Department of Pharmacology, School of Medicine, College of Medicine, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung, 80708, Taiwan.
Neurotox Res. 2014 Apr;25(3):262-70. doi: 10.1007/s12640-013-9414-3. Epub 2013 Jul 27.
Oxidative stress and survival motor neuron (Smn) protein deficiency are the major causes of motor neuronal death. Naloxone exhibits neuroprotection against ischemic stroke and anti-inflammation. In this study, we determined whether nanomolar naloxone provides neuroprotection under oxidative stress (H(2)O(2)) and Smn deficiency in a motor neuron-like cell line, NSC34. In H(2)O(2)-treated NSC34 cells, naloxone (1-10 nM) increased cell survival and mitochondria membrane potential. In addition, naloxone decreased NADPH oxidase (NOX) 2 activation, reactive oxygen species production and oxygen consumption rate. Moreover, naloxone increased anti-apoptotic Bcl-2 expression, attenuated apoptotic protein (Bax, cytochrome c, and caspase) expression and decreased apoptotic death. Furthermore, naloxone also increased Smn mRNA and protein expression. In Smn knockdown NSC34 cells, Smn deficiency significantly increased H(2)O(2) cytotoxicity. Naloxone exhibited neuroprotection at higher concentrations in Smn knockdown NSC34 cells than in control cells. In conclusion, naloxone attenuated neurotoxicity induced by H(2)O(2) and Smn deficiency. Our findings also revealed the involvement of Smn protein in naloxone protection and oxidative stress-related neurotoxicity.
氧化应激和运动神经元存活（Smn）蛋白缺乏是运动神经元死亡的主要原因。纳洛酮对缺血性中风和抗炎具有神经保护作用。在这项研究中，我们确定纳洛酮在氧化应激（H2O2）和运动神经元样细胞系 NSC34 中 Smn 缺乏的情况下，是否在纳洛酮（1-10 nM）下提供神经保护。在 H2O2 处理的 NSC34 细胞中，纳洛酮增加细胞存活率和线粒体膜电位。此外，纳洛酮降低 NADPH 氧化酶（NOX）2 激活、活性氧产生和耗氧量。此外，纳洛酮增加抗凋亡 Bcl-2 表达，减弱凋亡蛋白（Bax、细胞色素 c 和半胱天冬酶）表达并减少凋亡死亡。此外，纳洛酮还增加 Smn mRNA 和蛋白表达。在 Smn 敲低的 NSC34 细胞中，Smn 缺乏显着增加 H2O2 细胞毒性。在 Smn 敲低的 NSC34 细胞中，纳洛酮在较高浓度下表现出比对照细胞更强的神经保护作用。总之，纳洛酮减轻了 H2O2 和 Smn 缺乏引起的神经毒性。我们的研究结果还揭示了 Smn 蛋白在纳洛酮保护和氧化应激相关神经毒性中的参与。
