Symposium review: Milk fat globule size: Practical implications and metabolic regulation
Symposium review: Milk fat globule size: Practical implications and metabolic regulation
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DOI：
10.3168/jds.2018-15240
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发表时间：
2019-03-01
影响因子：
3.5
通讯作者：
Argov-Argaman, Nurit
中科院分区：
文献类型：
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作者：
Argov-Argaman, Nurit
乳脂球（MFG）的大小范围超过3个数量级，从小于200 nm到超过15 μ m。MFG大小的重要性来自于其与其脂质组和蛋白质组的紧密关联。更具体地说，与大的小球相比，小的MFG具有相对较高的膜含量，并且这种膜发挥多种积极的健康作用，如在人类和动物研究中所报道的。此外，MFG尺寸具有工业意义，因为它影响乳制品的物理化学和感官特性。关于MFG大小调节的研究很少，主要是因为各种混杂因素间接影响MFG大小。由于MFG的大小是确定之前和期间从乳腺上皮细胞分泌，其前体，细胞内的脂滴（LD）的大小调节的研究，已被用作理解的机制控制MFG大小的代理。在这篇综述中，我们提供了证据，为2个不同的机制调节LD大小在乳腺上皮细胞：共同调节脂肪含量和磷脂合成能力的细胞，LD之间的融合。后者由膜的极性脂质组成控制，并涉及线粒体酶。因此，这篇评论还讨论了MFG的大小调节在体内代谢的情况下，MFG的形态特征往往调制的条件下，涉及动物的能量状态的改变。
Milk fat globule (MFG) size ranges over 3 orders of magnitude, from less than 200 nm to over 15 mu m. The significance of MFG size derives from its tight association with its lipidome and proteome. More specifically, small MFG have relatively higher content of membrane compared with large globules, and this membrane exerts diverse positive health effects, as reported in human and animal studies. In addition, MFG size has industrial significance, as it affects the physicochemical and sensory characteristics of dairy products. Studies on the size regulation of MFG are scarce, mainly because various confounders indirectly affect MFG size. Because MFG size is determined before and during its secretion from mammary epithelial cells, studies on the size regulation of its precursors, the intracellular lipid droplets (LD), have been used as a proxy for understanding the mechanisms controlling MFG size. In this review, we provide evidence for 2 distinct mechanisms regulating LD size in mammary epithelial cells: co-regulation of fat content and triglyceride-synthesis capacity of the cells, and fusion between LD. The latter is controlled by the membrane's polar lipid composition and involves mitochondrial enzymes. Accordingly, this review also discusses MFG size regulation in the in vivo metabolic context, as MFG morphometric features are often modulated under conditions that involve animals' altered energy status.