BChE reactivators for nerve agent and pesticide OP detoxification in human tissue

BChE 重激活剂用于人体组织中的神经毒剂和农药 OP 解毒

基本信息

批准号：
8610134
负责人：
Zoran Radic
金额：
$ 41.27万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-30 至 2015-08-31
项目状态：
已结题

项目摘要

BChE reactivators for nerve agent and pesticide OP detoxification in human tissue Project Summary: We propose to develop a previously unexplored approach in therapy of nerve agent and pesticide OP exposure based on efficient reactivation of endogeneous BChE directly in human circulation and tissues. This approach is largely based on accelerated OP degradation of OPs directly in tissues where OPs enter and/or accumulate first during an exposure. Oxime assisted OP hydrolysis by BChE naturally present in lungs, intestine and plasma, thus provides a barrier to subsequent distribution of OPs to target sites in skeletal muscle and CNS. We recently demonstrated as a proof of principle, the functioning of oxime assisted, BChE based, catalytic OP bioscavenger in vitro, ex vivo and in vivo (Radi et al.,Biochem J 450, 2013,231-242). We demonstrated that TAB2OH, a newly developed oxime reactivator of human BChE had sufficient capacity to rapidly reactivate inactive, covalent OP- BChE conjugates in vitro, and enhance both protection and therapy of OP exposed mice when administered in combination with purified BChE. We now propose to utilize endogenous human BChE naturally present in lungs, intestine and plasma at nM concentrations instead of administering purified BChE, and to administer only highly efficient BChE reactivator to assist endogenous BChE in OP degradation. We assume that this will be possible since we recently developed a series of tertiary and quaternary imidazole based hBChE reactivators that are several fold more efficient in vitro than TAB2OH. The tertiary amines have the additional potential for blood-brain barrier and alveolar membrane permeation and oral bioavailability. We propose to investigate in vivo efficacy of new BChE reactivators in OP exposed mice and further refine their structure to improve their reactivation properties. This R21 proposed research, through accumulating in vitro kinetic parameters of reactivation and turnover of hBChE in the presence of an OP and taking the optimal compounds to an in vivo analysis in mouse, should uncover the potential of endogenous BChE reactivation in antidotal therapy. It should also lead to ascertaining the most efficacious dosage regimen and to assessing the limits of capitalizing on enhancing the potential of endogenous BChE through oxime-assisted catalysis. In short, is there an OP exposure level where oral or parenteral oximes directed to reactivating BChE are efficacious without having to resort to the cumbersome and risk- associated BChE fortification of activity in field and non-sterile conditions?

BChE 重激活剂用于人体组织中的神经毒剂和农药 OP 解毒项目摘要：我们建议开发一种以前未探索过的神经治疗方法基于内源性 BChE 有效再激活的药剂和农药 OP 暴露直接进入人体循环和组织。这种方法主要基于加速OP OPs 直接在 OPs 首先进入和/或积累的组织中降解接触。肟辅助 OP 水解，BChE 天然存在于肺、肠和血浆，从而为随后将 OP 分布到骨骼中的目标位点提供了障碍肌肉和中枢神经系统。我们最近证明了肟的功能，作为原理证明体外、离体和体内辅助、基于 BChE 的催化 OP 生物清除剂（Radi 等等人，Biochem J 450，2013，231-242）。我们证明了TAB2OH，一种新开发的肟人类 BChE 重新激活剂有足够的能力快速重新激活无活性的共价 OP- BChE 在体外结合，增强对 OP 暴露小鼠的保护和治疗与纯化的 BChE 联合施用。我们现在建议利用内源性人类 BChE 天然存在于肺、肠和血浆中，浓度为 nM，而不是施用纯化的 BChE，并仅施用高效的 BChE 重激活剂以协助 OP 降解中的内源性 BChE。我们认为这是可能的，因为我们最近开发了一系列基于三级和四级咪唑的 hBChE 重激活剂体外效率比 TAB2OH 高数倍。叔胺具有额外的血脑屏障和肺泡膜渗透和口服生物利用度的潜力。我们提议研究新型 BChE 重激活剂在 OP 暴露小鼠中的体内功效，并进一步细化其结构以提高其再活化性能。这项 R21 提出的研究，通过积累体外 hBChE 重新激活和更新的动力学参数 OP 的存在并采用最佳化合物进行小鼠体内分析，应该揭示内源性 BChE 重新激活在抗毒治疗中的潜力。也应该从而确定最有效的剂量方案并评估其限度通过肟辅助，利用增强内源性 BChE 的潜力催化。简而言之，口服或肠外肟是否存在一定的 OP 暴露水平？重新激活 BChE 是有效的，无需诉诸繁琐且有风险的方法现场和非无菌条件下相关 BChE 活性强化？