Table 1.
A list of studies providing evidence of mitochondrial alterations between young and old skeletal muscle from animals or humans. TFAM, mitochondrial transcription factor A; mtDNA, mitochondrial DNA; PGC-1α, peroxisome proliferator-activated receptor-γ coactivator-1α; ROS, reactive oxygen species; OXPHOS, oxidative phosphorylation; CS, citrate synthase; mPTP, mitochondrial permeability transition pore; ETC, electron transport chain.
| Species | Age Groups Studied | Relevant Finding in Old Skeletal Muscle | Reference |
|---|---|---|---|
| C57Bl/6 Mice | 7 vs. 30 months old | ↓ mitochondrial coupling | [80] |
| C57Bl/6 Mice | 2–15 months old | ↑ TFAM and mtDNA content | [81] |
| C57Bl/6 Mice | 2 vs. 24 months old | ↑ mitophagy ↑ mitochondrial fission |
[82] |
| C57Bl/6 Mice | 11–13 vs. 25–27 months old | ↓ autophagy | [83] |
| C5l/6 Mice | 3 vs. 18 months old | ↓ mitochondrial content ↓ mitochondrial biogenesis ↑ mitophagy flux |
[84] |
| Mice | 8–12 vs. 88–96 weeks old | ↑ mitochondrial fusion index | [85] |
| Wistar Rats | 3 vs. 26 months old | ↓ mitochondrial mass ↓ PGC-1α protein ↑ Fis1 and Mfs1 proteins |
[86] |
| Wistar Rats | 3–28 months old | ↑ mtDNA deletions ↓ respiratory enzymes |
[87] |
| Fischer 344 Brown Norway Rats | 5 vs. 35 months old | ↓ mitochondrial size ↑ mitochondrial fission proteins |
[67] |
| Fischer 344 Brown Norway Rats | 6 vs. 24 months old | ↓ autophagy | [88] |
| Fischer 344 Brown Norway Rats | 6 vs. 36 months old | ↓ mitochondrial content ↑ mitochondrial ROS production ↑ cytochrome c and endonuclease G release |
[56] |
| Fischer 344 Brown Norway Rats | 8–10 vs. 35–36 months old | ↓ OXPHOS proteins, CS activity, state III respiration, mPTP function ↑ free radical leak |
[89] |
| Fischer 344 Brown Norway Rats | 6 vs. 35–38 months old | =mitochondrial protein import machinery | [90] |
| Fischer 344 Brown Norway Rats | 6 vs. 36 months old | ↑ protein assembly =protein import |
[91] |
| Fischer 344 Brown Norway Rats | 5, 18, 36 months old | ↑ ETC abnormalities | [92] |
| Fischer 344 Brown Norway Rats | 5–6 vs. 35–36 months old | ↑ mitophagy flux | [93] |
| Rhesus Monkeys | 6, 9, 12 years old | ↑ enzyme abnormalities ↑ mtDNA deletion mutations |
[94] |
| Humans | 17–91 years old | ↓ respiratory activity of complex I, II, and IV | [95] |
| Humans | 18–89 years old | ↓ mtDNA, mRNA, and mitochondrial proteins ↓ mitochondrial ATP production |
[96] |
| Humans | 29–80 years old | ↓ oxidative capacity | [97] |
| Humans | 22–75 years old | ↓ mitochondrial transcriptome | [98] |
| Humans | 25–72 years old | ↓ ETC proteins ↓ ROS production |
[99] |
| Humans | 21–88 years old | ↑ TFAM mRNA and protein | [100] |
| Humans | 20–71 years old | ↑ mtDNA rearrangements | [101] |
| Humans | 49–93 years old | ↑ mtDNA deletion mutations | [102] |
| Humans | 20–80 years old | ↑ mtDNA deletions | [103] |
| Humans | 20–75 years old | ↓ mitochondrial enzymes activity ↓ mitochondrial biogenesis |
[104] |
| Humans | 21–75 years old | ↓ IMF mitochondrial size | [105] |
| Humans | 22–82 years old | ↓ mitochondrial respiration ↓ PGC-1α, COX I, and OPA proteins ↑ mitochondrial protein import machinery |
[106] |