WISP3 (CCN6) Regulates Milk Protein Synthesis and Cell Growth Through mTOR Signaling in Dairy Cow Mammary Epithelial Cells

2015 ◽  
Vol 34 (8) ◽  
pp. 524-533 ◽  
Author(s):  
Nan Jiang ◽  
Yu Wang ◽  
Zhiqiang Yu ◽  
Lijun Hu ◽  
Chaonan Liu ◽  
...  
2012 ◽  
Vol 92 (4) ◽  
pp. 433-442 ◽  
Author(s):  
Limin Lu ◽  
Xuejun Gao ◽  
Qingzhang Li ◽  
Jianguo Huang ◽  
Rong Liu ◽  
...  

Lu, L., Gao, X., Li, Q., Huang, J., Liu, R. and Li, H. 2012. Comparative phosphoproteomics analysis of the effects of L-methionine on dairy cow mammary epithelial cells. Can. J. Anim. Sci. 92: 433–442. L-methionine is an essential amino acid that plays fundamental roles in protein synthesis. Many nuclear phosphorylated proteins such as Stat5 (signal transducer and activator of transcription 5) and mTOR (mammalian target of rapamycin) regulate milk protein synthesis. But a comprehensive understanding of transcriptional and posttranscriptional regulation of milk protein synthesis is lacking. In the current study, two-dimensional gel electrophoresis (2-DE)/MS-based proteomics analysis was used to identify phosphoproteins responsible for milk protein synthesis in dairy cow mammary epithelial cells (DCMECs). The effects of L-methionine on DCMECs were analyzed by CASY (Counter Analyser System) technique, reversed phase high performance liquid chromatography. The results showed that rate of cell proliferation and expression of β-casein were increased in DCMECs treated with 0.6 mM L-methionine for 24 h. Five proteins for which expression was significantly increased in DCMECs were selected, and their expression changes were verified by quantitative real-time PCR and Western blot analysis. The five up-regulated expressed phosphoproteins included Staphylococcal nuclease domain-containing protein 1(SND1), Septin-6, Glycyl-tRNA synthetase (GARS), Twinfilin-1 and eukaryotic elongation factor1-beta (eEF1B). This study revealed that availability of L-methionine influences the levels of nuclear phosphorylated proteins of DCMECs which opens a new avenue for the study of the molecular mechanism linking to milk protein synthesis.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Honghui Li ◽  
Xue Liu ◽  
Zhonghua Wang ◽  
Xueyan Lin ◽  
Zhengui Yan ◽  
...  

2019 ◽  
Vol 86 (2) ◽  
pp. 181-187
Author(s):  
Bin Li ◽  
Zhuzha Basang ◽  
Lijun Hu ◽  
Liu Liu ◽  
Nan Jiang

AbstractThis research paper addresses the hypothesis that Septin6 is a key regulatory factor influencing amino acid (AA)-mediated cell growth and casein synthesis in dairy cow mammary epithelial cells (DCMECs). DCMECs were treated with absence of AA (AA−), restricted concentrations of AA (AAr) or normal concentrations of AA (AA+) for 24 h. Cell growth, expression of CSN2 and Septin6 were increased in response to AA supply. Overexpressing or inhibiting Septin6 demonstrated that cell growth, expression of CSN2, mTOR, p-mTOR, S6K1 and p-S6K1 were up-regulated by Septin6. Furthermore, overexpressing or inhibiting mTOR demonstrated that the increase in cell growth and expression of CSN2 in response to Septin6 overexpression were inhibited by mTOR inhibition, and vice versa. Our hypothesis was supported; we were able to show that Septin6 is an important positive factor for cell growth and casein synthesis, it up-regulates AA-mediated cell growth and casein synthesis through activating mTORC1 pathway in DCMECs.


Amino Acids ◽  
2016 ◽  
Vol 48 (9) ◽  
pp. 2179-2188 ◽  
Author(s):  
Qian Jiang ◽  
Liuqin He ◽  
Yongqing Hou ◽  
Jiashun Chen ◽  
Yehui Duan ◽  
...  

2016 ◽  
Vol 56 (11) ◽  
pp. 1803 ◽  
Author(s):  
Q. Tian ◽  
H. R. Wang ◽  
M. Z. Wang ◽  
C. Wang ◽  
S. M. Liu

The expression of CSN3, hormone receptor, the expression of genes regulating the mTOR, JAK–STAT signal pathways, and the relative content of к-casein as well as total casein were determined in the present study to explore the mechanism of the effect of lactogenic hormones on milk-protein synthesis in bovine mammary epithelial cells. The results showed that apoptosis of the cells was increased by inhibitor LY294002, while the expressions of genes encoding PKB, Rheb, PRAS40 and S6K1 in the mTOR signal pathway, JAK2, STAT5A in the JAK–STAT signal pathway, and genes encoding INSR, PRLR, NR3C1 and CSN3 were all downregulated, and the relative contents of κ-casein and total casein were decreased in the mammary epithelial cells compared with those in the control group. Comparatively, the inhibitory effects of AG-490 were more profound than those of LY294002, and the double block using both inhibitors had a greater effect than the single block. The CSN3 gene expression was downregulated and the content of milk casein was decreased by the inhibitors. In addition, the expression of the hormone receptor genes was downregulated. Our results suggest that lactogenic hormones, via their receptors in the membrane, regulated the JAK–STAT and m-TOR signal pathways, and affected cell proliferation and apoptosis, leading to changes in milk-protein synthesis.


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