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

BChE神经毒剂复活剂与农药OP在人体组织中的解毒 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有效再激活的毒剂和农药OP暴露 直接进入人体循环和组织。此方法在很大程度上基于加速运营 直接在组织中降解，在组织中OP首先进入和/或在 曝光。BChE天然存在于肺、肠和肺、肠、肾、肺、肠、肾等脏器中 因此，血浆为OPs随后在骨骼中的靶点分布提供了障碍 肌肉和中枢神经系统。作为原理的证明，我们最近证明了肟类的功能 辅助型、BChE基体内外催化型OP生物清除剂(RADI ET 等，Biochem J 450,2013,231-242)。我们证明了TAB2OH，一种新开发的肟类 人BChE的复活剂有足够的能力快速复活失活的共价OP- BChE在体外偶联，并增强对OP暴露小鼠的保护和治疗 与纯化的BChE联合给药。我们现在建议利用内源性人类 在NM浓度下，BChE自然存在于肺、肠道和血浆中，而不是 给予纯化的BChE，并仅给予高效BChE复活剂以辅助 内源BChE在OP降解中的作用。我们认为这是可能的，因为我们最近 开发了一系列基于咪唑的三元和四元hBChE复活剂，它们是 体外效率是TAB2OH的几倍。叔胺有额外的 血脑屏障和肺泡膜的渗透潜力和口服生物利用度。我们 建议研究新的BChE复活剂对OP暴露小鼠的体内疗效，并进一步 细化它们的结构以提高它们的再活化性能。这项R21提议的研究， 通过体外累积hBChE在体内的再活化和周转的动力学参数 OP的存在并将最佳化合物应用于小鼠体内分析，应 在解毒剂治疗中发现内源性BChE重新激活的潜力。它还应该 从而确定最有效的剂量方案，并评估 利用肟辅助提高内源性BChE的潜力 催化作用。简而言之，口服或非肠外给药是否存在OP暴露水平 重新激活BChE是有效的，而不必诉诸繁琐和风险- 现场和非无菌条件下的相关BCHE活动强化？

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?