Identifying Molecular Targets for the Proconvulsant Activity of TETS

对γ-氨基丁酸A型（GABAA）受体（GABAAR）的抑制是本发明的假定机制。 天然产物印防己毒素（PTX）的致毒活性 （TETS）和高能炸药六氢-1，3，5-三硝基-1，3，5-三嗪（RDX）。TETS，这是 在世界范围内被禁止生产，仍然可以在黑市上买到，并且与 每年有数千人中毒它在环境中非常稳定。RDX是一种环境 由于其在世界范围内的军事和民用用途，地下水和土壤中发现的污染物，它是一种非法的 滥用药物PTX是毒理学关注，因为像TETS和RDX一样，它被列为可信的威胁 美国国土安全部特工这三种化合物都能导致癫痫发作， 快速进展到癫痫持续状态和死亡;然而，TETS是迄今为止最有效的，具有致死剂量的 在人类中为7至10 mg，在啮齿动物中的LD 50为0.1 mg/kg，这使得它的效力比PTX高约40倍 比黑索今强1000倍目前还没有批准的个人医疗对策 严重中毒的人虽然有一些关于 PTX的分子作用位点和GABAAR亚型选择性，实际上对PTX的分子作用位点和GABAAR亚型选择性一无所知。 TETS和RDX的分子作用机制，而不是它们最可能是GABAAR抑制剂。 我们打算使用分子建模，全细胞膜片钳电生理学和基因敲除 斑马鱼中鉴定TETS和RDX与GABAA受体相互作用的亚基特异性的技术 并确定其是否与印防己毒素不同。用亚型选择性化合物/药物治疗 这将使我们能够确认哪些GABAA受体亚基组合对癫痫发作活性是重要的。 TETS和RDX，以及它们是否与介导PTX作用的受体亚基谱不同。详细 对TETS和RDX作用的分子机制的理解不仅将提供新的见解， 这些药物之间毒理学差异的生物学原因，但也将是重要的， 评价GABAA受体拮抗剂的“交叉阅读”风险评估方法的有效性， 制定有效的医学对策，以终止中毒个体的SE。

Inhibition of γ-aminobutyric acid type A (GABAA) receptors (GABAAR) is the presumed mechanism of the seizure-inducing activity of the natural product picrotoxin (PTX), the rodenticide tetramethylenedisulfotetramine (TETS) and the high-energy explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). TETS, which has been banned from production worldwide, is still readily available on the black market, and is associated with thousands of human poisonings per year. It is incredibly stable in the environment. RDX is an environmental contaminant found in both groundwater and soil due to its worldwide military and civilian use, and it is an illicit abuse substance. PTX is of toxicological concern, because like TETS and RDX, it is listed as a credible threat agent by the United States Department of Homeland Security. All three compounds can cause seizures that rapidly progress to status epilepticus and death; however, TETS is by far the most potent with a lethal dose of 7 to 10 mg in humans and an LD50 of 0.1 mg/kg in rodents, which makes it roughly ~40x more potent than PTX and ~1000x more potent than RDX. There currently is no approved medical countermeasure for individuals acutely intoxicated with these convulsant chemicals. While some information is available regarding the molecular site of action and the GABAAR subtype selectivity of PTX, practically nothing is known about the molecular mechanism of action of TETS and RDX other than that they are most probably GABAAR inhibitors. We intend to use molecular modeling, whole-cell patch-clamp electrophysiology and gene knockdown techniques in zebrafish to identify the subunit specificity of TETS and RDX interactions with GABAA receptors and to determine whether it differs from that of picrotoxin. Treatment with subtype selective compounds/drugs should allow us to confirm which GABAA receptor subunit combinations are important for the seizure activity of TETS and RDX, and whether they differ from the receptor subunit profile that mediate PTX action. Detailed understanding of the molecular mechanism(s) of action of TETS and RDX will not only provide novel insight as to the biological reasons for the toxicologic differences between these agents, but will also be important for evaluating the validity of “read across” risk assessment approaches for GABAA receptor antagonists, and for developing effective medical countermeasures for terminating SE in intoxicated individuals.