title: Disruption of CDH2/N-cadherin-based adherens junctions leads to apoptosis of ependymal cells and denudation of brain ventricular walls.
abstract: Disruption/denudation of the ependymal lining has been associated with the pathogenesis of various human CNS disorders, including hydrocephalus, spina bifida aperta, and periventricular heterotopia. It has been traditionally considered that ependymal denudation is a consequence of mechanical forces such as ventricular enlargement. New evidence indicates that ependymal disruption can precede ventricular dilation, but the cellular and molecular mechanisms involved in the onset of ependymal denudation are unknown. Here, we present a novel model to study ependymal cell pathophysiology and demonstrate that selective disruption of N-cadherin-based adherens junctions is sufficient to provoke progressive ependymal denudation. Blocking N-cadherin function using specific peptides that interfere with the histidine-alanine-valine extracellular homophilic interaction domain caused early pathologic changes characterized by disruption of zonula adherens and abnormal intracellular accumulation of N-cadherin. These changes then triggered massive apoptosis of ependymal cells and denudation of brain ventricular walls. Because no typical extrinsic mechanical factors such as elevated pressure or stretching forces are involved in this model, the critical role of N-cadherin-based adherens junctions in ependymal survival/physiology is highlighted. Furthermore, the results suggest that abnormal adherens junctions between ependymal cells should be considered as key components of the pathogenesis of CNS disorders associated with ependymal denudation.
authors: Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.
authors: Cristian
authors: C
authors: Oliver
authors: César A
authors: CA
authors: González
authors: Genaro
authors: G
authors: Alvial
authors: Carlos A
authors: CA
authors: Flores
authors: Esteban M
authors: EM
authors: Rodríguez
authors: Luis Federico
authors: LF
authors: Bátiz
mesh_terms: D022005:Adherens Junctions / Q000187:drug effects / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D015703:Antigens, CD / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D001921:Brain / Q000166:cytology*; D015820:Cadherins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D017097:Electric Impedance; D055724:Electrophysiological Phenomena / Q000187:drug effects; D004805:Ependyma / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D020287:In Situ Nick-End Labeling; D046529:Microscopy, Electron, Transmission; D009924:Organ Culture Techniques; D010447:Peptide Hydrolases / Q000276:immunology; D013347:Subcellular Fractions / Q000378:metabolism / Q000648:ultrastructure; D013997:Time Factors
chemical_list: D000906:Antibodies; D015703:Antigens, CD; C050361:CDH2 protein, human; D015820:Cadherins; D005904:Glial Fibrillary Acidic Protein; D010447:Peptide Hydrolases; C028759:oligopeptidase