CaMKII, endocannabinoids, synaptic plasticity and motor function

CaMKII、内源性大麻素、突触可塑性和运动功能

基本信息

批准号：
8536971
负责人：
ROGER J COLBRAN
金额：
$ 33.41万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-01 至 2017-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8536971
关键词：
2-arachidonylglycerol Ataxia Basal Ganglia Behavior Binding Biological Assay Brain Brain region Cells Cerebellum Complex Corpus striatum structure Depressed mood Dopamine Dopamine D2 Receptor Endocannabinoids Enzymes Equilibrium Excitatory Synapse Exhibits Follow-Up Studies Functional disorder Glutamates Glycerol Goals Hippocampus (Brain)Home environment Huntington Disease Hyperactive behavior Knock-in Mouse Learning Left Link Memory Mental Depression Metabolism Molecular Monitor Motor Motor Activity Motor Cortex Movement Movement Disorders Mus Mutant Strains Mice Mutation Neurons Output Parkinson Disease Pathway interactions Peptides Phosphorylation Phosphorylation Site Physiological Play Property Proteins Regulation Reporter Role Signal Transduction Site Slice Synapses Synaptic plasticity Testing Thalamic structure Tracer Transgenic Organisms base calmodulin-dependent protein kinase II cell type gamma-Aminobutyric Acid in vivo inhibitor/antagonist lipoprotein lipase motor deficit motor learning nervous system disorder new therapeutic target novel postsynaptic public health relevance selective expression synaptic depression synaptic function tool

项目摘要

DESCRIPTION (provided by applicant): The striatum plays a key role in motor activity/coordination and goal-directed, habitual learning. Normal striatal drive of motor activity requires precisely balanced opposing outputs from two types of striatal medium spiny neurons (MSNs) that express D1- and D2-dopamine(DA) receptors. A complex signaling cross-talk between glutamate and DA in D1- and D2-MSNs involves "on demand" Ca2+-dependent endocannabinoid (eCB) synthesis. Thus, DA, glutamate and eCBs collaborate to balance short- and long-term control of the two striatal output pathways by engaging distinct signaling mechanisms in the two MSN subtypes. Disruption of these mechanisms can induce motor deficits (e.g., Parkinson's Disease) or other abnormal striatal-based behaviors. Ca2+/calmodulin-dependent protein kinase II (CaMKII) has diverse bidirectional roles controlling excitatory synapses in hippocampus, cortex and cerebellum. While CaMKII is expressed in both striatal MSN subtypes, suggesting that it regulates excitatory inputs to striatal MSNs and motor activity, the precise functions of striatal CaMKII are poorly understood. Our analyses of knockin mutant mice with the Thr286 autophosphorylation site in CaMKII? replaced by Ala (T286A-KI mice) revealed specific roles for CaMKII in long- and short term eCB- dependent control of excitatory inputs to D1- and D2-MSNs. We also found that CaMKII? associates with and phosphorylates diacylglycerol lipase ? (DGL?), the rate-limiting enzyme for Ca2+-dependent synthesis of the most abundant brain eCB, 2-arachidonyl glycerol (2-AG). In addition, baseline hyperactivity of T286A-KI mice can be rescued by inhibiting 2-AG breakdown. These initial findings strongly support a novel hypothesis that CaMKII is a critical link between postsynaptic Ca2+ and the initiation of 2-AG signaling that controls striatal synapses and striatal based-behaviors. We also created novel transgenic eAC3I mice that selectively express a short CaMKII inhibitor peptide fused to eGFP in striatal MSNs. Three specific aims will exploit unique features of T286A-KI and eAC3I mice to test specific hypotheses about the roles of striatal CaMKII autophosphorylation and activity. 1. Test the hypothesis that Ca2+-dependent 2-AG synthesis is modulated by CaMKII. We will identify sites of phosphorylation and CaMKII-binding domains in DGL?. DGL? phosphorylation, DGL? activity and 2-AG synthesis will be investigated in heterologous cells and in striatal slices from WT, T286A-KI and eAC3I mice. 2. Test the hypothesis that CaMKII modulates eCB-dependent synaptic regulation in striatal MSNs. Short and long-term roles of CaMKII will be determined by comparing the properties of excitatory synaptic inputs to D1- and D2-MSNs in striatal slices from WT, T286A-KI and eAC3I mice, and by using CaMKII inhibitor peptides. 3. Test the hypothesis that CaMKII modulates eCB-dependent motor activity. We will evaluate motor activity and coordination under basal conditions and following pharmacological modulation of 2-AG metabolism in WT, T286A-KI and eAC3I mice.

描述（由申请人提供）：纹状体在运动活动/协调和目标指导的习惯性学习中起关键作用。正常的运动活动纹状体驱动需要从两种表达D1-和D2-多巴胺（DA）受体的两种类型的纹状体培养基神经元（MSN）中精确平衡的相对输出。 D1-和D2-MSN中谷氨酸和DA之间的复杂信号传导涉及“按需” Ca2+依赖性内源性大麻素（ECB）合成。因此，DA，谷氨酸和ECB合作，通过在两个MSN亚型中参与不同的信号传导机制来平衡两种纹状体输出途径的短期和长期控制。这些机制的破坏会引起运动缺陷（例如帕金森氏病）或其他基于纹状体的异常行为。 Ca2+/钙调蛋白依赖性蛋白激酶II（CAMKII）具有多种双向作用，可控制海马，皮质和小脑中的兴奋性突触。虽然CaMKII在两个纹状体MSN亚型中都表达，这表明它调节了对纹状体MSN和运动活性的兴奋性输入，但对纹状体CAMKII的精确功能知之甚少。我们用CAMKII中的Thr286自磷酸化位点对敲击蛋白突变小鼠的分析？由ALA（T286A-KI小鼠）取代，揭示了CAMKII在长期和短期ECB依赖性控制D1-和D2-MSN中的特定作用。我们还发现Camkii吗？与磷酸化的二酰基甘油脂肪酶合作？（DGL？），最丰富的脑欧洲央行，2-芳基二酰甘油（2-AG）的Ca2+依赖性合成的速率限制酶。此外，可以通过抑制2-AG分解来挽救T286A-KI小鼠的基线多动症。这些最初的发现强烈支持了一个新的假设，即CAMKII是突触后CA2+与控制纹状体突触和基于纹状体的行为的2AG信号的启动之间的关键联系。我们还创建了新型的转基因EAC3I小鼠，该小鼠有选择地表达短的CAMKII抑制剂肽肽在纹状体MSN中融合的EGFP。三个特定的目标将利用T286A-KI和EAC3I小鼠的独特特征来测试有关纹状体CAMKII自磷酸化和活性作用的特定假设。 1。检验假设Ca2+依赖性2-AG合成由CAMKII调节。我们将确定DGL中的磷酸化和CAMKII结合域的位置。 DGL？磷酸化，DGL？活性和2AG合成将在异源细胞和WT，T286A-KI和EAC3I小鼠的纹状体切片中进行研究。 2。检验CAMKII调节纹状体MSN中ECB依赖性突触调节的假设。 CAMKII的短期和长期作用将通过比较来自WT，T286A-KI和EAC3I小鼠的纹状体切片中的兴奋性突触输入与D1-和D2-MSN的性质，以及使用CAMKII抑制剂肽。 3。检验CAMKII调节ECB依赖运动活动的假设。我们将在基础条件下以及在WT，T286A-KI和EAC3I小鼠中对2AG代谢的药理调节后评估运动活性和协调。