The Role of the Extracellular Matrix in Alcohol Use Disorder

项目摘要 暴露于滥用药物，如酒精，诱导大脑的可塑性，并产生持续的药物相关性。 回忆这些大脑变化和药物记忆的持续激活被认为是 助长了毒瘾大量文献研究了三重突触（前突触和后突触）， 突触后细胞和星形胶质细胞）成瘾;然而，越来越多的证据表明， 突触，以表明细胞外基质（ECM）分子在这一过程中的额外参与。发动机控制模块 由糖蛋白、硫酸软骨素蛋白聚糖（CSPG）和酶的复杂网络组成， 它们相互作用以控制潜在的细胞可塑性和兴奋性。糖蛋白和CSPG聚集在 抑制性快速尖峰小白蛋白（PVB）中间神经元在整个大脑中形成神经元周网（PNN） 维持和加强突触在啮齿类动物中，PNN在急性暴露于 药物，这一过程依赖于神经胶质细胞的活性，神经胶质细胞分泌内源性蛋白酶切割PNN 件.在持续激活奖励记忆（即，依赖性），PNN数量增加， 表明与滥用药物相关的神经元集合被PNN包裹。虽然调查结果 在临床前成瘾模型中研究PNN是令人信服的，目前还没有关于PNN的数据， 患有酒精使用障碍（AUD）或其他物质使用障碍的人。这一建议的重点是酒精- 诱导PNNs和调节人类PNNs的分子的变化，以及如何修饰神经元- 啮齿类动物中的小胶质细胞信号级联改变了背景酒精奖励记忆的调节， PNN的组成。在目标1中，我们将使用以下方法评估人死后海马组织中的PNN密度： 定量明视野显微镜连同蛋白质和mRNA表达的措施，为几个 内源性ECM蛋白酶，GABA能神经元（例如，PVB）和突触标记物， 相同的受试者队列。我们预测，患有AUD的个体将具有增加的PNN数密度， PVB表达增加与ECM蛋白酶表达减少一致。这些发现将 描述PNN如何在患有AUD的人类中受到影响，并为评估PNN是否变化提供依据 在啮齿类动物模型中的物质使用障碍可以转化为人类。在目标2中，我们将使用小鼠来评估 如何敲除白细胞介素-33受体，ST2，影响奖励记忆使用条件性位置偏好。 白细胞介素-33由神经元以经验依赖性方式分泌，在那里它向其专性ST 2发出信号 受体介导几种内源性ECM蛋白酶的释放。我们预测， 白细胞介素-33受体的表达将阻碍介导记忆形成的蛋白水解级联反应， 巩固，从而抑制酒精诱导的位置偏好获得和巩固。我们相信 拟议的研究将告知靶向ECM的药理学药物的使用，以治疗AUD和其他疾病。 物质使用障碍，并将确认和扩大的结果，从临床前研究的ECM成瘾。

Project Summary Exposure to drugs of abuse, such as alcohol, induces plasticity in the brain and creates persistent drug-related memories. These brain changes and persistent activation of drug memories are believed to be central in contributing to drug addiction. A preponderance of literature has studied the tripartite synapse (pre- and postsynaptic cells, and astrocytes) in addiction; however, mounting evidence has implicated the tetrapartite synapse to indicate the additional involvement of extracellular matrix (ECM) molecules in this process. The ECM is comprised of a complex network of glycoproteins, chondroitin sulfate proteoglycans (CSPG), and enzymes, which interact to control underlying cell plasticity and excitability. Glycoproteins and CSPGs aggregate around inhibitory fast-spiking parvalbumin (PVB) interneurons throughout the brain to form perineuronal nets (PNN) which maintain and strengthen synapses. In rodents, PNNs are temporarily degraded after acute exposure to drugs, a process that relies on the activity of glial cells which secrete endogenous proteases that cleave PNN components. After persistent activation of reward memories (i.e., dependence), PNNs numbers are increased, indicating that neuronal ensembles associated with drugs of abuse are enveloped by PNNs. While the findings studying PNNs in preclinical addiction models are compelling, there are currently no data regarding PNNs in humans with alcohol use disorder (AUD) or other substance use disorders. This proposal focuses on alcohol- induced changes in PNNs and the molecules that regulate PNNs in humans, and how modifying neuron- microglia signaling cascades in rodents alters the regulation of contextual alcohol reward memory and the composition of PNNs. In Aim 1, we will evaluate PNN densities in human postmortem hippocampus tissue using quantitative brightfield microscopy together with measures of protein and mRNA expression for several of the endogenous ECM proteases, GABAergic neurons (e.g., PVB), and synaptic markers in tissue samples from the same subject cohort. We predict that individuals with AUD will have increased numerical densities of PNNs and increased PVB expression that coincide with decreased expression of ECM proteases. These findings will delineate how PNNs are impacted in humans with AUD and provide a basis for evaluating whether PNN changes in rodent models of substance use disorders are translatable to humans. In Aim 2, we will use mice to evaluate how knockout of the interleukin-33 receptor, ST2, impacts reward memory using conditioned place preference. Interleukin-33 is secreted by neurons in an experience-dependent manner, where it signals to its obligate ST2 receptor on microglia to mediate the release of several endogenous ECM proteases. We predict that knockout of the interleukin-33 receptor will impede the proteolytic cascades that mediate memory formation and consolidation, thereby curbing alcohol-induced place preference acquisition and consolidation. We believe the proposed studies will inform the use of pharmacologic agents which target the ECM to treat AUD and other substance use disorders, and will confirm and expand on findings from preclinical studies of the ECM in addiction.