TY - JOUR AU - Kim Jung-min AU - Lee Kyoung-pil AU - Park Soo-jin AU - Kang Saeromi AU - Huang Jin AU - Lee Jung-min AU - Sato Koichi AU - Chung Hae-young AU - Okajima Fumikazu AU - Im Dong-soon PY - 2017 TI - Omega-3 fatty acids induce Ca 2+ mobilization responses in human colon epithelial cell lines endogenously expressing FFA4 JF - Acta Pharmacologica Sinica; Vol 36, No 7 (July 2015): Acta Pharmacologica Sinica Y2 - 2017 KW - N2 - Aim: Free fatty acid receptor 4 (FFA4; formerly known as GPR120) is the G protein-coupled receptor (GPCR) for omega-3 polyunsaturated fatty acids. FFA4 has been found to express in the small intestines and colons of mice and humans. In this study we investigate the effects of omega-3 polyunsaturated fatty acids on FFA4 in human colon epithelial cells in vitro . Methods: HCT116 and HT-29 human colon epithelial cell lines endogenously expressing FFA4 were used. Intracellular Ca 2+ concentration ([Ca 2+ ] i ) was measured in fura 2-AM-loaded cells with fluorescence spectrophotometry. RT-PCR and immunohistochemistry were used to detect FFA4. Results: Ten to 100 μmol/L of omega-3 polyunsaturated fatty acids α -linolenic acid ( α LA) or eicosapentaenoic acid (EPA) induced dose-dependent [Ca 2+ ] i increase in HCT116 and HT-29 cells, whereas docosahexaenoic acid (DHA) had no effect. In addition, the omega-6 fatty acids linoleic acid and γ -linoleic acid also dose-dependently increase [Ca 2+ ] i , but the mono-unsaturated fatty acid oleic acid and saturated fatty acids such as stearic acid and palmitic acid had no effect. In HCT116 and HT-29 cells, the α LA-induced [Ca 2+ ] i increase was partially inhibited by pretreatment with EGTA, phospholipase C inhibitor edelfosine, cADPR inhibitors 8-bro-cADPR or DAB, and abolished by pretreatment with Ca 2+ ATPase inhibitor thapsigargin, but was not affected by G i/o protein inhibitor PTX or IP 3 R inhibitor 2-APB. Conclusion: Omega-3 and omega-6 long-chain polyunsaturated fatty acids (C18-20) induce Ca 2+ mobilization responses in human colonic epithelial cells in vitro through activation of FFA4 and PTX-insensitive G i/o protein, followed by Ca 2+ release from thapsigargin-sensitive Ca 2+ stores and Ca 2+ influx across the plasma membrane. UR - http://www.chinaphar.com/article/view/9353