title: L-arginine upregulates the gene expression of target of rapamycin signaling pathway and stimulates protein synthesis in chicken intestinal epithelial cells.
abstract: L-arginine (Arg) is an indispensable amino acid in avians and is required for growth. The aim of this study was to investigate the effects of L-Arg on protein synthesis and genes expression involved in target of rapamycin (TOR) signaling pathway in chicken enterocytes. Cells were cultured for 4 days in L-Arg-free Dulbecco's modified Eagle's medium containing 10, 100, 200, 400, or 600 μM L-Arg. Cell growth, cell cycle, protein synthesis, and protein degradation as well as mRNA expression levels of TOR, ribosomal protein S6 kinase 1 (S6K1), and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) were determined. The results showed that cell viability was enhanced by L-Arg with a maximal response at 10 to 400 μM. Increasing extracellular concentrations of L-Arg from 10 to 400 μM increased the cells in S and G2/M phase to a significant extent and decreased cell numbers in G0/G1 phase. Further more, addition of 100, 200, or 400 μM L-Arg to culture medium increased protein synthesis and reduced protein degradation in chicken intestinal epithelial cells. Consistent with the data on cell growth and protein turnover, supplementation of 100, 200, or 400 μM L-Arg increased the mRNA abundances of TOR, 4E-BP1, and S6K1. It was concluded the action of L-Arg involves in upregulating the genes expression of TOR cell signaling pathway which increases protein synthesis and reduces protein degradation.
authors.affiliation: Feed Science Institute, College of Animal Science, Zhejiang University, Hangzhou, China 310058.
authors.forename: C
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Feed Science Institute, College of Animal Science, Zhejiang University, Hangzhou, China 310058.
authors.forename: Y
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Feed Science Institute, College of Animal Science, Zhejiang University, Hangzhou, China 310058.
authors.forename: Qiang
authors.initials: Q
authors.lastname: He
authors.affiliation: Feed Science Institute, College of Animal Science, Zhejiang University, Hangzhou, China 310058 Poultry Production Department, Mansoura University, Mansoura 35516, Egypt.
authors.forename: M M M
authors.initials: MM
authors.lastname: Azzam
authors.affiliation: Feed Science Institute, College of Animal Science, Zhejiang University, Hangzhou, China 310058 jjlu@zju.edu.cn xtzou@zju.edu.cn.
authors.forename: J J
authors.initials: JJ
authors.lastname: Lu
authors.affiliation: Feed Science Institute, College of Animal Science, Zhejiang University, Hangzhou, China 310058 jjlu@zju.edu.cn xtzou@zju.edu.cn.
authors.forename: X T
authors.initials: XT
authors.lastname: Zou
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002478:Cells, Cultured; D002642:Chick Embryo; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D010750:Phosphoproteins; D012333:RNA, Messenger; D001120:Arginine; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases; C448901:ribosomal protein S6 kinase, 70kD, polypeptide 1
keywords: arginine; chicken epithelial cell; protein turnover; target of rapamycin