Key Laboratory of Dairy Science of Education Ministry , Northeast Agricultural University , Harbin 150030 , China.
Department of Life Sciences and Medicine , Kunming University of Science and Technology , Kunming 650500 , China.
J Agric Food Chem. 2019 Aug 28;67(34):9532-9542. doi: 10.1021/acs.jafc.9b03734. Epub 2019 Aug 16.
Murine mammary gland is an ideal model for studying the development and milk synthesis in dairy animals. MicroRNAs play an important role in milk synthesis and mammary gland development; however, the molecular mechanism of miR-142-3p continues to be poorly understood. Here, we knocked down miR-142-3p expression in vitro and vivo, increased the prolactin receptor expression and activated many downstream cellular proteins, such as mammalian target of rapamycin, sterol regulatory element-binding transcription factor 1, cyclin D1, and signal transducer and activator of transcription 5. Additionally, miR-142-3p knockdown in mouse mammary gland epithelial cells increased proliferation but not viability, induced cell cycle progression, decreased apoptosis, and increased the expression of triglycerides and β-casein. Moreover, miR-142-3p knockdown in murine mammary gland tissue in vivo affected the structure and function of the mammary gland, which showed an increased number of lobules and ducts and was more capable of producing milk. However, overexpression of miR-142-3p had the opposite effects. In summary, these data reveal that miR-142-3p regulates milk synthesis and the structure of murine mammary glands via PRLR-mediated multiple signaling pathways.
鼠乳腺是研究乳用动物乳腺发育和乳汁合成的理想模型。microRNAs 在乳汁合成和乳腺发育中发挥着重要作用；然而，miR-142-3p 的分子机制仍知之甚少。在这里，我们在体外和体内敲低 miR-142-3p 的表达，增加催乳素受体的表达并激活许多下游细胞蛋白，如雷帕霉素靶蛋白、固醇调节元件结合转录因子 1、细胞周期蛋白 D1 和信号转导和转录激活因子 5。此外，miR-142-3p 在小鼠乳腺上皮细胞中的敲低增加了增殖但不增加细胞活力，诱导细胞周期进程，减少细胞凋亡，并增加甘油三酯和β-酪蛋白的表达。此外，体内敲低鼠乳腺组织中的 miR-142-3p 影响乳腺的结构和功能，表现为小叶和导管数量增加，产奶能力增强。然而，miR-142-3p 的过表达则产生相反的效果。总之，这些数据表明，miR-142-3p 通过 PRLR 介导的多种信号通路调节乳汁合成和鼠乳腺的结构。
