Epigallocatechin-3-gallate inhibits VCAM-1 expression and apoptosis induction associated with LC3 expressions in TNFα-stimulated human endothelial cells.
Tumor necrosis factor alpha (TNF-α) promotes the expression of adhesion molecules and induces endothelial dysfunction, a process that can lead to atherosclerosis. Green tea consumption can inhibit endothelial dysfunction and attenuate the development of arteriosclerosis. The purpose of this study was to examine whether epigallocatechin-3-gallate (EGCG) prevents TNF-α-dependent endothelial dysfunction. Here, we compared the regulatory effects of the green tea components EGCG and L-theanine against TNF-α-induced stimulation of adhesion molecule expression and apoptosis induction, which is associated with autophagy. Monocytic cell adhesion to human endothelial cells was measured using a fluorescently-labeled cell line, U-937. Caspase 3/7 activity was examined with a fluorescent probe and fluorescence microscopy. In addition, we analyzed the expression of several genes by RT-PCR. TNF-α-modulation of LC3 and VCAM1 protein levels were investigated by Western blot (WB). TNF-α induced adhesion of U937 cells to endothelial cells, and gene expression associated with adhesion molecules and apoptosis. On the other hand, EGCG and L-theanine inhibited TNF-α-induced adhesion of U937 cells to endothelial cells and inhibited increases in ICAM1, CCL2 and VCAM1 expression. Furthermore, EGCG and L-theanine inhibited TNF-α-induced apoptosis-related gene expression (e.g., CASP9), and caspase activity while inhibiting TNFα-induced VCAM1, LC3A and LC3B protein expression. Meanwhile, treatment of endothelial cells with autophagy inhibitor 3-methyladenine (3-MA) blocked EGCG-induced expression of CASP9. Together, these results indicate that EGCG can modulate TNF-α-induced monocytic cell adhesion, apoptosis and autophagy. We thus conclude that EGCG might be beneficial for inhibiting TNF-α-mediated human endothelial disorders by affecting LC3 expression-related processes.
Department of Food Bioscience and Biotechnology, College of Bioresource Sciences, Nihon University (NUBS), Fujisawa, Japan. Electronic address: kyamagat@brs.nihon-u.ac.jp.
Kazuo
K
Yamagata
Department of Food Bioscience and Biotechnology, College of Bioresource Sciences, Nihon University (NUBS), Fujisawa, Japan.
Yajie
Y
Xie
Department of Food Bioscience and Biotechnology, College of Bioresource Sciences, Nihon University (NUBS), Fujisawa, Japan.
Sayaka
S
Suzuki
Department of Internal Medicine, Sanraku Hospital, Chiyoda-Ku, Tokyo, Japan.
Motoki
M
Tagami
D017209:Apoptosis; D020169:Caspases / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002448:Cell Adhesion; D002460:Cell Line; D018932:Chemokine CCL2 / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects*; D005971:Glutamates / Q000494:pharmacology; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*
C111835:CCL2 protein, human; D018932:Chemokine CCL2; D005971:Glutamates; C573420:ICAM1 protein, human; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; C026166:theanine; D002392:Catechin; C045651:epigallocatechin gallate; D020169:Caspases
Apotosis; EGCG; Theanine