Proteomic analysis reveals changes in energy metabolism of skeletal muscle in beef cattle supplemented with vitamin A.

BACKGROUND: Vitamin A has been reported as a factor influencing marbling deposition in meat animals. Although the mechanisms by which vitamin A regulates lipid metabolism in mature adipocytes were already well-established, information regarding molecular mechanisms underlying the effects of vitamin A on the regulation of the intramuscular fat deposition in beef cattle are still limited. Our objective was to assess molecular mechanisms involved in intramuscular fat deposition of beef cattle supplemented with vitamin A during the fattening phase using proteomic approach. RESULTS: Vitamin A supplementation during the fattening phase decreased the intramuscular fat deposition in beef cattle. The proteome and phospho-proteome analysis together with biological and networking analysis of the protein differentially abundant between treatments indicate that Vitamin A supplementation affects the overall energy metabolism of skeletal muscle, impairing lipid biosynthesis in skeletal muscle. CONCLUSION: Vitamin A supplementation at fattening phase impairs the intramuscular fat deposition in beef cattle likely by changing the energy metabolism of skeletal muscle. The interaction of retinoic acid and HSP70 may play a pivotal role in impairment of intramuscular fat deposition as a consequence of vitamin A supplementation by impairing de novo fatty acid synthesis due to a possible decrease in insulin sensitivity in the skeletal muscle. This article is protected by copyright. All rights reserved.