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.

中文翻译：

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蛋白质组学分析揭示补充维生素A的肉牛骨骼肌能量代谢变化

背景已报道维生素A是影响肉类动物大理石花纹沉积的一个因素。尽管维生素 A 调节成熟脂肪细胞脂质代谢的机制已经明确，但关于维生素 A 对肉牛肌肉内脂肪沉积调节作用的分子机制的信息仍然有限。我们的目标是使用蛋白质组学方法评估在育肥阶段补充维生素 A 的肉牛肌肉内脂肪沉积的分子机制。结果 在育肥阶段补充维生素 A 减少了肉牛的肌肉内脂肪沉积。蛋白质组和磷酸化蛋白质组分析以及对治疗之间差异丰富的蛋白质的生物学和网络分析表明，维生素 A 补充剂会影响骨骼肌的整体能量代谢，损害骨骼肌中的脂质生物合成。结论 育肥期补充维生素A可能通过改变骨骼肌的能量代谢来损害肉牛肌肉内脂肪沉积。视黄酸和 HSP70 的相互作用可能在肌肉内脂肪沉积受损中起关键作用，这是由于骨骼肌中胰岛素敏感性可能降低而损害脂肪酸从头合成而补充维生素 A 的结果。本文受版权保护。版权所有。