Arsenic induces reactive oxygen species-caused neuronal cell apoptosis through JNK/ERK-mediated mitochondria-dependent and GRP 78/CHOP-regulated pathways |
| |
| Authors: | Tien-Hui Lu To-Jung Tseng Chin-Chuan Su Feng-Cheng Tang Cheng-Chieh Yen Yu-Yun Liu Ching-Yao Yang Chin-Ching Wu Kuo-Liang Chen Dong-Zong Hung Ya-Wen Chen |
| |
| Institution: | 1. Department of Physiology, and Graduate Institute of Basic Medical Science, College of Medicine, China Medical University, Taichung 404, Taiwan;2. Department of Anatomy, College of Medicine, China Medical University, Taichung 404, Taiwan;3. Department of Otorhinolaryngology, Head and Neck Surgery, Changhua Christian Hospital, Changhua 500, Taiwan;4. Department of Occupational Medicine, Changhua Christian Hospital, Changhua City 500, Taiwan;5. Department of Occupational Safety and Health, College of Health Care and Management, Chung Shan Medical University, Taichung 402, Taiwan;6. Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan;g Department of Surgery, National Taiwan University Hospital, Taipei 100, Taiwan;h Department of Surgery, College of Medicine, National Taiwan University, Taipei 100, Taiwan;i Department of Public Health, China Medical University, Taichung 404, Taiwan;j Department of Urology, China Medical University Hospital, and School of Medicine, China Medical University, Taichung 404, Taiwan;k Division of Toxicology, Trauma & Emergency Center, China Medical University Hospital, Taichung 404, Taiwan |
| |
| Abstract: | Arsenic (As), a well-known high toxic metal, is an important environmental and industrial contaminant, and it induces oxidative stress, which causes many adverse health effects and diseases in humans, particularly in inorganic As (iAs) more harmful than organic As. Recently, epidemiological studies have suggested a possible relationship between iAs exposure and neurodegenerative disease development. However, the toxicological effects and underlying mechanisms of iAs-induced neuronal cell injuries are mostly unknown. The present study demonstrated that iAs significantly decreased cell viability and induced apoptosis in Neuro-2a cells. iAs also increased oxidative stress damage (production of malondialdehyde (MDA) and ROS, and reduction of Nrf2 and thioredoxin protein expression) and induced several features of mitochondria-dependent apoptotic signals, including: mitochondrial dysfunction, the activations of PARP and caspase cascades, and the increase in caspase-3 activity. Pretreatment with the antioxidant N-acetylcysteine (NAC) effectively reversed these iAs-induced responses. iAs also increased the phosphorylation of JNK and ERK1/2, but did not that p38-MAPK, in treated Neuro-2a cells. NAC and the specific JNK inhibitor (SP600125) and ERK1/2 inhibitor (PD98059) abrogated iAs-induced cell cytotoxicity, caspase-3/-7 activity, and JNK and ERK1/2 activation. Additionally, exposure of Neuro-2a cells to iAs triggered endoplasmic reticulum (ER) stress identified through several key molecules (GRP 78, CHOP, XBP-1, and caspase-12), which was prevented by NAC. Transfection with GRP 78- and CHOP-specific si-RNA dramatically suppressed GRP 78 and CHOP expression, respectively, and attenuated the activations of caspase-12, -7, and -3 in iAs-exposed cells. Therefore, these results indicate that iAs induces ROS causing neuronal cell death via both JNK/ERK-mediated mitochondria-dependent and GRP 78/CHOP-triggered apoptosis pathways. |
| |
| Keywords: | ROS reactive oxygen species MAPKs mitogen-activated protein kinases JNK c-Jun N-terminal kinase ERK extracellular signal-related kinase Nrf2 nuclear-factor-E2-related factor 2 PARP poly (ADP-ribose) polymerase NAC N-acetylcysteine ER stress endoplasmic reticulum stress GRP glucose-regulated protein CHOP C/EBP homologue protein XBP-1 X-box binding protein-1 si-RNA small interference RNA MMP mitochondrial membrane potential |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
