scholarly journals Camellia ( Camellia oleifera Abel.) seed oil promotes milk fat and protein synthesis‐related gene expression in bovine mammary epithelial cells

2019 ◽  
Vol 8 (1) ◽  
pp. 419-427 ◽  
Author(s):  
Wanqi Zhong ◽  
Jinglin Shen ◽  
Xiandong Liao ◽  
Xinlu Liu ◽  
Jing Zhang ◽  
...  
2020 ◽  
Vol 87 (2) ◽  
pp. 226-231
Author(s):  
Xiaoming Hou ◽  
Minghui Jiang ◽  
Jinyu Zhou ◽  
Shuyuan Song ◽  
Feng Zhao ◽  
...  

AbstractIn this research communication, a cell model with elevated β-CASEIN synthesis was established by stimulating bovine mammary epithelial cells with 0.6 mM methionine, and the genome-wide gene expression profiles of methionine-stimulated cells and untreated cells were investigated by RNA sequencing. A total of 458 differentially expressed genes (DEGs; 219 upregulated and 239 downregulated) were identified between the two groups. Gene Ontology (GO) analysis showed that the two highest-ranked GO terms in ‘molecular function’ category were ‘binding’ and ‘catalytic activity’, suggesting that milk protein synthesis in methionine-stimulated cells requires induction of gene expression to increase metabolic activity. Kyoto Encyclopedia of Genes and Genomes analysis revealed that within the ‘environmental information processing’ category, the subcategory that is most highly enriched for DEGs was ‘signal transduction’. cGMP-PKG, Rap1, calcium, cAMP, PI3K-AKT, MAPK, and JAK-STAT are the pathways with the highest number of DEGs, suggesting that these signaling pathways have potential roles in mediating methionine-induced milk protein synthesis in bovine mammary epithelial cells. This study provides valuable insights into the physiological and metabolic adaptations in cells stimulated with methionine. Understanding the regulation of this transition is essential for effective intervention in the lactation process.


1995 ◽  
Vol 108 (2) ◽  
pp. 519-527 ◽  
Author(s):  
P.L. Jones ◽  
N. Boudreau ◽  
C.A. Myers ◽  
H.P. Erickson ◽  
M.J. Bissell

The physiological role of tenascin in vivo has remained obscure. Although tenascin is regulated in a stage and tissue-dependent manner, knock-out mice appear normal. When tenascin expression was examined in the normal adult mouse mammary gland, little or none was present during lactation, when epithelial cells actively synthesize and secrete milk proteins in an extracellular matrix/lactogenic hormone-dependent manner. In contrast, tenascin was prominently expressed during involution, a stage characterized by the degradation of the extracellular matrix and the subsequent loss of milk production. Studies with mammary cell lines indicated that tenascin expression was high on plastic, but was suppressed in the presence of the laminin-rich, Engelbreth-Holm-Swarm (EHS) tumour biomatrix. When exogenous tenascin was added together with EHS to mammary epithelial cells, beta-casein protein synthesis and steady-state mRNA levels were inhibited in a concentration-dependent manner. Moreover, this inhibition by tenascin could be segregated from its effects on cell morphology. Using two beta-casein promoter constructs attached to the chloramphenicol acetyltransferase reporter gene we showed that tenascin selectively suppressed extracellular matrix/prolactin-dependent transcription of the beta-casein gene in three-dimensional cultures. Finally, we mapped the active regions within the fibronectin type III repeat region of the tenascin molecule that are capable of inhibiting beta-casein protein synthesis. Our data are consistent with a model where both the loss of a laminin-rich basement membrane by extracellular matrix-degrading enzymes and the induction of tenascin contribute to the loss of tissue-specific gene expression and thus the involuting process.


2012 ◽  
Vol 57 (No. 10) ◽  
pp. 469-480 ◽  
Author(s):  
T. Sigl ◽  
H.H.D. Meyer ◽  
S. Wiedemann

&nbsp;The objective of the present study was to refine a previously developed method to isolate primary bovine mammary epithelial cells (pBMEC) from fresh milk. Using this method, it was tested whether the number of pBMEC and the relation of recovered pBMEC to total somatic cell count vary within the individual lactation stages. Furthermore, the expression levels of the milk protein genes during the first twenty weeks of lactation were determined by quantitative PCR method. A total number of 152 morning milk samples were obtained from twenty-four Holstein-Friesian cows during the first 20 weeks of lactation (day 8, 15, 26, 43, 57, 113, and 141 postpartum). Numbers of extracted pBMEC were consistent at all time-points (1.1 &plusmn; 0.06 to 1.4 &plusmn; 0.03 &times;10<sup>3</sup>/ml) and an average value of RNA integrity number (RIN) was 6.3 &plusmn; 0.3. Percentage of pBMEC in relation to total milk cells (2.0 &plusmn; 0.2 to 6.7 &plusmn; 1.0%) correlated with milk yield. Expression patterns of the casein genes alpha (&alpha;)<sub>S1</sub>, (&alpha;)<sub>S2</sub>, beta (&beta;), and kappa (&kappa;) (CSN1S1, CSN1S2, CSN2, CSN3, respectively) and the whey protein genes &alpha;-lactalbumin (LALBA) and progestagen-associated endometrial protein (PAEP; known as &beta;-lactoglobulin) were shown to be comparable, i.e. transcripts of all six milk protein genes were found to peak during the first two weeks of lactation and to decline continuously towards mid lactation. However, mRNA levels were different among genes with CSN3 showing the highest and LALBA the lowest abundance. We hypothesized that milk protein gene expression has a pivotal effect on milk protein composition with no influence on milk protein concentration. This paper is the first to describe milk protein gene expression during lactation in pBMEC collected in milk. Future studies will be needed to understand molecular mechanisms in pBMEC including regulation of expression and translation throughout lactation. &nbsp;


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