title: Inflammation-induced alteration of astrocyte mitochondrial dynamics requires autophagy for mitochondrial network maintenance.
abstract: Accumulating evidence suggests that changes in the metabolic signature of astrocytes underlie their response to neuroinflammation, but how proinflammatory stimuli induce these changes is poorly understood. By monitoring astrocytes following acute cortical injury, we identified a differential and region-specific remodeling of their mitochondrial network: while astrocytes within the penumbra of the lesion undergo mitochondrial elongation, those located in the core-the area invaded by proinflammatory cells-experience transient mitochondrial fragmentation. In brain slices, proinflammatory stimuli reproduced localized changes in mitochondrial dynamics, favoring fission over fusion. This effect was triggered by Drp1 phosphorylation and ultimately resulted in reduced respiratory capacity. Furthermore, maintenance of the mitochondrial architecture critically depended on the induction of autophagy. Deletion of Atg7, required for autophagosome formation, prevented the reestablishment of tubular mitochondria, leading to marked reactive oxygen species accumulation and cell death. Thus, our data reveal autophagy to be essential for regenerating astrocyte mitochondrial networks during inflammation.
authors: Department for Life Quality Studies, Alma Mater Studiorum, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; Adolf Butenandt Institute, Neurobiochemistry, Ludwig Maximilians University Munich, Schillerstrasse 44, 80336 Munich, Germany. Electronic address: elisa.motori@age.mpg.de.
authors: Elisa
authors: E
authors: Motori
authors: Julien
authors: J
authors: Puyal
authors: Nicolas
authors: N
authors: Toni
authors: Alexander
authors: A
authors: Ghanem
authors: Cristina
authors: C
authors: Angeloni
authors: Marco
authors: M
authors: Malaguti
authors: Giorgio
authors: G
authors: Cantelli-Forti
authors: Benedikt
authors: B
authors: Berninger
authors: Karl-Klaus
authors: KK
authors: Conzelmann
authors: Magdalena
authors: M
authors: Götz
authors: Konstanze F
authors: KF
authors: Winklhofer
authors: Silvana
authors: S
authors: Hrelia
authors: Matteo
authors: M
authors: Bergami
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D001343:Autophagy; D000071193:Autophagy-Related Protein 7; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D034281:Dynamins / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology; D007371:Interferon-gamma / Q000494:pharmacology; D053583:Interleukin-1beta / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D063154:Mitochondrial Dynamics / Q000187:drug effects; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010766:Phosphorylation; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: C502661:Atg7 protein, mouse; D016207:Cytokines; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D008869:Microtubule-Associated Proteins; D017382:Reactive Oxygen Species; D007371:Interferon-gamma; D052247:Nitric Oxide Synthase Type II; C486391:Dnm1l protein, mouse; D034281:Dynamins; D000071193:Autophagy-Related Protein 7