【摘要】 目的探究Gd₂O₃:Eu³⁺双模态分子影像探针的肝毒性,并初步阐明其肝毒性的分子机制。方法离体LO2肝细胞与Gd₂O₃:Eu³⁺分子影像探针共孵育,CCK8法评估其细胞毒性作用,流式细胞仪分析其对细胞凋亡的影响。Balb/c小鼠尾静脉注射该分子影像探针建立动物在体模型,肝组织切片免疫组化检测肝组织中凋亡标志蛋白caspase3的激活情况。RT-q PCR检测凋亡相关信号通路p53、Bal-2和Bal-x L的m RNA表达水平,明确该分子影像探针引发肝毒性的相关分子机制。结果细胞实验表明,Gd₂O₃:Eu³⁺分子影像探针可引发肝细胞凋亡;动物实验表明,在肝组织内激活P53基因,抑制Bcl-2及Bcl-x L基因表达,同时激活caspase3蛋白,进而引发肝细胞的凋亡。结论从基因水平初步阐明Gd₂O₃:Eu³⁺分子影像探针的肝毒性分子机制,可能是通过激活肝脏组织内的p53,同时抑制Bcl-2、Bcl-x L基因表达,进而激活caspase3蛋白,而引发肝细胞的凋亡。更多还原

【Abstract】 Objective To explore the mechanism of hepatotoxicity induced by in vivo application of Gd₂O₃:Eu³⁺ dual-modal contrast nanoparticles. Methods LO2 hepatic cell was in vitro cultured with Gd₂O₃:Eu³⁺ nanoparticles for 12 h,24 h and 48 h. CCK8 method was used to evaluate the inhibition rate of cell proliferation cultured with different concen-trations of nanoparticles. LO2 cells were incubated with 10 μmol/L nanoparticles for 24 h prior being analyzed by flow cy-tometry for their apoptosis rate. Liver organ was harvested 1 day after injection of nanoparticles via tail veins of Balb/cmice. Cleavage caspase 3 protein in liver tissue section was detected by immunohistochemistry. In order to explore the hep-atotoxicity mechanism of nanoparticles,the expressions of m RNA of p53,Bal-2 and Bal-x L were detected by RT-q PCR.Results The activation of caspase3 protein indicated liver cell apoptosis after injection of Gd₂O₃:Eu³⁺ nanoparticles. Themechanism of it was through upregulating the expression of p53 gene,and downregulating the expression of Bcl-2 and Bcl-x Lgene. Conclusion The mechanism of hepatic toxicity induced by Gd₂O₃:Eu³⁺ nanoparticles was through activating p53 along with inhibiting Bcl-2 and Bcl-x L,as a result inducing the hepatic apoptosis of caspase3 protein.更多还原