Indian Journal of Animal Research

  • Chief EditorK.M.L. Pathak

  • Print ISSN 0367-6722

  • Online ISSN 0976-0555

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Indian Journal of Animal Research, volume 54 issue 11 (november 2020) : 1363-1366

Effects of Insulin on Milk Fat Synthesis by Regulating the Expressions of SREBP1 and mTOR in Bovine Mammary Epithelial Cells

Nan Li, Peng-Xia Zhang, Xin Huang, Hai-Tao Yao, Dong-Pu Liu, Shu Wang, Hai-Yan Luan
1The Basic Medical College, Jiamusi University, Jiamusi, Heilongjiang, 154002, China.
Cite article:- Li Nan, Zhang Peng-Xia, Huang Xin, Yao Hai-Tao, Liu Dong-Pu, Wang Shu, Luan Hai-Yan (2020). Effects of Insulin on Milk Fat Synthesis by Regulating the Expressions of SREBP1 and mTOR in Bovine Mammary Epithelial Cells. Indian Journal of Animal Research. 54(11): 1363-1366. doi: 10.18805/ijar.B-1171.
Due to the complexity of insulin in life activities, the role of insulin in mammalian lactation has not been well explained. To investigate the influence of insulin on milk fat synthesis, bovine mammary epithelial cells (BMECs) were cultured in treatment with insulin. We determined the content of Triglyceride (TG) in cell-free culture medium and found a notable increase in TG secrection. Lipid droplet staining study showed a consistent result. We also used real-time quantitative PCR and western blotting to detect the expression of signaling molecules related to milk fat synthesis. We found that insulin resulted in an obvious increase of SREBP-1, mTOR and lipogenic gene expression compared with the blank group. Taken together, our study reveals that insulin plays a significant role in milk fat synthesis.
  1. Bakan I., Laplante M. (2012). Connecting mTORC1 signaling to SREBP-1 activation. Curr Opin Lipidol. 23: 226-234.
  2. Bionaz M., Loor JJ. (2008). Gene networks driving bovine milk fat synthesis during the lactation cycle. BMC Genomics. 9: 366.
  3. Brown MS., Goldstein JL. (2009). Cholesterol feedback: from Schoenheimer’s bottle to Scap’s MELADL. J Lipid Res. 50 Suppl: S15-27.
  4. Horton JD., Goldstein JL., Brown MS. (2002). SREBPs: activators of the complete program of cholesterol and fatty acid synthesis in the liver. J Clin Invest. 109: 1125-1131.
  5. Huangxin, Zangyanli, Zhangminghui, et al. (2017). Nuclear Factor of êB1 is a Key Regulator for the Transcriptional Activation of Milk Synthesis in Bovine Mammary Epithelial Cells [J]. DNA and Cell Biology. 36(4): 295-302.
  6. Kim YM., Shin HT., Seo YH., Byun HO., Yoon SH., Lee IK., Hyun DH., Chung HY., Yoon G. (2010). Sterol regulatory element-binding protein (SREBP)-1-mediated lipogenesis is involved in cell senescence. J Biol Chem. 285: 29069-    29077.
  7. Li N., Zhao F., Wei C., Liang M., Zhang N., Wang C., Li QZ., Gao XJ. (2014). Function of SREBP1 in the milk fat synthesis of dairycow mammary epithelial cells. Int J Mol Sci. 15: 16998-17013.
  8. Li S., Brown MS., Goldstein JL. (2010). Bifurcation of insulin signaling pathway in rat liver: mTORC1 required for stimulation of lipogenesis, but not inhibition of gluconeogenesis. Proc Natl Acad Sci. USA. 107: 3441-3446.
  9. Li S., Ogawa W., Emi A., Hayashi K., Senga Y., Nomura K., Hara K., Yu D., Kasuga M. (2011). Role of S6K1 in regulation of SREBP1c expression in the liver. Biochem Biophys Res Commun. 412: 197-202.
  10. Nan LI, Cheng-jie WEI, Hai-yang MENG, et al. (2015). Vaccaria segetalis activates cellular lactation signaling pathway of dairy cow mammary epithelial cells in vitro. Indian Journal of Animal Research. 49(2): 199-204
  11. Neville MC., Picciano MF. (1997). Regulation of milk lipid secretion and composition. Annu Rev Nutr. 17: 159-183.
  12. Wan ZY., Tong HL., Li QZ., Gao XJ. (2011). Influence on cellular signal transduction pathway in dairy cow mammary gland epithelial cells by galactopoietic compound isolated from Vaccariae segetalis. Agricultural Sciences in China.10: 619-630.
  13. Wood TL., Richert MM., Stull MA., Allar MA. (2000). The insulin- like growth factors (IGFs) and IGF binding proteins in postnatal development of murine mammary glands. J Mammary Gland Biol Neoplasia. 5: 31-42.
  14. Yecies JL., Zhang HH., Menon S., Liu S., Yecies D., Lipovsky AI., Gorgun C., Kwiatkowski DJ., Hotamisligil GS., Lee CH., Manning BD. (2011). Akt stimulates hepatic SREBP1c and lipogenesis through parallel mTORC1-dependent and independent pathways. Cell Metab. 14: 21-32.
  15. Yu C, Luo C, Qu B, et al. (2014). Molecular network including eIF1AX, RPS7 and 14-3-3ã regulates protein translation and cell proliferation in bovine mammary epithelial cells [J]. Archives of Biochemistry and Biophysics. 2014: 142-    155.
  16. Zhang, X., Zhao, F., Si, Y., Huang, Y., Yu, C., Luo, C., et al. (2014). GSK3beta regulates milk synthesis in and proliferation of dairy cow mammary epithelial cells via the mTOR/ S6K1 signaling pathway. Molecules. 19: 9435–9452. 

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