title: NMDA receptor blockade in the developing cortex induces autophagy-mediated death of immature cortical GABAergic interneurons: An ex vivo and in vivo study in Gad67-GFP mice.
abstract: In neonates, excitotoxicity is a major process involved in hypoxic-ischemic brain lesions, and several research groups have suggested the use of NMDA antagonists for neuroprotection. However, despite their clinical interest, there is more and more evidence suggesting that, in the immature brain, these molecules exert deleterious actions on migrating GABAergic interneurons by suppressing glutamatergic trophic inputs. Consequently, preventing the side effects of NMDA antagonists would be therapeutically useful. Because macroautophagy is involved in the adaptive response to trophic deprivation, the aim of the present study was to investigate the impact of autophagy modulators on the MK801-induced death of immature GABAergic interneurons and to characterize the crosstalk between autophagic and apoptotic mechanisms in this cell type. Ex vivo, using cortical slices from NMRI and Gad67-GFP mice, we show that blockade of the NMDA receptor results in an accumulation of autophagosomes due to the disruption of the autophagic flux. This effect precedes the activation of the mitochondrial apoptotic pathway, and the degeneration of immature GABAergic neurons present in developing cortical layers II-IV and is prevented by 3-MA, an autophagy inhibitor. In contrast, modulators of autophagy (3-MA, rapamycin) do not interfere with the anti-excitotoxic and neuroprotective effect of MK801 observed in deep layers V and VI. In vivo, 3-MA blocks the rapid increase in caspase-3 cleavage induced by the blockade of NMDA receptors and prevents the resulting long-term decrease in Gad67-GFP neurons in layers II-IV. Together, these data suggest that, in the developing cortex, the suppression of glutamatergic inputs through NMDA receptor inhibition results in the impairment of the autophagic flux and the subsequent switch to apoptotic death of immature GABAergic interneurons. The concomitant inhibition of autophagy prevents this pro-apoptotic action of the NMDA blocker and favors the long-term rescue of GABAergic interneurons without interfering with its neuroprotective actions. The use of autophagy modulators in the developing brain would create new opportunities to prevent the side effects of NMDA antagonists used for neuroprotection or anesthesia.
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France.
authors: Christian
authors: C
authors: Roux
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France.
authors: Caroline
authors: C
authors: Aligny
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France.
authors: Céline
authors: C
authors: Lesueur
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France.
authors: Virginie
authors: V
authors: Girault
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France.
authors: Valery
authors: V
authors: Brunel
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France.
authors: Yasmina
authors: Y
authors: Ramdani
authors: Department of Pathology, Rouen University Hospital, Rouen, France.
authors: Damien
authors: D
authors: Genty
authors: Research Platform of Cell Imagery (PRIMACEN), France; Laboratory of Glycobiology and Plant Extracellular Matrix (GLYCOMEV) EA 4358, France.
authors: Azeddine
authors: A
authors: Driouich
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Pathology, Rouen University Hospital, Rouen, France.
authors: Annie
authors: A
authors: Laquerrière
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Neonatal Paediatrics and Intensive Care, Rouen University Hospital, Rouen, France.
authors: Stéphane
authors: S
authors: Marret
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France.
authors: Carole
authors: C
authors: Brasse-Lagnel
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France. Electronic address: bruno.gonzales@univ-rouen.fr.
authors: Bruno J
authors: BJ
authors: Gonzalez
authors: Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France.
authors: Soumeya
authors: S
authors: Bekri
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001343:Autophagy / Q000187:drug effects / Q000235:genetics*; D053148:Caspase 3 / Q000378:metabolism; D002540:Cerebral Cortex / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D059330:GABAergic Neurons / Q000187:drug effects / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D005968:Glutamate Decarboxylase / Q000235:genetics / Q000378:metabolism*; D007166:Immunosuppressive Agents / Q000494:pharmacology; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D008954:Models, Biological; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D013997:Time Factors
chemical_list: D018691:Excitatory Amino Acid Antagonists; D007166:Immunosuppressive Agents; C480860:Map1lc3b protein, mouse; D008869:Microtubule-Associated Proteins; D016194:Receptors, N-Methyl-D-Aspartate; C025946:3-methyladenine; D016291:Dizocilpine Maleate; D007770:L-Lactate Dehydrogenase; D053148:Caspase 3; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; D000225:Adenine
keywords: Apoptosis; Atg5; Caspase-3; Excitotoxicity; GABA interneurons; Immature cortex; LC3/Atg8