Single Muscle Fiber Proteomics Reveals Fiber-Type-Specific Features of Human Muscle Aging

Publication date: 13 June 2017
Source:Cell Reports, Volume 19, Issue 11
Author(s): Marta Murgia, Luana Toniolo, Nagarjuna Nagaraj, Stefano Ciciliot, Vincenzo Vindigni, Stefano Schiaffino, Carlo Reggiani, Matthias Mann
Skeletal muscle is a key tissue in human aging, which affects different muscle fiber types unequally. We developed a highly sensitive single muscle fiber proteomics workflow to study human aging and show that the senescence of slow and fast muscle fibers is characterized by diverging metabolic and protein quality control adaptations. Whereas mitochondrial content declines with aging in both fiber types, glycolysis and glycogen metabolism are upregulated in slow but downregulated in fast muscle fibers. Aging mitochondria decrease expression of the redox enzyme monoamine oxidase A. Slow fibers upregulate a subset of actin and myosin chaperones, whereas an opposite change happens in fast fibers. These changes in metabolism and sarcomere quality control may be related to the ability of slow, but not fast, muscle fibers to maintain their mass during aging. We conclude that single muscle fiber analysis by proteomics can elucidate pathophysiology in a sub-type-specific manner.

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Teaser

Murgia et al. use mass-spectrometry-based proteomics to compare single muscle fibers of younger and older subjects, which revealed that glycolysis and glycogen metabolism decrease strongly in aging fast, but not slow, muscle fibers. The proteomic changes revealed here help to explain differential loss of muscle performance in aging.


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