摘要
目的探讨七氟醚对新生大鼠海马组蛋白脱乙酰酶2(HDAC2)变化以及长期学习记忆功能的影响。方法新生6 d龄SD大鼠90只随机分为对照组(吸入O23L·min^(-1))、七氟醚组[吸入O2﹢七氟醚(每天2 h,×3 d)]和CAY10683组(七氟醚吸入前2 h,腹腔注射HDAC2抑制剂CAY106832 mg·kg^(-1)),每组n=30。Westernblot法检测不同时间点(最后1次吸入七氟醚后24、48、72h3个时间点)海马CA1区HDAC2、脑源性神经营养因子(BDNF)及前体BDNF(proBDNF)、酪氨酸激酶B(TrkB)及磷酸化TrkB(p-TrkB)的表达水平。28 d后,用Morris水迷宫检测大鼠学习记忆功能;Golgi-Cox染色观察突触可塑性和突触相关蛋白:突触蛋白1(Syn1)、生长相关蛋白43(GAP-43)和突触后密度蛋白95(PSD-95)水平。体外实验检测HDAC2质粒转染原代神经元对BDNF/TrkB信号的影响,以及TrkB与HDAC2联合表达对树突细胞数量和总长度的影响。结果吸入七氟醚导致大鼠学习记忆损害,突触相关蛋白表达下调,海马树突棘密度降低,proBDNF和HDAC2表达水平升高,BDNF和p-TrkB表达降低。CAY10683干预可部分逆转七氟醚暴露导致的学习记忆损害和突触可塑性降低。CAY10683可阻断proBDNF和HDAC2蛋白表达上调,增加BDNF和p-TrkB表达水平。与对照神经元比较,HDAC2上调的海马神经元中HDAC2和proBDNF表达均显著升高(P<0.05),而成熟的BDNF(mBDNF)、TrkB和p-TrkB表达显著降低(P<0.05)。与单独表达HDAC2比较,TrkB与HDAC2联合表达可使树突细胞数量和总树突长度显著增加(P<0.05)。结论七氟醚暴露可通过上调HDAC2活性抑制BDNF/TrkB信号激活,从而导致神经元树突棘发育异常和大鼠认知损害。
Aim To examine histone deacetylase 2(HDAC2)changes in sevoflurane inhalation in neonatal rat in the hippocampus CA1 region,and to examine the effect of sevoflurane inhalation on longterm learning and memory capacity.Methods Rats at postnatal day 6(PND6)were i.p.injected with HDAC2 inhibitor CAY10683 before exposure to sevoflurane for 2 h·d^(-1)for three days.The expression levels of HDAC2,BDNF,its precursor(pro BDNF),Trk B and phosphorylation of Trk B(p-Trk B)were detected at different time points.After 28 d,morris water maze was used to examine learning and memory function;Golgi-Cox staining was used to investigate synaptic plasticity and synaptic-related proteins,such as synapsin I(Syn1),growth associated protein 43(GAP-43),and postsynaptic density protein 95(PSD-95).In vitro,the effect of HDAC2 plasmid transfection on BDNF/Trk B signal and the effect of Trk B and HDAC2 co-expression on the number and total length of dendritic cells were detected.Results Inhalation of sevoflurane led to learning and memory dysfunction,the expression of the synaptic-related proteins downregulated,dendritic spine density in the hippocampus decreased,the expression level of pro BDNF and HDAC2 increased,and the expression of BDNF and p-Trk B reduced.Interestingly,CAY10683 reversed the learning and memory dysfunction and the reduction of synaptic plasticity induced by sevoflurane exposure.Furthermore,CAY10683 blocked the upregulation of pro BDNF and HDAC2 protein expression and increased the expression of BDNF and p-Trk B.In vitro,compared with the control neurons,the expression of HDAC2 and pro BDNF in hippocampal neurons upregulated by HDAC2 were significantly increased(P<0.05),while the expression of m BDNF,Trk B and p-Trk B in mature BDNF were significantly decreased(P<0.05).Compared with the expression of HDAC2 alone,the combined expression of Trk B and HDAC2 significantly increased the number of dendritic cells and the total dendritic length(P<0.05).Conclusion Sevoflurane exposure could lead to dendritic development abnormalities and cognitive dysfunction by inhibiting the BDNF/Trk B signal via upregulating HDAC2 activity.
作者
屈晓莉
宋巍
贾建章
乔杰
张大志
QU Xiao-li;SONG Wei;JIA Jian-zhang;QIAN Jie;ZHANG Da-zhi(Department of Anesthesiology,Tongchuan City Maternal and Child Health Care,Tongchuan 727007,China;Department of Anesthesiology,Tongchuan People’s Hospital,Tongchuan 727000,China;Department of Pain,Tongchuan People’s Hospital,Tongchuan 727000,China)
出处
《中国临床神经科学》
2021年第5期481-488,共8页
Chinese Journal of Clinical Neurosciences
基金
2018年杨凌示范区科技计划项目(编号:2018SF-11)。
