Role of telomeres in vascular senescence.

Telomeres are DNA regions composed of TTAGGG repeats that are located at the ends of chromosomes. Specific proteins associate with the telomeres and form non-nucleosomal DNA-protein complexes that serve as protective caps for the chromosome ends. There is accumulating evidence that progressive telomere shortening is closely related to cardiovascular disease. For example, vascular cell senescence has been reported to occur in human atherosclerotic lesions and this change is associated with telomere shortening. Impairment of telomere integrity causes vascular dysfunction, which is prevented by the activation of telomerase. Mice with short telomeres develop hypertension and exhibit impaired neovascularization. Short telomeres have also been reported in the leukocytes of patients with cardiovascular disease or various cardiovascular risk factors. Although it remains unclear whether short telomeres directly cause cardiovascular disease, manipulation of telomere function is potentially an attractive strategy for the treatment of vascular senescence.