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Analyzing the Size, Shape, and Directionality of Networks of Coupled Astrocytes
Published on: October 4, 2018
Regulated ATP release from astrocytes through lysosome exocytosis
Zhijun Zhang1, Gang Chen, Wei Zhou
1Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Nature Cell Biology
|July 10, 2007
Summary
Astrocytes release ATP from lysosomes to propagate calcium (Ca2+) waves and modulate synaptic function. This study reveals regulated lysosome exocytosis as the mechanism for ATP release in astrocytes.
Area of Science:
- Neuroscience
- Cell Biology
- Astrocyte Biology
Background:
- Astrocyte-derived adenosine triphosphate (ATP) is crucial for calcium (Ca2+) wave propagation and synaptic modulation.
- The mechanisms and sources of ATP release from astrocytes remain largely unknown.
Purpose of the Study:
- To elucidate the mechanism and source of ATP release from astrocytes.
- To investigate the role of lysosome exocytosis in astrocyte function.
Main Methods:
- FM dye labeling of astrocytes to visualize lysosomes.
- Time-lapse confocal imaging and Total-Internal-Reflection Fluorescence Microscopy (TIRFM).
- Stimulation with extracellular ATP, glutamate, or potassium cyanide to induce exocytosis.
Main Results:
- FM dyes selectively labeled astrocyte lysosomes.
- Extracellular ATP or glutamate triggered partial lysosome exocytosis.
- Ischemic insult induced both partial and full lysosome exocytosis.
- Lysosomes were identified as a major intracellular ATP store.
- Selective lysosome lysis abolished both ATP release and Ca2+ wave propagation.
Conclusions:
- Regulated lysosome exocytosis is the primary mechanism for ATP release from astrocytes.
- Lysosome exocytosis plays critical roles in physiological and pathological astrocyte functions, including Ca2+ wave propagation.
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