Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow 83844.
Department of Biological Sciences, Auburn University, Auburn, AL 36849.
J Dairy Sci. 2021 Sep;104(9):10415-10425. doi: 10.3168/jds.2021-20138. Epub 2021 Jul 1.
As milk production in dairy cattle continues to increase, so do the energetic and nutrient demands on the dairy cow. Difficulties making the necessary metabolic adjustments for lactation can impair lactation performance and increase the risk of metabolic disorders. The physiological adaptations to lactation involve the mammary gland and extramammary tissues that coordinately enhance the availability of precursors for milk synthesis. Changes in whole-body metabolism and nutrient partitioning are accomplished, in part, through the bioenergetic and biosynthetic capacity of the mitochondria, providing energy and diverting important substrates, such as AA and fatty acids, to the mammary gland in support of lactation. With increased oxidative capacity and ATP production, reactive oxygen species production in mitochondria may be altered. Imbalances between oxidant production and antioxidant activity can lead to oxidative damage to cellular structures and contribute to disease. Thus, mitochondria are tasked with meeting the energy needs of the cell and minimizing oxidative stress. Mitochondrial function is regulated in concert with cellular metabolism by the nucleus. With only a small number of genes present within the mitochondrial genome, many genes regulating mitochondrial function are housed in nuclear DNA. This review describes the involvement of mitochondria in coordinating tissue-specific metabolic adaptations across lactation in dairy cattle and the current state of knowledge regarding mitochondrial-nuclear signaling pathways that regulate mitochondrial proliferation and function in response to shifting cellular energy need.
随着奶牛产奶量的持续增加，奶牛对能量和营养的需求也在增加。在泌乳过程中难以进行必要的代谢调整会损害泌乳性能并增加代谢紊乱的风险。泌乳的生理适应涉及乳腺和乳腺外组织，它们协调增强了用于合成牛奶的前体的可用性。通过线粒体的生物能量和生物合成能力，完成了全身代谢和养分分配的变化，为乳腺提供能量并将重要的底物（如 AA 和脂肪酸）转移到乳腺，以支持泌乳。随着氧化能力和 ATP 产生的增加，线粒体中活性氧的产生可能会发生改变。氧化剂产生和抗氧化活性之间的不平衡会导致细胞结构的氧化损伤，并导致疾病。因此，线粒体的任务是满足细胞的能量需求并最大程度地减少氧化应激。线粒体功能与细胞核协同调节细胞代谢。由于线粒体基因组中仅存在少数基因，因此许多调节线粒体功能的基因都位于核 DNA 中。这篇综述描述了线粒体在协调奶牛泌乳过程中组织特异性代谢适应中的作用，以及当前关于核-线粒体信号通路的知识状况，该信号通路可响应不断变化的细胞能量需求来调节线粒体的增殖和功能。
