Recently, growing evidence has indicated an important role of the complement system, a crucial component of immunity, in mediating neuroinflammation and promoting neuronal apoptosis following closed head injury (CHI). We previously reported that transplanted induced neural stem cells (iNSCs) pre-treated with CHI mouse serum could enhance complement receptor type 1-related protein y (Crry) expression and ameliorate complement-mediated damage in mouse CHI models. However, the mechanism underlying the elevated levels of Crry expression remains elusive. CHI models were established using a standardized weight-drop device. We collected CHI mouse serum at 12 h post-trauma. RT-QPCR assay, western blot analysis, complement deposition assay, Akt inhibition assay, flow cytometry, cell transplantation, and functional assay were utilized to clarify the mechanism of Crry expression in iNSCs receiving CHI mouse serum treatment. We observed dramatic increases in the levels of Crry expression and Akt activation in iNSCs receiving CHI mouse serum treatment. Remarkably, Akt inhibition led to the reduction of Crry expression in iNSCs. Intriguingly, the treatment of iNSC-derived neurons with recombinant complement receptor 2-conjugated Crry (CR2-Crry), which inhibits all complement pathways, substantially enhanced Crry expression and Akt activation in neurons after CHI mouse serum treatment. In subsequent in vitro experiments of pre-treatment of iNSCs with CR2-Crry, we observed significant increases in the levels of Crry expression and Akt activation in iNSCs and iNSC-derived astrocytes and neurons post-treatment with CHI mouse serum. Additionally, an in vivo study showed that intracerebral-transplanted iNSCs pre-treated with CR2-Crry markedly enhanced Crry expression in neurons and protected neurons from complement-dependent damage in the brains of CHI mice. INSCs receiving CR2-Crry pre-treatment increased the levels of Crry expression in iNSCs and iNSC-derived astrocytes and neurons and attenuated complement-mediated injury following CHI.

中文翻译：

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在闭合性颅脑损伤小鼠模型中，诱导的神经干细胞移植物通过Crry和Akt之间的相互作用发挥神经保护作用

最近，越来越多的证据表明，补体系统是免疫的重要组成部分，在介导闭合性颅脑损伤（CHI）后介导神经炎症和促进神经元凋亡方面起着重要作用。我们先前曾报道过，用CHI小鼠血清预处理的移植诱导神经干细胞（iNSCs）可以增强补体受体1型相关蛋白y（Crry）的表达，并减轻小鼠CHI模型中补体介导的损伤。但是，Crry表达水平升高的潜在机制仍然难以捉摸。CHI模型是使用标准化的减肥设备建立的。我们在创伤后12小时收集了CHI小鼠血清。RT-QPCR分析，蛋白质印迹分析，补体沉积分析，Akt抑制分析，流式细胞仪，细胞移植，通过功能和功能分析来阐明在接受CHI小鼠血清治疗的iNSC中Crry表达的机制。我们观察到接受CHI小鼠血清治疗的iNSC中Crry表达水平和Akt激活水平显着增加。值得注意的是，抑制Akt导致iNSC中Crry表达降低。有趣的是，在CHI小鼠血清处理后，重组补体受体2-结合的Crry（CR2-Crry）可治疗iNSC衍生的神经元，抑制所有补体途径，显着增强神经元中Crry的表达和Akt激活。在随后的用CR2-Crry预处理iNSC的体外实验中，我们观察到iCHIC和iNSC来源的星形胶质细胞和神经元用CHI小鼠血清处理后，Crry表达水平和Akt激活水平显着增加。此外，一项体内研究表明，经CR2-Crry预处理的脑内移植iNSCs显着增强了神经元中Crry的表达，并保护了神经元免受CHI小鼠大脑中补体依赖性损伤的影响。接受CR2-Crry预处理的INSC可以增加iNSC和iNSC衍生的星形胶质细胞和神经元中Crry的表达水平，并减轻CHI后补体介导的损伤。