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Modeling Fragile X Syndrome in Human Pluripotent Cells

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Part of the book series: Stem Cell Biology and Regenerative Medicine ((STEMCELL))

Abstract

Fragile X syndrome (FXS) is the leading cause of inherited intellectual disability in males, affecting approximately one in every 4,000 boys and one in 8,000 girls worldwide. A tri-nucleotide CGG expansion at the 5′ untranslated region of the fragile X mental retardation 1 (FMR1) gene leads to CpG methylation of the region and is accompanied by epigenetic changes, resulting in the silencing of the gene. The product of the FMR1 gene is the fragile X mental retardation protein (FMRP). FMRP is most abundant in the brain and testes and is known to play a major role in synaptic plasticity. Due to the high evolutionary conservation of FMRP, several animal models were created to study the disease. Work on fly and mouse models collected valuable data regarding aberrant pathways associated with the syndrome. Although these models were successful in understanding some aspects of the disease, there is no animal model for the study of neither the CGG expansion, nor the epigenetic silencing due to the unique molecular mechanism underlying the syndrome in humans. Work on human tissues was initially restricted to chorion villus taken from fetuses or brain samples taken from postmortem-affected individuals. The generation of human embryonic fragile X cells (FXS-ESCs) and FXS derived induced pluripotent stem cells (FXS-iPSCs) opened the way to study new aspects of the disease and better understand the initial processes which are at the base of the syndrome. Work on FXS-ESCs revealed that silencing of the FMR1 gene happens during differentiation of pluripotent cells into somatic cells and that the silencing process is initiated by histone modifications followed by DNA methylation and heterochromatization. Studies on both FXS-ESCs and FXS-iPSCs revealed aberrant neural differentiation already at the early stages of neurogenesis. FX-iPSCs and their derivatives hold great potential for drug screening. Future work will search for new small molecules for the reactivation of the gene or the major pathways it plays a part in. As many questions regarding the effects caused by the silencing of FMR1 and the expansion mechanism remain unanswered, pluripotent stem cells will serve as a valuable source for FXS disease modeling both as a general model and in a patient-specific manner.

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References

  1. Santoro MR, Bray SM, Warren ST. Molecular mechanisms of fragile X syndrome: a twenty-year perspective. Annu Rev Pathol. 2012;7:219–45.

    Article  CAS  PubMed  Google Scholar 

  2. Lubs H. A marker X chromosome. Am J Hum Genet. 1969;21:231–44.

    CAS  PubMed Central  PubMed  Google Scholar 

  3. Garber KB, Visootsak J, Warren ST. Fragile X syndrome. Eur J Hum Genet. 2008;16:666–72.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  4. Boyle L, Kaufmann WE. The behavioral phenotype of FMR1 mutations. Am J Med Genet Part C Semin Med Genet. 2010;154C:469–76.

    Article  PubMed  Google Scholar 

  5. Penagarikano O, Mulle JG, Warren ST. The pathophysiology of fragile X syndrome. Annu Rev Genomics Hum Genet. 2007;8:109–29.

    Article  CAS  PubMed  Google Scholar 

  6. Wang T, Bray SM, Warren ST. New perspectives on the biology of fragile X syndrome. Curr Opin Genet Dev. 2012;22:256–63.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  7. Callan MA, Zarnescu DC. Heads-up: new roles for the fragile X mental retardation protein in neural stem and progenitor cells. Genesis. 2011;49:424–40.

    Article  CAS  PubMed  Google Scholar 

  8. Verkerk AJMH, et al. Identification of a gene (FMR-1) containing a CGG repeat coincident with a breakpoint cluster region exhibiting length variation in fragile X syndrome. Cell. 1991;65:905–14.

    Article  CAS  PubMed  Google Scholar 

  9. Krawczun MS, Jenkins EC, Brown WT. Analysis of the fragile-X chromosome: localization and detection of the fragile site in high resolution preparations. Hum Genet. 1985;69:209–11.

    Article  CAS  PubMed  Google Scholar 

  10. Sutcliffe JS, et al. DNA methylation represses FMR-1 transcription in fragile X syndrome. Hum Mol Genet. 1992;1:397–400.

    Article  CAS  PubMed  Google Scholar 

  11. Coffee B, Zhang F, Warren ST, Reines D. Acetylated histones are associated with FMR1 in normal but not fragile X-syndrome cells. Nat Genet. 1999;22:98–101.

    Article  CAS  PubMed  Google Scholar 

  12. Coffee B, Zhang F, Ceman S, Warren ST, Reines D. Histone modifications depict an aberrantly heterochromatinized FMR1 gene in fragile X syndrome. Am J Hum Genet. 2002;71:923–32.

    Article  PubMed Central  PubMed  Google Scholar 

  13. Fu YH, et al. Variation of the CGG repeat at the fragile X site results in genetic instability: resolution of the Sherman paradox. Cell. 1991;67:1047–58.

    Article  CAS  PubMed  Google Scholar 

  14. Pietrobono R, et al. Molecular dissection of the events leading to inactivation of the FMR1 gene. Hum Mol Genet. 2005;14:267–77.

    Article  CAS  PubMed  Google Scholar 

  15. Smeets HJ, et al. Normal phenotype in two brothers with a full FMR1 mutation. Hum Mol Genet. 1995;4:2103–8.

    Article  CAS  PubMed  Google Scholar 

  16. Devys D, Lutz Y, Rouyer N, Bellocq JP, Mandel JL. The FMR-1 protein is cytoplasmic, most abundant in neurons and appears normal in carriers of a fragile X premutation. Nat Genet. 1993;4:335–40.

    Article  CAS  PubMed  Google Scholar 

  17. Ashley CT, Wilkinson KD, Reines D, Warren ST. FMR1 protein: conserved RNP family domains and selective RNA binding. Science. 1993;262:563–6.

    Article  CAS  PubMed  Google Scholar 

  18. Feng Y, et al. Fragile X mental retardation protein: nucleocytoplasmic shuttling and association with somatodendritic ribosomes. J Neurosci. 1997;17:1539–47.

    CAS  PubMed  Google Scholar 

  19. Miyashiro KY, et al. RNA cargoes associating with FMRP reveal deficits in cellular functioning in FMR1 null mice. Neuron. 2003;37:417–31.

    Article  CAS  PubMed  Google Scholar 

  20. Feng Y, et al. FMRP associates with polyribosomes as an mRNP, and the I304N mutation of severe fragile X syndrome abolishes this association. Mol Cell. 1997;1:109–18.

    Article  CAS  PubMed  Google Scholar 

  21. Khandjian EW, et al. Biochemical evidence for the association of fragile X mental retardation protein with brain polyribosomal ribonucleoparticles. Proc Natl Acad Sci U S A. 2004;101:13357–62.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  22. Stefani G, Fraser CE, Darnell JC, Darnell RB. Fragile X mental retardation protein is associated with translating polyribosomes in neuronal cells. J Neurosci. 2004;24:7272–6.

    Article  CAS  PubMed  Google Scholar 

  23. Napoli I, et al. The fragile X syndrome protein represses activity-dependent translation through CYFIP1, a new 4E-BP. Cell. 2008;134:1042–54.

    Article  CAS  PubMed  Google Scholar 

  24. Caudy AA, Myers M, Hannon GJ, Hammond SM. Fragile X-related protein and VIG associate with the RNA interference machinery. Genes Dev. 2002;16:2491–6.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  25. Ishizuka A, Siomi M, Siomi H. A Drosophila fragile X protein interacts with components of RNAi and ribosomal proteins. Genes Dev. 2002;16:2497–508.

    Google Scholar 

  26. Plante I, et al. Dicer-derived microRNAs are utilized by the fragile X mental retardation protein for assembly on target RNAs. J Biomed Biotechnol. 2006;2006:64347.

    PubMed Central  PubMed  Google Scholar 

  27. Jin P, et al. Biochemical and genetic interaction between the fragile X mental retardation protein and the microRNA pathway. Nat Neurosci. 2004;7:113–7.

    Article  CAS  PubMed  Google Scholar 

  28. Pan L, Zhang Y, Woodruff E, Broadie K. The Drosophila fragile X gene negatively regulates neuronal elaboration and synaptic differentiation. Curr Biol. 2004;14:1863–70.

    Article  CAS  PubMed  Google Scholar 

  29. Zhang YQ, et al. Drosophila fragile X-related gene regulates the MAP1B homolog Futsch to control synaptic structure and function. Cell. 2001;107:591–603.

    Article  CAS  PubMed  Google Scholar 

  30. Morales J, et al. Drosophila fragile X protein, DFXR, regulates neuronal morphology and function in the brain. Neuron. 2002;34:961–72.

    Article  CAS  PubMed  Google Scholar 

  31. Bolduc FV, Bell K, Cox H, Broadie KS, Tully T. Excess protein synthesis in Drosophila fragile X mutants impairs long-term memory. Nat Neurosci. 2008;11:1143–5.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  32. Dockendorff TC, et al. Drosophila lacking dfmr1 activity show defects in circadian output and fail to maintain courtship interest. Neuron. 2002;34:973–84.

    Article  CAS  PubMed  Google Scholar 

  33. Ashley CT, et al. Human and murine FMR-1: alternative splicing and translational initiation downstream of the CGG-repeat. Nat Genet. 1993;4:244–51.

    Article  CAS  PubMed  Google Scholar 

  34. Grossman AW, Aldridge GM, Weiler IJ, Greenough WT. Local protein synthesis and spine morphogenesis: fragile X syndrome and beyond. J Neurosci. 2006;26:7151–5.

    Article  CAS  PubMed  Google Scholar 

  35. Dutch-belgian T, Van Der RH, Oerlemans F, Hoogeveen T, Oostra BA. Fmr1 knockout mice: a model to study fragile X mental retardation. The Dutch-Belgian Fragile X Consortium. Cell. 1994;78:23–33.

    Google Scholar 

  36. Brouwer JR, et al. Elevated Fmr1 mRNA levels and reduced protein expression in a mouse model with an unmethylated Fragile X full mutation. Exp Cell Res. 2007;313:244–53.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  37. Castrén M, et al. Altered differentiation of neural stem cells in fragile X syndrome. Proc Natl Acad Sci U S A. 2005;102:17834–9.

    Article  PubMed Central  PubMed  Google Scholar 

  38. Willemsen R, Bontekoe CJM, Severijnen L-A, Oostra BA. Timing of the absence of FMR1 expression in full mutation chorionic villi. Hum Genet. 2002;110:601–5.

    Article  CAS  PubMed  Google Scholar 

  39. Eiges R, et al. Developmental study of fragile X syndrome using human embryonic stem cells derived from preimplantation genetically diagnosed embryos. Cell Stem Cell. 2007;1:568–77.

    Article  CAS  PubMed  Google Scholar 

  40. Turetsky T, et al. Laser-assisted derivation of human embryonic stem cell lines from IVF embryos after preimplantation genetic diagnosis. Hum Reprod. 2008;23:46–53.

    Article  CAS  PubMed  Google Scholar 

  41. Telias M, Segal M, Ben-Yosef D. Neural differentiation of fragile X human embryonic stem cells reveals abnormal patterns of development despite successful neurogenesis. Dev Biol. 2013;374:32–45.

    Article  CAS  PubMed  Google Scholar 

  42. Hatton D, Sideris J. Autistic behavior in children with fragile X syndrome: prevalence, stability, and the impact of FMRP. Am J Med Genet A. 1813;2006:1804–13.

    Google Scholar 

  43. Kaufmann WE, et al. Autism spectrum disorder in fragile X syndrome: communication, social interaction, and specific behaviors. Am J Med Genet A. 2004;129A:225–34.

    Article  PubMed  Google Scholar 

  44. Urbach A, Bar-Nur O, Daley GQ, Benvenisty N. Differential modeling of fragile X syndrome by human embryonic stem cells and induced pluripotent stem cells. Cell Stem Cell. 2010;6:407–11.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  45. Sheridan SD, et al. Epigenetic characterization of the FMR1 gene and aberrant neurodevelopment in human induced pluripotent stem cell models of fragile X syndrome. PLoS One. 2011;6, e26203.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  46. Alisch RS, et al. Genome-wide analysis validates aberrant methylation in fragile X syndrome is specific to the FMR1 locus. BMC Med Genet. 2013;14:18.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  47. Bar-Nur O, Caspi I, Benvenisty N. Molecular analysis of FMR1 reactivation in fragile-X induced pluripotent stem cells and their neuronal derivatives. J Mol Cell Biol. 2012;4:180–3.

    Article  PubMed  Google Scholar 

  48. Liu J, et al. Signaling defects in iPSC-derived fragile X premutation neurons. Hum Mol Genet. 2012;21:3795–805.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

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Correspondence to Nissim Benvenisty .

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Halevy, T., Benvenisty, N. (2015). Modeling Fragile X Syndrome in Human Pluripotent Cells. In: Zatz, M., Keith Okamoto, O. (eds) Stem Cells in Modeling Human Genetic Diseases. Stem Cell Biology and Regenerative Medicine. Springer, Cham. https://doi.org/10.1007/978-3-319-18314-5_1

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