Neuronal Soluble Fas Ligand Drives M1-Microglia Polarization after Cerebral Ischemia
Neuronal Soluble Fas Ligand Drives M1-Microglia Polarization after Cerebral Ischemia
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脑缺血后神经元可溶性 Fas 配体驱动 M1-小胶质细胞极化
DOI：
10.1111/cns.12575
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发表时间：
2016-09-01
影响因子：
5.5
通讯作者：
Xu, Yun
中科院分区：
文献类型：
--
作者：
Meng, Hai-Lan;Li, Xiao-Xi;Xu, Yun
目的本研究探讨了神经元中 sFasL 的表达以及神经元 sFasL 在调节小胶质细胞表型中的潜在作用。方法在体内，FasL 突变体 (gld) 和野生型 (wt) 小鼠均诱导大脑中动脉闭塞 (MCAO)。在体外，对来自 wt/gld 小鼠的原代皮质神经元或小胶质细胞或共培养物进行氧糖剥夺（OGD）。通过ELISA评估上清液中的sFasL水平。将神经元条件培养基 (NCM) 或外源 sFasL 应用于有或没有 FasL 中和抗体的原代小胶质细胞。通过Western blot测定JAK2/STAT3和NF-B通路的蛋白表达。进一步阐明了wt/gld小鼠的小胶质细胞表型对缺血神经元命运的影响。结果在体内，与野生型小鼠相比，MCAO后gld小鼠的M1标记物（CD16、CD32和iNOS）减弱。在体外，OGD 后神经元释放更多 sFasL。 OGD 后 NCM 和外源 sFasL 均可触发 M1 小胶质细胞极化。然而，这种 M1 表型转变被 FasL 中和抗体或 gld NCM 部分阻断。一致的是，外源 sFasL 处理后小胶质细胞中的 JAK2/STAT3 和 NF-B 信号通路均被激活。与野生型小鼠相比，gld小鼠制备的M1条件培养基可以保护神经元免受OGD损伤。结论缺血神经元释放sFasL，这有助于M1-小胶质细胞极化。潜在机制可能涉及 JAK2/STAT3 和 NF-B 信号通路的激活。
AimsThis study explored sFasL expression in neurons and the potential role of neuronal sFasL in modulating the microglial phenotypes.MethodsIn vivo, middle cerebral artery occlusion (MCAO) was induced in both FasL-mutant (gld) and wild-type (wt) mice. In vitro, primary cortical neuron or microglia or coculture from wt/gld mice was subjected to oxygen glucose deprivation (OGD). sFasL level in the supernatant was evaluated by ELISA. Neuronal-conditioned medium (NCM) or exogenous sFasL was applied to primary microglia with or without FasL neutralizing antibody. Protein expression of JAK2/STAT3 and NF-B pathways were determined by Western blot. The effect of microglia phenotype from wt/gld mice on the fate of ischemic neurons was further elucidated.ResultsIn vivo, compared with wild-type mice, M1 markers (CD16, CD32 and iNOS) were attenuated in gld mice after MCAO. In vitro, post-OGD neuron released more sFasL. Both post-OGD NCM and exogenous sFasL could trigger M1-microglial polarization. However, this M1 phenotype shift was partially blocked by utilization of FasL neutralizing antibody or gld NCM. Consistently, JAK2/STAT3 and NF-B signal pathways were both activated in microglia after exogenous sFasL treatment. Compared with wild-type mice, M1-conditioned medium prepared from gld mice protected neuron against OGD injury.ConclusionsIschemic neurons release sFasL, which contributes to M1-microglial polarization. The underlying mechanisms may involve the activation of JAK2/STAT3 and NF-B signaling pathways.