5-Aza-cdR可能通过提高海马组织内NR2B磷酸化水平改善小鼠学习和记忆能力

5-Aza-cdR improves learning capacity and memory through enhancing NR2B phosphorylation level in hippocampus of mice

目的研究5-氮杂-2′-脱氧胞苷(5-Aza-CdR)对小鼠在跳台实验中的学习和记忆能力及其海马组织中NR2B 1472位点的酪氨酸磷酸化(p-Y1472 NR2B)的影响。方法将小鼠随机分为对照组(control)和5-Aza-CdR处理组(5-Aza-CdR)。侧脑室内注射10μmol/L 5-Aza-CdR,通过跳台实验检测小鼠的行为、学习和记忆能力。采用real-time PCR检测小鼠海马组织中NR2B mRNA的表达;Western blot和免疫荧光检测小鼠海马组织NR2B和磷酸化NR2B-Y1472(p-Y1472 NR2B)的表达水平。结果5-Aza-CdR组小鼠在跳台实验中潜伏期增加,错误次数减少,学习和记忆能力明显提高(P<0.05),同时,小鼠海马组织中NR2B mRNA和蛋白的表达水平均无明显变化,NR2B-Y1472的磷酸化水平升高(P<0.05),CDK5活性降低(P<0.05)。CA1区和CA3区NR2B荧光强度无差异,而CA1区p-Y1472 NR2B显著升高(P<0.05)。结论5-Aza-CdR对学习和记忆能力的影响可能与海马中p-Y1472 NR2B磷酸化相关。

Objective To study the effects of 5-Aza-2′-deoxycytidine(5-Aza-CdR)on learning and memory capacity of mice by step-down test and tyrosine phosphorylation of NR2B 1472 site(p-Y1472 NR2B)in hippocampus.Methods Mice were randomly divided into control group(control)and 5-Aza-CdR treatment group(5-Aza-CdR).In the test,5-Aza-CdR(10μmol/L)was administered to treatment group mice via intracerebroventricular injection.The ability of learning and memory in mice was evaluated by step-down test.The mRNA level of NR2B in hippocampal tissues of mice was measured by real-time PCR.NR2B and p-Y1472 NR2B in hippocampal tissues of mice were measured by Western blot and immunofluorescence.Results In the 5-Aza-CdR treatment group,the latency period was increased,the error records were decreased,the behavioral memory was significantly improvedin step-down test(P<0.05).While the expression of NR2B mRNA and protein in the hippocampus of mice was not significantly changed,the phosphorylation of p-Y1472 NR2B was increased(P<0.05),and CDK5 activity was decreased(P<0.05).There was no difference in NR2B fluorescence intensity between CA1 region and CA3 region,while p-Y1472 NR2B in CA1 region was significantly increased(P<0.05).Conclusions The effects of 5-Aza-CdR on behavioral memory ability may be related to the p-Y1472 NR2B in the hippocampus of mice.