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: 8633738
• 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/8633738
• 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; 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 Pathway Gene; Specimen; System; Techniques; Testing; Thyroid Gland; Thyroid Hormone Receptor; Thyroid Hormones; Thyroxine; Traumatic Brain Injury; Tretinoin; Triiodothyronine; Veterans; Woman; base; chromatin immunoprecipitation; cognitive function; embryonic stem cell; genome-wide; hippocampal pyramidal neuron; hormone analog; improved; in vitro Model; in vivo; inhibitor/antagonist; nerve injury; nerve stem cell; neural growth; neurodevelopment; neuron loss; neuronal growth; neuronal patterning; neuronal survival; novel; public health relevance; receptor binding; relating to nervous system; response; response to injury; stem; therapeutic target; tool; transcription factor; transcription factor USF; transport inhibitor; uptake

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.

三碘甲腺原氨酸（T3）和视黄酸（RA）对于正常神经元分化是必需的， 增长我们已经利用神经元细胞系，并且胚胎干（ES）细胞分化成神经元细胞。 神经元，以确定T3和RA基因的目标。甲状腺激素受体（TR）是主要的 在神经元中表达的同种型，具有与TR不同的特征。在上一次赠款中， 在此期间，我们确定了RA和T3在神经发育中的联系。RA刺激表达 单羧酸转运蛋白8（Mct 8）甲状腺激素转运蛋白，反过来促进 神经元T3摄取。据报道，患有严重精神发育迟滞和神经功能缺损的人， 基因突变导致Mct 8，Allan-Herndon-达德利综合征，这些人是 T3治疗无效。创伤性脑损伤（TBI）模型显示脑组织中T3水平降低。 血清和大脑。本项目将重点研究T3和RA在促进神经生长中的作用， 分化以及从损伤中恢复。我们将进一步探讨T3和RA基因的作用机制， 调节和调节信号转导途径。我们将确定的职能作用， 甲状腺转运蛋白，特别是MCT 8和MCT 10，及其对神经元生长的影响， 分化和神经元特异性基因表达。我们发明了一种技术 小鼠ES细胞转化为锥体神经元，这是研究T3在脑中作用的独特模型。我们还将 啮齿类动物急、慢性脑缺血模型脑内特异性基因表达的研究 创伤性脑损伤我们将使用甲状腺转运抑制剂和转运蛋白mRNA敲低来确定甲状腺功能。 T3转运的功能重要性。甲状腺激素类似物DITPA不需要Mct 8 神经转运蛋白进入神经元，将是一个互补的工具，以探测的重要性， 甲状腺运输我们将使用抑制剂和敲除途径成分，以确定 Wnt/连环蛋白和MEK/ERK MAPK通路在调节神经元增殖中的作用， 甲状腺激素转运我们将利用遗传学方法来确定TR的作用， TR通过T3介导的基因促进神经分化、生长和延长神经元存活。 我们将评估锥体神经元中已知的T3调节基因对生长和发育的重要性， 分化，以及进行全基因组ChIP-Seq项目，基于TR结合， 鉴定新的T3调节基因。我们将确定调节T3调节的因子的作用， 神经元的生长和分化，包括鸡卵清蛋白上游的作用 转录因子（COUP-TF 1）和钙调蛋白依赖性激酶IV（CamKIV）。最后我们将 测试急性和慢性TBI后啮齿动物脑区中T3信号通路基因的表达 模型我们的假设是，RA对信号转导通路的特异性作用和T3对 核基因表达促进神经元分化和生长并延长神经元存活， 对损伤的反应可以概括神经元生长的发育模式， 分化我们的目标是确定有潜力促进神经细胞凋亡的治疗靶点。 在TBI等条件下的分化和生长。