Mitochondrial Dysfunction in Astrocytes Impairs the Generation of Reactive Astrocytes and Enhances Neuronal Cell Death in the Cortex Upon Photothrombotic Lesion

Frontiers in Molecular Neuroscience

Ravi Jagasia¹  Silke Keiner²  Ruth Beckervordersandforth³  Christian Fiebig³  D. Chichung Lie⁴  Iris Schäffner⁴  Birgit Ebert⁴ 

[1] F. Hoffmann-La Roche, Ltd., CNS Discovery, Pharma Research and Early Development, Basel, Switzerland;Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany;Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany;Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany;

关键词: mitochondrial metabolism;    astrocytes;    stroke/photothrombotic lesion;    electron transport chain;    oxidative phosphorylation;    reactive gliosis;   

DOI  :  10.3389/fnmol.2019.00040

来源: DOAJ

【 摘 要 】

Mitochondria are key organelles in regulating the metabolic state of a cell. In the brain, mitochondrial oxidative metabolism is the prevailing mechanism for neurons to generate ATP. While it is firmly established that neuronal function is highly dependent on mitochondrial metabolism, it is less well-understood how astrocytes function rely on mitochondria. In this study, we investigate if astrocytes require a functional mitochondrial electron transport chain (ETC) and oxidative phosphorylation (oxPhos) under physiological and injury conditions. By immunohistochemistry we show that astrocytes expressed components of the ETC and oxPhos complexes in vivo. Genetic inhibition of mitochondrial transcription by conditional deletion of mitochondrial transcription factor A (Tfam) led to dysfunctional ETC and oxPhos activity, as indicated by aberrant mitochondrial swelling in astrocytes. Mitochondrial dysfunction did not impair survival of astrocytes, but caused a reactive gliosis in the cortex under physiological conditions. Photochemically initiated thrombosis induced ischemic stroke led to formation of hyperfused mitochondrial networks in reactive astrocytes of the perilesional area. Importantly, mitochondrial dysfunction significantly reduced the generation of new astrocytes and increased neuronal cell death in the perilesional area. These results indicate that astrocytes require a functional ETC and oxPhos machinery for proliferation and neuroprotection under injury conditions.

【 授权许可】

Unknown