Involvement of hemeoxygenase-1 in di(2-ethylhexyl) phthalate (DEHP)-induced apoptosis of Neuro-2a cells
Involvement of hemeoxygenase-1 in di(2-ethylhexyl) phthalate (DEHP)-induced apoptosis of Neuro-2a cells
复制标题
DOI：
10.2131/jts.39.217
复制
发表时间：
2014-04-01
影响因子：
2
通讯作者：
Tsukahara, Shinji
中科院分区：
文献类型：
--
作者：
Aung, Kyaw Htet;Win-Shwe, Tin-Tin;Tsukahara, Shinji
已知广泛使用的增塑剂邻苯二甲酸二（2-乙基己基）酯 (DEHP) 会诱导神经元细胞凋亡，但 DEHP 诱导细胞凋亡的机制尚未得到充分探索。我们最近发现，暴露于 DEHP 会增加小鼠大脑中血红素加氧酶 (HO)-1（一种氧化应激相关酶）的表达。在这项研究中，我们使用小鼠神经母细胞瘤细胞系 Neuro-2a 来研究 HO-1 是否参与 DEHP 诱导的细胞凋亡，该细胞强制表达 SCAT3（一种 caspase-3 活性的荧光指标）。本研究中使用 1、10 或 100 μM 的 DEHP 剂量来模拟人类接触 DEHP 的水平。对表达 SCAT3 的 Neuro-2a 细胞的实时图像分析显示，100 μM 的 DEHP 显着增加了细胞中的 caspase-3 活性，但在 1 或 10 μM 时没有显着增加。我们测量了暴露于 DEHP 的 Neuro-2a 细胞中的 HO-1 mRNA 水平，发现 100 μM 的 DEHP 使 HO-1 mRNA 水平显着增加，但在 1 或 10 μM 时则没有。表达 SCAT3 的 Neuro-2a 细胞的实时图像分析是 进一步确定 HO-1 siRNA 通过 caspase-3 激活对 DEHP 诱导细胞凋亡的影响。我们发现 HO-1 基因的敲低会抵消 DEBT 激活 caspase-3 的作用。这些结果表明HO-1参与DEHP诱导的细胞凋亡。此外，这项研究表明，高剂量 DEHP 暴露会诱导 Neuro-2a 细胞中 caspase-3 依赖性细胞凋亡，这至少部分是由 HO-1 基因上调介导的。
A widely-used plasticizer di(2-ethylhexyl) phthalate (DEHP) is known to induce apoptosis in neurons, although the mechanisms responsible for DEHP-induced apoptosis is not well explored yet. We recently showed that exposure to DEHP increases the expression of hemeoxygenase (HO)-1, an oxidative stress related enzyme, in the mice brain. In this study, we investigated whether HO-1 is involved in DEHP-induced apoptosis using a mouse neuroblastoma cell line Neuro-2a, which forcibly express SCAT3, a fluorescent indicator of caspase-3 activity. The doses of DEHP at 1, 10 or 100 mu M were used in the present study to mimic the level of human exposure to DEHP. Live image analysis of SCAT3-expressing Neuro-2a cells revealed that caspase-3 activity in the cells was significantly increased by DEHP at 100 mu M but not 1 or 10 mu M. We measured HO-1 mRNA level in Neuro-2a cells exposed to DEHP and found significant increase in HO-1 mRNA level by DEHP at 100 mu M but not 1 or 10 mu M. Live image analysis of SCAT3-expresisng Neuro-2a cells was further performed to determine the effects of HO-1 siRNA in DEHP-induced apoptosis via caspase-3 activation. We found that knockdown of HO-1 gene nullifies the effects of DEBT to activate caspase-3. These results suggest that HO-1 is involved in DEHP-induced apoptosis. Moreover, this study demonstrates that high-dose DEHP exposure induces caspase-3-dependent apoptosis, which is at least partially mediated by the up-regulation of HO-1 gene, in Neuro-2a cells.