Elucidation of the mechanisms by which cells recognize and respond to different levels of androgens

阐明细胞识别和响应不同水平雄激素的机制

• 批准号: 10418461
• 负责人: Donald P McDonnell
• 金额: $ 66.5万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10418461
• 关键词: Address; Affinity; Androgen Analogues; Androgen Receptor; Androgens; Andrology; Anemia; Architecture; Binding; Biochemical; Biological; Biological Models; Biology; Biosensor; Cachexia; Cell Cycle Proteins; Cell Proliferation; Cells; Chemicals; Chromatin; Climacteric; Complex; Cryoelectron Microscopy; Data; Development; Dimerization; Dose; E2F transcription factors; Exhibits; FOXM1 gene; FRAP1 gene; Gene Expression; Genetic; Genetic Translation; Global Change; Hormones; Hypogonadism; In Vitro; Ligand Binding; Ligands; Liver; Malignant neoplasm of prostate; Menopause; Messenger RNA; Metabolic; Molecular; Muscle; Nuclear Receptors; Osteoporosis; Output; Ovarian; Pathologic; Pathway interactions; Pharmacology; Pharmacology Study; Phenocopy; Phenotype; Physiological; Process; Prostate; Prostate Cancer therapy; Protein-Protein Interaction Map; RIPK1 gene; RNA Helicase; RNA-Binding Proteins; Role; Specificity; Structure; Surface; Syndrome; Testing; Tissues; Work; associated symptom; base; bone; cancer therapy; dimer; in vivo; insight; malignant breast neoplasm; monomer; mouse model; next generation; non-genomic; preference; programs; receptor; recruit; response; sarcopenia; small molecule; tool; transcription factor; tumor growth

An unanswered fundamental question in andrology is how cells recognize and respond in a different manner to different levels of physiological and synthetic androgens. It is assumed that since androgens differ primarily in their relative binding affinity for the androgen receptor (AR) that they are distinguished by how well they enable the formation of similar receptor-coregulator complexes and that this manifests as a quantitative continuum of the same responses. However, leveraging compelling new data we propose the alternate, albeit not mutually exclusive, possibility that androgen dose regulates the relative abundance of AR monomers and dimers in cells and that these forms of the receptor have different coregulator binding preferences resulting in different biological outputs. Indeed, using in vitro systems that model exposure from castrate (low dose; LD) to eugonadal levels and above (high dose; HD), we have determined that the global changes in chromatin architecture, transcription factor cistrome, and gene expression in cells are substantially different, with the changes induced by LD androgens (monomeric AR) being associated with cell proliferation and HD androgens (dimeric AR) inducing a program associated with a differentiated phenotype. A similar distinction in response to androgen levels was observed in vivo. Further, we made the surprising observation that both LD and HD androgens facilitate an AR dependent, non-genomic activation of mTOR but that the resulting translational outputs are different, such that LD but not HD androgens facilitate increased translation of mRNAs encoding key cell cycle proteins (i.e. E2F1, FOXM1). Importantly, we have identified high affinity AR ligands that do not allow receptor dimerization and have shown that their actions phenocopy those of LD androgens. Thus, by using receptor oligomerization state as a biosensor cells are able to respond differently to different levels of androgens; a process that can be exploited in the development of new AR modulators for the treatment of cancer and other androgenopathies. Hypothesis: Androgen receptor expressing cells possess biochemical mechanisms that enable them to manifest qualitatively distinct biological responses to different exposure levels of androgens enabling the same hormone to exhibit different activities in the same cell. Aims: (1) Define the mechanism(s) that enable cells to sense and respond to different levels of androgens, (2) Elucidate the mechanisms by which androgens activate mTOR and regulate mRNA translational specificity, and (3) Use small molecule-based approaches to explore the physiological and pathological importance of pathways and processes that enable cells to respond differently to different levels of androgens. Impact: In addition to probing the pharmacology of AR this study will formally test the “coregulator hypothesis” that differential engagement of functionally distinct coregulators allows the same ligand to exhibit different activities in and between cells. This will also enable the establishment of a conceptual framework that will inform the mechanisms that determine the molecular pharmacology of other ligand-regulated nuclear receptors.

雄科学方面的一个未解决的基本问题是细胞如何以不同的方式识别和反应 不同级别的物理和合成雄激素。假定既然雄激素在 它们对雄激素受体（AR）的相对结合亲和力是通过它们启用的能力来区分的 形成相似的受体调节仪复合物，这表现为定量连续体 相同的回答。但是，利用引人注目的新数据，我们提出了替代方案，尽管不是相互的 独家，雄激素剂量调节细胞中AR单体和二聚体的相对抽象的可能性 并且这些形式的接收器具有不同的键盘结合偏好，导致不同的生物学 输出。实际上，使用从castrate（低剂量； LD）接触到Eugonadal水平的体外系统 以及以上（高剂量； HD），我们确定染色质体系结构的全局变化，转录 因子cistrome和细胞中的基因表达基本不同，其变化由LD诱导 雄激素（单体AR）与细胞增殖和HD雄激素（二聚体AR）诱导A 与差异化表型相关的程序。响应雄激素水平的类似区别是 在体内观察到。此外，我们做出了令人惊讶的观察结果，即LD和HD Androgens都喜欢AR MTOR的依赖性，非基因组激活，但所产生的翻译输出不同，因此 LD但不是HD雄激素促进编码关键细胞周期蛋白的mRNA翻译的增加（即E2F1， FOXM1）。重要的是，我们已经确定了不允许受体二聚体并具有的高亲和力配体 表明他们的作用是LD雄激素的作用。通过将受体寡聚状态用作一个 生物传感器细胞对不同水平的雄激素的反应不同。可以利用的过程 在开发用于治疗癌症和其他雄激素病的新AR调节剂中。 假设：雄激素受体表达细胞具有生化机制，使它们能够 表现出对不同暴露水平的雄激素的定性生物学反应，使其能够相同 在同一细胞中暴露了不同活动的马。 目的：（1）定义使细胞能够感知和响应不同级别雄激素的机制，（2） 阐明雄激素激活mTOR并调节mRNA平移特异性的机制，并 （3）使用基于分子的小方法来探索途径的物理和病理重要性 以及使细胞能够对不同水平的雄激素做出不同反应的过程。 影响：除了探测AR的药理学外，这项研究还将正式检验“核心节假设” 功能上不同的核心调节器的差异参与使相同的配体暴露了不同的配体 细胞和之间的活动。这也将使建立一个概念框架，以告知 决定其他配体调节的核接收器的分子药理学的机制。