Effects Of Essential Amino Acids, Glucose And Insulin On Proliferation And Protein Synthesis In Bovine Mammary Epithelial Cells

The objectives of this study were to investigate the regulatory effects of essential AA(EAA),insulin(INS),glucose(GLU)and their interactions on proliferation,gene mRNA expression and phosphorylation state of signaling proteins in bovine mammary epithelial cells(MAC-T),to explore which regularity is more sensitive.The experiment included a single factor repeat design(Amino Acid: 0,0.36,1.8,3.6,5.4,7.2 mmol/L;glucose: 0,4.375,8.75,13.123,17.5,35,70 mmol/L;insulin: 0,25,50,75,100,400,1600 ng/mL)and two factorial arrangement of treatments(0 or 7.2 mmol/L amino acid with 0 or 17.5 mmol/L glucose;0 or 7.2 mmol/L amino acid with 0 or 100 ng/mL insulin).This study include three parts.The purpose of part 1 was to examine effects of EAA,GLU and INS on bovine mammary epithelial cells relative growth rate,the result of this study were showed that EAA,GLU or INS has a significant effect on proliferation(P<0.05).The purpose of part 2 was to examine effects of EAA,GLU and INS on the gene mRNA expression in MAC-T.The result of this study were showed that EAA,GLU or INS has a significant effect on the k-casein(CSN3)mRNA expression(P<0.01).The purpose of part 3 was to examine effects of EAA,GLU and INS on phosphorylation state of signaling proteins.The result of this study were showed that EAA has a significant effect on the phosphorylation state of mTOR(Ser2448),S6K1(Thr389)and 4EBP1(Thr37/46)(P<0.01),GLU has a significant effect(P<0.01)on the phosphorylation state of AMPK(Thr172),INS has a significant effect(P<0.01)on the phosphorylation state of AKT(Ser473).In conclusion,EAA,GLU or INS has a significant effect on proliferation,gene mRNA expression and phosphorylation state of signaling proteins in MAC-T cells(P<0.01),and has additive effect among nutrition.