RESISTANCE & MODULATION OF LEVAMISOLE RECEPTOR CHANNELS

描述(改编自申请者摘要)：蛔虫病和钩虫 全世界有16亿人携带病毒，2 百分之百的病例会造成生命损失。驱虫药，包括左旋咪唑和 相关药物(吡喃酮和奥沙泰尔)，用于对抗线虫寄生虫， 但耐药性的发展是一个令人担忧的问题。长期目标是 通过保护驱虫药的功效来改善和保护人类健康 通过控制和逆转耐药性来控制药物。应用程序的目标 就是找出调节反应敏感性的机制 线虫寄生虫左旋咪唑受体通道。我们的中心假设是 相互竞争的过程(磷酸化-去磷酸化)调节左旋咪唑 反应，过程的修改可能会产生减少或 抵抗力增加。我们提出这一假设的基础是：1) 分析显示左旋咪唑上一致的调节磷酸化位点 受体；2)我们已发表的和初步的数据显示血管通畅性降低 抗性线虫中的左旋咪唑受体通道；3)强有力的初步数据 这表明，左旋咪唑的反应是通过抑制蛋白激酶而减少的。 这项研究的基本原理是，一旦监管机制 左旋咪唑受体通道是已知的，药理学方法可以 制定以预防或克服耐药性，并维持药效 左旋咪唑和相关驱虫药。在大多数实验中，我们将使用 猪蛔虫电生理检测技术的研究 受体通道。电流电压钳肌瓣的制备 技术将被用于筛选药物效果。我们将使用肌囊 用于测量门控动力学影响的制备和膜片钳技术 线虫的左旋咪唑受体通道。我们将追求两个目标 实现我们当前目标的具体目标：1)通过以下方式确定机制 哪些线虫寄生虫限制了它们对受体的反应(P-开放)，并成为 对左旋咪唑的抗性；2)确定增加P-开放值的机制 受体，以逆转对左旋咪唑的耐药性。我们将测试我们的 左旋咪唑耐药性可通过增加受体逆转的假说 不同种类抗性线虫的磷酸化。这项研究是 创新是因为很少有团队进行寄生虫电生理学和其他研究 还没有开发出线虫寄生虫肌泡制剂 左旋咪唑受体通道的膜片钳记录。我们期待着 研究以确定降低左旋咪唑反应的机制(减少 所以寄生虫对左旋咪唑产生了抗药性，并展示了这一点 阻力是可以逆转的。这项研究具有重要的意义，因为它的应用 预计结果将导致控制和克服 对左旋咪唑类驱虫药的抗药性。

DESCRIPTION (Adapted from the Applicant's Abstract): Ascariasis and hookworm infections are carried by 1.6 billion people throughout the world and in 2 percent of cases cause loss of life. Anthelmintics, including levamisole and related drugs (pyrantel and oxantel), are used to combat nematode parasites, but the development of resistance is a concern. The long-range objective is to improve and protect human health by protecting the efficacy of anthelmintic drugs by controlling and reversing resistance. The objective of the application is to identify mechanisms that regulate the sensitivity of the response of nematode parasite levamisole receptor channels. Our central hypothesis is that competing processes (phosphorylation-dephosphorylation) modulate levamisole responses, and that modification of the processes can produce a decrease or increase in resistance. We developed this hypothesis on the basis of: 1) analysis showing consensus regulatory phosphorylation sites on levamisole receptors; 2) our published and preliminary data showing reduced patency of levamisole receptor channels in resistant nematodes; 3) strong preliminary data that shows levamisole responses are reduced by inhibition of protein kinases. The rationale for the research is that, once mechanisms for regulating levamisole receptor channels are known, pharmacological approaches can be formulated to prevent or overcome resistance, and to maintain the efficacy of levamisole and related anthelmintics. In most experiments we will use electrophysiological techniques on Ascaris suum to examine the properties of the receptor channel. Muscle-flap preparations with current- and voltage-clamp techniques will be used for screening drug effects. We will use muscle-vesicle preparations and patch-clamp technology to measure effects on gating kinetics of levamisole receptor channels of nematode parasites. We will pursue two specific aims to accomplish our current objective: 1) determine mechanisms by which nematode parasites limit their response (P-open) of receptors, and become resistant to levamisole; 2) determine mechanisms that increase P-open values of receptors, in order to reverse resistance to levamisole. We will test our hypothesis that levamisole resistance can be reversed by increased receptor phosphorylation in different species of resistant nematodes. The research is innovative because few groups carry out parasite electrophysiology and others have not developed nematode parasite muscle-vesicle preparations for patch-clamp recordings from levamisole receptor channels. We expect the research to identify mechanisms that decrease levamisole responses (reduce P-open) so parasites become resistant to levamisole and to demonstrate how this resistance can be reversed. The research is significant because application of the results is expected to lead towards methods that will control and overcome resistance to anthelmintics of the levamisole class.