P2 - Role of mGluR5/CK1-CK2/DARPP-32 Pathway in Psychostimulant Effects

众所周知，DARPP-32在生理条件下是纹状体信号的关键整合因子，在精神刺激剂中也是如此。除多巴胺外，谷氨酸等多种神经递质作用于并修饰DARPP-32下游信号。我们的研究已经证明了多条信号通路汇聚在DARPP-32上在药物滥用作用中的重要性，最近我们开发了最先进的技术，证明这些信号事件在不同亚群的中棘神经元(MSN)中受到特异性调控，这些MSN差异地表达D1型和D2型多巴胺受体。我们正在进行的研究将集中在mGluRs的研究上，mGluRs是参与谷氨酸依赖的DARPP-32调节的一个重要的GPCR，以及两个激酶，CKI和CK2。CKI在mGluR5/DARPP-32途径中起着关键作用，而CK2在调控DARPP-32核转运中起着至关重要的作用。我们已经为提出的三个目标中的每一个建立了新的小鼠系，这将使我们不仅能够研究精神刺激剂在体内的影响，而且还可以评估D1-和D2-MSN在这些现象中的相对重要性。为了解决这些问题，我们在计划项目赠款的项目2中提出了三个目标。 在Aim I中，我们将研究新发现的mGluRs调节因子Norbin在精神刺激剂作用中的作用。在AIM II中，我们将在体内研究CK1在mGluRs/DARPP-32途径中的作用。我们还将进一步描述CK16过度表达的小鼠，这些小鼠表现出一些重新命名为ADHD的行为特征。我们将进一步解决观察到的DL和D2受体通路之间的差异。在目标III中，我们将研究CK2在精神刺激剂的作用中的作用，在DL和D2-MSN中都使用特定的KO策略。本项目的成果将补充本计划项目赠款的其他两个项目。此外，我们还将与项目1和项目3进行一些合作研究，包括项目1涉及脊柱形态的研究，以及项目3涉及磷蛋白质组研究和行为研究。

It is well established that DARPP-32 is a key integrator of striatal signaling in physiological conditions as well as in the context of psychostimulants. Beside dopamine, various neurotransmitters such as glutamate act on and modify DARPP-32 downstream signaling. Our studies have demonstrated the importance of multiple signaling pathways converging on DARPP-32 in the action of drugs of abuse, and recently we have developed state-of-the-art technologies proving that these signaling events are specifically regulated in different sub-populations of medium spiny neurons (MSNs) that differentially express Dl and D2 types of dopamine receptor. Our ongoing research will focus on studies of mGluRS, an important GPCR invovled in glutamate-dependent DARPP-32 regulation, and two kinases, CKI and CK2. CKI is a crucial player in the mGluR5/DARPP-32 pathway and CK2 is essential for regulation of DARPP-32 nuclear trafficking. We have generated novel mouse lines for each of the three proposed Aims that will allow us not only to study the impact of psychostimulants in vivo but also to evaluate the relative importance of D1- and D2-MSNs in these phenomena. To address these questions we propose three Aims in Project 2 of the Program Project Grant. In Aim I we will study the role of the newly discovered mGluRS regulator Norbin in the actions of psychostimulants. In Aim II we will study the role of CK1 in the mGluRS/DARPP-32 pathway in vivo. We will also further charcterize the CK16 over expressing mice that present some behavioral features that ressembles ADHD. We will further address differences observed between Dl and D2 receptor pathways. In Aim III we will study the role of CK2 in the actions of psychostimulants, in both Dl and D2-MSNs using specific KO strategies. Results from this Project will complement the other two Projects of this Program Project grant. In addition we will also carry out a number of collaborative studies with Projects 1 and 3, including studies involving spine morphology with Project 1 and phosphoproteomic studies and behavioral studies with Project 3.