TARGETS OF THYROID HORMONE ACTION IN DEVELOPING BRAIN

本项目的总体目标是了解 哺乳动物中枢神经系统发育的分子机制 神经系统在众多的生理因素影响， 中枢神经系统，甲状腺激素是众所周知的是必不可少的， 适当的发展。甲状腺激素缺乏症在短期的关键 在人类和实验动物中， 动物甲状腺激素的作用是通过核介导的， 受体，调节特定靶基因的表达， 对激素结合的反应。虽然我们对它的功能了解很多， 甲状腺激素受体，这些受体调节的基因， 大脑的发育在很大程度上是未知的。研究的主要目的 这里提出的是识别和表征基因的表达， 在这段时间里，大脑受到甲状腺激素的调节， 甲状腺激素对正常发育至关重要。 潜在的靶基因已被确定使用消减 与聚合酶链式反应扩增偶联杂交， 分离对甲状腺激素应答上调基因， 发育中的老鼠大脑发育和组织特异性模式 候选基因的表达将使用北方DNA测序法测定。 分析和原位杂交，以确定那些最有可能 在中枢神经系统发育中的作用。核苷酸全 将确定所选基因的序列，并将一级氨基酸 序列推断将产生抗体以确定表达 蛋白质的模式和亚细胞定位，使用Western 分析和免疫组织化学方法。一个重要的长期目标， 本项目旨在确定甲状腺激素的功能作用， 神经系统发育中的反应基因产物。详细 了解甲状腺激素影响大脑的机制 发展应该是有价值的，最终试图治疗 中枢神经系统的发育和退化性疾病。

The overall objective of this project is to gain an understanding of the molecular mechanisms underlying the development of the mammalian central nervous system. Among the many physiological factors that influence the central nervous system, thyroid hormone is known to be essential for proper development. Thyroid hormone deficiency during a short critical period produces severe neurological defects in humans and in experimental animals. The actions of thyroid hormone are mediated through nuclear receptors, which regulate the expression of specific target genes in response to hormone binding. Although much is known about the function of thyroid hormone receptors, the genes regulated by these receptors in the developing brain are largely unknown. The main objective of the research proposed here is to identify and characterize genes whose expression in the brain is regulated by thyroid hormone during the period of time in which thyroid hormone is known to be critical for proper development. Potential target genes have been identified using subtractive hybridization coupled with polymerase chain reaction amplification to isolate genes that are up-regulated in response to thyroid hormone in developing rat brain. Developmental and tissue specific patterns of expression for the candidate genes will be determined,using Northern analysis and in situ hybridization to identify those most likely to have a role in central nervous system development. The complete nucleotide sequence will be determined for selected genes and the primary amino acid sequence deduced. Antibodies will be produced to determine expression patterns and subcellular localization of the proteins using Western analysis and immunohistochemical methods. An important long term goal of this project is to determine the functional role of thyroid hormone responsive gene products in nervous system development. A detailed understanding the mechanisms by which thyroid hormone effects brain development should be of value in ultimately attempting to treat developmental and degenerative diseases of the central nervous system.