Telomere length in different tissues of elderly patients

Telomeres are supposed to play a role in cellular aging and might contribute to the genetic background of human aging and longevity. During the past few years telomere length has been measured in various human tissues. However, very little is known about the individual telomere loss in different tissues from the same donor. Therefore we have measured telomere restriction fragment (TRF) length in three unrelated tissues (leukocytes, skin and synovial tissue) of nine elderly patients (age range 73–95 years old). Dependent on the tissue specific proliferation rate we have found significantly shorter telomeres (6546 ± 519 bp, mean ± S.D.) in leukocytes compared to skin (7792 ± 596 bp, P < 0.01) and synovial tissue (7910 ± 420 bp, P < 0.001). In general, we have observed an inverse relationship between donor age and TRF length which becomes significant in leukocytes (P = 0.04, R2 = 0.49) and skin specimens (P = 0.006, R2 = 0.81). Interestingly, linear correlations (P values between 0.017 and 0.038, R2 values between 0.54 and 0.79) were also obtained on comparison of telomere length in each pair of two different tissues from the same donor without taking donor age into account. This suggests that genetic determination of the regulation of telomere length is tissue-independent. Furthermore, our results indicate that TRF measurement in easily accessible tissues such as blood could serve as a surrogate parameter for the relative telomere length in other tissues.