Constitutive Reactive Oxygen Species Generation from Autophagosome/Lysosome in Neuronal Oxidative Toxicity
Constitutive Reactive Oxygen Species Generation from Autophagosome/Lysosome in Neuronal Oxidative Toxicity
复制标题
DOI：
10.1074/jbc.m109.053058
复制
发表时间：
2010-01-01
影响因子：
4.8
通讯作者：
Takeuchi, Toshiyuki
中科院分区：
文献类型：
--
作者：
Kubota, Chisato;Torii, Seiji;Takeuchi, Toshiyuki
活性氧（ROS）参与多种细胞死亡过程，包括脑缺血损伤。我们发现谷氨酸诱导的小鼠海马细胞系的ROS积累和相关的细胞死亡通过药物抑制自噬或溶酶体活性而延迟。然而，谷氨酸不刺激自噬，这是通过蛋白质标志物LC3来评估的，线粒体组织和溶酶体膜通透性的变化都没有观察到。氧化还原探针PF-H(2)TMRos的荧光分析显示，自噬体和/或溶酶体是除线粒体外基础ROS生成的主要位点。自噬和溶酶体抑制剂降低了它们的基础ROS生成，并导致线粒体ROS的爆发延迟。另一方面，血清消耗或高细胞密度培养导致线粒体活性的衰减，导致线粒体中组成ROS产生的损失和ROS爆发。因此，线粒体和溶酶体内组成性ROS的产生使细胞容易受到谷氨酸诱导的氧化细胞毒性的影响。同样，自噬和溶酶体抑制剂可减少大鼠缺血模型中的神经细胞死亡。我们认为缺血期间的细胞损伤受自噬体和/或溶酶体以及线粒体中ros生成活性的调节。
Reactive oxygen species (ROS) are involved in several cell death processes, including cerebral ischemic injury. We found that glutamate-induced ROS accumulation and the associated cell death in mouse hippocampal cell lines were delayed by pharmacological inhibition of autophagy or lysosomal activity. Glutamate, however, did not stimulate autophagy, which was assessed by a protein marker, LC3, and neither changes in organization of mitochondria nor lysosomal membrane permeabilization were observed. Fluorescent analyses by a redox probe PF-H(2)TMRos revealed that autophagosomes and/or lysosomes are the major sites for basal ROS generation in addition to mitochondria. Treatments with inhibitors for autophagy and lysosomes decreased their basal ROS production and caused a burst of mitochondrial ROS to be delayed. On the other hand, attenuation of mitochondrial activity by serum depletion or by high cell density culture resulted in the loss of both constitutive ROS production and an ROS burst in mitochondria. Thus, constitutive ROS production within mitochondria and lysosomes enables cells to be susceptible to glutamate-induced oxidative cytotoxicity. Likewise, inhibitors for autophagy and lysosomes reduced neural cell death in an ischemia model in rats. We suggest that cell injury during periods of ischemia is regulated by ROS-generating activity in autophagosomes and/or lysosomes as well as in mitochondria.