Leucine and histidine independently regulate milk protein synthesis in bovine mammary epithelial cells via mTOR signaling pathway

Abstract

Abstract:The aim of this study is to investigate the effects of leucine (Leu) and histidine (His) on the expression of both the mammalian target of rapamycin (mTOR) signaling pathway-related proteins and caseins in immortalized bovine mammary epithelial cells (CMEC-H), using a single supplement through Western blotting. The Earle's balanced salt solution (EBSS) was set as the control group and other treatment groups, based on the EBSS, were added with different concentrations of Leu or His, respectively. The results showed that, compared with the control group, the expression of caseins and the phosphorylation of mTOR (Ser Similarly, the His supplementation from 0.15 to 9.60 mmol/L increased the expression of αs2-casein, β-casein, κ-casein, P-mTOR (Ser 2481 ), P-Raptor (Ser 792 ), P-S6K1 (Thr 389 ), P-4EBP1 (Thr 37 ), P-eIF4E (Ser 209 ), and P-eEF2 (Thr 56 ) (P<0.01) in CMEC-H, whereas the αs1-casein expression was only reduced at 9.60 mmol/L His, G protein β subunit-like protein (GβL) at 0.15 and 9.60 mmol/L His, and P-RPS6 at 4.80 to 9.60 mmol/L His. Our linear regression model assay suggested that the αs1-casein expression was positively correlated with P-mTOR (P<0.01), P-S6K1 (P<0.01), and P-eEF2 (P<0.01) for the addition of Leu, while the expressions of β-casein (P<0.01) and κ-casein (P<0.01) were positively correlated with P-eEF2 for the addition of His. In conclusion, the milk protein synthesis was up-regulated through activation of the mTOR pathway with the addition of Leu and His in CMEC-H.

Effect of interaction between leucine and acetate on the milk protein synthesis in bovine mammary epithelial cells

“…Leu increased CSN1S1, CSN2, and CSN3 abundance in BMECs (Gao et al, 2015). Leu increased CSN1S1, CSN2, and CSN3 abundance in BMECs (Gao et al, 2015).…”

“…At present, the effect of AA on milk protein synthesis was widely demonstrated. Leu increased CSN1S1, CSN2, and CSN3 abundance in BMECs (Gao et al, 2015). Liu et al (2012) reported that the supplement of Leu significantly increases the expression of STAT5A and STAT5 has a positive effect on the expression of CSN2.…”

“…The previous study found that Leucine (Leu) (Gao, Hu, Zheng, & Wang, 2015) or acetate (Sheng, 2015) alone regulates the milk protein synthesis in bovine mammary gland epithelial cells (BMECs). The previous study found that Leucine (Leu) (Gao, Hu, Zheng, & Wang, 2015) or acetate (Sheng, 2015) alone regulates the milk protein synthesis in bovine mammary gland epithelial cells (BMECs).…”

Safety and efficacy of l‐histidine monohydrochloride monohydrate produced by fermentation with Escherichia coli (NITE BP‐02526) for all animal species

“…The production of milk, protein, casein and lactose were significantly higher following histidine supplementation (2.5 g/L in water for drinking or diet supplemented with 13.6 g/d) compared to control (Doelman et al, 2008;Hadrov a et al, 2012). Gao et al (2015) investigated the effects of leucine and histidine on the mammalian target of rapamycin (mTOR) signalling pathway in milk protein synthesis using CMEC-H (bovine mammary epithelial cells) and demonstrated that leucine or histidine stimulated the expression of different forms of caseins.…”

Molecular nutrition: basic understanding of the digestion, absorption, and metabolism of nutrients

“…Compared with 17% crude protein (CP) group and 20% CP group, the 14% CP group presented the lowest average daily feed intake (ADFI) and average daily gain (ADG), as well as the expression of ASCT2, 4F2hc, and ATB 0 mRNA in the jejunum, indicating that a 14% CP diet supplemented with crystalline amino acid (AA) may not transport enough AA into the body to maintain growth performance in piglets. Gao et al (2015) demonstrated that L-leucine and L-histidine supplementation in medium both can upregulate milk proteins, such as α-casein, β-casein, and κ-casein synthesis via the activation of mammalian target of rapamycin (mTOR) pathway in bovine mammary epithelial cells. Nie C.X.…”