Ji Zhenjun, Wang Zhen, Chen Zhe, Jin Hao, Chen Chen, Chai Senlin, Lv Haining, Yang Ling, Hu Yakun, Dong Rong, Lai Kefang
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Institute of Respiratory Disease, Guangzhou, China, Medical School of Southeast University, Nanjing, China.
Physiol Res. 2018 May 4;67(2):293-305. doi: 10.33549/physiolres.933654. Epub 2018 Jan 5.
The aim of this study was to investigate the effects of melatonin on oxidative stress, the expression of transient receptor potential melastatin-2 (TRPM2) in guinea pig brains, and the influence of melatonin on oxidative stress in lungs and airway inflammation induced by particulate matter 2.5 (PM2.5). A particle suspension (0.1 g/ml) was nasally administered to the guinea pigs to prepare a PM2.5 exposure model. Cough frequency and cough incubation period were determined through RM6240B biological signal collection and disposal system. Oxidative stress markers, including malondialdehyde (MDA), total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), and glutathione peroxidase (GSH-Px), in the medulla oblongata were examined through spectrophotometer. Reactive oxygen species (ROS) were detected in the hypoglossal nucleus, cuneate nucleus, Botzinger complex, dorsal vagal complex, and airway through dihydroethidium fluorescence. Hematoxylin-eosin (HE) staining and substance P expression via immunohistochemistry revealed the inflammatory levels in the airway. TRPM2 was observed in the medulla oblongata through immunofluorescence and Western blot. The ultrastructure of the blood-brain barrier and neuronal mitochondria was determined by using a transmission electron microscope. Our study suggests that melatonin treatment decreased PM2.5-induced oxidative stress level in the brains and lungs and relieved airway inflammation and chronic cough. TRPM2 might participate in oxidative stress in the cough center by regulating cough.
本研究旨在探讨褪黑素对氧化应激的影响、豚鼠脑内瞬时受体电位香草酸亚型2（TRPM2）的表达，以及褪黑素对细颗粒物2.5（PM2.5）诱导的肺部氧化应激和气道炎症的影响。将颗粒悬浮液（0.1 g/ml）经鼻腔给予豚鼠以制备PM2.5暴露模型。通过RM6240B生物信号采集与处理系统测定咳嗽频率和咳嗽潜伏期。通过分光光度计检测延髓中氧化应激标志物，包括丙二醛（MDA）、总抗氧化能力（T-AOC）、总超氧化物歧化酶（T-SOD）和谷胱甘肽过氧化物酶（GSH-Px）。通过二氢乙锭荧光检测舌下神经核、楔束核、包钦格复合体、迷走背核和气道中的活性氧（ROS）。苏木精-伊红（HE）染色和免疫组化检测P物质表达以揭示气道炎症水平。通过免疫荧光和蛋白质印迹法在延髓中观察TRPM2。使用透射电子显微镜确定血脑屏障和神经元线粒体的超微结构。我们的研究表明，褪黑素治疗可降低PM2.5诱导的脑和肺氧化应激水平，并减轻气道炎症和慢性咳嗽。TRPM2可能通过调节咳嗽参与咳嗽中枢的氧化应激。
