The protective role of selenium against dental amalgam-induced intracellular oxidative toxicity through the TRPV1 channel in DBTRG glioblastoma cells

Abstract Objective The exposure to mercury (Hg) from dental amalgams is a suspected causative factor in neurological diseases. This study investigated the toxic effects of two different amalgam compositions related to Hg and the protective effects of selenium against the toxic effects of Hg through the TRPV1 channel in the human DBTRG glioblastoma cell line. Methodology Six groups of the cells were organized. Analyses of cell viability, apoptosis, caspase 3 and caspase 9 activities, mitochondrial membrane depolarization, reactive oxygen species (ROS) production, and Western Blotting for protein expression levels were performed. Results Cell viability values were lower in amalgam with high copper (HCu) and low copper (LCu) groups independently of time but were increased by selenium and capsazepine (p<0.001 and p<0.05). Conversely, apoptosis rates, caspase 3 and caspase 9 expression, ROS formation, mitochondrial membrane depolarization, and protein expression levels were higher in the HCu and LCu groups but were decreased by selenium (p<0.001 and p<0.05). Conclusions Selenium combined with an amalgam of either HCu or LCu decreases the toxic effects created by Hg in human DBTRG glioblastoma cells.

摘要 研究目的：牙科汞合金暴露引发的汞（Hg）暴露，被怀疑是神经系统疾病的潜在致病因素。本研究以人DBTRG胶质母细胞瘤细胞系为模型，探究两种不同汞合金成分相关的汞毒性作用，以及硒通过瞬时受体电位香草酸亚型1（TRPV1）通道对抗汞毒性的保护效果。
研究方法：本实验设置6组细胞样本。检测指标包括细胞活力、细胞凋亡、半胱氨酸天冬氨酸蛋白酶3（caspase 3）与半胱氨酸天冬氨酸蛋白酶9（caspase 9）活性、线粒体膜电位去极化、活性氧（ROS）生成量，以及用于检测蛋白表达水平的蛋白质印迹（Western Blotting）实验。
研究结果：高铜（HCu）与低铜（LCu）汞合金组的细胞活力均显著低于对照组，且该差异不受培养时间影响；硒与辣椒平（capsazepine）处理可显著提升细胞活力（p<0.001 及 p<0.05）。与之相反，HCu组与LCu组的细胞凋亡率、caspase 3与caspase 9的蛋白表达水平、ROS生成量、线粒体膜电位去极化程度及蛋白表达水平均显著升高，而硒处理可有效降低上述指标（p<0.001 及 p<0.05）。
研究结论：硒联合高铜或低铜汞合金，可减轻汞对人DBTRG胶质母细胞瘤细胞产生的毒性损伤。