AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats
Abstract Background The local supply of energy-yielding nutrients such as glucose seems to affect the synthesis of milk components in the mammary gland (MG). Thus, our study was conducted to investigate the effects of locally available MG glucose supply (LMGS) on amino acid (AA) sensing and utilizat...
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doaj-11ace34d0c5f45839b32de227000da7e2021-02-14T12:05:10ZengBMCJournal of Animal Science and Biotechnology2049-18912020-02-0111111210.1186/s40104-020-0434-6AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goatsJie Cai0Diming Wang1Feng-Qi Zhao2Shulin Liang3Jianxin Liu4Institute of Dairy Science, College of Animal Sciences, Zhejiang UniversityInstitute of Dairy Science, College of Animal Sciences, Zhejiang UniversityInstitute of Dairy Science, College of Animal Sciences, Zhejiang UniversityInstitute of Dairy Science, College of Animal Sciences, Zhejiang UniversityInstitute of Dairy Science, College of Animal Sciences, Zhejiang UniversityAbstract Background The local supply of energy-yielding nutrients such as glucose seems to affect the synthesis of milk components in the mammary gland (MG). Thus, our study was conducted to investigate the effects of locally available MG glucose supply (LMGS) on amino acid (AA) sensing and utilization in the MG of lactating dairy goats. Six dosages of glucose (0, 20, 40, 60, 80, and 100 g/d) were infused into the MG through the external pudendal artery to investigate the dose-dependent changes in mammary AA uptake and utilization (Exp.1) and the changes in mRNA and protein expression of the AMPK-mTOR pathway (Expt.2). Results In Exp.1, total milk AA concentration was highest when goats were infused with 60 g/d glucose, but lower when goats were infused with 0 and 100 g/d glucose. Increasing LMGS quadratically changed the percentages of αS2-casein and α-lactalbumin in milk protein, which increased with infusions from 0 to 60 g/d glucose and then decreased with infusions between 60 and 100 g/d glucose. The LMGS changed the AA availability and intramammary gland AA utilization, as reflected by the mammary AA flux indexes. In Exp.2, the mRNA expression of LALBA in the MG increased quadratically with increasing LMGS, with the highest expression at dose of 60 g/d glucose. A high glucose dosage (100 g/d) activated the general control nonderepressible 2 kinase, an intracellular sensor of AA status, resulting in a reduced total milk AA concentration. Conclusions Our new findings suggest that the lactating MG in dairy goats may be affected by LMGS through regulation of the AA sensory pathway, AA utilization and protein synthesis, all being driven by the AMPK-mTOR pathway.https://doi.org/10.1186/s40104-020-0434-6Amino acid profileAMPK signalingGlucose supplyMammary glandMilk protein component |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jie Cai Diming Wang Feng-Qi Zhao Shulin Liang Jianxin Liu |
spellingShingle |
Jie Cai Diming Wang Feng-Qi Zhao Shulin Liang Jianxin Liu AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats Journal of Animal Science and Biotechnology Amino acid profile AMPK signaling Glucose supply Mammary gland Milk protein component |
author_facet |
Jie Cai Diming Wang Feng-Qi Zhao Shulin Liang Jianxin Liu |
author_sort |
Jie Cai |
title |
AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats |
title_short |
AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats |
title_full |
AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats |
title_fullStr |
AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats |
title_full_unstemmed |
AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats |
title_sort |
ampk-mtor pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats |
publisher |
BMC |
series |
Journal of Animal Science and Biotechnology |
issn |
2049-1891 |
publishDate |
2020-02-01 |
description |
Abstract Background The local supply of energy-yielding nutrients such as glucose seems to affect the synthesis of milk components in the mammary gland (MG). Thus, our study was conducted to investigate the effects of locally available MG glucose supply (LMGS) on amino acid (AA) sensing and utilization in the MG of lactating dairy goats. Six dosages of glucose (0, 20, 40, 60, 80, and 100 g/d) were infused into the MG through the external pudendal artery to investigate the dose-dependent changes in mammary AA uptake and utilization (Exp.1) and the changes in mRNA and protein expression of the AMPK-mTOR pathway (Expt.2). Results In Exp.1, total milk AA concentration was highest when goats were infused with 60 g/d glucose, but lower when goats were infused with 0 and 100 g/d glucose. Increasing LMGS quadratically changed the percentages of αS2-casein and α-lactalbumin in milk protein, which increased with infusions from 0 to 60 g/d glucose and then decreased with infusions between 60 and 100 g/d glucose. The LMGS changed the AA availability and intramammary gland AA utilization, as reflected by the mammary AA flux indexes. In Exp.2, the mRNA expression of LALBA in the MG increased quadratically with increasing LMGS, with the highest expression at dose of 60 g/d glucose. A high glucose dosage (100 g/d) activated the general control nonderepressible 2 kinase, an intracellular sensor of AA status, resulting in a reduced total milk AA concentration. Conclusions Our new findings suggest that the lactating MG in dairy goats may be affected by LMGS through regulation of the AA sensory pathway, AA utilization and protein synthesis, all being driven by the AMPK-mTOR pathway. |
topic |
Amino acid profile AMPK signaling Glucose supply Mammary gland Milk protein component |
url |
https://doi.org/10.1186/s40104-020-0434-6 |
work_keys_str_mv |
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