Analysis of Cardiac Development in Ts65Dn Mice

Ts65Dn 小鼠心脏发育分析

• 批准号: 7127747
• 负责人: CLARA S MOORE
• 金额: $ 18.99万
• 依托单位: FRANKLIN AND MARSHALL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7127747
• 关键词: Downs syndrome; atrioventricular node; biotechnology; cardiogenesis; cell migration; congenital heart disorder; congenital heart septum defect; developmental genetics; disease /disorder model; embryo /fetus cell /tissue; endocardium; fluorescent in situ hybridization; genetic markers; genetically modified animals; heart valves; immunocytochemistry; laboratory mouse; mammalian embryology; mesenchyme; myocardium; northern blottings; trisomy

DESCRIPTION (provided by applicant): PROJECT SUMMARY: Ts65Dn mice represent the best-characterized animal model for Down syndrome (DS). These mice carry the T65Dn marker chromosome, producing trisomy for a region of mouse chromosome 16 (MMU16) that includes orthologs of about 50% of the genes on human chromosome 21 (HSA21). Forty percent of DS individuals display congenital heart defects (CHD), and we hypothesize that the Ts65Dn mice will display phenotypes related to defective cardiac development. We have demonstrated that the transmission rate of segmental trisomy in Ts65Dn is near the expected 50% at birth, but declines to 34% of offspring by weaning, with selective loss of Ts65Dn neonates within 48 hours of birth. Gross anatomical and histological examination of cadavers indicates aortic arch and AV cushion related septal defects in Ts65Dn neonates. These observations support the hypothesis that one or more candidate genes for DS CHD occur within the trisomic region of Ts65Dn. We will examine genes contained in distal MMU16 and proteins normally expressed in the endocardial cushions to determine if the pathways of cell signaling and differentiation critical to normal cardiac septation are modulated by overexpression of the Ts65Dn genes. We plan to investigate the cardiac development of Ts65Dn mice through the following Specific Aims: 1. Determine the range of cardiac anomalies present in Ts65Dn embryos. Gross plus histological examination using light and scanning electron microscopy will be performed on embryonic hearts of the eupoid (wild type, wt) and trisomic siblings at critical stages of cardiac morphogenesis to determine the incidence and phenotypic range of cardiac defects in Ts65Dn offspring. 2. Analyze the process of epithelial to mesenchymal transformation (EMT), critical to AV endocardial cushion formation, in Ts65Dn transgenic hearts using an in vitro EMT/ migration assay. 3. Investigate the biochemical and molecular differences between Ts65Dn and wt cardiac tissues with emphasis on genes within the Ts65Dn region. Cardiac developmental gene markers and candidate DS CHD genes will be analyzed using in situ hybridization and immunohistology to determine the temporal- spatial patterns of gene and protein expression in endocardial cushions and derivative structures. RATIONALE: Mouse models are commonly used to analyze underlying genetic causes of human disease, as well as to identify the genes that are critical for normal mammalian development. Defining the dosage sensitive genes and the mechanisms by which their misexpression contributes to congenital heart defects in DS will provide insights into the roles of diploid genes during normal cardiac development and may suggest ameliorative strategies for congenital heart defects in DS or euploid individuals.

描述（由申请人提供）：项目摘要：TS65DN小鼠代表了唐氏综合症（DS）的最佳特征动物模型。这些小鼠携带T65DN标记染色体，为小鼠染色体16（MMU16）的区域产生三体染色体，其中包括大约50％的人类染色体基因的直系同源物（HSA21）。 40％的DS个体表现出先天性心脏缺陷（CHD），我们假设TS65DN小鼠将显示与心脏发育缺陷有关的表型。我们已经证明，TS65DN中节段三体的传输速率接近预期的50％，但通过断奶而下降到后代的34％，在出生后48小时内选择性损失TS65DN NEONANES。尸体的总解剖学和组织学检查表明TS65DN新生儿中主动脉弓和AV缓冲相关的间隔缺陷。这些观察结果支持以下假设：DS CHD的一个或多个候选基因出现在TS65DN的三方区域内。我们将检查远端MMU16中包含的基因和通常在心内膜垫中表达的蛋白质，以确定通过TS65DN基因过表达对正常心脏分离至关重要的细胞信号传导和分化的途径。我们计划通过以下特定目的研究TS65DN小鼠的心脏发育：1。确定TS65DN胚胎中存在的心脏异常范围。在心脏形态发生的临界阶段，将对使用光和扫描电子显微镜进行总体加上扫描电子显微镜检查，以确定TS65DN后代的心脏缺陷的发生率和表型范围。 2。使用体外EMT/迁移测定法，在TS65DN转基因心脏中分析上皮到间充质转化（EMT）的过程。 3。研究TS65DN和WT心脏组织之间的生化和分子差异，重点是TS65DN区域内的基因。心脏发育基因标记和候选DS CHD基因将使用原位杂交和免疫组织学分析，以确定心内膜垫和衍生物结构中基因和蛋白质表达的时间空间模式。基本原理：小鼠模型通常用于分析人类疾病的潜在遗传原因，以及鉴定对正常哺乳动物发育至关重要的基因。定义剂量敏感基因以及它们的表现有助于DS中先天性心脏缺陷的机制将提供对二倍体基因在正常心脏发育过程中的作用的见解，并可能提出对DS或Euploid个体中先天性心脏缺陷的改善策略。

项目成果

The power of comparative and developmental studies for mouse models of Down syndrome.

• DOI: 10.1007/s00335-007-9030-8
• 发表时间: 2007-07
• 期刊: MAMMALIAN GENOME
• 影响因子: 2.5
• 作者: Moore, Clara S.;Roper, Randall J.
• 通讯作者: Roper, Randall J.

Cardiovascular development and survival during gestation in the Ts65Dn mouse model for Down syndrome.

唐氏综合症 Ts65Dn 小鼠模型妊娠期间的心血管发育和存活。

• DOI: 10.1002/ar.21301
• 发表时间: 2011
• 期刊: Anatomical record (Hoboken, N.J. : 2007)
• 作者: Lorandeau,CandiceG;Hakkinen,LaurenA;Moore,ClaraS
• 通讯作者: Moore,ClaraS