Lysosome exocytosis is involved in astrocyte ATP release after oxidative stress induced by H2O2

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 H2O2 in astrocytes. Methods Astrocytes were isolated from the cortex of neonatal rats. Intracellular lysosomes and calcium signals were stained in astrocytes before and after H2O2 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. H2O2 stimulation resulted in the decrease of lysosomes staining and the increase of extracellular ATP, compared to the control (p Conclusion Our results indicated that H2O2 induced ATP release from intracellular to extracellular via lysosome exocytosis. The increase of intracellular Ca2+ was necessary for lysosome release under oxidative stress induced by H2O2.