title: Modeling neuronal defects associated with a lysosomal disorder using patient-derived induced pluripotent stem cells.
abstract: By providing access to affected neurons, human induced pluripotent stem cells (iPSc) offer a unique opportunity to model human neurodegenerative diseases. We generated human iPSc from the skin fibroblasts of children with mucopolysaccharidosis type IIIB. In this fatal lysosomal storage disease, defective α-N-acetylglucosaminidase interrupts the degradation of heparan sulfate (HS) proteoglycans and induces cell disorders predominating in the central nervous system, causing relentless progression toward severe mental retardation. Partially digested proteoglycans, which affect fibroblast growth factor signaling, accumulated in patient cells. They impaired isolation of emerging iPSc unless exogenous supply of the missing enzyme cleared storage and restored cell proliferation. After several passages, patient iPSc starved of an exogenous enzyme continued to proliferate in the presence of fibroblast growth factor despite HS accumulation. Survival and neural differentiation of patient iPSc were comparable with unaffected controls. Whereas cell pathology was modest in floating neurosphere cultures, undifferentiated patient iPSc and their neuronal progeny expressed cell disorders consisting of storage vesicles and severe disorganization of Golgi ribbons associated with modified expression of the Golgi matrix protein GM130. Gene expression profiling in neural stem cells pointed to alterations of extracellular matrix constituents and cell-matrix interactions, whereas genes associated with lysosome or Golgi apparatus functions were downregulated. Taken together, these results suggest defective responses of patient undifferentiated stem cells and neurons to environmental cues, which possibly affect Golgi organization, cell migration and neuritogenesis. This could have potential consequences on post-natal neurological development, once HS proteoglycan accumulation becomes prominent in the affected child brain.
authors.affiliation: Institut Pasteur, Unité Rétrovirus et Transfert Génétique, 28 rue du Dr Roux, F-75015 Paris, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lemonnier
authors.forename: Stéphane
authors.initials: S
authors.lastname: Blanchard
authors.forename: Diana
authors.initials: D
authors.lastname: Toli
authors.forename: Elise
authors.initials: E
authors.lastname: Roy
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Bigou
authors.forename: Roseline
authors.initials: R
authors.lastname: Froissart
authors.forename: Isabelle
authors.initials: I
authors.lastname: Rouvet
authors.forename: Sandrine
authors.initials: S
authors.lastname: Vitry
authors.forename: Jean Michel
authors.initials: JM
authors.lastname: Heard
authors.forename: Delphine
authors.initials: D
authors.lastname: Bohl
mesh_terms: D000118:Acetylglucosaminidase / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism; D008247:Lysosomes / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008954:Models, Biological; D009084:Mucopolysaccharidosis III / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology*; D009154:Mutation; D009474:Neurons / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism
chemical_list: D019812:Heparan Sulfate Proteoglycans; C033079:alpha-N-acetyl-D-glucosaminidase; D000118:Acetylglucosaminidase