Leucyl-tRNA Synthetase Regulates Lactation and Cell Proliferation via mTOR Signaling in Dairy Cow Mammary Epithelial Cells

International Journal of Molecular Sciences

Lina Wang¹  Ye Lin¹  Yanjie Bian¹  Lili Liu¹  Li Shao¹  Lin Lin¹  Bo Qu¹  Feng Zhao¹  Xuejun Gao¹ 

[1] Key Laboratory of Dairy Science of Ministry of Education, Northeast Agricultural University, Harbin 150030, China;

关键词: dairy cow mammary epithelial cells;    lactation;    leucine;    cell proliferation;    LeuRS;    mTOR;   

DOI  :  10.3390/ijms15045952

来源: mdpi

【 摘 要 】

The role of LeuRS, an aminoacyl-tRNA synthetase, as an intracellular l-leucine sensor for the mTORC1 pathway has been the subject of much research recently. Despite this, the association between LeuRS and lactation in dairy cow mammary epithelial cells (DCMECs) remains unknown. In this study, we found that LeuRS expression in mammary gland tissue was significantly higher during lactation than pregnancy. Moreover, our data demonstrates that LeuRS is localized in the cytoplasm. Treatment with leucine increased DCMECs viability and proliferation, as well as mammalian target of rapamycin (mTOR), p-mTOR, ribosomal protein S6 kinase 1 (S6K1), p-S6K1, β-Casein, sterol regulatory element binding protein 1c (SREBP-1c), glucose transporter 1 (GLUT1), and Cyclin D1 mRNA and protein expression. Secretion of lactose and triglyceride were also increased. siRNA-mediated knockdown of LeuRS led to reduction in all of these processes. Based on these data, LeuRS up-regulates the mTOR pathway to promote proliferation and lactation of DCMECs in response to changes in the intracellular leucine concentration.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland