TY - JOUR
T1 - Antiallergic tea catechin, (-)-epigallocatechin-3-O-(3-O-methyl)-gallate, suppresses FcεRl expression in human basophilic KU812 cells
AU - Fujimura, Yoshinori
AU - Tachibana, Hirofumi
AU - Maeda-Yamamoto, Mari
AU - Miyase, Toshio
AU - Sano, Mitsuaki
AU - Yamada, Koji
PY - 2002/9/25
Y1 - 2002/9/25
N2 - We previously found that the O-methylated derivative of (-)-epigallocatechin-3-O-gallate (EGCg), (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG″3Me), has potent antiallergic activity. The high-affinity IgE receptor, FcεRI, is found at high levels on basophils and mast cells and plays a key role in a series of acute and chronic human allergic reactions. To understand the mechanism of action for the antiallergic EGCG″3Me, the effect of EGCG″3Me on the cell surface expression of FcεRI in human basophilic KU812 cells was examined. Flow cytometric analysis showed that EGCG″3Me was able to decrease the cell surface expression of FcεRI. Moreover, immunoblot analysis revealed that total cellular expression of the FcεRI α chain decreased upon treatment with EGCG″3Me. FcεRI is a tetrameric structure comprising one α chain, one β chain, and two γ chains. The level of mRNA production of each subunit in KU812 cells was investigated. EGCG″3Me reduced FcεRI α and γ mRNA levels. The cross-linkage of FcεRI causes the activation of basophils, which leads to the secretion of inflammatory mediators including histamine. EGCG″3Me treatment inhibited the FcεRI cross-linking-induced histamine release. These results suggested that EGCGε3Me can negatively regulate basophil activation through the suppression of FcεRI expression.
AB - We previously found that the O-methylated derivative of (-)-epigallocatechin-3-O-gallate (EGCg), (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG″3Me), has potent antiallergic activity. The high-affinity IgE receptor, FcεRI, is found at high levels on basophils and mast cells and plays a key role in a series of acute and chronic human allergic reactions. To understand the mechanism of action for the antiallergic EGCG″3Me, the effect of EGCG″3Me on the cell surface expression of FcεRI in human basophilic KU812 cells was examined. Flow cytometric analysis showed that EGCG″3Me was able to decrease the cell surface expression of FcεRI. Moreover, immunoblot analysis revealed that total cellular expression of the FcεRI α chain decreased upon treatment with EGCG″3Me. FcεRI is a tetrameric structure comprising one α chain, one β chain, and two γ chains. The level of mRNA production of each subunit in KU812 cells was investigated. EGCG″3Me reduced FcεRI α and γ mRNA levels. The cross-linkage of FcεRI causes the activation of basophils, which leads to the secretion of inflammatory mediators including histamine. EGCG″3Me treatment inhibited the FcεRI cross-linking-induced histamine release. These results suggested that EGCGε3Me can negatively regulate basophil activation through the suppression of FcεRI expression.
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U2 - 10.1021/jf025680z
DO - 10.1021/jf025680z
M3 - Article
C2 - 12236706
AN - SCOPUS:0037174393
VL - 50
SP - 5729
EP - 5734
JO - Journal of Agricultural and Food Chemistry
JF - Journal of Agricultural and Food Chemistry
SN - 0021-8561
IS - 20
ER -