Necroptosis Mediates TNF-Induced Toxicity of Hippocampal Neurons

作者：Liu Shan; Wang Xing; Li Yun; Xu Lei; Yu Xiaoliang; Ge Lin; Li Jun; Zhu Yongjin^*; He Sudan

来源：Biomed Research International, 2014, 2014: 290182.

DOI：10.1155/2014/290182

Tumor necrosis factor-alpha (TNF-alpha) is a critical proinflammatory cytokine regulating neuroinflammation. Elevated levels of TNF-alpha have been associated with various neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. However, the signaling events that lead to TNF-alpha-initiated neurotoxicity are still unclear. Here, we report that RIP3-mediated necroptosis, a form of regulated necrosis, is activated in the mouse hippocampus after intracerebroventricular injection of TNF-alpha RIP3 deficiency attenuates TNF-alpha -initiated loss of hippocampal neurons. Furthermore, we characterized the molecular mechanism of TNF-alpha-induced neurotoxicity in HT-22 hippocampal neuronal cells. HT-22 cells are sensitive to TNF-alpha only upon caspase blockage and subsequently undergo necrosis. The cell death is suppressed by knockdown of CYLD or RIP1 or RIP3 or MLKL, suggesting that this necrosis is necroptosis and mediated by CYLD-RIP1-RIP3-MLKL signaling pathway. TNF-alpha -induced necroptosis of HT-22 cells is largely independent of both ROS accumulation and calcium influx although these events have been shown to be critical for necroptosis in certain cell lines. Taken together, these data not only provide the first in vivo evidence for a role of RIP3 in TNF-alpha -induced toxicity of hippocampal neurons, but also demonstrate that TNF-alpha promotes CYLD-RIP1-RIP3-MLKL-mediated necroptosis of hippocampal neurons largely bypassing ROS accumulation and calcium influx.

• 出版日期2014
• 单位苏州大学