Upregulation of NOX2 and NOX4 Mediated by TGF-β Signaling Pathway Exacerbates Cerebral Ischemia/Reperfusion Oxidative Stress Injury
Upregulation of NOX2 and NOX4 Mediated by TGF-β Signaling Pathway Exacerbates Cerebral Ischemia/Reperfusion Oxidative Stress Injury
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TGF-β 信号通路介导的 NOX2 和 NOX4 上调加剧脑缺血/再灌注氧化应激损伤
DOI：
10.1159/000489450
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发表时间：
2018-01-01
影响因子：
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通讯作者：
Yang, Zhong-Bao
中科院分区：
文献类型：
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作者：
Lou, Zheng;Wang, Ai-Ping;Yang, Zhong-Bao
背景/目的：缺血性脑卒中仍然是主要的致残性疾病之一，具有较高的发病率和死亡率。NADPH氧化酶（NOX）衍生的活性氧（ROS）在脑缺血/再灌注（I/R）损伤中起重要作用。然而，调控ROS生成的机制仍未完全阐明。本研究旨在探讨转化生长β (tgf - β)信号在ROS生成中的作用。方法：采用大鼠I/R损伤，用缺氧/再氧化（H/R）和/或激活素受体样激酶（ALK5）抑制剂Sb505124或siRNA处理PC-12细胞。采用神经学评分、氯化三苯四唑染色、苏木精和伊红染色、梗死体积测定、TUNEL染色和caspase-3活性测定来评估脑损伤。实时聚合酶链反应和Western blot检测tgf - β和氧化应激相关基因的表达；分别采用分光光度法和荧光显微镜法测定氮氧化物活性和活性氧水平。结果：I/R可导致严重脑损伤（神经功能受损、脑梗死、组织水肿、细胞凋亡）、tgf - β信号激活（ALK5上调、SMAD2/3磷酸化）和氧化应激（NOX2/4上调、ROS快速释放[氧化爆发]）。然而，Sb505124显著逆转了这些改变，并保护大鼠免受I/R损伤。和动物实验结果一样。H/R也有助于tgf - β信号激活和氧化应激。同样，抑制ALK5或敲低ALK5可显著逆转PC-12细胞中的这些改变。除ALK5敲低外，ALK5抑制对PC-12细胞中ALK5的表达无影响。结论：我们的研究表明，tgf - β信号激活参与了NOX2/NOX4表达的调控，并加重了脑I/R损伤。(C) 2018作者：瑞士巴塞尔，Karger AG出版。
Background/Aims: Ischemic stroke is still one of the leading debilitating diseases with high morbidity and mortality. NADPH oxidase (NOX)-derived reactive oxygen species (ROS) play an important role in cerebral ischemia/reperfusion (I/R) injury. However, the mechanism underlying the regulation of ROS generation is still not fully elucidated. This study aims to explore the role of transforming growth beta (TGF-beta) signals in ROS generation. Methods: Sprague Dawley rats were subjected to I/R injury, and PC-12 cells were challenged by hypoxia/reoxygenation (H/R) and/or treated with activin receptor-like kinase (ALK5) inhibitor Sb505124 or siRNA against ALK5. Brain damage was evaluated using neurological scoring, triphenyl tetrazolium chloride staining, hematoxylin and eosin staining, infarct volume measurement, TUNEL staining, and caspase-3 activity measurement. Expression of TGF-beta and oxidative stress-related genes was analyzed by real-time polymerase chain reaction and Western blot; NOX activity and ROS level were measured using spectrophotometry and fluorescence microscopy, respectively. Results: I/R contributed to severe brain damage (impaired neurological function, brain infarction, tissue edema, apoptosis), TGF-beta signaling activation (upregulation of ALK5, phosphorylation of SMAD2/3) and oxidative stress (upregulation of NOX2/4, rapid release of ROS [oxidative burst]). However, Sb505124 significantly reversed these alterations and protected rats against I/R injury. As in the animal results. H/R also contributed to TGF-beta signaling activation and oxidative stress. Likewise, the inhibition of ALK5 or ALK5 knockdown significantly reversed these alterations in PC-12 cells. Other than ALK5 knockdown, ALK5 inhibition had no effect on the expression of ALK5 in PC-12 cells. Conclusions: Our studies demonstrated that TGF-beta signaling activation is involved in the regulation of NOX2/NOX4 expression and exacerbates cerebral I/R injury. (C) 2018 The Author(s) Published by Karger AG, Basel.