Modulation and Resistance of Levamisole Receptor Channels

描述（由申请人提供）：蛔虫和钩虫感染影响全球16亿人。包括左旋咪唑和相关药物（吡喃酮）在内的驱虫药被用于对抗线虫寄生虫，耐药性是一种威胁。我们的长期目标是通过确定逆转耐药性的方法来提高驱虫药的功效，从而改善人类健康。本应用程序的目的是测试左旋咪唑受体的单通道特性和描述线虫对左旋咪唑敏感性变化和改变效力的模型。我们的中心假设是，线虫肌肉上的l亚型乙酰胆碱受体离子通道的结构和孔隙使其对左旋咪唑更敏感，对钙的渗透性更强；由神经肽AF2产生的乙酰胆碱通道（调节）反应的增加涉及cAMP、Ca进入和激酶活性。这项研究的基本原理是，随着对左旋咪唑激活受体通道的调节机制的了解，可以制定药理学方法来克服耐药性。我们将使用a . suum， C. elegans和零突变体的肌肉制剂，采用电流钳，电压钳和膜片钳技术测试l-亚型乙酰胆碱通道的Ca通透性和亚基组成，并测试AF2调制模型。我们将追求3个目标：1)确定a . suum肌乙酰胆碱受体N-， L-和B-亚型的钙通透性，从而确定首选靶点；2)通过膜片钳实验确定秀丽隐杆线虫l亚型乙酰胆碱通道所需亚基；3)研究钙和AF2影响不同AChR通道亚型打开的机制和药理学，从而提高胆碱能驱虫药的反应和效力。这项研究具有创新性，因为我们将秀丽隐杆线虫的新知识与线虫寄生虫的先进电生理学相结合，包括用于膜片钳记录的肌肉囊泡准备。我们期望这项研究能够确定增加胆碱能驱虫药效力的其他策略。该研究具有重要意义，因为其应用结果将为控制和克服左旋咪唑类驱虫药的抗性提供新的途径。

DESCRIPTION (provided by applicant): Ascariasis and hookworm infection affect 1.6 billion people across the world. Anthelmintics, including levamisole and related drugs (pyrantel), are used to combat nematode parasites, and resistance is a threat. Our long-range objective is to improve human health by increasing the efficacy of anthelmintic drugs by identifying approaches to reverse resistance. The objective of this application is to test single-channel properties of levamisole receptors and a model that describes changes in the sensitivity of nematodes to levamisole and alters potency. Our central hypothesis is that the structure and pore of the L-subtype acetylcholine receptor ion-channel on nematode muscle makes it more sensitive to levamisole and more permeable to Ca; and the increased response of acetylcholine channels (modulation) produced by the neuropeptide, AF2, involves cAMP, Ca entry and kinase activity. The rationale for the research is that, as the mechanisms for modulating responses to levamisole activated receptor channels become known, pharmacological approaches can be formulated to overcome resistance. We will use muscle preparations of A. suum, C. elegans and null-mutants with current-clamp, voltage-clamp and patch-clamp technology to test the Ca permeability and subunit composition of L-subtype acetylcholine channels and to test a model for AF2 modulation. We will pursue 3 aims: 1) determine the Ca permeability of N-, L- and B- subtypes of A. suum muscle acetylcholine receptors and thereby identify a preferred target site; 2) determine in patch-clamp experiments in C. elegans, the subunit requirements of the L-subtype acetylcholine channel; 3) characterize, n A. suum muscle, the mechanism & pharmacology by which calcium and AF2 affect the opening of different AChR channel subtypes, in order to increase responses and potency of cholinergic anthelmintics. The research is innovative because we are combining new knowledge from C. elegans with advanced electrophysiology of nematode parasites including muscle-vesicle preparations for patch-clamp recordings. We expect the research to identify additional strategies that increase the potency of cholinergic anthelmintics. The research is significant because application of the results will to lead to new approaches to control and overcome resistance to anthelmintics of the levamisole class.