原儿茶酸促进人脂肪干细胞体外增殖的研究

为了寻找能够促进干细胞增殖的药物，观察了中药益智仁（Alpinia oxyphylln）中提取的原儿茶酸对人脂肪干细胞体外增殖的影响，并对其作用机制进行了初步的探讨．人脂肪干细胞能在体外分化为神经元样细胞，并对凋亡的PC-12细胞起到保护作用．原儿茶酸能够促进人脂肪干细胞的增殖，且呈现明显的剂量依赖性和时间依赖性．流式细胞术检测细胞DNA含量的结果显示，原儿茶酸处理组细胞S期所占比例明显增加，其中，1．5mmol／L原儿茶酸处理组细胞S期所占比例与对照组相比增加2倍以上．同时，该组细胞G2／M期所占比例明显增加，G0／G1期所占比例明显下降．蛋白质免疫印迹结果显示，1．5mmol／L原儿茶酸处理组细胞周期素D1（cyclinD1）的表达明显升高．cyclin D1-siRNA转染显著抑制了原儿茶酸对人脂肪干细胞体外增殖的促进作用．流式细胞术检测细胞表面标志物，成骨诱导和脂肪诱导的结果显示，原儿茶酸处理后，人脂肪干细胞仍保持间充质干细胞多分化潜能的特性．上述结果提示，原儿茶酸有可能在人脂肪干细胞介导的干细胞移植治疗中发挥作用．

Proliferative Enhancement of Human Adipose Tissue-derived Stromal Cells by Protocatechuic Acid From Alpinia oxyphylla In vitro

In an effort to find drugs for facilitating proliferation of transplanted stem cells to provide adequate new tissue, the influence of PCA from A. oxyphylla on the proliferation capacity of hADSCs in vitro was examined. Human ADSCs could differentiate into neuron-like cells in vitro, and protect PC-12 cells from apoptosis induced by serum deprivation. Cell counts showed that treatment of hADSCs with 0.5 mmol/L, 1.0 mmol/L and 1.5 mmol/L of PCA for 48 h increased the cell numbers in a dose-dependent manner. In addition, the cell numbers of hADSCs at various time points after treatment of 1.5 mmol/L PCA were increased in a time-dependent manner. Flow cytometric analysis of DNA content demonstrated the cell cycle progress from G1 phase to S phase. The most pronounced effect was seen with 1.5 mmol/L PCA, where the fraction of cells in S phase increased more than 2 folds, accompanied by a significant increase in the fraction of cells in G2/M phase and a significant decrease in the fraction of cells in G0/G1 phase. Western blot analysis revealed the elevated expression of cyclin D1 in hADSCs induced by 1.5 mmol/L PCA treatment. Furthermore, cyclin D1-siRNA transfection significantly inhibited the promotion of cell proliferation by PCA. Flow cytometric analysis of the cell surface antigens, osteogenic induction and adipogenic induction demonstrated that after PCA treatment, hADSCs retained their morphological and functional characteristics of multipotential mesenchymal progenitors. The proliferative enhancement of PCA suggests the possibility that PCA may be useful in hADSCs-mediated therapy.