GLUCOCORTICOSTEROID RECEPTOR AND CLEFT PALATE IN MICE

已知小鼠品系在它们对以下疾病的易感性方面不同： 皮质类固醇导致的腭裂 它还表明，这 皮质类固醇（CORT）反应性的变化与遗传有关。 在主要组织相容性复合体（MHC， 小鼠中的H-2）。 我们已经证明，H-2单倍型的差异， 足以改变CORT诱导的腭裂易感性， 正常长成熟的时间变化。 我们的新数据显示 CORT中这些单倍型特异性差异的机制 反应性可能与调节表达的因素有关 糖皮质激素受体（GR），这是编码外的H-2 基因组区域。 我们设计了一系列的具体目标， 良好表征的H-2同源小鼠模型和免疫化学， 生物化学和分子方法来检验H-2 GR表达和/或功能的相关调节是一个关键 调节CORT反应性的分子机制，因此，CORT- 诱发腭裂 目标1. GR翻译和翻译后 调控：对单倍型特异性进行定性和定量分析 自然伽马特征和空间格局的变化 在H-2同源小鼠中呈进行性发育分布。 目的 2. GR转录调控：比较单倍型特异性 稳态水平、发育表达和 H-2同源基因GR mRNA原位时空定位 逐步发展的菌株。 目标3。 GR功能分析： 阐明H-2相关GR功能差异的机制 在H-2同源小鼠中，通过比较 (a)配体-GR与特异性高亲和力GRE DNA（GR-GRE）的结合 结合），和（B）四种蛋白的mRNA表达和空间分布 发育中表达的“皮质激素反应”基因（EGF，TGF-β 1，TGF-β 2）， TGF-β 2、TGF-β 3）。 示范 GR表达和CORT反应的单倍型特异性变异- 活性将支持H-2复合物含有 编码调节GR的反式作用因子的遗传信息 表达和/或功能。 然后我们将进行基因定位， 糖皮质激素反应基因的克隆研究 在小鼠17号染色体上的H-2复合体处或附近的基因座（GRG）， 随后是人类同源物。

It is known that mouse strains differ in their susceptibility to corticosteroid-induced cleft palate. It has also been shown that this variation in corticosteroid (CORT) responsiveness is related to genetic variation in loci at or near the major histocompatibility complex (MHC, H-2 in mice). We have demonstrated that H-2 haplotype differences are sufficient to alter CORT-induced susceptibility to cleft palate and temporal changes in normal long maturation. Our new data indicates that the mechanism for these haplotype-specific differences in CORT responsiveness is likely related to factors modulating the expression of the glucocorticoid receptor (GR), which is encoded outside the H-2 genomic region. We have designed a series of Specific Aims using the well characterized H-2 congenic mouse model and immunochemical, biochemical and molecular methodologies to test the hypothesis that H-2 associated modulation of GR expression and/or function is a key molecular mechanism regulating CORT responsiveness and, hence, CORT- induced cleft palate. Aim 1. GR translational and post-translational regulation: to analyze haplotype-specific qualitative and quantitative variation in GR characteristics and pattern of in situ spatial distribution with progressive development among H-2 congenic mice. Aim 2. GR transcriptional regulation: to compare haplotype-specific differences in the steady state levels, developmental expression, and in situ spatiotemporal localization of GR mRNA among H-2 congenic strains with progressive development. Aim 3. GR function analysis: to delineate the mechanism of H-2 associated differences in GR function among H-2 congenic mice by comparing haplotype-specific variation in (a) ligand-GR binding to a specific high affinity GRE DNA (GR-GRE binding), and (b) mRNA expression and spatial distribution of four developmentally expressed "CORT-responsive" genes (EGF, TGF-beta1, TGF- beta2, TGF-beta3) in the presence of exogenous CORT. The demonstration of haplotype-specific variation in GR expression and CORT respons- iveness will support the hypothesis that the H-2 complex contains genetic information encoding trans-acting factors which regulate GR expression and/or function. We will then pursue gene mapping and cloning studies to identify the glucocorticoid responsiveness gene locus (GRG) at or near the H-2 complex on mouse chromosome 17, subsequently human homologs.