Ohtsu Y, Nakagawa Y, Nagasawa M, Kojima I (IMCR, Gunma Univ.) Takeda S (Graduate School of Technology, Gunma Univ.) Arakawa H (Graduate School of Medicine, Gunma Univ.)
About
Sweet taste receptor regulates GLP-1 secretion in enteroendocrine L-cells. We investigated the signaling system activated by this receptor using Hutu-80 cells. We stimulated them with sucralose, saccharin, acesulfame K and glycyrrhizin. These sweeteners stimulated GLP-1 secretion, which was attenuated by lactisole. All these sweeteners elevated cytoplasmic cyclic AMP ([cAMP]c) whereas only sucralose and saccharin induced a monophasic increase in cytoplasmic Ca2+ ([Ca2+]c). Removal of extracellular calcium or sodium and addition of a Gq/11 inhibitor greatly reduced the [Ca2+]c responses to two sweeteners. In contrast, acesulfame K induced rapid and sustained reduction of [Ca2+]c. In addition, glycyrrhizin first reduced [Ca2+]c which was followed by an elevation of [Ca2+]c. Reductions of [Ca2+]c induced by acesulfame K and glycyrrhizin were attenuated by a calmodulin inhibitor or by knockdown of the plasma membrane calcium pump. These results indicate that various sweet molecules act as biased agonists and evoke strikingly different patterns of intracellular signals.
Paper information
Diverse signaling systems activated by the sweet taste receptor in human GLP-1-secreting cells.
Ohtsu Y, Nakagawa Y, Nagasawa M, Takeda S, Arakawa H, Kojima I.
Mol Cell Endocrinol. 394: 70-79, 2014
Online URL
http://www.ncbi.nlm.nih.gov/pubmed/25017733
