Dietary restriction increases skeletal muscle mitochondrial respiration but not mitochondrial content in C57BL/6 mice.
(2012) Mechanisms of Ageing and Development — Vol. 133, p. 37-45 (2012)
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- Abstract
- Dietary restriction (DR) is suggested to induce mitochondrial biogenesis, although recently this has been challenged. Here we determined the impact of 1, 9 and 18 months of 30% DR in male C57BL/6 mice on key mitochondrial factors and on mitochondrial function in skeletal muscle, relative to age-matched ad libitum (AL) controls. We examined proteins and mRNAs associated with mitochondrial biogenesis and measured mitochondrial respiration in permeabilised myofibres using high resolution respirometry. 30% DR, irrespective of duration, had no effect on citrate synthase activity. In contrast, total and nuclear protein levels of PGC-1α, mRNA levels of several mitochondrial associated proteins (Pgc-1α, Nrf1, Core 1, Cox IV, Atps) and cytochrome c oxidase content were increased in skeletal muscle of DR mice. Furthermore, a range of mitochondrial respiration rates were increased significantly by DR, with DR partially attenuating the age-related decline in respiration observed in AL controls. Therefore, DR did not increase mitochondrial content, as determined by citrate synthase, in mouse skeletal muscle. However, it did induce a PGC-1α adaptive response and increased mitochondrial respiration. Thus, we suggest that a functionally 'efficient' mitochondrial electron transport chain may be a critical mechanism underlying DR, rather than any net increase in mitochondrial content per se.
- Affiliations
University of Aberdeen, U.K. Institute of Biological and Environmental Sciences
Citations
Hempenstall S., Page, M., Wallen K.R., & Selman C. (2012). Dietary restriction increases skeletal muscle mitochondrial respiration but not mitochondrial content in C57BL/6 mice. Mechanisms of Ageing and Development, 133, 37-45. https://doi.org/10.1016/j.mad.2011.12.002 (Original work published 2012)