Lin-Holderer Jiemeng, Li Lexiao, Gruneberg Daniel, Marti Hugo H, Kunze Reiner
Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany.
Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany.
Neuropharmacology. 2016 Jun;105:228-240. doi: 10.1016/j.neuropharm.2016.01.023. Epub 2016 Jan 19.
Oxidative stress is a hallmark of ischemic stroke pathogenesis causing neuronal malfunction and cell death. Up-regulation of anti-oxidative genes through activation of the NF-E2-related transcription factor 2 (Nrf2) is one of the key mechanisms in cellular defense against oxidative stress. Fumaric acid esters (FAEs) represent a class of anti-oxidative and anti-inflammatory molecules that are already in clinical use for multiple sclerosis therapy. Purpose of this study was to investigate whether FAEs promote neuronal survival upon ischemia, and analyze putative underlying molecular mechanisms in neurons. Murine organotypic hippocampal slice cultures, and two neuronal cell lines were treated with dimethyl fumarate (DMF) and monomethyl fumarate (MMF). Ischemic conditions were generated by exposing cells and slice cultures to oxygen-glucose deprivation (OGD), and cell death was determined through propidium iodide staining. Treatment with both DMF and MMF immediately after OGD during reoxygenation strongly reduced cell death in hippocampal cultures ex vivo. Both DMF and MMF promoted neuronal survival in HT-22 and SH-SY5Y cell lines exposed to ischemic stress. DMF but not MMF activated the anti-oxidative Nrf2 pathway in neurons. Accordingly, Nrf2 knockdown in murine neurons abrogated the protective effect of DMF but not MMF. Moreover, FAEs did not activate the hypoxia-inducible factor (HIF) pathway suggesting that this pathway may not significantly contribute to FAE mediated neuroprotection. Our results may provide the basis for a new therapeutic approach to treat ischemic pathologies such as stroke with a drug that already has a broad safety record in humans.
氧化应激是缺血性脑卒中发病机制的一个标志，可导致神经元功能障碍和细胞死亡。通过激活核因子E2相关因子2（Nrf2）上调抗氧化基因是细胞抵御氧化应激的关键机制之一。富马酸酯（FAEs）是一类抗氧化和抗炎分子，已用于治疗多发性硬化症。本研究旨在探讨富马酸酯是否能促进缺血后神经元存活，并分析神经元中潜在的分子机制。用富马酸二甲酯（DMF）和富马酸单甲酯（MMF）处理小鼠脑片培养物和两种神经元细胞系。通过将细胞和脑片培养物暴露于氧-葡萄糖剥夺（OGD）来模拟缺血条件，并通过碘化丙啶染色测定细胞死亡情况。在复氧期间，在OGD后立即用DMF和MMF处理可显著降低体外海马培养物中的细胞死亡。DMF和MMF均可促进暴露于缺血应激的HT-22和SH-SY5Y细胞系中的神经元存活。DMF而非MMF可激活神经元中的抗氧化Nrf2途径。因此，在小鼠神经元中敲低Nrf2可消除DMF而非MMF的保护作用。此外，富马酸酯未激活缺氧诱导因子（HIF）途径，提示该途径可能对富马酸酯介导的神经保护作用贡献不大。我们的研究结果可能为一种新的治疗方法提供基础，即用一种在人类中已有广泛安全记录的药物来治疗缺血性疾病，如中风。
