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Mitochondrial regulation is altered in skeletal muscle from high and low functioning elderly individuals
Author(s) -
Joseph AnnaMaria,
Wohlgemuth Stephanie E.,
Adhihetty Peter J.,
Buford Thomas W.,
Lees Hazel A.,
Aranda Juan M.,
Sandesara Bhanuprasad D.,
Pahor Marco,
Manini Todd M.,
Marzetti Emanuele,
Leeuwenburgh Christiaan
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.1114.4
Subject(s) - mfn2 , skeletal muscle , fis1 , medicine , sirt3 , sarcopenia , mitochondrial fusion , endocrinology , cytochrome c oxidase , mitochondrion , biology , mitochondrial dna , microbiology and biotechnology , biochemistry , enzyme , nad+ kinase , gene , sirtuin
Mitochondrial dysfunction in aged skeletal muscle is involved in sarcopenia and may contribute to reduced physical function in the elderly. We examined whether mitochondrial regulation differed in muscle from elderly subjects classified as high‐ or low‐functioning (HF, LF; 70–99 yrs) according to scores on the Short Physical Performance Battery test (HF≥l11; LF≤7), when compared to young subjects (YS; 20–35 yrs). Mitochondrial respiration rates in permeabilized myofibers and cytochrome c oxidase enzyme activity (mitochondrial content marker) tended to be lower in HF and were significantly lower (p<0.05) in LF subjects when compared to YS. PGC‐1α, a mitochondrial regulator, was 47% and 64% lower (p<0.05) in HF and LF subjects, respectively, compared to YS. Sirt3, a mitochondrial deacetylase, was similarly reduced (50%; p<0.05) in HF and LF subjects. The mitochondrial fusion protein, Opa1, was markedly suppressed in HF and LF (p<0.05) but no changes were evident in Mfn2, Drp1 or Fis1. Additionally, LF but not HF subjects, displayed significant abnormalities in key mitochondrial import proteins (cytosolic and mitochondrial Hsp70, and Tom22; p<0.05). Our findings indicate that mitochondrial regulatory pathways are impaired in skeletal muscle from elderly subjects (HF and LF) when compared to YS, but that this is more evident in LF subjects, and may play a role in the differential physical abilities of the elderly.