新型体外Bio-PK/PD模拟系统的建立及其对SPRC代谢致毒的机理研究

Drug metabolism mediated toxicity is one of the most important causes for drug withdrawal from the market. Therefore, the early prediction of metabolism toxicity is very crucial for the effective exploitation of innovative drugs. However, efficacious model for in vitro prediction of metabolism mediated toxicity is still unavailable now. Based on the results of our previous study, we will construct a novel "Bio-PK/PD" simulation system, which is made up of "3+X" chambers. In this system , the "3" chambers are affused with rat microsomes extracted from diverse metabolic organs to imitate the main human metabolic tissues/metabolic styles. Meanwhile, the "X" chamber is infused with human target cells used for toxicity studies. Through operating this simulation system in an active metabolic network by multiple tissues and manners, we will establish a dynamic perfusion cycle which can simulate the drug pharmacokinetics in vivo by applying mathematic models and eventually obtain the metabolism toxic effects of candidate drugs qualitatively or quantitatively. Innovative drug SPRC was reported to be involved in the possess of metabolism toxicity. Therefore, the "Bio-PK/PD" is suitable platform for its study in the toxicity mechanisms through molecular biologic methods and DNA chip. Hence, successful demonstration and accurate prediction of the metabolism mediatede toxicity for drug SPRC via the "Bio-PK/PD" simulation system will provide a novel research tools of "drug-metabolism-toxicity" in the future.

药物代谢介导的毒性作用是导致很多药物撤市的重要原因之一，其早期预测对于创新药物的有效开发非常重要，但目前仍缺少有效的体外整体研究模型。本研究基于前期研究结果，构建"3+X"的新型体外Bio-PK/PD模拟系统，"3"腔室加入大鼠主要代谢器官的微粒体孵育体系，模拟体内重要代谢组织/代谢方式，"X"腔室加入毒性研究的人源靶细胞，各腔室间模拟体内循环灌注，通过多组织、多种方式的动态网络代谢过程的模拟，定性或者定量研究候选化合物的代谢过程及其对靶细胞的毒性作用，并应用数学模型建立体内外相关性。采用该系统研究创新药物S-炔丙基半胱氨酸（SPRC）可能的肠毒性是否由代谢过程所介导，并采用基因芯片及分子生物学技术，对效应细胞在药物暴露中信号通路变化进行研究，阐明SPRC的致毒机理。通过SPRC毒性机理的研究为预测创新药物体内代谢介导的毒性作用提供范例，最终建立一种新型的"药物-代谢-毒性"系统研究方法。

基于药物代谢介导的毒性作用以及目前体外代谢模型的局限性，本课题建立了一种新型的“药物-代谢-毒性”系统研究方法。首先，发明和制备了具有温敏特性的新型微粒体水凝胶代谢系统；在此基础上，将药物与该体系共同作用于特定的效应细胞，预测药物及其代谢物对细胞的作用，进而评估代谢后的药效、毒性等。通过微粒体水凝胶代谢体系评估和筛选了候选化合物川木通、Manazamine A和千层纸素、汉黄芩素、黄芩苷和拉帕替尼衍生物L-L系列化合物等，发现千层纸素代谢后药效显著增加；选取千层纸素进行进一步的体内外验证，发现代谢产物M318可能是千层纸素抗肿瘤作用产生的新机。在此基础上，围绕微粒体水凝胶代谢系统，建立了一套动态的Bio-PK/PD循环灌流系统，以甲苯磺丁脲为模型药物，结合PBPK模型合理预测了其体内行为，该循环系统弥补了传统静态孵育的不足。更有利于预测出更加趋近于体内真实的代谢行为。另外，进一步通过引入效应细胞腔室，将药物代谢系统与药效考察结合起来，高度模拟药物在体内经血液循环、代谢、并作用于靶细胞的体内过程，综合考察药物的PK 和PD 过程，成功完整构建了Bio-PK/PD 代谢系统。总之，该系统的发明和研究，为候选化合物的筛选提供了新的思路和方法，更加真实地反应药物在体内的处置和作用过程。