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南京医科大学学报(自然科学版)                                  第43卷第2期
               ·156 ·                     Journal of Nanjing Medical University(Natural Sciences)   2023年2月


             ·基础医学·

              ApoE敲除导致小鼠耳蜗螺旋神经元功能损伤



              汤序军,王红顺,姚          俊,曹 新    *
              南京医科大学医学遗传学系,江苏 南京               211166




             [摘    要] 目的:探究载脂蛋白E(apolipoprotein E,ApoE)基因缺陷引起小鼠耳蜗螺旋神经节处听神经损伤的可能机制。方
              法:对ApoE基因敲除(ApoE )小鼠进行听性脑干反应(auditory brainstem response,ABR)检测,并分析波群振幅及延迟期。免
                                   -/-
              疫荧光及HE染色分析耳蜗螺旋神经节内听神经及带状突触的病理损伤情况。蛋白质印迹、qRT⁃PCR 等实验检测Lim激酶1
             (LIM domain kinase 1,Limk1)、丝切蛋白1(cofilin1)蛋白表达及磷酸化水平,并检测磷脂酰肌醇3激酶(phosphatidylinositide 3⁃
              kinases,PI3K)通路激活情况。结果:ApoE 小鼠ABR检测中波Ⅰ的振幅缩短,延迟期延长。螺旋神经节处染色结果显示ApoE 小
                                             -/-
                                                                                                            ⁃/⁃
              鼠带状突触及听神经纤维数量减少,并伴随结构受损。Western blot、qRT⁃PCR 及免疫荧光染色发现 Limk1 与 cofilin1 在 ApoE
              敲除后蛋白磷酸化水平出现显著性下降,同时PI3K通路激活被抑制。结论:ApoE基因缺陷会引起耳蜗螺旋神经节处带状突
              触及听神经损伤,并可能与神经元肌动蛋白细胞骨架密切相关。
             [关键词] 载脂蛋白E;耳蜗;螺旋神经元
             [中图分类号] R392.2                    [文献标志码] A                       [文章编号] 1007⁃4368(2023)02⁃156⁃09
              doi:10.7655/NYDXBNS20230202



              Functional impairment of cochlear spiral neurons caused by ApoE defect in mice

              TANG Xujun,WANG Hongshun,YAO Jun,CAO Xin    *
              Department of Medical Genetics,Nanjing Medical University,Nanjing 211166,China


             [Abstract] Objective:The current study aims to investigate the possible mechanism of auditory nerve injury at the spiral ganglion of
              the cochlea induced by apolipoprotein E(ApoE) gene deficiency in mice. Methods:Auditory brainstem response(ABR) were
                                       -/-
              measured in ApoE knockout(ApoE )mice,and the amplitude and latency of the wave groups were analyzed. Immunofluorescence and
              H&E staining were used to analyze the pathological damage of auditory nerve and ribbon synapsesin the spiral ganglion. Western blot
              and qRT⁃PCR were used to detect the protein expression and phosphorylation levels of LIM kinase 1(Limk1)and cofilin1,and to
                                                                                                -/-
              detect the phosphatidylinositide 3⁃kinases(PI3K)pathway activation. Results:The amplitude of wave Ⅰ in ApoE mice by ABR was
              shortened and the latency was prolonged. The spiral ganglion staining showed that the number of ribbon synapses and auditory nerve
                                   -/-
              fibers were reduced in ApoE  mice,accompanied by the structural damage. Western blotting,qRT⁃PCR and immunofluorescence
              staining revealed that Limk1 and cofilin1 showed a significant decrease in protein phosphorylation levels after ApoE knockdown,while
              the PI3K pathway activation was inhibited. Conclusion:ApoE gene deficiency could damage the ribbon synapse and auditory nerve at
              the spiral ganglion of the cochlea,which might be related to the actin cytoskeleton of theauditory nerve.
             [Key words] apolipoprotein E;cochlear;spiral ganglion neurons
                                                                         [J Nanjing Med Univ,2023,43(02):156⁃163,168]






                  载脂蛋白 E(apolipoprotein E,ApoE)是一类脂             体介导,参与将胆固醇传递至靶组织/细胞,从而广
              结合蛋白,在肝和脑内含量丰富               [1-2] 。ApoE 通过受      泛参与到胆固醇代谢、突触可塑性、神经突生长、突
                                                                触发生和炎症发生等生物学过程中                 [3-4] 。已知ApoE

             [基金项目] 国家自然科学面上项目(32070587)                        功能缺陷会导致血脂异常、动脉粥样硬化以及其他
              ∗                                                 综合征,如阿尔兹海默病、帕金森病                 [1,5] 等。近期研
              通信作者(Corresponding author),E⁃mail:caoxin@njmu.edu.cn
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