title: Neuronal Dysfunction in iPSC-Derived Medium Spiny Neurons from Chorea-Acanthocytosis Patients Is Reversed by Src Kinase Inhibition and F-Actin Stabilization.
abstract: Chorea-acanthocytosis (ChAc) is a fatal neurological disorder characterized by red blood cell acanthocytes and striatal neurodegeneration. Recently, severe cell membrane disturbances based on depolymerized cortical actin and an elevated Lyn kinase activity in erythrocytes from ChAc patients were identified. How this contributes to the mechanism of neurodegeneration is still unknown. To gain insight into the pathophysiology, we established a ChAc patient-derived induced pluripotent stem cell model and an efficient differentiation protocol providing a large population of human striatal medium spiny neurons (MSNs), the main target of neurodegeneration in ChAc. Patient-derived MSNs displayed enhanced neurite outgrowth and ramification, whereas synaptic density was similar to controls. Electrophysiological analysis revealed a pathologically elevated synaptic activity in ChAc MSNs. Treatment with the F-actin stabilizer phallacidin or the Src kinase inhibitor PP2 resulted in the significant reduction of disinhibited synaptic currents to healthy control levels, suggesting a Src kinase- and actin-dependent mechanism. This was underlined by increased G/F-actin ratios and elevated Lyn kinase activity in patient-derived MSNs. These data indicate that F-actin stabilization and Src kinase inhibition represent potential therapeutic targets in ChAc that may restore neuronal function.
  
  
  
  Chorea-acanthocytosis (ChAc) is a fatal neurodegenerative disease without a known cure. To gain pathophysiological insight, we newly established a human in vitro model using skin biopsies from ChAc patients to generate disease-specific induced pluripotent stem cells (iPSCs) and developed an efficient iPSC differentiation protocol providing striatal medium spiny neurons. Using patch-clamp electrophysiology, we detected a pathologically enhanced synaptic activity in ChAc neurons. Healthy control levels of synaptic activity could be restored by treatment of ChAc neurons with the F-actin stabilizer phallacidin and the Src kinase inhibitor PP2. Because Src kinases are involved in bridging the membrane to the actin cytoskeleton by membrane protein phosphorylation, our data suggest an actin-dependent mechanism of this dysfunctional phenotype and potential treatment targets in ChAc.
authors.affiliation: Department of Neurology and.
authors.forename: Nancy
authors.initials: N
authors.lastname: Stanslowsky
authors.affiliation: Center for Regenerative Therapies Dresden.
authors.forename: Peter
authors.initials: P
authors.lastname: Reinhardt
authors.affiliation: Division of Neurodegenerative Diseases, Department of Neurology.
authors.forename: Hannes
authors.initials: H
authors.lastname: Glass
authors.affiliation: Department of Neurology and.
authors.forename: Norman
authors.initials: N
authors.lastname: Kalmbach
authors.affiliation: Department of Neurology and.|Center for Systems Neuroscience, 30559 Hannover, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Naujock
authors.affiliation: Institute of Neuroanatomy, Hannover Medical School, 30625 Hanover, Germany.
authors.forename: Niko
authors.initials: N
authors.lastname: Hensel
authors.affiliation: Institute of Neuroanatomy, Hannover Medical School, 30625 Hanover, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Lübben
authors.affiliation: Center for Regenerative Therapies Dresden.|Division of Neurodegenerative Diseases, Department of Neurology.|German Center for Neurodegenerative Diseases Dresden, and.
authors.forename: Arun
authors.initials: A
authors.lastname: Pal
authors.affiliation: Department of Neurology and.
authors.forename: Anna
authors.identifier: 0000-0001-5735-0202
authors.initials: A
authors.lastname: Venneri
authors.affiliation: Department of Medicine, University of Verona and AOUI Verona, Policlinico GB Rossi, 37134 Verona, Italy, and.
authors.forename: Francesca
authors.initials: F
authors.lastname: Lupo
authors.affiliation: Department of Medicine, University of Verona and AOUI Verona, Policlinico GB Rossi, 37134 Verona, Italy, and.
authors.forename: Lucia
authors.initials: L
authors.lastname: De Franceschi
authors.affiliation: Institute of Neuroanatomy, Hannover Medical School, 30625 Hanover, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Claus
authors.affiliation: Center for Regenerative Therapies Dresden.
authors.forename: Jared
authors.initials: J
authors.lastname: Sterneckert
authors.affiliation: Center for Regenerative Therapies Dresden.|Division of Neurodegenerative Diseases, Department of Neurology.|German Center for Neurodegenerative Diseases Dresden, and.|Department of Neurology, University of Rostock, Rostock, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Storch
authors.affiliation: Center for Regenerative Therapies Dresden.|Division of Neurodegenerative Diseases, Department of Neurology.|German Center for Neurodegenerative Diseases Dresden, and.|Universitäts Centrum für seltene Erkrankungen, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hermann
authors.affiliation: Department of Neurology and Wegner.Florian@mh-hannover.de.|Center for Systems Neuroscience, 30559 Hannover, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Wegner
mesh_terms: D000199:Actins / Q000378:metabolism*; D000328:Adult; D002454:Cell Differentiation; D002478:Cells, Cultured; D003342:Corpus Striatum / Q000378:metabolism / Q000473:pathology*; D005260:Female; D059330:GABAergic Neurons / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism / Q000473:pathology*; D054546:Neuroacanthocytosis / Q000378:metabolism* / Q000473:pathology*; D009474:Neurons; D009435:Synaptic Transmission; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000199:Actins; D019061:src-Family Kinases
keywords: Src kinase; actin cytoskeleton; chorea-acanthocytosis; human induced pluripotent stem cells; patch-clamp electrophysiology; striatal medium spiny neurons