TSHR and Thyrocyte Development

TSHR 和甲状腺细胞发育

基本信息

批准号：
8034531
负责人：
REIGH-YI LIN
金额：
$ 3.9万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-06 至 2011-03-10
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8034531
关键词：
Animals Biological Models Cardiac Myocytes Cell Differentiation process Cell Lineage Cells Characteristics Development Differentiation Antigens Differentiation and Growth Disease ES Cell Line Embryo Embryonic Development Endoderm Exons Fluorescence Genes Germ Layers Goals Green Fluorescent Proteins Growth Growth Factor Hepatocyte Hormones In Vitro Inner Cell Mass Insulin Insulin-Like Growth Factor I Iodide Peroxidase Knockout Mice Lead Modeling Molecular Mus Outcome Pancreas Pathway interactions Pattern Phenotype Population Production Receptor Signaling Relative (related person)Research Personnel Role SCID Mice Severe Combined Immunodeficiency Source Staging Stem cells Thyroglobulin Thyroid Gland Thyrotropin Thyrotropin Receptor Time Transplantation adult stem cell blastocyst body system early embryonic stage embryo tissue embryonic stem cell gastrulation human disease implantation in vivo insight interstitial cell novel programs research study sodium-iodide symporter stem cell differentiation

项目摘要

Our long-term goal is to elucidate the molecular mechanisms by which thyroid stem cells differentiate into definitive thyrocytes. We specifically focus on thyroid stimulating hormone (TSH), as it is the major hormone in the control of thyroid growth and function. To examine whether TSH directly regulates thyroid development, we generated a TSHR null mouse by replacing exon 1 of the mTSHR gene with green fluorescent protein. We found that TSHR''' mice were severely hypothyroid and died at 4 weeks. Heterozygous mice were unaffected. Intense green fluorescence was detected in thyroid follicles of both TSHR +/ - and TSHR-/- mice. Of note is that follicles in TSHR-/- mice were poorly developed with fewer follicular cells, implying that the follicular growth and differentiation were dependent on TSH. To access early embryonic stages of development, we obtained the TSHR +/ - ES cell line. In addition to providing functional characterization of the TSHR in the thyroid in vivo, these ES cells have enabled us to track thyrocyte induction and its specification to the thyroid cell lineage in the ES cell differentiation model. Two specific aims are proposed. Specific aim 1 will focus on the induction and specification of thyroid lineage during ES cell differentiation. We will investigate when are TSHR and TSH expressed during in vitro differentiation of TSHR +/ - and TSHR -/- ES cells. We will also examine the temporal and spatial expression of TSHR relative to differentiation markers indicative of thyroid lineages in TSHR +/- and TSHR -/- ES cells. More importantly, we will characterize TSH/TSHR signaling in thyrocyte development and investigate whether insulin and insulin growth factor-1 can up-regulate thyroglobulin, a characteristic of mature thyrocytes. Specific Aim 2 will investigate the in vivo thyrocyte potential of TSHR-positive populations using actual murine embryos or ES cell differentiation model. First, we will further characterize the thyroid phenotypes of TSHR +/ - and TSHR -/- mouse embryos during postimplantation development. We will next investigate whether TSHR-positive cells from embryonic tissues have thyrocyte potential. Finally, we will determine whether TSHR-positive cells from ES cells can differentiate into functional thyrocytes in SCID mice. The outcome of these experiments will provide a clearer understanding of the characteristic of embryonic thyroid cells and of how these cells relate to definitive thyrocyte lineage. These studies may have important implications not only for our understanding of normal thyroid development but may provide insights into mechanisms underlying human diseases.

我们的长期目标是阐明甲状腺干细胞分化为确定的甲状腺细胞的分子机制。我们特别关注甲状腺刺激激素（TSH），因为它是控制甲状腺生长和功能的主要激素。为了检查TSH是否直接调节甲状腺发育，我们通过用绿色荧光蛋白代替MTSHR基因的外显子1来产生TSHR无效小鼠。我们发现TSHR''小鼠严重甲状腺功能低下，死于4周。杂合小鼠不受影响。在TSHR +/ - 和TSHR - / - 小鼠的甲状腺卵泡中检测到强烈的绿色荧光。值得注意的是，TSHR - / - 小鼠中的卵泡发育不良，卵泡细胞较少，这意味着卵泡生长和分化取决于TSH。为了访问发育的早期胚胎阶段，我们获得了TSHR +/ -ES细胞系。除了提供 TSHR在体内的功能表征，这些ES细胞使我们能够跟踪甲状腺细胞诱导及其对ES细胞分化模型中甲状腺细胞谱系的规范。提出了两个具体目标。特定的目标1将集中于ES细胞分化过程中甲状腺谱系的诱导和规范。我们将研究TSHR和TSH在TSHR +/ - 和TSHR - / - ES细胞的体外分化期间表达的时间。我们还将检查TSHR相对于分化标记的时间和空间表达，指示TSHR +/-和TSHR - / - ES细胞中甲状腺谱系。更重要的是，我们将在甲状腺细胞发育中表征TSH/TSHR信号传导，并研究胰岛素和胰岛素生长因子-1是否可以上调甲状腺球蛋白，这是成熟甲状腺细胞的特征。具体目标2将使用实际的鼠类胚胎或ES细胞分化模型研究TSHR阳性群体的体内甲状腺细胞电位。首先，我们将进一步表征TSHR +/ - 和TSHR - / - 小鼠胚胎在植入后发育过程中的甲状腺表型。接下来，我们将调查来自胚胎的TSHR阳性细胞是否组织具有甲状腺细胞的潜力。最后，我们将确定来自ES细胞的TSHR阳性细胞是否可以区分SCID小鼠的功能性甲状腺细胞。这些实验的结果将对胚胎甲状腺细胞的特征以及这些细胞与确定的甲状腺细胞谱系的关系提供更清晰的理解。这些研究可能不仅对我们对正常甲状腺发育的理解具有重要意义，而且可以提供对人类疾病潜在机制的见解。