赖氨酸去甲基化酶5C抑制剂CPI-455减轻β-淀粉样蛋白致海马神经元损伤的作用和机制

CPI-455,a lysine demethylase 5C inhibitor,alleviatesβ-Amyloid peptide induced damage in hippocampal neurons

目的 研究赖氨酸去甲基化酶5C(KDM5C)抑制剂CPI-455对β-淀粉样蛋白肽(Aβ)诱导的海马神经元损伤的保护作用和机制。方法 原代培养大鼠海马神经元,使用10μmol/L和50μmol/L的Aβ_(25-35)制备神经元损伤模型;随后加入5μmol/L的CPI-455处理48 h, CCK-8检测海马神经元细胞存活率;免疫荧光染色检测神经元中组蛋白第三亚基四号赖氨酸的三甲基化(H3K4me3)丰度和脑源性神经营养因子(BDNF)的表达;Western blot检测神经元中BDNF蛋白量变化;染色质免疫沉淀(ChIP)检测bdnf基因启动子区H3K4me3丰度和KDM5C结合量。结果 5μmol/L的CPI-455处理可增加细胞核内H3K4me3丰度;Aβ_(25-35)明显降低海马神经元细胞的存活率,CPI-455能够减轻10μmol/L Aβ_(25-35)所致神经元损伤,而对50μmol/L Aβ_(25-35)所致损伤无明显效果;CPI-455可增强细胞内BDNF的表达,上调bdnf基因启动子区H3K4me3丰度。结论 CPI-455通过上调海马神经元中BDNF的表达而减轻Aβ诱导的细胞损伤。

Objective To study the protective effect and mechanism of CPI-455,a lysine demethylase 5C(KDM5C)inhibitor,onβ-Amyloid peptide(Aβ)induced damage in hippocampal neurons.Methods Primary neuronal cells from rat hippocampus were damaged using 10μmol/L or 50μmol/L Aβ_(25-35)-.After treatment with 5μmol/L CPI-455 for 48h,the survival rate of hippocampal neurons was measured by CCK-8.The level of histone H3 lysine 4 trimethylation(H3K4me3)and brain-derived neurotrophic factor(BDNF)in neurons were detected by immunofluorescence staining.The expression changes of BDNF in neurons were tested by Western blot.The status of H3K4me3 and binding level of KDM5C in the promoter region of bdnf gene were analyzed by chromatin immunoprecipitation(ChIP).Results The level of H3K4me3 in the nucleus was increased when treated with 5μmol/L CPI-455.Aβ_(25-35) significantly reduced the survival rate of hippocampal neurons,while CPI-455 could partilly reverse the cell damage caused by 10μmol/L Aβ_(25-35),but had no obvious protective effect when neurons were damaged by 50μmol/L Aβ_(25-35)-CPI-455 could up-regulate the expression of BDNF in neurons via increasing the level of H3K4me3 in the promoter region of bdnf gene.Conclusion CPI-455 might alleviate Aβ-induced neuron damage by enhancing the expression of BDNF.