The Role of the Extracellular Matrix in Alcohol Use Disorder

项目摘要 接触滥用药物，如酒精，会诱导大脑的可塑性，并产生与药物有关的持续性 回忆。这些大脑变化和药物记忆的持续激活被认为是 导致吸毒成瘾。大多数文献已经研究了三方突触(前和 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四分体 突触提示细胞外基质(ECM)分子参与这一过程。ECM 由糖蛋白、硫酸软骨素蛋白多糖(CSPG)和酶组成的复杂网络， 它们相互作用，控制潜在的细胞可塑性和兴奋性。糖蛋白和CSPG聚集在 分布于脑内的抑制性快速放电小白蛋白(PVB)中间神经元形成周围神经网(PNN) 来维持和加强突触。在啮齿动物中，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来裂解PNN 组件。在持续激活奖励记忆(即依赖)之后，PNN数量增加， 这表明与滥用药物相关的神经元群被三叉神经节所包裹。虽然调查结果 在临床前成瘾模型中研究PNNS是引人注目的，目前还没有关于PNNS的数据 有酒精使用障碍(AUD)或其他物质使用障碍的人。这项提案的重点是酒精- 诱导PNNS和调节PNNS的分子的变化，以及如何修改神经元- 啮齿动物小胶质细胞信号级联改变背景酒精奖赏记忆的调节 PNNS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 定量明场显微镜结合蛋白质和mRNA表达的测量 内源性ECM蛋白酶、GABA能神经元(如PVB)和突触标志物 同一组受试者。我们预测，AUD患者的PNN和PNN的数字密度将会增加 PVB表达增加，与ECM蛋白水解酶表达降低一致。这些发现将 描述PNN如何影响患有AUD的人类，并为评估PNN是否发生变化提供依据 在啮齿动物模型中，物质使用障碍是可以遗传给人类的。在目标2中，我们将使用小鼠来评估 白细胞介素33受体ST2敲除如何通过条件性位置偏爱影响奖赏记忆。 白介素33是由神经元以经验依赖的方式分泌的，它向其专有的ST2发出信号 小胶质细胞上的受体，介导几种内源性细胞外基质蛋白的释放。我们预测淘汰赛 白介素33受体的表达将阻碍蛋白水解级联反应，而蛋白水解级联反应介导记忆的形成和 整合，从而抑制酒精诱导的位置偏好获得和整合。我们相信 建议的研究将告知使用针对ECM的药理学药物来治疗AUD和其他 物质使用障碍，并将确认和扩大对成瘾的ECM的临床前研究的结果。

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.