA replication-dependent loss of telomere tracts, which ca...

Quantitative theory of telomere length regulation and cellular senescence.

In normal somatic cells, telomere length shortens with each cell replication. This progressive shortening is associated with cellular senescence and apoptosis. Germ cells, stem cells, and the majority of cancer cells express telomerase, an enzyme that extends telomere length and, when expressed at sufficient levels, can immortalize or extend the life span of a cell line. It is believed that tel...