Epigallocatechin-3-gallate regulates cell growth, cell cycle and phosphorylated nuclear factor-KB in human dermal fibroblasts

• Published in: 中国药理学报：英文版 2011, Vol.32 (5), p.637-646
• Main Author: Dong-Wook HAN Mi Hee LEE Hak Hee KIM Suong-Hyu HYON Jong-Chul PARK
• Format: Article
• Language: English
• Subjects: cDNA微阵列; 人类; 核因子KB; 皮肤成纤维细胞; 磷酸化; 细胞周期蛋白依赖性激酶; 细胞生长; 表没食子儿茶素没食子酸酯
• ISSN: 1671-4083; 1745-7254

Aim： To investigate the effects of （-）epigallocatechin-3-gallate （EGCG）, the main polyphenol in green tea, on cell growth, cell cycle and phosphorylated nuclear factor-KB （pNF-KB） expression in neonatal human dermal fibroblasts （nHDFs）. Methods： The proliferation and cell-cycle of nHDFs were determined using WST-8 cell growth assay and flow cytometry, respectively. The apoptosis was examined using DNA ladder and Annexin V-FITC assays. The expression levels of pNF-KB and cell cycle-related genes and proteins in nHDFs were measured using cDNA microarray analyses and Western blot. The cellular uptake of EGCG was examined using fluorescence （FITC）-Iabeled EGCG （FITC-EGCG） in combination with confocal microscopy. Results： The effect of EGCG on the growth of nHDFs depended on the concentration tested. At a low concentration （200 μmol/L）, EGCG resulted in a slight decrease in the proportion of cells in the S and G2/M phases of cell cycle with a concomitant increase in the proportion of cells in Go/G1 phase. At the higher doses （400 and 800μmol/L）, apoptosis was induced. The regulation of EGCG on the expression of pNF-KB was also concentration-dependent, whereas it did not affect the unphosphorylated NF-κB expression, cDNA microarray analysis showed that cell cycle-related genes were down-regulated by EGCG （200 μmol/L）. The expression of cyclins A/B and cyclin-dependent kinase I was reversibly regulated by EGCG （200 μmol/L）. FITC-EGCG was found to be internalized into the cytoplasm and translocated into the nucleus of nHDFs. Conclusion： EGCG, through uptake into cytoplasm, reversibly regulated the cell growth and expression of cell cycle-related proteins and genes in normal fibroblasts.