Department of Theoretic Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin, China.
J Anim Physiol Anim Nutr (Berl). 2022 Nov;106(6):1420-1430. doi: 10.1111/jpn.13756. Epub 2022 Aug 3.
Lysine is one of the essential amino acids. The effect of lysine on milk protein and milk fat anabolism has been reported, but the effect on mammary glands development has not been studied in detail. The normal development of the mammary glands at puberty is crucial to lactation of mammals. In this study, to explore the effect of lysine on mammary glands development, we fed different concentrations of lysine (0.025%, 0.05%, 0.1%) to pubertal mice and found that the addition of 0.1% lysine to drinking water significantly promoted mammary glands development. Furthermore, we treated mMECs (mouse mammary epithelial cells) with different concentrations of lysine (0, 0.2, 0.4, 0.6, 0.8 and 1 mM) to explore the underlying mechanism, and found that lysine promoted the proliferation of mMECs and development of mammary glands through PI3K/AKT/mTOR signalling pathway in pubertal mice. Overall, the results of this study revealed that lysine activated the PI3K/AKT/mTOR signal axis, elevated protein concentrations of cell proliferation markers, such as PCNA, Cyclin D1 and D3, and enhanced the proliferation of mMECs, finally promoted the murine mammary glands development at puberty.
赖氨酸是必需氨基酸之一。已有研究报道赖氨酸对乳蛋白和乳脂合成有影响，但对乳腺发育的影响尚未详细研究。青春期乳腺的正常发育对哺乳动物的泌乳至关重要。在这项研究中，为了探讨赖氨酸对乳腺发育的影响，我们给青春期小鼠喂食不同浓度的赖氨酸（0.025%、0.05%、0.1%），结果发现，在饮水中添加 0.1%的赖氨酸可显著促进乳腺发育。此外，我们用不同浓度的赖氨酸（0、0.2、0.4、0.6、0.8 和 1mM）处理 mMECs（小鼠乳腺上皮细胞），以探讨其潜在机制，发现赖氨酸通过 PI3K/AKT/mTOR 信号通路促进青春期小鼠的 mMECs 增殖和乳腺发育。总的来说，本研究结果表明，赖氨酸激活了 PI3K/AKT/mTOR 信号轴，提高了细胞增殖标志物如 PCNA、Cyclin D1 和 D3 的蛋白浓度，并增强了 mMECs 的增殖，最终促进了青春期小鼠的乳腺发育。
