Effetto dell’assunzione con la dieta di supplementi di n-3 PUFA sul trascrittoma muscolare negli anziani

J. Yoshino, G.I. Smith, S.C. Kelly, S. Julliand, D.N. Reeds, B. Mittendorfer

Physiol Rep. 2016;4(11). pii: e12785

Dietary fish oil-derived n-3 PUFA supplementation can increase muscle mass, reduce oxygen demand during physical activity, and improve physical function (muscle strength and power, and endurance) in people. The results from several studies conducted in animals suggest that the anabolic and performance-enhancing effects of n-3 PUFA are at least in part transcriptionally regulated.

The effect of n-3 PUFA therapy on the muscle transcriptome in people is unknown. In this study, we used muscle biopsy samples collected during a recently completed randomized controlled trial that found that n-3 PUFA therapy increased muscle mass and function in 20 older adults (aged 60-85 year) to provide a comprehensive assessment of the effect of n-3 PUFA therapy on the skeletal muscle gene expression profile in these people.

 Using the microarray technique, we found that several pathways involved in regulating mitochondrial function and extracellular matrix organization were increased and pathways related to calpain- and ubiquitin-mediated proteolysis and inhibition of the key anabolic regulator mTOR were decreased by n-3 PUFA therapy. However, the effect of n-3 PUFA therapy on the expression of individual genes involved in regulating mitochondrial function and muscle growth, assessed by quantitative RT-PCR, was very small. 

Comment: These results indicate that the beneficial effects of n-3 PUFA on muscle mass and function/physical performance may be in part transcriptionally regulated and involves gene set pathways related to mitochondrial function, structural support, and anabolic signaling and proteolysis. Although the effect of n-3 PUFA therapy on the expression of individual genes was small, a coordinated up- or downregulation of genes in specific pathways, identified by using the microarray technique, could have significant effects on muscle mass and function.