吗啡导致中枢神经系统免疫抑制的机制和干预

Morphine is by far one of the most effective analgesic drugs in clinics. However, long-term application of morphine caused central nervous system immunosuppression, and showed as abnormally high incidences of brain opportunistic infections and tumors. The mechanism remains unclear. Microglia acts as the immune cell in the central nervous system. Our previous studies showed that microglial cell dysfunction was mediated by TLR2 (Toll-like receptor 2) signaling pathway after morphine treatment, β-arrestin 2 was involved in this process.This project is to observe morphine-induced peroxide damage, apoptosis and immune response of microglia in vitro and in vivo, and to investigate the role of TLR2 signaling pathway, including NF-κ b, JNK, GSK-3β, reactive oxygen species, and inflammatory factor. Furthermore, we will study the reglation of β-arrestin in this mechanism, and explore the interventional effects of beta-arrestin - 2 gene regulation, JNK inhibitor and antioxidant on morphine-induced immunosuppression.

吗啡是迄今为止最有效的临床镇痛药物之一。但是长期应用吗啡导致中枢神经系统免疫抑制，表现为异常高发的脑部机会性感染和肿瘤，机制仍不清楚。小胶质细胞是中枢神经系统的免疫防御细胞。我们既往的研究提示，长期吗啡作用后TLR2（Toll-like receptor 2）信号通路在小胶质细胞功能紊乱中有重要作用，而且β-arrestin 2参与此调控过程。本课题拟在体外和体内实验中观察长期吗啡作用后小胶质细胞过氧化损伤、凋亡和免疫应答功能改变，研究吗啡长期作用后小胶质细胞的TLR2以及相关信号通路变化，包括NF-κb，JNK，GSK-3β，过氧化物和炎症因子水平；通过β-arrestin 2表达检测和表达上调/表达抑制，明确β-arrestin在上述机制中的调控作用；并探讨β-arrestin 2基因、JNK抑制剂和抗氧化剂联合调控的干预作用。

本研究使用小鼠原代小胶质细胞培养和人原代单核细胞培养，一方面，在小鼠原代小胶质细胞中，使用吗啡作用后，检测TLRs信号通路表达和免疫相关microRNAs的表达水平改变，确定miR-155的表达异常，并与吗啡诱导的免疫反应异常较为一致，使用双荧光素酶实验，确定KCNN3作为miR-155的靶基因。另一方面，基因芯片筛选海洛因患者外周血单核细胞的免疫相关microRNAs的表达水平改变，使用Realtime-PCR进一步验证，确定has-miR-582-5p和has-miR-590-5p的在人单核细胞中的表达异常，并与吗啡诱导的免疫反应异常较为一致，使用双荧光素酶实验，确定CREB1/CREB5作为其靶基因，并对TLRs信号通路下游基因NF-κB产生潜在影响。通过以上研究，本课题进一步探讨了吗啡导致外周和中枢免疫紊乱的机制，对于吗啡诱导机体免疫紊乱机制的全面阐明具有重要意义。