OPEN IN READ APP
JOURNAL ARTICLE

Exercise training attenuates aging-associated mitochondrial dysfunction in rat skeletal muscle: role of PGC-1α

Chounghun Kang, Eunhee Chung, Gary Diffee, Li Li Ji
Experimental Gerontology 2013, 48 (11): 1343-50
23994518
Aged skeletal muscle demonstrates declines in muscle mass and deterioration of mitochondrial content and function. Peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) plays an important role in promoting muscle mitochondrial biogenesis in response to exercise training, but its role in senescent muscle is not clear. In the present study we hypothesize that a downregulation of the PGC-1α signaling pathway contributes to mitochondrial deterioration in aged muscle whereas endurance training ameliorates the deficits. Three groups of Fischer 344/BNF1 rats were used: young, sedentary (Y, 4 months); old, sedentary (O, 22 months); and old trained (OT, 22 months), subjected to treadmill running at 17.5 m/min, 10% grade for 45 min/day, 5 days/week for 12-weeks. PGC-1α mRNA and nuclear PGC-1α protein content in the soleus muscle were both decreased in O vs. Y rats, whereas OT rats showed a 2.3 and 1.8-fold higher PGC-1α content than O and Y rats, respectively (P<0.01). Mitochondrial transcription factor A (Tfam), cytochrome c (Cyt c) and mitochondrial (mt) DNA contents were significantly decreased in O vs. Y rats, but elevated by 2.2 (P<0.01), 1.4 (P<0.05) and 2.4-fold (P<0.01), respectively, in OT vs. O rats. In addition, Tfam and mtDNA showed 1.6 and 1.8-fold (P<0.01) higher levels, respectively, in OT vs. Y rats. These adaptations were accompanied by significant increases in the expression of the phosphorylated form of AMP-activated kinase (AMPK) (P<0.01), p38 mitogen-activated kinase (MAPK) (P<0.05) and silent mating type information regulator 2 homolog 1 (SIRT1) (P<0.01) in OT rats. Furthermore, OT rats showed great levels of phosphorylation in cAMP responsive element binding protein (p-CREB) and DNA binding compared to O and Y rats. These data indicate that endurance training can attenuate aging-associated decline in mitochondrial protein synthesis in skeletal muscle partly due to upregulation of PGC-1α signaling.

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Available on the App Store

Available on the Play Store
Remove bar
Read by QxMD icon Read
23994518
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"