Insight into the Mechanisms of Combined Toxicity of Single-Walled Carbon Nanotubes and Nickel Ions in Macrophages: Role of P2X7 Receptor
Insight into the Mechanisms of Combined Toxicity of Single-Walled Carbon Nanotubes and Nickel Ions in Macrophages: Role of P2X7 Receptor
复制标题
深入了解单壁碳纳米管和镍离子在巨噬细胞中的联合毒性机制：P2X(7) 受体的作用
DOI：
10.1021/acs.est.6b03842
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发表时间：
2016-11-15
影响因子：
11.4
通讯作者：
Ren, Xiaomin
中科院分区：
文献类型：
--
作者：
Cui, Xuejing;Wan, Bin;Ren, Xiaomin
纳米材料与环境污染物的共存需要深入了解其联合毒性及其机制。在这项工作中，我们发现，共暴露于非细胞毒性水平的单壁碳纳米管（SWCNTs）（10 μ g/mL）和镍（20 μ M）的混合物诱导巨噬细胞的细胞毒性显着。然而，在Ni 2 +/SWCNT共暴露或Ni 2+单暴露后检测到几乎等量的细胞内Ni 2+，表明没有发生Ni 2+的增强的细胞摄取。SDS-PAGE分析显示，无论暴露顺序（共暴露，Ni 2+预处理或后处理）如何，Ni 2 +/SWCNT暴露的细胞中保留的SWCNT比单独SWCNT暴露的多50%，表明Ni 2+抑制了SWCNT的胞吐。增加的单壁碳纳米管的细胞剂量可以定量地解释Ni 2 +/单壁碳纳米管混合物对细胞的毒性升高。P2 X（7）R的激动剂（ATP）和拮抗剂（o-ATP）可以调节细胞内SWCNT的含量，从而调节细胞的细胞毒性。此外，P2 X（7）靶向siRNA对P2 X（7）R的抑制减弱了Ni 2+的抑制作用。因此得出结论，Ni 2+通过抑制P2 X（7）R阻碍SWCNT胞吐，导致SWCNT的更高细胞内保留和升高的细胞毒性。我们的工作确定胞吐抑制是SWCNT/Ni 2+毒性的重要机制，并揭示了P2 X（7）R的关键作用。介导这种抑制作用。
Coexistence of nanomaterials and environmental pollutants requires in-depth understanding of combined toxicity and underlying mechanism. In this work, we found that coexposure to the mixture of noncytotoxic level of single-walled carbon nanotubes (SWCNTs) (10 mu g/mL) and Ni2+ (20 mu M) induced significant cytotoxicity in macrophages. However, almost equal amount of intracellular Ni2+ was detected after Ni2+/SWCNT coexposure or Ni2+ single exposure, indicating no enhanced cellular uptake of Ni2+ occurred. SDS-PAGE analysis revealed 50% more SWCNTs retained in Ni2+/SWCNT exposed cells than that with SWCNT exposure alone, regardless of the exposure sequence (coexposure, Ni2+ pre- or post-treatment), suggesting inhibited SWCNT exocytosis by Ni2+. The increased cellular dose of SWCNTs could quantitatively account for the elevated toxicity of Ni2+/SWCNT mixture to cells. It was then found that agonist (ATP) and antagonist (o-ATP) of P2X(7)R could regulate intracellular SWCNT amount and the cytotoxicity accordingly. In addition, inhibition of P2X(7)R by P2X(7)-targeting siRNA diminished the inhibitory effect of Ni2+. It was therefore concluded that Ni2+ impeded SWCNT exocytosis by inhibiting P2X(7)R, leading to higher intracellular retention of SWCNTs and elevated cytotoxicity. Our work identified exocytosis inhibition as an important mechanism for SWCNT/Ni2+ toxicity, and revealed the crucial role of P2X(7)R. in mediating such inhibitory effect.