Neuropharmacology Section, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA.
J Neuroimmune Pharmacol. 2012 Mar;7(1):187-201. doi: 10.1007/s11481-011-9309-0. Epub 2011 Aug 26.
Increasing evidence suggests a possible involvement of neuroinflammation in some psychiatric disorders, and also pharmacological reports indicate that anti-inflammatory effects are associated with therapeutic actions of psychoactive drugs, such as anti-depressants and antipsychotics. The purpose of this study was to explore whether clozapine, a widely used antipsychotic drugs, displays anti-inflammatory and neuroprotective effects. Using primary cortical and mesencephalic neuron-glia cultures, we found that clozapine was protective against inflammation-related neurodegeneration induced by lipopolysaccharide (LPS). Pretreatment of cortical or mesencephalic neuron-glia cultures with clozapine (0.1 or 1 μM) for 24 h attenuated LPS-induced neurotoxicity. Clozapine also protected neurons against 1-methyl-4-phenylpyridinium(+) (MPP(+))-induced neurotoxicity, but only in cultures containing microglia, indicating an indispensable role of microglia in clozapine-afforded neuroprotection. Further observation revealed attenuated LPS-induced microglial activation in primary neuron-glia cultures and in HAPI microglial cell line with clozapine pretreatment. Clozapine ameliorated the production of microglia-derived superoxide and intracellular reactive oxygen species (ROS), as well as the production of nitric oxide and TNF-α following LPS. In addition, the protective effect of clozapine was not observed in neuron-glia cultures from mice lacking functional NADPH oxidase (PHOX), a key enzyme for superoxide production in immune cells. Further mechanistic studies demonstrated that clozapine pretreatment inhibited LPS-induced translocation of cytosolic subunit p47(phox) to the membrane in microglia, which was most likely through inhibiting the phosphoinositide 3-kinase (PI3K) pathway. Taken together, this study demonstrates that clozapine exerts neuroprotective effect via the attenuation of microglia activation through inhibition of PHOX-generated ROS production and suggests potential use of antipsychotic drugs for neuroprotection.
越来越多的证据表明神经炎症可能参与某些精神疾病，药理学研究也表明抗炎作用与精神活性药物（如抗抑郁药和抗精神病药）的治疗作用有关。本研究旨在探讨广泛使用的抗精神病药氯氮平是否具有抗炎和神经保护作用。通过原代皮质和中脑神经元-胶质细胞培养，我们发现氯氮平可对抗脂多糖（LPS）诱导的炎症相关神经退行性变。皮质或中脑神经元-胶质细胞培养物用氯氮平（0.1 或 1 μM）预处理 24 h 可减轻 LPS 诱导的神经毒性。氯氮平还可保护神经元免受 1-甲基-4-苯基吡啶鎓（MPP(+））诱导的神经毒性，但仅在含有小胶质细胞的培养物中，表明小胶质细胞在氯氮平提供的神经保护中不可或缺。进一步观察发现，氯氮平预处理可减弱 LPS 诱导的原代神经元-胶质细胞和 HAPI 小胶质细胞系中小胶质细胞的激活。氯氮平可改善 LPS 诱导的小胶质细胞衍生的超氧阴离子和细胞内活性氧（ROS）的产生，以及一氧化氮和 TNF-α的产生。此外，在缺乏功能性 NADPH 氧化酶（PHOX）的神经元-胶质细胞培养物中，氯氮平的保护作用未被观察到，PHOX 是免疫细胞中超氧阴离子产生的关键酶。进一步的机制研究表明，氯氮平预处理可抑制 LPS 诱导的小胶质细胞中胞质亚基 p47(phox)向膜的易位，这很可能是通过抑制磷酸肌醇 3-激酶（PI3K）途径实现的。综上所述，本研究表明氯氮平通过抑制 PHOX 产生的 ROS 产生来减弱小胶质细胞的激活，从而发挥神经保护作用，并提示抗精神病药可能用于神经保护。
