Skeletal muscle mitochondrial volume and myozenin-1 protein differences exist between high versus low anabolic responders to resistance training

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1 School of Kinesiology, Auburn University, Auburn, Alabama, United States
2 Research, Lockwood, LLC, Draper, Utah, United States
DOI
10.7287/peerj.preprints.26933v1
Published
Accepted
Subject Areas
Cell Biology, Kinesiology
Keywords
MYOZ1, muscle hypertrophy, citrate synthase
Copyright
© 2018 Roberts et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Roberts M, Romero M, Mobley C, Mumford P, Roberson P, Haun C, Vann C, Osburn S, Holmes H, Greer R, Lockwood C, Parry H, Kavazis A. 2018. Skeletal muscle mitochondrial volume and myozenin-1 protein differences exist between high versus low anabolic responders to resistance training. PeerJ Preprints 6:e26933v1

Abstract

Background. We sought to examine how 12 weeks of resistance exercise training (RET) affected skeletal muscle myofibrillar and sarcoplasmic protein levels along with markers of mitochondrial physiology in high versus low anabolic responders. Methods. Untrained college-aged males were classified as anabolic responders in the top 25th percentile [HI; n=13, dual x-ray absorptiometry total body muscle mass change (Δ) =+3.1±0.3 kg, Δ vastus lateralis (VL) thickness =+0.59±0.05 cm, Δ muscle fiber CSA =+1426±253 μm2) and bottom 25th percentile (LO; n=12, +1.1±0.2 kg, +0.24±0.07 cm, +5±209 μm2; p<0.001 for all Δ scores compared to HI]. VL muscle prior to (PRE) and following RET (POST) was assayed for myofibrillar and sarcoplasmic protein concentrations, myosin and actin protein content, and markers of mitochondrial volume. Myofibrillar protein levels of genes related to new myofibril formation as well as whole lysate PGC1-α protein levels were also assessed. Results. Main effects of cluster (HI>LO, p=0.018, Cohen’s d=0.737) and time (PRE>POST, p=0.037, Cohen’s d=-0.589) were observed for citrate synthase activity, although no significant interaction existed. POST myofibrillar myozenin-1 protein levels were up-regulated in the LO cluster (+25%, p=0.025, Cohen’s d = 0.691). No interactions or main effects existed for other assayed markers. Our data suggest myofibrillar or sarcoplasmic protein concentrations do not differ between HI versus LO anabolic responders prior to or following a 12-week RET program. Discussion. Greater mitochondrial volume in HI responders may have facilitated greater anabolism, and myofibril myozenin-1 protein levels may represent a biomarker that differentiates anabolic responses to RET. However, mechanistic research validating these hypotheses is needed.

Author Comment

This is a submission to PeerJ for review.

Supplemental Information

Raw data (EXL format)

Raw data in EXL format ready to be entered into data processing software (e.g., SPSS).

DOI: 10.7287/peerj.preprints.26933v1/supp-1

Raw Coomassie and Western blot images

Raw Coomassie and Western blot images

DOI: 10.7287/peerj.preprints.26933v1/supp-2