VITAMIN D RESISTANCE AND RELATED DISORDERS

维生素 D 抵抗和相关疾病

• 批准号: 2573695
• 负责人: J BARSONY
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2573695
• 关键词: 1,25 dihydroxycholecalciferol; clinical research; confocal scanning microscopy; cyclic GMP; endoplasmic reticulum; fibroblasts; genetic disorder; green fluorescent proteins; human subject; microtubules; receptor coupling; receptor expression; vitamin D receptors; vitamin D resistant rickets

With the recognition that vitamin D is the precursor for the steroid hormone, calcitriol, it has become possible to characterize defects in the target actions of calcitriol. We have demonstrated a broad spectrum of manifestations of hereditary resistance to calcitriol. This syndrome usually results from a mutation in the gene for the vitamin D receptor. Skin fibroblasts from subjects with hereditary resistance to calcitriol all display abnormalities in this effector system, and defects in many discrete steps of this pathway have been identified with these cells. Cells with mutations in the calcitriol effector pathway can be used to explore mechanisms of calciferol action. They have been used to establish that the vitamin D receptor mediates an extremely rapid (within 1-3 min) rise of cyclic GMP in response to calcitriol and to demonstrate that cGMP plays a role in receptor translocation. These cells have also been used to show that certain receptor mutations compromise many receptor functions but allow another functions to be retained normally. This establishes that calcitriol receptors couple to different responses by distinct mechanisms. With the development of a new, pharmacologically relevant fluorescent calcitriol, it became possible to study vitamin D receptor activation in living cells and recognize abnormalities in vitamin D receptor translocation from the cytoplasm to the nucleus. The fluorescent calcitriol allowed the use of confocal microscopy to identify the association of vitamin D receptors with endoplasmic reticulum and microtubules, and to visualize intranuclear target sites.Transient expression of a green fluorescent protein glucocorticoid receptor chimeric protein allowed us to study the activation of another steroid receptor in real-time by microscopy, and allowed the generalization of our findings on vitamin D receptor activation process.

认识到维生素D是类固醇的前体 激素，骨化三醇，它已经有可能表征缺陷的 骨化三醇的靶向作用。我们已经展示了一个广泛的 骨化三醇遗传性抵抗的表现谱。 这种综合征通常是由于基因突变引起的 维生素D受体。遗传性疾病患者的皮肤成纤维细胞 对骨化三醇的抵抗在这个效应器中都表现出异常。 这条途径的许多离散步骤中的缺陷已经被 与这些细胞相一致。骨化三醇基因突变的细胞 效应通路可用于探讨骨化醇的作用机制 行动。它们已被用来确定维生素D受体 在1-3分钟内调节循环GMP的极快速升高 对骨化三醇的反应，并证明cGMP在 受体易位。这些细胞也被用来证明 某些受体突变损害了许多受体功能，但 允许其他功能正常保留。这就确立了 骨化三醇受体通过不同的方式偶联到不同的反应 机制。随着一种新的、药理上相关的 荧光骨化三醇使研究维生素D受体成为可能 活细胞的激活与维生素D的异常识别 受体从细胞质转位到细胞核。这个 荧光骨化三醇使共聚焦显微镜的使用 确定维生素D受体与内质的关系 网状和微管，并显示核内靶点 一种绿色荧光蛋白的瞬时表达 糖皮质激素受体嵌合蛋白使我们能够研究 通过显微镜实时激活另一种类固醇受体，以及 允许对我们关于维生素D受体的发现进行推广 激活过程。