Laboratory of Cell Biology, College of Nutrition, Koshien University, Takarazuka, Hyogo 665-0006, Japan.
Eur J Cell Biol. 2013 Jan;92(1):30-43. doi: 10.1016/j.ejcb.2012.10.002. Epub 2012 Nov 9.
Since resveratrol is considered to exert a unique dual effect, protective for normal cells but toxic to tumor cells, its action on undifferentiated (original) and differentiated PC12 cells was analyzed, because undifferentiated cells are tumorigenic and differentiated ones are neuronal in nature. Compared to resveratrol-untreated cells in both undifferentiated and differentiated cell groups, cells treated with different doses of resveratrol, at dosages of 1, 10 and 100 μM, showed the following alterations. Dying/dead cells were significantly increased in a dose-dependent manner in undifferentiated cells, but they were unchanged at doses of up to 10 μM resveratrol in differentiated cells. In living cells, neurites were short in undifferentiated cells, but drastically elongated with an increased number in differentiated cells. The expression of SIRT1 was drastically reduced in undifferentiated cells, but stable in differentiated cells. SIRT3 was significantly enhanced in a dose-dependent manner at resveratrol doses of up to 10 μM in both cells, with reduction and more enhanced at a dosage of 100 μM in undifferentiated and differentiated cells, respectively. Mitochondrial number and ATP synthase β subunit expression was unaltered at doses of up to 10 μM and were significantly reduced at doses of 100 μM in undifferentiated cells, but they were significantly increased in a dose-dependent manner, with a slight reduction in the ATP synthase at doses of 100 μM, in differentiated cells. In a dose-dependent manner, the number of autophagosomes and the LC3-II/LC3-I ratio were significantly less in undifferentiated cells and greater in differentiated cells. Also, in a dose-dependent manner, the expression of phosphorylated AMP-activated kinase (AMPK) was significantly less in undifferentiated cells and greater in differentiated cells. Resveratrol-induced AMPK suppression and activation, possibly through the modulation of SIRT protein activity, may thus be related to the inhibition and promotion of mitochondrial and autophagic functions, leading to cell death and survival in undifferentiated and differentiated cells, respectively.
由于白藜芦醇被认为具有独特的双重作用，对正常细胞具有保护作用，而对肿瘤细胞则具有毒性，因此分析了它对未分化（原始）和分化 PC12 细胞的作用，因为未分化细胞具有致瘤性，而分化细胞则具有神经元特性。与未分化和分化细胞组中未经白藜芦醇处理的细胞相比，用不同剂量的白藜芦醇（1、10 和 100 μM）处理的细胞表现出以下变化。未分化细胞中，死亡/死亡细胞的数量随剂量依赖性增加，而在分化细胞中，白藜芦醇剂量高达 10 μM 时，细胞数量不变。在活细胞中，未分化细胞的神经突较短，但分化细胞的神经突明显延长且数量增加。SIRT1 的表达在未分化细胞中急剧降低，但在分化细胞中保持稳定。在白藜芦醇剂量高达 10 μM 的情况下，SIRT3 以剂量依赖性方式显著增强，而在未分化和分化细胞中，白藜芦醇剂量为 100 μM 时则减少且增强更明显。线粒体数量和 ATP 合酶 β 亚基表达在 10 μM 剂量下不变，在未分化细胞中 100 μM 剂量下显著降低，但在分化细胞中以剂量依赖性方式显著增加，ATP 合酶在 100 μM 剂量下略有减少。自噬体数量和 LC3-II/LC3-I 比值在未分化细胞中以剂量依赖性方式显著减少，而在分化细胞中则显著增加。此外，磷酸化 AMP 激活的蛋白激酶 (AMPK) 的表达在未分化细胞中以剂量依赖性方式显著减少，而在分化细胞中则显著增加。因此，白藜芦醇诱导的 AMPK 抑制和激活可能通过调节 SIRT 蛋白活性，与未分化和分化细胞中分别抑制和促进线粒体和自噬功能有关，导致细胞死亡和存活。
