FPRL1-specific anti-inflammatory compounds: Alzheimer's

描述（由申请人提供）：该项目的总体目标是开发g蛋白偶联受体FPRL1（甲酰基肽受体样1）的拮抗剂，以验证阻断该受体可以防止阿尔茨海默病中炎症细胞积聚成斑块，从而防止神经元变性的假设。FPRL1受体已被证明在阿尔茨海默病大脑斑块和缠结中积累的人单核吞噬细胞上表达。此外，42个氨基酸形式的β -淀粉样蛋白已被证明可以激活FPRL1受体并诱导这些吞噬细胞趋化。因此，通过阻断FPRL1受体，我们希望能够防止这些炎症细胞在AD病变中的积累，以及由此引起的炎症过程导致的神经元变性。在这个I期申请中，我们首先提出构建并验证一种既表达FPRL1受体又表达混杂G蛋白的细胞系，该混杂G蛋白允许该受体偶联到细胞内钙途径。该细胞系将使我们能够快速和低成本地筛选14,000种高度多样化的化合物库，以检测FPRL1受体的拮抗剂活性。该文库包括来自50种不同结构类别的新颖且高度多样化的化合物，这些化合物具有刚性支架，并且可以进行快速合成修饰，以便后期先导优化。我们的筛选标准是找到至少一种化合物，在10 μ m浓度下阻断FPRL1介导的细胞内钙增加50%或更多。符合这一标准的化合物将在以下试验中进一步评估：1)在相同的细胞内钙测定中，这些化合物将获得完整的EC50曲线；2)抑制肽W介导的GTP-g-S与表达FPRL1受体的细胞细胞膜结合的增加；3)抑制来自表达FPRL1受体的细胞的放射性碘化肽W与膜的结合；4)抑制淀粉样蛋白β 42介导的全细胞内钙的增加。在所有这些测试中，Ki值为10 uM或更低的化合物（除了肽W结合测试）将进入二期应用，在二期应用中，它们将被优化并在纳摩尔水平上发挥效力。在第二阶段，优化后的化合物将在AD小鼠模型中测试其阻止吞噬细胞积聚到脑病变的能力。最终，最好的化合物将被授权给制药公司进行临床试验。

DESCRIPTION (provided by applicant): The overall objective of this project is to develop an antagonist for the G-protein-coupled receptor FPRL1 (formyl peptide receptor-like 1) to test the hypothesis that blocking this receptor will prevent accumulation of inflammatory cells into plaques in Alzheimers disease, and thereby prevent neuronal degeneration. FPRL1 receptors have been shown to be expressed on human mononuclear phagocytes which accumulate in plaques and tangles in AD brain. Further, the 42-amino acid form of beta-amyloid has been shown to activate FPRL1 receptors and induce chemotaxis in these phagocytes. Thus, by blocking the FPRL1 receptor we expect to prevent accumulation of these inflammatory cells in AD lesions and consequent neuronal degeneration resulting from inflammatory processes. In this Phase I application, we first propose constructing and validating a cell line that expresses both the FPRL1 receptor and a promiscous G protein that will allow this receptor to couple to the intracellular calcium pathway. This cell line will allow us to rapidly and inexpensively screen a highly diverse library of 14,000 compounds, for antagonist activicty at the FPRL1 receptor. This library includes novel and highly diverse compounds from 50 different structural classes that have rigid scaffold and are amenable to rapid synthetic modification for later lead optimization. Our screening criteria is to find at least one compound that blocks the FPRL1 -mediated increase in intracellular calcium by 50% or more at a concentration of 10 uM. Compounds meeting this criteria will be evaluated further in the following assays: 1) full EC50 curves will be obtained for such compounds in the same intracellular calcium assay; 2) inhibition of peptide W mediated increase in GTP-g-S binding to membranes from cells expressing the FPRL1 receptor; 3) inhibition of radio-iodinated peptide W binding to membranes from cells expressing FPRL1 receptor and 4) inhibition of amyloid beta 42 mediated increase in intracellular calcium in whole cells. Compounds having Ki values of 10 uM or lower in all of these assays (except the peptide W binding assay) will be carried forward to a Phase 2 application in which they will be optimized and rendered potent at the nanomolar level. In Phase II, optimized compounds will be tested in a mouse model of AD for their ability to prevent phagocyte accumulation into brain lesions. Ultimately, the best compound will be licensed to a pharmaceutical company for clinical trials.