Department of Physiology, and Graduate Institute of Basic Medical Science, College of Medicine, China Medical University, No. 91 Hsueh-Shih Road, Taichung 40402, Taiwan.
Toxicol Lett. 2010 Dec 15;199(3):333-40. doi: 10.1016/j.toxlet.2010.09.016. Epub 2010 Nov 2.
Pyrrolidine dithiocarbamate (PDTC) is widely used in pesticides, fungicides, insecticides, and herbicides. Copper (Cu) is a toxic heavy metal in the environment, and an essential trace metal element in the body, which is involved in many biological processes as a catalytic cofactor. The present study is designed to investigate the cellular toxicity of PDTC, CuCl(2), and PDTC/Cu complex exposure in lung alveolar epithelial cells that serve primary structural and functional roles in the lungs. The results showed that PDTC or CuCl(2) alone did not affect cell viability, but PDTC/Cu complex significantly decreased lung alveolar epithelial cell viability. PDTC/Cu complex also significantly increased intracellular copper concentration, but PDTC or CuCl(2) alone had low levels of copper. PDTC/Cu complex dramatically enhanced the JNK protein phosphorylation and ERK protein phosphorylation proteins. PDTC/Cu complex did not affect the p38 protein phosphorylation. PDTC/Cu complex was capable of activating the apoptosis-related caspases including caspase-9, caspase-7, and caspase-3, which could be reversed by the addition of JNK inhibitor SP600125 or transfection of MAPK8 short hairpin RNA. PDTC/Cu complex also increased cytosolic cytochrome c and decreased mitochondrial transmembrane potential. The Bcl-2 mRNA and protein expressions were decreased in lung epithelial cells treated with PDTC/Cu complex, which could be reversed by SP600125. Furthermore, PDTC/Cu complex could trigger the expressions of ER stress-associated signaling molecules including Grp78, Grp94, caspase-12, ATF4, and CHOP, which could be reversed by SP600125. Taken together, these results indicate that exposure to PDTC/Cu complex induces cytotoxicity and apoptosis in alveolar epithelial cells via the mitochondria- and ER-stress-related signaling pathways.
吡咯烷二硫代氨基甲酸盐（PDTC）广泛应用于农药、杀真菌剂、杀虫剂和除草剂中。铜（Cu）是环境中的一种有毒重金属，也是体内必需的痕量金属元素，作为一种催化辅因子参与许多生物过程。本研究旨在研究 PDTC、CuCl(2)和 PDTC/Cu 络合物暴露对肺肺泡上皮细胞的细胞毒性，肺肺泡上皮细胞在肺部中起主要的结构和功能作用。结果表明，PDTC 或 CuCl(2)单独作用不会影响细胞活力，但 PDTC/Cu 络合物显著降低肺肺泡上皮细胞活力。PDTC/Cu 络合物还显著增加细胞内铜浓度，但 PDTC 或 CuCl(2)单独作用时铜浓度较低。PDTC/Cu 络合物显著增强 JNK 蛋白磷酸化和 ERK 蛋白磷酸化蛋白。PDTC/Cu 络合物对 p38 蛋白磷酸化没有影响。PDTC/Cu 络合物能够激活凋亡相关的半胱天冬酶，包括 caspase-9、caspase-7 和 caspase-3，这些可以通过添加 JNK 抑制剂 SP600125 或转染 MAPK8 短发夹 RNA 来逆转。PDTC/Cu 络合物还增加了细胞质中的细胞色素 c 和减少了线粒体跨膜电位。PDTC/Cu 络合物处理的肺上皮细胞中 Bcl-2mRNA 和蛋白表达减少，这可以通过 SP600125 逆转。此外，PDTC/Cu 络合物可以触发与内质网应激相关的信号分子的表达，包括 Grp78、Grp94、caspase-12、ATF4 和 CHOP，这些可以通过 SP600125 逆转。综上所述，这些结果表明，暴露于 PDTC/Cu 络合物通过线粒体和内质网应激相关信号通路诱导肺泡上皮细胞的细胞毒性和细胞凋亡。
