Thyroid Hormone and Retinoic Acid Regulation of Gene Expression

甲状腺激素和视黄酸对基因表达的调节

• 批准号: 8974308
• 负责人: GREGORY A BRENT
• 金额: --
• 依托单位: VA GREATER LOS ANGELES HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8974308
• 关键词: Acute; Adult; Allan-Herndon-Dudley syndrome; Apoptosis; Area; Binding; Biological Preservation; Brain; Brain Diseases; Brain Injuries; Brain region; Calmodulin; Candidate Disease Gene; Cell Line; Cell model; ChIP-seq; Chickens; Chronic; Development; Differentiation and Growth; ES Cell Line; Elderly; Embryo; Enzymes; Gene Activation; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Gene Mutation; Gene Targeting; Genes; Genetic; Goals; Grant; Health; Human; Hypothyroidism; Hypoxia; In Vitro; Individual; Injury; Iodide Peroxidase; Lead; Ligands; Link; MAP Kinase Gene; MEKs; Mediating; Messenger RNA; Metabolic Pathway; Modeling; Modification; Mood Disorders; Mus; Neurologic Deficit; Neuronal Differentiation; Neurons; Nuclear; Ovalbumin; Pathway interactions; Pattern; Phosphotransferases; Process; Profound Mental Retardation; Protein Isoforms; Recovery; Refractory; Regulation; Reporting; Rodent; Rodent Model; Role; Sampling; Serum; Signal Transduction Pathway; Signaling Protein; Specimen; System; Techniques; Testing; Thyroid Gland; Thyroid Hormone Receptor; Thyroid Hormones; Thyroxine; Traumatic Brain Injury; Tretinoin; Triiodothyronine; Veterans; Woman; base; cognitive function; embryonic stem cell; genetic approach; genome-wide; hippocampal pyramidal neuron; hormone analog; improved; in vitro Model; in vivo; inhibitor/antagonist; knock-down; nerve injury; nerve stem cell; neural growth; neurodevelopment; neuron loss; neuronal growth; neuronal patterning; neuronal survival; novel; receptor binding; relating to nervous system; response; response to injury; stem; therapeutic target; tool; transcription factor; transcription factor USF; transport inhibitor; type 2 deiodinase (D2); uptake

DESCRIPTION (provided by applicant): Triiodothyronine (T3) and retinoic acid (RA) are essential for normal neuronal differentiation and growth. We have utilized neuronal cell lines, and embryonic stem (ES) cells differentiated into neurons, to identify T3 and RA gene targets. Thyroid hormone receptor (TR) � is the predominant isoform expressed in neurons and has features distinct from those of TR�. In the previous grant period we identified a link between RA and T3 in neural development. RA stimulates expression of the Monocarboxylate Transporter 8 (Mct8) thyroid hormone transporter, which in turn promotes neuronal T3 uptake. Profound mental retardation and neurologic deficits are reported in humans with gene mutations that inactivate Mct8, Allan-Herndon-Dudley Syndrome, and these individuals are refractory to treatment with T3. Traumatic Brain Injury (TBI) models show reduced levels of T3 in the serum and brain. This project will focus on the role of T3 and RA in promoting neural growth and differentiation as well as recovery from injury. We will identify the mechanisms of T3 and RA gene regulation and modulation of signal transduction pathways. We will determine the functional role of thyroid transporters, especially MCT8 and MCT10, and their influence on neuronal growth, differentiation, and neuron-specific gene expression. We have developed a technique to differentiate mouse ES cells into pyramidal neurons, a unique model to study T3 action in the brain. We will also study gene expression in specific brain areas of specimens from rodent models of acute and chronic TBI. We will use thyroid transport inhibitors and transporter mRNA knockdowns to determine the functional importance of T3 transport. The thyroid hormone analog, DITPA, does not require the Mct8 neural transporter to enter neurons and will be a complimentary tool to probe the importance of the thyroid transport. We will use inhibitors and knockdowns of pathway components to determine the role of the Wnt/� catenin and MEK/ERK MAPK pathways in regulation of neuronal proliferation and thyroid hormone transport. We will utilize genetic approaches to determine the role of TR� and TR� on T3-mediated genes to promote neural differentiation, growth and to prolong neuronal survival. We will evaluate known T3-regulated genes in pyramidal neurons important for growth and differentiation, as well as performing a genome-wide ChIP-Seq project, based on TR� binding, to identify new T3-regulated genes. We will determine the role of factors that modulate T3-regulation of neuronal growth and differentiation, including the actions of Chicken Ovalbumin Upstream Transcription Factor (COUP-TF1) and Calmodulin-Dependent Kinase IV (CamKIV). Finally, we will test expression of T3 signaling pathway genes in rodent brain areas after an acute and chronic TBI model. Our hypothesis is that specific actions of RA on signal transduction pathways and T3 on nuclear gene expression promote neuronal differentiation and growth and prolong neuronal survival, and the response to injury may recapitulate the developmental patterns of neuronal growth and differentiation. Our goal is to identify therapeutic targets with the potential to promote neural differentiation and growth in conditions such as TBI.

描述（由申请人提供）： 三碘甲醇（T3）和视黄酸（RA）对于正常的神经元分化和生长至关重要。我们利用神经元细胞系和分化为神经元的胚胎干细胞（ES）细胞来鉴定T3和RA基因靶标。甲状腺骑术受体（TR）是在神经元中表达的主要同工型，其特征与TR的特征不同。在上一个赠款期间，我们确定了在神经元开发中RA和T3之间的联系。 RA刺激单羧酸盐转运蛋白8（MCT8）甲状腺雌马转运蛋白的表达，这又促进了神经元T3摄取。在具有失活MCT8，Allan-Herndon-Dudley综合征的基因突变的人类中，据报道了深刻的智力低下和神经系统缺陷，并且这些人对用T3治疗难治性。创伤性脑损伤（TBI）模型显示血清和大脑中T3水平降低。该项目将着重于T3和RA在促进神经元生长和分化以及损伤中恢复中的作用。我们将确定T3和RA基因调节的机制以及信号转移途径的调节。我们将确定甲状腺转运蛋白，尤其是MCT8和MCT10的功能作用，及其对神经元生长，分化和神经特异性基因表达的影响。我们已经开发了一种将小鼠ES细胞分化为锥体神经元的技术，这是研究大脑中T3作用的独特模型。我们还将研究急性和慢性TBI啮齿动物模型的标本特定大脑区域的基因表达。我们将使用甲状腺转运抑制剂和转运蛋白mRNA敲低来确定T3转运的功能重要性。甲状腺激素类似物DITPA不需要MCT8神经元转运蛋白进入神经元，并且将是探测甲状腺转运重要性的免费工具。我们将使用途径组件的抑制剂和敲低来确定Wnt/r链球蛋白和MEK/ERK MAPK途径在调节神经元增殖和甲状腺激素转运方面的作用。我们将利用遗传学方法来确定Tr。和Tr。在T3介导的基因上的作用，以促进神经元分化，生长和延长神经元存活。我们将评估对生长和分化重要的锥体神经元中已知的T3调节基因，并基于TR构成进行全基因组芯片seq项目，以识别新的T3调节基因。我们将确定调节神经元生长和分化的T3调节的因素的作用，包括鸡卵形蛋白上游转录因子（COUP-TF1）和钙调蛋白依赖蛋白依赖性激酶IV（CAMKKIV）的作用。最后，我们将在急性和慢性TBI模型后测试啮齿动物脑区域中T3信号通路基因的表达。我们的假设是，RA对信号转导途径和T3对核基因表达的特定作用促进了神经元分化，生长以及延长神经元存活，并且对损伤的反应可能会概括神经元生长和分化的发育模式。我们的目标是确定在TBI等疾病中促进神经元分化和生长的潜力的治疗靶标。