Identification of Altered Molecular Signature of Down Syndrome iPS Cells

描述（由申请人提供）：该申请涉及广泛的挑战领域（14）干细胞和特定的挑战主题，14- hl -101：通过分析来自确定基因型的受影响个体的重编程诱导多能干细胞，开发心脏、血管、肺和血液疾病的分子特征。唐氏综合征（DS）患儿表现出一系列临床异常，包括异常造血细胞发育的显著发生率。多达10%的新生儿退行性椎体滑移患者表现出短暂性骨髓增生性疾病（TMD）的迹象，这是一种巨核细胞前体细胞异常增殖的疾病。此外，患有TMD的婴儿易患白血病。DS患儿血液学异常的自然历史表明，21三体在妊娠期间直接和功能性地促进了胎儿肝脏中造血细胞的异常扩张。与这一假设相一致的是，最近的两项研究表明，患有DS的人胎儿在巨核细胞红系祖细胞以及红系和巨核细胞集落形成单位中都表现出显著的扩增。为了更好地确定整倍体和21三体造血祖细胞之间的分子差异，我们建议比较患有和不患有DS的个体产生的诱导多能干细胞（iPSCs）的基因表达和甲基化谱。此外，我们将比较这两组iPSCs的造血分化潜能，作为研究DS对血细胞发育和疾病影响的另一种手段。我们的具体目标是：1)从患有唐氏综合征和未患有唐氏综合征的个体中生成和表征三体和整倍体iPSCs； 2)比较未分化的DS和野生型iPSCs以及源自这些iPSCs的造血祖细胞中microRNAs和mrna的表达；3)表征DS和整倍体iPSCs的表观基因组。我们的长期目标是确定我们在21三体细胞中检测到的哪些microrna、mrna或甲基化差异导致了DS的异常造血。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (14) Stem Cells and specific Challenge Topic, 14-HL-101: Develop molecular signatures for heart, vascular, lung, and blood diseases by profiling reprogrammed induced pluripotent stem cells derived from affected individuals of defined genotypes. Children with Down syndrome (DS) show a spectrum of clinical abnormalities, including a remarkable incidence of abnormal hematopoietic cell development. As many as 10% of newborns with DS show evidence of transient myeloproliferative disorder (TMD), a disease in which megakaryocyte precursor cells proliferate abnormally. Moreover, infants with TMD show a predisposition to leukemia. The natural history of hematologic abnormalities in children with DS suggests that trisomy 21 directly and functionally contributes to aberrant expansion of hematopoietic cells in the fetal liver during gestation. Consistent with this hypothesis, two studies have recently demonstrated that human fetuses with DS show a significant expansion in megakaryocyte erythroid progenitors and in both erythroid and megakaryocytic colony forming units. In order to better define the molecular differences between euploid and trisomy 21 hematopoietic progenitors, we propose to compare gene expression and methylation profiles of induced pluripotent stem cells (iPSCs) generated from individuals with and without DS. In addition, we will compare the hematopoietic differentiation potential of these two groups of iPSCs as another means to study the effect of DS on blood cell development and disease. Our specific aims are: 1) To generate and characterize trisomic and euploid iPSCs from individuals with and without Down syndrome, 2) To compare the expression of microRNAs and mRNAs in undifferentiated DS and wild-type iPSCs and hematopoietic progenitors derived from these groups of iPSCs, and 3) To characterize the epigenome of DS versus euploid iPSCs. Our long-term goal is to determine which of the microRNAs, mRNAs or methylation differences we detect in trisomy 21 cells contribute to aberrant hematopoiesis in DS. PUBLIC HEALTH RELEVANCE: This research is relevant to multiple human diseases: 1) transient myeloproliferative disease in children with DS, 2) acute leukemia in children with DS, and 3) multiple non-hematopoietic phenotypes that characterize human DS. For complex genetic diseases, such as Down syndrome, powerful new approaches, including the use of human iPSCs, are absolutely critical to improve our understanding of the molecular basis of the disease and the discovery of novel approaches to alleviate symptoms of this disease.