1.Stimulation of Cl- secretion by AlF4- and vanadate in T84 cells.
Tae Ho HWANG ; Jin Sup JUNG ; Hae Rahn BAE ; Il YUN ; Sang Ho LEE
Journal of Korean Medical Science 1994;9(6):497-504
We investigated the mechanism of Cl- secretion by fluoroaluminate(AlF4-) and sodium orthovanadate(vanadate) using the human colonic T84 cell line. T84 cell monolayers grown on collagen-coated filters were mounted in Ussing chambers to measure short circuit current(ISC). Serosal addition of AlF4- or vanadate to T84 monolayers produced a sustained increase in ISC. Removal of Ca2+ from the serosal bathing solution partially inhibited AlF4-(-)and vanadate-induced ISC, and readministration of Ca2+ restored AlF4-(-)and vanadate-induced ISC. Carbachol application in the presence of forskolin, AlF4- or vanadate induced a synergistic increase of ISC. Forskolin and vanadate significantly increased cellular cAMP level, while carbachol and AlF4- did not. Carbachol, AlF4- and vanadate significantly increased [Ca2+]i. After Na+ in mucosal bathing solution was replaced with K+, and the mucosal membrane of T84 cell was permeabilized with amphotericin B, AlF4-, vanadate, and carbachol increased K+ conductance, but forskolin did not. After sodium chloride in serosal bathing solution was replaced with sodium gluconate and the serosal membrane was permeabilized with nystatin, forskolin, AlF4-, and vanadate increased Cl- conductance, but carbachol did not. AlF4-(-)induced ISC was remarkably inhibited by the pretreatment of pertussis toxin(2 micrograms/ml) for 2 hours. These results indicate that AlF4- and vanadate can increase Cl- secretion via simultaneous stimulation of Cl- channel and K+ channel in T84 cells. However, the AlF4- action is mostly attributed to stimulation of pertussis toxin-sensitive G-proteins, whereas the vanadate action mostly results from G protein-independent mechanisms.
Aluminum/*pharmacology
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Amphotericin B/pharmacology
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Carbachol/pharmacology
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Cell Polarity
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Cells, Cultured/drug effects
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Chloride Channels/drug effects/*physiology
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Chlorides/*physiology
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Colon
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Electrophysiology
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Fluorine/*pharmacology
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Forskolin/pharmacology
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GTP-Binding Proteins/physiology
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Human
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Pertussis Toxin
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Potassium/pharmacology
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Potassium Channels/drug effects/physiology
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Second Messenger Systems
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Signal Transduction
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Support, Non-U.S. Gov't
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Vanadates/*pharmacology
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Virulence Factors, Bordetella/pharmacology
2.The synthetic peptide, His-Phe-Tyr-Leu-Pro-Met, is a chemoattractant for Jukat T cells.
Youn Dong KIM ; Yoe Sik BAE ; Jun Chul PARK ; Pann Ghill SUH ; Sung Ho RYU
Experimental & Molecular Medicine 2001;33(4):257-262
His-Phe-Tyr-Leu-Pro-Met (HFYLPM) is a synthetic peptide that stimulates Jurkat T cells resulting in intracellular calcium ([Ca2+]i) increase in a pertussis toxin (PTX)-sensitive manner. We have examined the physiological role of the peptide in T cell activity by comparative investigation of intracellular signaling pathways accompanied with HFYLPM-induced T cell chemotaxis with a well-known chemokine, stromal cell-derived factor-1 (SDF-1)-induced signalings. Wortmannin and genistein inhibited both of HFYLPM- and SDF-1-induced Jurkat T cell chemotaxis indicating that phosphoinositide-3-kinase and tyrosine kinase activity were required for the processes. However, U-73122 and BAPTA/AM preferentially blocked HFYLPM- but not SDF-1-induced T cell chemotaxis. It indicates that phospholipase C/calcium signaling is necessary for only chemotaxis by HFYLPM. One of the well-known cellular molecules involving chemotaxis, extracellular signal-regulated protein kinase (ERK), was activated by SDF-1 but not by HFYLPM ruling out a possible role of ERK on the peptide-mediated chemotaxis. These results indicate that the synthetic peptide, HFYLPM, stimulates T cell chemotaxis showing unique signaling and provide a useful tool for the study of T cell activation mechanism.
1-Phosphatidylinositol 3-Kinase/metabolism
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Androstadienes/pharmacology
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Calcium/metabolism
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Cell Line
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Chemokines, CXC/*pharmacology
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Chemotaxis, Leukocyte/drug effects/*physiology
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Dose-Response Relationship, Drug
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Genistein/pharmacology
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Human
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Jurkat Cells
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Oligopeptides
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Peptide Fragments/chemical synthesis/metabolism/*physiology
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Pertussis Toxin
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Phospholipase C/metabolism
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Protein-Tyrosine Kinase/metabolism
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Signal Transduction/drug effects
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T-Lymphocytes/*drug effects
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Virulence Factors, Bordetella/pharmacology
3.The synthetic peptide, His-Phe-Tyr-Leu-Pro-Met, is a chemoattractant for Jukat T cells.
Youn Dong KIM ; Yoe Sik BAE ; Jun Chul PARK ; Pann Ghill SUH ; Sung Ho RYU
Experimental & Molecular Medicine 2001;33(4):257-262
His-Phe-Tyr-Leu-Pro-Met (HFYLPM) is a synthetic peptide that stimulates Jurkat T cells resulting in intracellular calcium ([Ca2+]i) increase in a pertussis toxin (PTX)-sensitive manner. We have examined the physiological role of the peptide in T cell activity by comparative investigation of intracellular signaling pathways accompanied with HFYLPM-induced T cell chemotaxis with a well-known chemokine, stromal cell-derived factor-1 (SDF-1)-induced signalings. Wortmannin and genistein inhibited both of HFYLPM- and SDF-1-induced Jurkat T cell chemotaxis indicating that phosphoinositide-3-kinase and tyrosine kinase activity were required for the processes. However, U-73122 and BAPTA/AM preferentially blocked HFYLPM- but not SDF-1-induced T cell chemotaxis. It indicates that phospholipase C/calcium signaling is necessary for only chemotaxis by HFYLPM. One of the well-known cellular molecules involving chemotaxis, extracellular signal-regulated protein kinase (ERK), was activated by SDF-1 but not by HFYLPM ruling out a possible role of ERK on the peptide-mediated chemotaxis. These results indicate that the synthetic peptide, HFYLPM, stimulates T cell chemotaxis showing unique signaling and provide a useful tool for the study of T cell activation mechanism.
1-Phosphatidylinositol 3-Kinase/metabolism
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Androstadienes/pharmacology
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Calcium/metabolism
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Cell Line
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Chemokines, CXC/*pharmacology
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Chemotaxis, Leukocyte/drug effects/*physiology
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Dose-Response Relationship, Drug
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Genistein/pharmacology
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Human
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Jurkat Cells
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Oligopeptides
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Peptide Fragments/chemical synthesis/metabolism/*physiology
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Pertussis Toxin
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Phospholipase C/metabolism
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Protein-Tyrosine Kinase/metabolism
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Signal Transduction/drug effects
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T-Lymphocytes/*drug effects
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Virulence Factors, Bordetella/pharmacology