钛离子对Jurkat T细胞增殖及其胞内钙离子浓度的影响

Effect of titanium ions on the proliferation and intracellular calcium concentration in Jurkat T cells

目的:探讨一定浓度下的钛离子对体外培养的Jurkat T细胞活化增殖及其胞内钙离子(Ca^(2+))浓度变化的影响。方法:(1)MTT比色法检测T细胞增殖率分别为50%、95%时钛离子的浓度,将最大及中间增殖率的钛离子浓度作为实验组浓度。(2)根据植物血凝素(PHA)预先活化或不活化Jurkat T细胞分成两组,分别与上一步实验结果所得浓度的钛离子培养,然后用激光共聚焦显微镜检测24h内Jurkat T细胞内Ca^(2+)含量及分布变化。结果:(1)钛离子浓度低于100μmol/L时,T细胞可被钛离子活化增殖,增殖率随浓度增加而上升;浓度在100~200μmol/L时,增殖率下降;浓度高于200μmol/L时,细胞呈抑制状态。(2)当细胞外液含Ca^(2+)时,钛离子浓度为50μmol/L、100μmol/L,活化的T细胞内的Ca^(2+)浓度都呈上升趋势,当细胞外液含Ca^(2+)时,钛离子浓度为5μmol/L、10μmol/L、50μmol/L、100μmol/L,活化和未活化的T细胞内的Ca^(2+)浓度均呈上升趋势,且活化后的T细胞Ca^(2+)浓度上升更为显著,与对照组比较,差异均有统计学意义(均P<0.05)。在不含Ca^(2+)的细胞外液中,活化和未活化的细胞内的Ca^(2+)浓度均未见明显变化,且与对照组相比较,差异均无统计学意义(均P>0.05)。结论:四价钛离子浓度低于100μmol/L时,可活化增殖Jurkat T细胞;在含Ca^(2+)的细胞外液的T细胞中,当钛离子浓度为50μmol/L、100μmol/L时,经PHA活化的细胞内的Ca^(2+)浓度暂时上升;当T细胞在不含Ca^(2+)的细胞外液中,细胞内的Ca^(2+)浓度均未观察到明显变化。

Objective：To investigate the effect of titanium ions on the changes of intracellular calcium con centration and proliferation in Jurkat T cells. Methods： MTT assay was performed to determine the concentrations of titanium ions at which the cell proliferation rate was increased by 50% or 95%. The Jurkat T cells were divided into two groups： T cells pre-activated by phytohemagglutinin （PHA） or resting T cells without pre-activation. After co-culture with titanium ions at selected concentration for 24 hours, the distribution of calcium cations and content changes were detected by the laser scanning confoeal microscope. Results： （1） When the concentration of titanium ions was lower than 100 μmol/L, T cells could be activa ted and the proliferate rate was increased along with the concentration of titanium ions. When the concentration of titanium was between 100-200 μmol/L, the proliferation rate declined. Once the concentration of titanium ions exceeded 200 μmol/L, cells proliferation were suppressed. （2） When extracellular solution containing Ca2＋, after treating with different concentrations of titanium ions （5 μmol/L, 10 μmol/L, 50 μmol/L and 100 μmol/L）, the intracellular calcium concentration increased in both resting cells group and activated cells group, and the rise within activated T cells group was much more significant （ P 〈0.05）. Compared to non-treated control cells, the difference were significant （ P 〈0.05）. When extracellular solution was without Ca2＋ , the intracellular Ca2＋ concentration was not significantly changed in both groups, and compared with the control group, the difference was not statistically significant as well （ P〉 0.05）. Conclusion： Concentration of titanium ions below 100 μmol/L could promote Jurkat T cells＇ activation and proliferation. Titanium ions could stimulate the pre-actived T cells when extracellular solution containing Ca2＋ , which resulted in the increase of intracellular calcium concentration.