S100B and APP promote a gliocentric shift and impaired neurogenesis in Down syndrome neural progenitors

• Published in: PloS one 2011-07, Vol.6 (7), p.e22126-e22126
• Main Authors: Lu, Jie, Esposito, Giuseppe, Scuderi, Caterina, Steardo, Luca, Delli-Bovi, Laurent C, Hecht, Jonathan L, Dickinson, Bryan C, Chang, Christopher J, Mori, Takashi, Sheen, Volney
• Format: Article
• Language: English
• Subjects: Alzheimer's disease; Amyloid beta-protein; Amyloid beta-Protein Precursor - genetics; Amyloid beta-Protein Precursor - metabolism; Amyloid precursor protein; Animals; Apoptosis; Apoptosis - genetics; Apoptosis - physiology; BASIC BIOLOGICAL SCIENCES; Biology; Blotting, Western; Brain; Cell cycle; Cell death; Cell growth; cell staining; Cells, Cultured; Central nervous system; Chromosome 21; Cognitive ability; Cortex (frontal); Degeneration; Developmental disabilities; Down syndrome; Down Syndrome - genetics; Down Syndrome - metabolism; Down's syndrome; enzyme-linked immunoassays; Enzyme-Linked Immunosorbent Assay; Fetuses; Genes; Genetic engineering; Humans; hyperexpression techniques; In Situ Nick-End Labeling; In Vitro Techniques; Kinases; Medical schools; Medicine; Membrane Potential, Mitochondrial - genetics; Membrane Potential, Mitochondrial - physiology; Mental disorders; Mice; Mice, Transgenic; Mitochondria; Mortality; Nerve Growth Factors - genetics; Nerve Growth Factors - metabolism; Neural stem cells; Neurodegeneration; Neurodegenerative diseases; Neurogenesis; Neurogenesis - genetics; Neurogenesis - physiology; neuronal death; Neurons; Neurons - cytology; Neurons - metabolism; Oxidative stress; Oxidative Stress - genetics; Oxidative Stress - physiology; Paracrine signalling; Pathology; Pharmacology; Pharmacy; Physiology; Progenitor cells; Proteins; Rodents; S100 Calcium Binding Protein beta Subunit; S100 Proteins - genetics; S100 Proteins - metabolism; S100b protein; Secretions; Stem cells; Stem Cells - cytology; Stem Cells - metabolism; Studies; Transcription factors
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0022126

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.