FPRL1-specific anti-inflammatory compounds: Alzheimer's

描述（由申请人提供）：本项目的总体目标是开发G蛋白偶联受体FPRL 1（甲酰肽受体样1）的拮抗剂，以检验阻断该受体将防止炎症细胞在阿尔茨海默病中积聚成斑块，从而防止神经元变性的假设。已显示FPRL 1受体在人单核吞噬细胞上表达，其在AD脑中的斑块和缠结中积累。此外，42-氨基酸形式的β-淀粉样蛋白已显示激活FPRL 1受体并诱导这些吞噬细胞中的趋化性。因此，通过阻断FPRL 1受体，我们期望防止这些炎性细胞在AD病变中的积累和随后由炎性过程引起的神经元变性。在这个I期申请中，我们首先提出构建和验证一个细胞系，该细胞系表达FPRL 1受体和一个混杂的G蛋白，这将允许该受体与细胞内钙通道偶联。该细胞系将使我们能够快速和廉价地筛选高度多样化的14，000种化合物库，用于FPRL 1受体的拮抗剂活性。该库包括来自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，并且易于快速合成修饰以用于随后的先导物优化。我们的筛选标准是找到至少一种化合物，其在10 μ M的浓度下阻断FPRL 1介导的细胞内钙增加50%或更多。1）在相同的细胞内钙测定中获得这些化合物的完整EC 50曲线; 2）抑制肽W介导的GTP-g-S与来自表达FPRL 1受体的细胞的膜结合的增加; 3）抑制放射性碘化肽W与来自表达FPRL 1受体的细胞的膜的结合和4）抑制淀粉样蛋白β 42介导的全细胞中细胞内钙的增加。在所有这些试验中（肽W结合试验除外）Ki值为10 μ M或更低的化合物将进入第2阶段应用，在该阶段应用中，它们将被优化并在纳摩尔水平上发挥效力。在II期，将在AD小鼠模型中测试优化的化合物防止吞噬细胞积聚到脑病变中的能力。最终，最好的化合物将被授权给一家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.