Role of hippocampal CD200R1 in perioperative neurocognitive disorders in mice / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of hippocampal CD200 receptor 1(CD200R1)in peri-operative neurocognitive disorders(PND)in mice.Methods Sixty clean-grade male C57BL/6 mice,aged 9-10 months,weighing 32-38 g,were used in the study.The experiment was performed in two parts.Ex-periment Ⅰ Thirty-six mice were divided into 2 groups(n＝18 each)using a random number table meth-od control group(group C)and PND group.Group C only received isoflurane anesthesia.Partial left lo-bectomy of the liver was performed under isoflurane anesthesia in group PND.Contextual fear conditioning test was performed at 1,3 and 7 days after surgery,and the freezing time was recorded.The mice were then sacrificed,and the hippocampus was isolated for determination of interleukin-1β(IL-1β)and tumor necrosis factor-α(TNF-α)contents(by enzyme-linked immunosorbent assay)and CD200 and CD200R1 expression(by Western blot).ExperimentⅡ Twenty-four mice were divided into 2 groups(n＝12 each)using a random number table method: CD200-Fc group and IgG1-Fc group.Recombinant proteins CD200-Fc and human IgG1-Fc were injected into the lateral cerebral ventricle in CD200-Fc group and IgG1-Fc group,respectively.Partial left lobectomy of the liver was performed after the end of injection.Contextual fear conditioning test was performed at 1 and 3 days after surgery,and the freezing time was recorded.Re-sults Experiment Ⅰ Compared with group C,the freezing time in the contextual fear conditioning test was significantly shortened,and the contents of IL-1β were increased at 1 and 3 days after surgery,the contents of TNF-α were increased at 3 and 7 days after surgery,and the expression of CD200 and CD200R1 was up-regulated at 1 day after surgery in group PND(P＜0.05).ExperimentⅡ Compared with IgG1-Fc group,the freezing time in the contextual fear conditioning test was significantly prolonged at 1 day after surgery in CD200-Fc group(P＜0.05).Conclusion Up-regulated expression of hippocampal CD200R1 is the endogenous protective mechanism of PND in mice.