scholarly journals Meat hydrolysate and essential amino acid-induced glucagon-like peptide-1 secretion, in the human NCI-H716 enteroendocrine cell line, is regulated by extracellular signal-regulated kinase1/2 and p38 mitogen-activated protein kinases

2006 ◽  
Vol 191 (1) ◽  
pp. 159-170 ◽  
Author(s):  
Raylene A Reimer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Kinase ◽  
Cell Line ◽  
Essential Amino Acids ◽  
Enteroendocrine Cell ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Glucagon-like peptide-1 (GLP-1) is a potent insulin secretagogue released from L-cells in the intestine. Meat hydrolysate (MH) is a powerful activator of GLP-1 secretion in the human enteroendocrine NCI-H716 cell line, but the mechanisms involved in nutrient-stimulated GLP-1 secretion are poorly understood. The objective of this study was to characterize the intracellular signalling pathways regulating MH- and amino acid-induced GLP-1 secretion. Individually, the pharmacological inhibitors, SB203580 (inhibitor of p38 mitogen-activated protein kinase (MAPK)), wortmannin (inhibitor of phosphatidyl inositol 3-kinase) and U0126 (inhibitor of mitogen activated or extracellular signal-regulated protein kinase (MEK1/2) upstream of extracellular signal-regulated kinase (ERK)1/2) all inhibited MH-induced GLP-1 secretion. Further examination of the MAPK pathway showed that MH increased the phosphorylation of ERK1/2, but not p38 or c-Jun N-terminal kinase over 2–15 min. Incubation with SB203580 resulted in a decrease in phosphorylated p38 MAPK and a concomitant increase in the phosphorylation of ERK1/2. Phosphorylation of ERK1/2 was augmented by co-incubation of MH with SB203580. Inhibitors of protein kinase A and protein kinase C did not inhibit MH-induced GLP-1 secretion. In contrast to non-essential amino acids, essential amino acids (EAAs) increased GLP-1 secretion and similar to MH, activated ERK1/2. However, they also activated p38-suggesting type of protein may affect GLP-1 secretion. In conclusion, there appears to be a crosstalk between p38 and ERK1/2 MAPK in the human enteroendocrine cell with the activation of ERK1/2 common to both MH and EAA. Understanding the cellular pathways involved in nutrient-stimulated GLP-1 secretion has important implications for the design of new treatments aimed at increasing endogenous GLP-1 release in type-2 diabetes and obesity.

scholarly journals Expression and adaptive regulation of amino acid transport system A in a placental cell line under amino acid restriction

Reproduction ◽  
2006 ◽  
Vol 131 (5) ◽  
pp. 951-960 ◽  
Author(s):  
H N Jones ◽  
C J Ashworth ◽  
K R Page ◽  
H J McArdle
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cell Line ◽  
Transport System ◽  
Amino Acid Transport ◽  
Essential Amino Acids ◽  
Acid Transport ◽  
Amino Acid Transport System ◽  
Transcellular Transport ◽  
System A

Trans-placental transport of amino acids is vital for the developing fetus. Using the BeWo cell line as a placental model, we investigated the effect of restricting amino acid availability on amino acid transport system type A. BeWo cells were cultured either in amino acid-depleted (without non-essential amino acids) or control media for 1, 3, 5 or 6 h. System A function was analysed using α(methyl-amino)isobutyric acid (MeAIB) transcellular transport studies. Transporter (sodium coupled neutral amino acid transporter (SNAT1/2)) expression was analysed at mRNA and protein level by Northern and Western blotting respectively. Localisation was carried out using immunocytochemistry. MeAIB transcellular transport was significantly (P< 0.05) increased by incubation of the cells in amino acid-depleted medium for 1 h, and longer incubation times caused further increases in the rate of transfer. However, the initial response was not accompanied by an increase in SNAT2 mRNA; this occurred only after 3 h and further increased for the rest of the 6-h incubation. Similarly, it took several hours for a significant increase in SNAT2 protein expression. In contrast, relocalisation of existing SNAT2 transporters occurred within 30 min of amino acid restriction and continued throughout the 6-h incubation. When the cells were incubated in medium with even lower amino acid levels (without non-essential plus 0.5 × essential amino acids), SNAT2 mRNA levels showed further significant (P< 0.0001) up-regulation. However, incubation of cells in depleted medium for 6 h caused a significant (P= 0.014) decrease in the expression of SNAT1 mRNA. System L type amino acid transporter 2 (LAT2) expression was not changed by amino acid restriction, indicating that the responses seen in the system A transporters were not a general cell response. These data have shown that placental cells adaptin vitroto nutritional stress and have identified the physiological, biochemical and genomic mechanisms involved.

scholarly journals Cyclic AMP triggers glucagon-like peptide-1 secretion from the GLUTag enteroendocrine cell line

Diabetologia ◽  
2007 ◽  
Vol 50 (10) ◽  
pp. 2181-2189 ◽  
Author(s):  
A. K. Simpson ◽  
P. S. Ward ◽  
K. Y. Wong ◽  
G. J. Collord ◽  
A. M. Habib ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Cell Line ◽  
Enteroendocrine Cell ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Piperine, as a TAS2R14 agonist, stimulates secretion of glucagon-like peptide-1 in human enteroendocrine cell line Caco-2

2021 ◽  
Author(s):  
Ting-Ting Huang ◽  
Pan-Pan Gu ◽  
Ting Zheng ◽  
Ling-Shan Gou ◽  
Yao-Wu Liu
Keyword(s):  
Cell Line ◽  
Molecular Mechanism ◽  
Metabolic Diseases ◽  
Enteroendocrine Cell ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Piperine is reported to ameliorate common metabolic diseases, however, the molecular mechanism is still unclear. In the present study, we examined whether piperine could stimulate glucagon-like peptide-1 (GLP-1) secretion in...

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