title: A glial origin for periventricular nodular heterotopia caused by impaired expression of Filamin-A.
abstract: Periventricular nodular heterotopia (PH) is a human brain malformation caused by defective neuronal migration that results in ectopic neuronal nodules lining the lateral ventricles beneath a normal appearing cortex. Most affected patients have seizures and their cognitive level varies from normal to severely impaired. Mutations in the Filamin-A (or FLNA) gene are the main cause of PH, but the underlying pathological mechanism remains unknown. Although two FlnA knockout mouse strains have been generated, none of them showed the presence of ectopic nodules. To recapitulate the loss of FlnA function in the developing rat brain, we used an in utero RNA interference-mediated knockdown approach and successfully reproduced a PH phenotype in rats comparable with that observed in human patients. In FlnA-knockdown rats, we report that PH results from a disruption of the polarized radial glial scaffold in the ventricular zone altering progression of neural progenitors through the cell cycle and impairing migration of neurons into the cortical plate. Similar alterations of radial glia are observed in human PH brains of a 35-week fetus and a 3-month-old child, harboring distinct FLNA mutations not previously reported. Finally, juvenile FlnA-knockdown rats are highly susceptible to seizures, confirming the reliability of this novel animal model of PH. Our findings suggest that the disorganization of radial glia is the leading cause of PH pathogenesis associated with FLNA mutations. Rattus norvegicus FlnA mRNA (GenBank accession number FJ416060).
authors.affiliation: INMED, Parc Scientifique de Luminy, Marseille, France; Université de la Mé diterranée, UMR S901 Aix-Marseille 2, Marseille, France; Inserm Unité 901, Marseille, France.
authors.forename: Aurelie
authors.initials: A
authors.lastname: Carabalona
authors.forename: Shirley
authors.initials: S
authors.lastname: Beguin
authors.forename: Emilie
authors.initials: E
authors.lastname: Pallesi-Pocachard
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Buhler
authors.forename: Christophe
authors.initials: C
authors.lastname: Pellegrino
authors.forename: Karen
authors.initials: K
authors.lastname: Arnaud
authors.forename: Philippe
authors.initials: P
authors.lastname: Hubert
authors.forename: Mehdi
authors.initials: M
authors.lastname: Oualha
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Siffroi
authors.forename: Sabrina
authors.initials: S
authors.lastname: Khantane
authors.forename: Isabelle
authors.initials: I
authors.lastname: Coupry
authors.forename: Cyril
authors.initials: C
authors.lastname: Goizet
authors.forename: Antoinette Bernabe
authors.initials: AB
authors.lastname: Gelot
authors.forename: Alfonso
authors.initials: A
authors.lastname: Represa
authors.forename: Carlos
authors.initials: C
authors.lastname: Cardoso
mesh_terms: D000818:Animals; D002465:Cell Movement; D049109:Cell Proliferation; D002540:Cerebral Cortex / Q000196:embryology / Q000378:metabolism* / Q000473:pathology; D002552:Cerebral Ventricles / Q000473:pathology; D003285:Contractile Proteins / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D064448:Filamins; D006801:Humans; D007223:Infant; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D019579:Neocortex / Q000196:embryology / Q000378:metabolism / Q000473:pathology; D058953:Neural Stem Cells / Q000378:metabolism / Q000502:physiology; D009457:Neuroglia / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D009474:Neurons / Q000502:physiology; D054091:Periventricular Nodular Heterotopia / Q000378:metabolism* / Q000473:pathology*; D034622:RNA Interference; D051381:Rats; D012640:Seizures / Q000209:etiology
chemical_list: D003285:Contractile Proteins; D064448:Filamins; D008840:Microfilament Proteins