ABSTRACT: Analysis of genes that were differentially expressed in mutant VUB03_DM1 as compared to controls VUB01 and SA01 undifferentiated hES cells Embryonic stem (ES) cell lines provide, theoretically, unlimited access to any needed amount of any specific cell phenotype of an organism, due to their unique capacities at indefinite self-renewal and pluripotency (Smith 2001; Trounson 2006). These properties allow using the progeny of ES cell lines to model human pathologies (Martinat, Shendelman et al. 2004; Lerou and Daley 2005; Ben-Nun and Benvenisty 2006). In particular, human ES cell lines derived from embryos characterized as gene-carriers following pre-implantation genetic diagnosis (PGD) for any one of major monogenic diseases (Pickering, Minger et al. 2005; Mateizel, De Temmerman et al. 2006) may be considered as perfect cellular replicas of those diseases, as they exhibit the exact genotypes associated to them. Here, we confirm this hypothesis by demonstrating that the cell progeny of an ES cell line derived from an embryo with myotonic dystrophy type 1 (DM1) displayed the morphological stigma associated to the expression of the mutant gene –so-called intranuclear foci- as well as abnormal alternate splicing of the insulin receptor, a characteristic feature of DM1. Further differential transcriptomic analysis of the DM1 gene-carrying cells with phenotypically similar populations from native ES cell lines revealed abnormal expression of 89 genes, among which 48 were down-regulated and 39 over-expressed. This study demonstrates that DM1, though a disease with relatively late clinical onset, is associated with expression of genetic defects early on during development. It underlines the value of PGD-derived ES cell lines as a tool to decipher molecular mechanisms of genetic diseases. Ben-Nun, I. F. and N. Benvenisty (2006). Human embryonic stem cells as a cellular model for human disorders. Mol Cell Endocrinol 252(1-2): 154-9. Lerou, P. H. and G. Q. Daley (2005). Therapeutic potential of embryonic stem cells. Blood Rev 19(6): 321-31. Martinat, C., S. Shendelman, et al. (2004). Sensitivity to oxidative stress in DJ-1-deficient dopamine neurons: an ES- derived cell model of primary Parkinsonism. PLoS Biol 2(11): e327. Mateizel, I., N. De Temmerman, et al. (2006). Derivation of human embryonic stem cell lines from embryos obtained after IVF and after PGD for monogenic disorders. Hum Reprod 21(2): 503-11. Pickering, S. J., S. L. Minger, et al. (2005). Generation of a human embryonic stem cell line encoding the cystic fibrosis mutation deltaF508, using preimplantation genetic diagnosis. Reprod Biomed Online 10(3): 390-7. Smith, A. G. (2001). Embryo-derived stem cells: of mice and men. Annu Rev Cell Dev Biol 17: 435-62. Trounson, A. (2006). The production and directed differentiation of human embryonic stem cells. Endocr Rev 27(2): 208-19. Keywords: disease state analysis
