Role of Ca2+/calmodulin-dependent protein kinase II in dendritic spine remodeling during epileptiform activity in vitro.
Role of Ca2+/calmodulin-dependent protein kinase II in dendritic spine remodeling during epileptiform activity in vitro.
复制标题
Ca2/钙调蛋白依赖性蛋白激酶 II 在体外癫痫样活动期间树突棘重塑中的作用。
DOI：
10.1002/jnr.22033
复制
发表时间：
2009
影响因子：
4.2
通讯作者：
Green,StevenH
中科院分区：
文献类型：
--
作者：
Zha,Xiang-ming;Dailey,MichaelE;Green,StevenH
癫痫样活动(EA)在体内和体外都会导致树突棘和突触的丢失。由于CaMKII与突触发生和突触可塑性有关，我们利用大鼠海马片培养，研究了CaMKII在电针对脊髓的影响中的作用。为了可视化切片中锥体神经元中的树突和突触后密度(PSD)，我们使用生物转染来表达游离GFP或特异性标记PSD的PSD95-YFP构建。这使我们能够区分两类树突：含有PSD的棘突和没有PSD的丝状足突，平均而言，它比棘长。根据这些标准，48小时的电针导致脊椎数量的减少。免疫印迹结果显示，电针可提高脑片CaMKII活性。通过抑制CaMKII的特异性多肽抑制剂AIP的表达，可以减少基础状态下的脊椎数目，但不能防止电针引起的脊椎丢失。然而，在电针条件下，AIP增加了树突轴上的丝状孢子数量和PSD数量。这些数据表明，在基础或电针条件下，CaMKII活性在树突棘的维持和重塑中至少有两个作用。首先，CaMKII活动促进脊柱和脊柱PSD的维持。第二，CaMKII活性抑制电针诱导的丝状足的形成，并抑制主干PSD的增加，这显然是通过促进PSD从树突干移到脊柱和/或选择性地稳定脊椎而不是主干PSD来实现的。©2009威利-利斯，Inc.
Epileptiform activity (EA) in vivo and in vitro induces a loss of dendritic spines and synapses. Because CaMKII has been implicated in synaptogenesis and synaptic plasticity, we investigated the role of CaMKII in the effects of EA on spines, using rat hippocampal slice cultures. To visualize dendrites and postsynaptic densities (PSDs) in pyramidal neurons in the slices, we used biolistic transfection to express either free GFP or a PSD95‐YFP construct that specifically labels PSDs. This allowed us to distinguish two classes of dendritic protrusions: spines that contain PSDs, and filopodia that lack PSDs and that are, on average, longer than spines. By these criteria, 48 hr of EA caused a decrease specifically in the number of spines. Immunoblots showed that EA increased CaMKII activity in the slices. Inhibition of CaMKII by expression of AIP, a specific peptide inhibitor of CaMKII, reduced spine number under basal conditions and failed to prevent EA‐induced spine loss. However, under EA conditions, AIP increased the number of filopodia and the number of PSDs on the dendritic shaft. These data show at least two roles for CaMKII activity in maintenance and remodeling of dendritic spines under basal or EA conditions. First, CaMKII activity promotes the maintenance of spines and spine PSDs. Second, CaMKII activity suppresses EA‐induced formation of filopodia and suppresses an increase in shaft PSDs, apparently by promoting translocation of PSDs from dendritic shafts to spines and/or selectively stabilizing spine rather than shaft PSDs. © 2009 Wiley‐Liss, Inc.