Lysosome exocytosis is involved in astrocyte ATP release after oxidative stress induced by H2O2. (13th July 2019)

• Record Type: Journal Article
• Authors: Li, Zongwei; Gu, Yong; Wen, Ruoxue; Shen, Fanxia; Tian, Heng-Li; Yang, Guo-Yuan; Zhang, Zhijun
• Is Part Of: Neuroscience letters. Volume 705(2019)
• Page Start: 251
• Page End: 258
• Publication Date: 2019-07-13
• Subjects: ATP adenosine triphosphate -- EGFP enhanced green fluorescent protein -- GFAP glial cell and glial fibrillary acidic protein -- ROS reactive oxygen species -- GPN glycyl-phenylalanine 2-naphthylamide -- BAPTA 1, 2-bis-(O-aminophenoxy)-ethane-N, N, N', N'-tetraacetic acid -- ER endoplasmic reticulum; Astrocyte -- ATP -- Lysosome exocytosis -- Oxidative stress; Neurology -- Periodicals; Neurology -- Periodicals; Research -- Periodicals; Neurologie -- Périodiques; Neuroanatomie -- Périodiques; Neuropharmacologie -- Périodiques; Neurophysiologie -- Périodiques; Neurology; Periodicals; Electronic journals; 617.48
• DOI: 10.1016/j.neulet.2019.03.046
• Languages: English
• ISSNs: 0304-3940

Abstract

Highlights: Oxidative damage led to a boost of lysosome exocytosis instead of cell rupture. Intracellular calcium elevation was necessary for lysosome exocytosis under oxidative stress. Lysosomal exocytosis involved in extracellular ATP increase after H2 O2 stimulation. Abstract: Background and purpose: Studies demonstrated that oxidative damage decreased intracellular ATP level in astrocytes. However, the pathway mediated ATP level decrease is obscure. Our previous study found intracellular ATP could be released via lysosome exocytosis in astrocytes. Here, we explored whether lysosome exocytosis was involved in ATP release during oxidative stress induced by H2 O2 in astrocytes. Methods: Astrocytes were isolated from the cortex of neonatal rats. Intracellular lysosomes and calcium signals were stained in astrocytes before and after H2 O2 stimulation. ATP molecules location and ATP level were detected by immunostaining and bioluminescence method, respectively. Extracellular β-Hexosaminidase and LDH were examined by colorimetric method. Results: We found that ATP located in lysosome of astrocytes. H2 O2 stimulation resulted in the decrease of lysosomes staining and the increase of extracellular ATP, compared to the control ( p < 0.05). At the same time, intracellular Fluo4 signals and β-Hexosaminidase level were also increased ( p < 0.05). Extracellular LDH level did not show an increase, suggesting that there is no cell membrane damage after H2 O2 stimulation. Glycyl-phenylalanine 2-naphthylamide blocked lysosome exocytosis and inhibited ATP release in astrocytes after H2 O2 -treatment ( p < 0.05). Conclusion: Our results indicated that H2 O2 induced ATP release from intracellular to extracellular via lysosome exocytosis. The increase of intracellular Ca 2+ was necessary for lysosome release under oxidative stress induced by H2 O2 .