Relationship between protein and mitochondrial DNA oxidative injury and telomere length and muscle loss in healthy elderly subjects.
A blood sample and muscle biopsies were obtained from 54 elderly subjects. Twenty-seven subjects aged 77+/-3 years, had experienced a change in fat free mass (FFM) of +194+/-282g/year (lean body mass maintainers) and 27 subjects aged 78+/-3 years, had a change in FFM of -487+/-209g/year (lean body mass losers). Muscle biopsies were also obtained from 10 healthy subjects aged 34+/-4 years. In muscle, the ratio of mitochondrial DNA (mtDNA) to nuclear DNA (nDNA) and telomere length were assessed and deposition of 4-hydroxy-2-nonenal adducts (4HNE) was visualized by electron microscopy. In FFM maintainers, losers and young controls, the ratio of mtDNA to nDNA was 2.1 (95% confidence intervals (CI), 0.1-31.7), 1.5 (95% CI, 0.2-15.7) and 18.6 (95% CI, 2.8-46.2), respectively. 4HNE deposition was 5.9 (95% CI, 1.5-28), 4.9 (95% CI, 0.9-13) and 3.4 (95% CI, 1.1-4.6) gold particles/microm(2), respectively. Telomere length, expressed as T/S ratio, was 0.06 (95% CI, 0.01-0.16), 0.06 (95% CI, 0.03-0.27) and 0.34 (95% CI, 0.1-1.34), respectively (p<0.02 or less for all comparisons between elderly and young subjects).
Bunout
Daniel
D
Institute of Nutrition and Food Technology, University of Chile, Macul 5540, Santiago, Chile. dbunout@inta.cl
Backhouse
Claudia
C
Leiva
Laura
L
Barrera
Gladys
G
Sierralta
Walter
W
de la Maza
María Pía
MP
Hirsch
Sandra
S
D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000447:Aldehydes / Q000378:metabolism; D001706:Biopsy; D001823:Body Composition / Q000502:physiology; D016022:Case-Control Studies; D004249:DNA Damage; D004272:DNA, Mitochondrial / Q000378:metabolism*; D006801:Humans; D018482:Muscle, Skeletal / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D018709:Statistics, Nonparametric; D016615:Telomere / Q000378:metabolism*
D000447:Aldehydes; D004272:DNA, Mitochondrial; C027576:4-hydroxy-2-nonenal