title: S100B and APP promote a gliocentric shift and impaired neurogenesis in Down syndrome neural progenitors.
abstract: Down syndrome (DS) is a developmental disorder associated with mental retardation (MR) and early onset Alzheimer's disease (AD). These CNS phenotypes are attributed to ongoing neuronal degeneration due to constitutive overexpression of chromosome 21 (HSA21) genes. We have previously shown that HSA21 associated S100B contributes to oxidative stress and apoptosis in DS human neural progenitors (HNPs). Here we show that DS HNPs isolated from fetal frontal cortex demonstrate not only disturbances in redox states within the mitochondria and increased levels of progenitor cell death but also transition to more gliocentric progenitor phenotypes with a consequent reduction in neuronogenesis. HSA21 associated S100B and amyloid precursor protein (APP) levels are simultaneously increased within DS HNPs, their secretions are synergistically enhanced in a paracrine fashion, and overexpressions of these proteins disrupt mitochondrial membrane potentials and redox states. HNPs show greater susceptibility to these proteins as compared to neurons, leading to cell death. Ongoing inflammation through APP and S100B overexpression further promotes a gliocentric HNPs phenotype. Thus, the loss in neuronal numbers seen in DS is not merely due to increased HNPs cell death and neurodegeneration, but also a fundamental gliocentric shift in the progenitor pool that impairs neuronal production.
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Jie
authors.initials: J
authors.lastname: Lu
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Esposito
authors.forename: Caterina
authors.initials: C
authors.lastname: Scuderi
authors.forename: Luca
authors.initials: L
authors.lastname: Steardo
authors.forename: Laurent C
authors.initials: LC
authors.lastname: Delli-Bovi
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Hecht
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Dickinson
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Chang
authors.forename: Takashi
authors.initials: T
authors.lastname: Mori
authors.forename: Volney
authors.initials: V
authors.lastname: Sheen
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000502:physiology; D015153:Blotting, Western; D002478:Cells, Cultured; D004314:Down Syndrome / Q000235:genetics / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D020287:In Situ Nick-End Labeling; D066298:In Vitro Techniques; D053078:Membrane Potential, Mitochondrial / Q000235:genetics / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism*; D055495:Neurogenesis / Q000235:genetics / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D018384:Oxidative Stress / Q000235:genetics / Q000502:physiology; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000235:genetics / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D016564:Amyloid beta-Protein Precursor; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human; C579159:S100b protein, mouse