DHA （docosahexaenoic acid） and EPA （eicosapentaenoic acid） induced intracellular calcium increase in taste receptor cells purified from mouse circumvallate papillae. We have demonstrated that DHA and EPA induced c...DHA （docosahexaenoic acid） and EPA （eicosapentaenoic acid） induced intracellular calcium increase in taste receptor cells purified from mouse circumvallate papillae. We have demonstrated that DHA and EPA induced calcium increase respectively via cPLA2 （cytosolic phospholipase A2） type lVc and calcium independent iPLA2 （phospholipase A2） type VI. Intracellular calcium increases via PLC （phospholipase C） pathway and leads to a calcium effiux and further SOC （stored operated calcium） channels activation. An abundant increase in intracellular calcium will induce exocytosis of neurotransmitters into the extracellular medium. Our results suggest that DHA and EPA induced calcium signaling, and should be implicated in the transmission of lipid gustatory information to afferent nerve fibers, as shown previously with linoleic acid.展开更多
Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultu...Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultured rat IIEC-6 cells with or without the pretreatment of intracellular Ca2+ chelator were exposed to Y-ir-radiation of 6 Gy, the total and phosphorylated MAPKs in the cells were determined with Western blotting and apoptosis was examined with flow cytometry. Activities of Extracellular signal-regulated protein kinase (ERK) and p38 MAPK were determined by using immuoprecipitation followed by Western blotting. Results: In response to γ-irradiation, phosphorylation of ERK was not significantly observed, while the levels of phosphorylated c-Jun NH2-terminal kinase (JNK) and p38 MAPK were increased in 30 min and reached the peak 2 h after exposure to 6 Gy γ-irradiation, though the cell viability was significantly lowered 12 h. On the other hand, no obvious changes were seen in the total protein levels of ERK, JNK and p38 MAPK. Chelation of intracellular Ca2+ almost completely suppressed the JNK and p38 MAPK phosphorylation induced by γ-irradia-tion, but removal of external Ca2+ had no such effect. Activation of p38 MAPK, but not of ERK, was seen to have a correlation with γ-irradiation induced apoptosis. Conclusion: The results suggest that γ-irradiation is a potent activator for JNK and p38 MAPK, and Ca2+ mobilized from intracellular stores plays an important role in the activation of MAPKs and the induction of apoptosis in IEC-6 cells.展开更多
文摘DHA （docosahexaenoic acid） and EPA （eicosapentaenoic acid） induced intracellular calcium increase in taste receptor cells purified from mouse circumvallate papillae. We have demonstrated that DHA and EPA induced calcium increase respectively via cPLA2 （cytosolic phospholipase A2） type lVc and calcium independent iPLA2 （phospholipase A2） type VI. Intracellular calcium increases via PLC （phospholipase C） pathway and leads to a calcium effiux and further SOC （stored operated calcium） channels activation. An abundant increase in intracellular calcium will induce exocytosis of neurotransmitters into the extracellular medium. Our results suggest that DHA and EPA induced calcium signaling, and should be implicated in the transmission of lipid gustatory information to afferent nerve fibers, as shown previously with linoleic acid.
基金in part by Natural Sciences Foundation of China (No. 39870239)by the Sasagawa Fellowship,Japan.
文摘Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultured rat IIEC-6 cells with or without the pretreatment of intracellular Ca2+ chelator were exposed to Y-ir-radiation of 6 Gy, the total and phosphorylated MAPKs in the cells were determined with Western blotting and apoptosis was examined with flow cytometry. Activities of Extracellular signal-regulated protein kinase (ERK) and p38 MAPK were determined by using immuoprecipitation followed by Western blotting. Results: In response to γ-irradiation, phosphorylation of ERK was not significantly observed, while the levels of phosphorylated c-Jun NH2-terminal kinase (JNK) and p38 MAPK were increased in 30 min and reached the peak 2 h after exposure to 6 Gy γ-irradiation, though the cell viability was significantly lowered 12 h. On the other hand, no obvious changes were seen in the total protein levels of ERK, JNK and p38 MAPK. Chelation of intracellular Ca2+ almost completely suppressed the JNK and p38 MAPK phosphorylation induced by γ-irradia-tion, but removal of external Ca2+ had no such effect. Activation of p38 MAPK, but not of ERK, was seen to have a correlation with γ-irradiation induced apoptosis. Conclusion: The results suggest that γ-irradiation is a potent activator for JNK and p38 MAPK, and Ca2+ mobilized from intracellular stores plays an important role in the activation of MAPKs and the induction of apoptosis in IEC-6 cells.
