Phenylalanine and valine differentially stimulate milk protein synthetic and energy-mediated pathway in immortalized bovine mammary epithelial cells
Studies on promoting milk protein yield by supplementation of amino acids have been globally conducted. Nevertheless, there is a lack of knowledge of what pathways affected by individual amino acid in mammary epithelial cells that produce m...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Korean Society of Animal Sciences and Technology
2020-03-01
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| Series: | Journal of Animal Science and Technology |
| Subjects: | |
| Online Access: | http://www.ejast.org/archive/view_article?pid=jast-62-2-263 |
| Summary: | Studies on promoting milk protein yield by supplementation of amino acids have
been globally conducted. Nevertheless, there is a lack of knowledge of what
pathways affected by individual amino acid in mammary epithelial cells that
produce milk in practice. Phenylalanine (PHE) and valine (VAL) are essential
amino acids for dairy cows, however, researches on mammary cell levels are still
lacking. Thus, the aim of this study was conducted to evaluate the effects of
PHE and VAL on milk protein synthesis-related and energy-mediated cellular
signaling in vitro using immortalized bovine mammary epithelial
(MAC-T) cells. To investigate the effects of PHE and VAL, the following
concentrations were added to treatment medium: 0, 0.3, 0.6, 0.9, 1.2, and 1.5
mM. The addition of PHE or VAL did not adversely affect cell viability compared
to control group. The concentrations of cultured medium reached its maximum at
0.9 mM PHE and 0.6 mM VAL (p < 0.05). Therefore,
aforementioned 2 treatments were analyzed for proteomics. Glucose transporter 1
and mammalian target of rapamycin mRNA expression levels were up-regulated by
PHE (166% and 138%, respectively) (p < 0.05). Meanwhile,
sodium-dependent neutral amino acids transporter type 2 (ASCT2)
and β-casein were up-regulated by VAL (173% in ASCT2,
238% in and 218% in β-casein) (p < 0.05). A total of
134, 142, and 133 proteins were detected in control group, PHE treated group,
and VAL treated group, respectively. Among significantly fold-changed proteins,
proteins involved in translation initiation or energy metabolism were detected,
however, expressed differentially between PHE and VAL. Thus, pathway analysis
showed different stimulatory effects on energy metabolism and transcriptional
pathways. Collectively, these results showed different stimulatory effects of
PHE and VAL on protein synthesis-related and energy-mediated cellular signaling
in MAC-T cells. |
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| ISSN: | 2672-0191 2055-0391 |