A novel D2O tracer method to quantify RNA turnover as a biomarker of de novo ribosomal biogenesis, in vitro, in animal models, and in human skeletal muscle

Brook, Matthew S.; Wilkinson, D.J.; Mitchell, W. Kyle; Lund, Jonathan N.; Phillips, Bethan E.; Szewczyk, Nathaniel J.; Kainulainen, H.; Lensu, S.; Koch, L.G.; Britton, S.L.; Greenhaff, Paul L.; Smith, K.; Atherton, Philip J.

Abstract

Current methods to quantify in vivo RNA dynamics are limited. Here, we developed a novel stable isotope (D2O) methodology to quantify RNA synthesis (i.e., ribosomal biogenesis) in cells, animal models, and humans. First, proliferating C2C12 cells were incubated in D2O-enriched media and myotubes ±50 ng/ml IGF-I. Second, rat quadriceps (untrained, n = 9; 7-wk interval-“like” training, n = 13) were collected after ~3-wk D2O (70 atom %) administration, with body-water enrichment monitored via blood sampling. Finally, 10 (23 ± 1 yr) men consumed 150-ml D2O followed by 50 ml/wk and undertook 6-wk resistance exercise (6 × 8 repetitions, 75% 1-repetition maximum 3/wk) with body-water enrichment monitored by saliva sampling and muscle biopsies (for determination of RNA synthesis) at 0, 3, and 6 wk. Ribose mole percent excess (r-MPE) from purine nucleotides was analyzed via GC-MS/MS. Proliferating C2C12 cell r-MPE exhibited a rise to plateau, whereas IGF-I increased myotube RNA from 76 ± 3 to 123 ± 3 ng/μl and r-MPE by 0.39 ± 0.1% (both P < 0.01). After 3 wk, rat quadriceps r-MPE had increased to 0.25 ± 0.01% (P < 0.01) and was greater with running exercise (0.36 ± 0.02%; P < 0.01). Human muscle r-MPE increased to 0.06 ± 0.01 and 0.13 ± 0.02% at 3/6 wk, respectively, equating to synthesis rates of ~0.8%/day, increasing with resistance exercise to 1.7 ± 0.3%/day (P < 0.01) and 1.2 ± 0.1%/day (P < 0.05) at 3/6 wk, respectively. Therefore, we have developed and physiologically validated a novel technique to explore ribosomal biogenesis in a multimodal fashion.

Citation

Brook, M. S., Wilkinson, D., Mitchell, W. K., Lund, J. N., Phillips, B. E., Szewczyk, N. J., Kainulainen, H., Lensu, S., Koch, L., Britton, S., Greenhaff, P. L., Smith, K., & Atherton, P. J. (2017). A novel D2O tracer method to quantify RNA turnover as a biomarker of de novo ribosomal biogenesis, in vitro, in animal models, and in human skeletal muscle. AJP - Endocrinology and Metabolism, 313(6), Article E681-E689. https://doi.org/10.1152/ajpendo.00157.2017

• Journal Article Type: Article
• Acceptance Date: Aug 14, 2017
• Online Publication Date: Aug 15, 2017
• Publication Date: Dec 1, 2017
• Deposit Date: Dec 6, 2017
• Publicly Available Date: Aug 16, 2018
• Journal: AJP: Endocrinology and Metabolism
• Print ISSN: 0193-1849
• Electronic ISSN: 1522-1555
• Publisher: American Physiological Society
• Peer Reviewed: Peer Reviewed
• Volume: 313
• Issue: 6
• Article Number: E681-E689
• DOI: https://doi.org/10.1152/ajpendo.00157.2017
• Keywords: Ribosomal biogenesis; D2O; RNA synthesis; Muscle
• Public URL: https://nottingham-repository.worktribe.com/output/897797
• Publisher URL: https://doi.org/10.1152/ajpendo.00157.2017
• Contract Date: Dec 6, 2017