| As one of the three major nutrients, dietary protein plays an important role in in the metabolism and the growth and development of life, which also is the mainly effect factors to affect the growth and carcass constitute of livestock and poultry. When dietary protein was intaked, it wil be digested by a variety of digestive enzymes in the small intestine, and be boken down into kinds of amino acids and peptides, and then absorbed by the digestive system. Most of of peptides were eventually broken down into amino acids in cells, and be further used. The essence of protein nutrition is amino acid nutrition. Amino acids could be divided into essential amino acids and non-essential amino acid in traditional nutrition. For a long time, the essential amino acids are the focus in animal nutrition research, however, far less condition on non-essential amino acids. Recent studies have found that"non-essential amino acid" does not meet the needs of their own growth, lactation, and health in the current swine feeding way and standard nutritional requirements. At present, the relevant functional amino acids on intestinal health and intestinal protein synthesis has been reported, but the detailed mechanism is still not very clear. There are rarely reports on the effect from functional amino acids on protein metabolism and the related signal pathways regulation in mammary gland cells. In the present study, we choose porcine intestinal epithelial cells (IPEC-1) and porcine mammary epithelial cells (PMEC) as the research object, focused on several functional amino acid, including arginine (Arg), glutamate (Glu), glutamine (Gln) and proline (Pro), the effect from functional amino acids on protein synthesis and related signal pathways via determination of cell proliferation and protein synthesis, protein degration and the key gene express profiles in related signal pathways. The results will benefit the application of functional amino acids in pig breeding industry.1 The metabonomics differences between lactation sows with high and low lactation performanceThe aim of this study was trying to find biomarkers to reflect the lactation performance of sows through compare analysis of serum metabonomics between pigs with high and low lactation performance. Sixteen sows with the same genetic background, similar birth rank, but with significant dfferent lactation performance. The plasma were collected and saved as two group, The A group with high lactation performace and B group with low lactation performance, each group had 8 repeats. LC-MS analysis were done towards each samples, and the changes of metabolites were identified according to test results. The changed metabolites, mainly amino acids, unsaturated fatty acids, organic acids, neurotransmitter were screened in the present study. The changed amino acids includ arginine (higher in group A than group B, P<0.05), proline and leucine (lower in group A than group B, P< 0.05). The changed unsaturated fatty acids includ oleic acid, linoleic acid, arachidonic acid (higher in group A than in group B, P<0.05). The changed organic acids includ malic acid, succinic acid (P>0.05). The changed neurotransmitter was dopamine (obviously lower in group A than that in group B, P<0.05). The metabolites identification was according to the Variable Importance in the Projection using PLS-DA model, which was difined as>1. Of which, arginine is the most outstanding. The serous concentration of Arg in group A is higher with a 0.397 fold than that in group B (P=0.003), which shows the importance of arginine in the sow lactation process. Therefore, starting from the test results, trying to find out key metabolite that influence the performance of the sow lactation is particularly important.2 The effect of Arg, Glu, Gin and Pro on protein metabolism and related signal pathways in intestinal epithelial cellsThe porcine IPEC-1 was selected as the research object. Adding different concentration of Arg, Glu, Gln, Pro to medium respectively, the cells were collected on the day 0,2,4,6, and then cell numbers were counted. The results show that each of Arg, Glu, Gln and Pro can promote cell proliferation, decrese cell apoptosis, and Arg shows the strongest effect, especially under the concentration of 0.12 mM, which can promote intestinal epithelial cell proliferation with a 10% fold. Based on the results above, Arg was further studied on the protein synthesis and the related signal pathways in IPEC-1. The results show that the expression of p-mTOR、p-4EBP1 and p-p70S6 in IPEC-1 cultured with 100 μM and 35OμM Arg concentration were higher than 10μM group (P<0.05). No difference in the expression of mTOR and 4EBP1 (P>0.05) were detected. The expression of p-PI3K、Akt、p-Akt and Bcl-2 in IPEC-1 cultured in 100 μM and 350μM were higher than in 10μM medium (P<0.05). The expression of p-PI3K, Akt, p-Akt and Bcl-2 in IPEC-1 were lower in 100μM Arg+L-NAME than in 100μM Arg group (P<0.05). The expression of p-PI3K, Akt and p-Akt in IPEC-1 were lower in 350μM Arg+L-NAME than in 350μM Arg group (P<0.05).3 The effect of Arg on protein synthesis and related signal pathways in porcine mammary epithelial cellsThe regulation function and mechanism of Arg on cell proliferation of porcine mammary epithelial cells(PMEC) were studied in vitro. The results showed culture supplementation of Arg benefit the growth of PMEC. Arg obviously promote the cell proliferation of PMEC in 0.25 mM and 0.5 mM arginine during the whole training stage. In the initial stage, the treatment cells have no difference (P>0.05). In day 3, the number of cells of 0.25 and 0.5 mM Arg treatment group were increased by 17.6%(P< 0.05) and 20.1 (P<0.05) compared with control group. In day 5, the number of cells in 0.25 mM and 0.5 mM treatment group were increased by 27.6%(P<0.01) and 29.3%(P<0.01) than the control group, respectively. In day 7, the number of cells in 0.25 mM and 0.5 mM treatment group were increased by 33.1%(P<0.01) and 34.3%(P<0.01) than the control group, respectively. The control group and and 0.5 mM and 1 mM Arg treated group in the whole stage had no significant differences. When the arginine concentration in cell culture were increased from 0.1 mM to 2 mM, cell protein concentrations were also significantly increased by 50.8%(P<0.01) and 57.8%(P< 0.01) respectively. The Arg 2 group had no difference with other groups in cell total protein concentration, but with highest a-casin content. From Arg 0 group to Arg 1 group, the a-casin synthesis increased along with increased Arg concentions in cell cultures. From Arg 2 group to Arg 8 group, the a-casin synthesis decreased along with increased Arg concentions in cell cultures. The effect of Arg on the synthesis of β-casin in PMEC is similar to that of a-casin. As for the expression of JAK2、STAT5、mTOR、S6K, Arg treated groups up-regulated their expression (P<0.05), with the highest expression in Arg 2 group. However, the expression of 4EBP1were inhibited when treated with high Arg.4 The effect from Arg, Glu, Gln and Pro on reproductive performention of sowsThe effect of dietary supplementation of 1% of Arg, Gln, Pro, Glu respectively with based pregnant sows and nursing sow material formula on sow reproductive performance were assessed. Dietary supplementation of Arg, Glu, Gln benefit the sow reproductive performance. The supplementation of Arg, Glu and Gln The increased piglet numbers in each litter (P>0.05), neonatal litter weight and weaning weight (P<0.05), while Pro had no effects. No effects were found on food intake by dietary adding of Arg, Glu, Gln, Pro respectively. But arginine had no effect on litter birth weight of the next generation of on different reprodcuctive times sows (P>0.05). Dietary supplementation of Arg, Glu, Gln, Pro respectively also had no effect on sow oestrus interval (P>0.05). |
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