Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907-2091, USA.
Insect Biochem Mol Biol. 2012 Nov;42(11):846-53. doi: 10.1016/j.ibmb.2012.07.011.
Ticks transmit a wide variety of disease causing pathogens to humans and animals. Considering the global health impact of tick-borne diseases, there is a pressing need to develop new methods for vector control. We are exploring arthropod dopamine receptors as novel targets for insecticide/acaricide development because of their integral roles in neurobiology. Herein, we developed a screening assay for dopamine receptor antagonists to further characterize the pharmacological properties of the two D₁-like dopamine receptors (Isdop1 and Isdop2) identified in the Lyme disease vector, Ixodes scapularis, and develop a screening assay for receptor antagonists. A cell-based, cyclic AMP luciferase reporter assay platform was implemented to screen the LOPAC(1280) small molecule library for Isdop2 receptor antagonists, representing the first reported chemical library screen for any tick G protein-coupled receptor. Screening resulted in the identification of 85 "hit" compounds with antagonist activity at the Isdop2 receptor. Eight of these chemistries were selected for confirmation assays using a direct measurement of cAMP, and the effects on both Isdop1 and Isdop2 were studied for comparison. Each of these eight compounds showed antagonistic activity at both Isdop1 and Isdop2, although differences were observed regarding their relative potencies. Furthermore, comparison of the pharmacological properties of the tick dopamine receptors with that of the AaDOP2 receptor from the yellow fever mosquito and the human dopamine D₁ receptor (hD₁) revealed species-specific pharmacological profiles of these receptors. Compounds influencing dopaminergic functioning, such as the dopamine receptor antagonists discovered here, may provide lead chemistries for discovery of novel acaricides useful for vector control
蜱传播多种病原体给人类和动物。考虑到蜱传疾病对全球健康的影响，迫切需要开发新的方法来控制媒介。我们正在探索节肢动物多巴胺受体作为杀虫剂/杀螨剂开发的新靶标，因为它们在神经生物学中具有重要作用。在此，我们开发了一种多巴胺受体拮抗剂筛选测定法，以进一步表征在莱姆病媒介硬蜱中鉴定的两种 D₁样多巴胺受体（Isdop1 和 Isdop2）的药理学特性，并开发一种受体拮抗剂筛选测定法。我们实施了基于细胞的环 AMP 荧光素酶报告基因测定平台，以筛选 LOPAC(1280)小分子文库中的 Isdop2 受体拮抗剂，这是首次针对任何蜱 G 蛋白偶联受体进行化学文库筛选。筛选鉴定出 85 种具有 Isdop2 受体拮抗活性的“命中”化合物。这 8 种化学物质中有 8 种被选择用于使用 cAMP 的直接测量进行确认测定，并且研究了它们对 Isdop1 和 Isdop2 的影响以进行比较。这 8 种化合物中的每一种都显示出对 Isdop1 和 Isdop2 的拮抗活性，尽管观察到它们的相对效力存在差异。此外，将蜱多巴胺受体的药理学特性与黄热病蚊子的 AaDOP2 受体和人多巴胺 D₁受体（hD₁）进行比较，揭示了这些受体的物种特异性药理学特征。影响多巴胺能功能的化合物，如这里发现的多巴胺受体拮抗剂，可能为发现用于媒介控制的新型杀螨剂提供先导化学物质。
