Abstract 1380: Beneficial Effects of Long-term Endurance Exercise on Leukocyte Telomere Biology
Background: Epidemiological data show that physical activity is associated with reduced cardiovascular morbidity and mortality. Age is the major cause of cardiovascular disease. Telomeres and telomere-regulating proteins determine the aging process on the cellular level. This study examines telomere biology and senescence-associated factors in endurance athletes and matched controls without physical activity.
Methods: Leukocytes where isolated from the peripheral blood of professional young track & field athletes (n=32, age 20.4 years, running 73±5 km/week), aged athletes performing regular endurance training (n=25, age 51.1 years, running 80±8 km/week, 35 years training history) and two control groups of age-matched, physically inactive healthy volunteers (26 young and 21 aged subjects).
Results: Telomere repeat amplification protocols revealed an activation of leukocyte telomerase in young athletes to 256±19% and in elderly athletes to 182±11% compared to controls. Western blots showed an up-regulation of the telomere-capping protein TRF2 in young (179±1%) as well as in aged athletes (176±10%). FlowFISH assays and real-time PCR measurements of leukocyte telomere length showed no difference between young athletes and young controls. Sedentary elder controls exhibited a significant reduction of leukocyte telomere length (FF: 53±3%; PCR: 70±8%; vs. young controls). Importantly, there was a striking conservation of telomere length in aged athletes (FF: 88±4%; PCR: 84±7%; vs. young controls). Further analysis of telomere-associated proteins and cellular senescence regulators demonstrated an increase of TRF2, Ku70 and Ku80 mRNA and a reduced protein expression of Chk2, p16 and p53 in aged athletes compared to untrained elder controls.
Conclusions: Our data suggest that beneficial effects of exercise on telomere proteins and senescence-associated factors occur in leukocytes of young track & field athletes. In elderly athletes with a history of long-term continuous exercising we found a potent activation of leukocyte telomerase and conservation of telomere length. These findings improve the molecular understanding of beneficial vascular effects of physical activity and implicate an “anti-aging” effect of physical exercise.