Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
In Vitro Cell Dev Biol Anim. 2022 May;58(5):384-395. doi: 10.1007/s11626-022-00682-x. Epub 2022 Jun 1.
The cell proliferation of bovine mammary epithelial cells (BMECs) and consequent milk synthesis are regulated by multiple factors. The purpose of this study was to examine the effect of 14-3-3β on cellular proliferation and milk fat/β-casein synthesis in BMECs and reveal its underlying mechanisms. In this study, we employed gene function analysis to explore the regulatory effect and molecular mechanisms of 14-3-3β on milk synthesis and proliferation in BMECs. We found that leucine and IGF-1 enhance cell proliferation and milk synthesis in a 14-3-3β-dependent manner and only exhibiting such effect in the presence of 14-3-3β. We further determined that 14-3-3β interacts with the IGF1R self-phosphorylation site and it additionally mediated leucine and IGF-1 to stimulate the synthesis of milk through the IGF1R-AKT-mTORC1 signaling pathway. In summary, our data indicated that 14-3-3β mediates the expression of milk fat and protein stimulated by leucine and IGF-1, leading to lactogenesis through IGF1R signaling pathway in BMECs.
牛乳腺上皮细胞（BMEC）的细胞增殖和随后的乳汁合成受多种因素调控。本研究旨在探讨 14-3-3β 对 BMEC 中细胞增殖和乳脂肪/β-酪蛋白合成的影响，并揭示其潜在机制。在这项研究中，我们采用基因功能分析来探讨 14-3-3β 对 BMEC 中乳汁合成和增殖的调节作用及其分子机制。我们发现亮氨酸和 IGF-1 以 14-3-3β 依赖的方式增强细胞增殖和乳汁合成，并且仅在存在 14-3-3β 的情况下才表现出这种作用。我们进一步确定 14-3-3β 与 IGF1R 自身磷酸化位点相互作用，并且它还通过 IGF1R-AKT-mTORC1 信号通路介导亮氨酸和 IGF-1 刺激乳的合成。总之，我们的数据表明 14-3-3β 介导亮氨酸和 IGF-1 刺激的乳脂肪和蛋白质的表达，通过 IGF1R 信号通路在 BMEC 中导致泌乳。
