偏向激动中枢CCK系统在甲基苯丙胺成瘾及神经损伤防治中的应用研究

METH is a strong addictive drug. Long-term abuse of METH can cause behavioral, psychological, and cognitive function disorders. Our preliminary studies suggested that CCK-8 had the potential to be developed as a METH-abuse prevention drug. However, we found that CCK-8 treatment had side effects while functioning, as it is a non-specific agonist of CCK receptor. Recent studies have revealed that G-protein-coupled receptors have biased-agonism signaling, such as forming receptor heterodimer or directly reacting with the non-G-protein regulatory factor beta-arrestin. The biased-agonism signaling presents higher signal specificity and diversity, so that the side effects of the biased agonism ligands are much smaller than natural ligands. However, it remains unclear whether the central nervous CCK system has biased-agonism signal pathway and play special functions. This project aims to clear the intervention effect and the related side effects of the central nervous CCK system agonism on METH-induced addiction and nerve damages. It will also be explored whether the receptor heterodimerization and beta-arrestin-mediated biased-agonism signaling play roles in the central nervous CCK system and what function it has. We are looking forward to providing theoretical basis for the application of the central nervous CCK system biased-agonism in METH-abuse prevention and treatment.

METH具有较强的成瘾性，长期滥用可导致行为、精神和认知功能异常。本课题组前期研究结果提示CCK-8具备潜力作为METH滥用防治药物进行开发。但是，由于CCK-8是CCK受体的非特异性激动剂，在发挥功能的同时也会产生副作用。近年研究发现，G蛋白偶联受体还存在偏向激动信号，如形成受体异源二聚体或与非G蛋白调控因子beta-arrestin直接作用，呈现更高的信号特异性和多样性，使得偏向激动配体的副作用比天然配体少得多。中枢CCK系统是否也存在偏向性信号途径并发挥特殊功能尚不明确。本项目旨在明确激动中枢CCK系统对METH成瘾及神经损伤过程的干预作用及其相关副作用，阐明中枢CCK系统是否存在受体异源二聚化和 beta-arrestin介导的非G蛋白偶联偏向性信号并发挥何种功能，以期为偏向激动中枢CCK系统应用于METH滥用防治提供理论依据。

METH具有较强的成瘾性，长期滥用可导致行为、精神和认知功能异常。本课题组前期研究结果提示八肽胆囊收缩素（CCK-8）具备潜力作为METH滥用防治药物进行开发。但是，由于CCK-8是CCK受体的非特异性激动剂，在发挥功能的同时也会产生副作用。近年研究发现，G蛋白偶联受体还存在偏向激动信号，如形成受体异源二聚体或与非G蛋白调控因子β-arrestin直接作用，呈现更高的信号特异性和多样性，使得偏向激动配体的副作用比天然配体少得多。本项目首先建立METH诱导的条件性位置偏爱和行为敏化模型、METH诱导的SH-SY5Y细胞凋亡模型和METH诱导的N9小胶质细胞活化模型，发现中枢CCK系统可通过CCK2R偶联的β-arrestin 2偏向信号途径调控METH诱导的条件性位置偏爱和行为敏化形成过程，并可以通过CCK2R偶联的β-arrestin 2偏向信号途径抑制METH诱导的SH-SY5Y细胞凋亡；发现CCK-8可通过CCK2R在体内和体外均以剂量依赖的方式抑制METH诱导的小胶质细胞活化、NF-κB信号通路的激活以及炎症因子IL-6和TNF-α的释放。另外，还发现中枢CCK系统调节METH成瘾及神经损伤过程的空间特异性，敲减伏隔核核部CCK1R和杏仁核CCK2R对METH诱导的条件性位置偏爱具有抑制作用，提示不同脑区的CCK受体亚型所发挥的功能并不一致。综上，本项目阐明了中枢CCK受体及受体后信号传递方式，明确了CCK2R偶联的β-arrestin 2“偏向激动”中枢CCK系统应用于METH成瘾及神经损伤防治的可能性，为开发靶向于中枢CCK系统、效果明确且副作用小的戒毒药物提供了理论依据，具有重要的理论价值和研究意义。