Afobazole Modulates Microglial Function via Activation of Both σ-1 and σ-2 Receptors
Afobazole Modulates Microglial Function via Activation of Both σ-1 and σ-2 Receptors
复制标题
DOI：
10.1124/jpet.111.182816
复制
发表时间：
2011-10-01
影响因子：
3.5
通讯作者：
Katnik, Chris
中科院分区：
文献类型：
--
作者：
Cuevas, Javier;Rodriguez, Alex;Katnik, Chris
小胶质细胞在伴随各种中枢神经系统疾病（如缺血性中风）的神经炎症反应中起关键作用，ATP是调节这些细胞对这些病理生理条件的反应的主要信号分子。进行实验以确定阿夫巴唑对小胶质细胞功能的影响，并鉴定阿夫巴唑影响小胶质细胞的分子机制。发现阿夫巴唑以浓度依赖性方式抑制小胶质细胞对ATP和UTP化学吸引的迁移反应。sigma-1或sigma-2受体的抑制降低了afobazole对小胶质细胞的作用。除了抑制小胶质细胞迁移外，阿夫巴唑激活σ受体还降低了在分离的小胶质细胞中局部应用ATP和UTP产生的细胞内钙升高。此外，afobazole阻断了小胶质细胞中快速应用ATP引起的膜电流。综上所述，我们的数据表明，阿夫巴唑抑制小胶质细胞对P2 Y和P2 X嘌呤能受体激活的反应，作为一个泛选择性σ受体激动剂。除了调节对嘌呤能受体激活的反应外，还评估了阿夫巴唑对体外缺血期间小胶质细胞存活的影响。在体外缺血期间应用阿夫巴唑减少缺血发作期间和24小时恢复期后小胶质细胞死亡。此外，当阿夫巴唑仅在缺血发作后应用时，仍然观察到细胞存活的显著增强。因此，阿夫巴唑通过σ受体起作用以降低小胶质细胞对ATP的反应，并在缺血期间和之后提供细胞保护。
Microglial cells play a critical role in the neuroinflammatory response that accompanies various diseases of the central nervous system, such as ischemic stroke, and ATP is a major signaling molecule regulating the response of these cells to these pathophysiological conditions. Experiments were carried out to determine the effects of afobazole on microglial function and to identify the molecular mechanisms by which afobazole affects microglial cells. Afobazole was found to inhibit migration of microglial cells in response to ATP and UTP chemoattraction in a concentration-dependent manner. Inhibition of either sigma-1 or sigma-2 receptors decreased the effects of afobazole on microglia. In addition to inhibiting microglial cell migration, activation of sigma receptors by afobazole decreased intracellular calcium elevation produced by focal application of ATP and UTP in isolated microglial cells. Furthermore, afobazole blocked membrane currents elicited by rapid application of ATP in microglial cells. Taken together, our data indicate that afobazole inhibits microglial response to P2Y and P2X purinergic receptor activation by functioning as a pan-selective sigma-receptor agonist. In addition to modulating response to purinergic receptor activation, the effects of afobazole on microglial survival during in vitro ischemia were assessed. Application of afobazole during in vitro ischemia decreased microglial cell death during the ischemic episode and after a 24-h recovery period. Moreover, when afobazole was only applied after the ischemic episode, a significant enhancement in cell survival was still observed. Thus, afobazole acts via sigma receptors to decrease microglial response to ATP and provides cytoprotection during and after ischemia.