羟基酪醇对HEB和U251细胞增殖及凋亡的影响

Effects of hydroxytyrosol on proliferation and apoptosis of HEB and U251 cells

目的研究羟基酪醇对脑胶质细胞HEB和脑胶质瘤细胞U251增殖及凋亡的影响,及其对U251细胞凋亡影响的可能机制。方法采用MTT法检测羟基酪醇对HEB和U251细胞增殖的影响,电镜观察对细胞超微结构的影响,流式细胞术检测对细胞周期及细胞凋亡率的影响,Western blot法检测对Caspase-3和Bcl-2蛋白表达水平的影响。结果羟基酪醇能明显抑制HEB和U251细胞的增殖,其中对U251细胞抑制作用更明显,同一时间点最大抑制率所对应的羟基酪醇浓度均较HEB细胞低。1.728和0.820 mmol/L羟基酪醇分别作用HEB和U251细胞48 h后,细胞出现微绒毛减少、异染色质聚集、核固缩和核质比例降低等现象。0.432、0.864和1.728 mmol/L羟基酪醇作用HEB细胞48 h时,细胞凋亡率分别为(43.59±0.13)%、(59.72±0.15)%和(83.88±0.05)%;0.205、0.410和0.820 mmol/L羟基酪醇作用U251细胞48 h时,细胞凋亡率分别为(33.95±0.06)%、(29.79±0.12)%和(45.12±0.20)%,两种细胞均被明显阻滞在S期。HEB和U251细胞中Bcl-2蛋白表达量均随羟基酪醇浓度的升高而略有降低,而Caspase-3蛋白的表达量则均有上升趋势。结论羟基酪醇能明显抑制HEB和U251细胞增殖,并诱导其凋亡。在相同浓度羟基酪醇作用下,U251细胞更易被诱导凋亡,这将为羟基酪醇运用于脑胶质瘤的预防及治疗提供了理论依据。

Objective To investigate the effects of hydroxytyrosol(HT)on proliferation and apoptosis of human brain glial HEB cells and brain glioma U251 cells as well as the possible mechanism of HT in influencing the apoptosis of U251 cells.Methods The effects of HT on proliferations of HEB and U251 cells were evaluated by MTT assay,while that on the ultrastructure by microscopy,those on cell cycle and apoptosis rate by flow cytometry,and those on expression levels of Caspase-3 and Bcl-2 proteins by Western blot.Results HT significantly inhibited the proliferations of HEB and U251 cells,while showed more significant inhibition to U251 cells,of which the concentration corresponding to the highest inhibition rate was lower than that to HEB cells at the same time points.Microvilli reduction,euchromatin aggregation,nuclear condensation and nuclear-cytoplasm ratio descending were observed in the HEB and U251 cells after treatment with 1.728 and 0.820 mmol/L HT for 48 h respectively.The apoptosis rates of HEB cells were(43.59±0.13)%,(59.72±0.15)%and(83.88±0.05)%after treatment with 0.432,0.864 and 1.728 mmol/L HT for 48 h respectively.However,the apoptosis rates of U251 cells were(33.95±0.06)%,(29.79±0.12)%and(45.12±0.20)%after treatment with 0.205,0.410 and 0.820 mmol/L HT for 48 h respectively.Both the cell cycles were arrested at S stage obviously. The expression levels of Bcl-2 protein in HEB and U251 cells decreased slightly with the increasing HTconcentration,while the expression level of Caspase-3 protein showed an increasing tendency. Conclusion HTsignificantly inhibited the proliferation and induced the apoptosis of HEB and U251 cells. U251 cells were more easily tobe leaded to apoptosis than HEB cells after treatment with HT at the same concentrations. It provided a theoretical basisfor application of HT to the prevention and therapy of glioma.