Project 3: Elucidation of Biochemical and Behavioral Efficacies of Antipsychotics

具体目标 在经典药理学中，激动剂激活单一线性信号转导途径，而激动剂激活单一线性信号转导途径。 拮抗剂阻断激动剂的作用并且不具有内在活性。在过去的几年里， 信号转导途径不仅仅是信号传导的线性级联。取而代之的是 组织成复杂的信号网络，需要高水平的监管，以产生精确和独特的 细胞反应。因此，给定的受体，通过各种配体诱导的功能构象， 通过与不同信号伙伴的交互来参与多种模式。这样，给定的配体可以 结合受体，并作为一种信号传导途径的拮抗剂，同时作为另一种信号传导途径的激动剂， 匡威。这一特性是建立了几个G蛋白偶联受体（GPCR）-最重要的 治疗干预的目标。重要的是，临床使用的药物中没有一种是在 这些多个信号的考虑。此外，激动剂和拮抗剂很少完全 选择性的，并且对于给定的受体，可以通过影响各种受体介导的过程， 作为与G蛋白的相互作用，脱敏，内化，下调，和受体介导的 非G蛋白信号成分的支架。不幸的是，这些生理相关性 财产没有得到充分的重视。因此，确定化合物的功能选择性可能有助于揭示 不仅有不同的生物过程，还有特定的功能结果。目前，功能性 对精神病学的选择性是未知的。这对于抗精神病药物尤其重要，因为多巴胺（DA） D2受体（D2 R）拮抗作用基本上是所有这些药物的先决条件;然而，它们的其他内在 活动是模糊的。拟议研究的总体目标是检查行为反应， 抗精神病化合物，并阐明信号转导机制是必不可少的， 精神分裂症样临床前遗传和药理学小鼠模型中的抗精神病疗效 行为。对于行为，研究了抗精神病化合物对运动活动、前脉冲抑制（PPI）、潜伏期抑制（PR）和运动抑制（PR）的影响。 DA转运蛋白（DAT）敲除（KO）、N-甲基-D-天冬氨酸（NMDA） 受体NR 1-亚基敲低（KD）和用安非他明（AMPH）或苯环己哌啶处理的C57 BL/6小鼠 (PCP)来复制类似精神分裂症的状态信号转导通路的分子指纹图谱 （MFSTP）将被执行以分析抗精神病化合物对各种信号转导的影响 包括蛋白激酶A（PKA）和DA和cAMP调节的磷蛋白32（DARPP-32）的形式。 32）、Akt/蛋白激酶B（PKB或Akt）和糖原合成酶激酶33（GSK 3）、磷脂酶C（PLC），和 细胞外信号调节的丝裂原活化蛋白激酶（ERK）途径。目前的实验 项目#3将通过提供临床前模型来测试体内 不同抗精神病药物改善精神分裂症样行为的选择性和有效性 并将这些反应与信号转导的改变相关联。我们的项目#3也将补充 来自Wyeth的核心项目，其中将在精神分裂症样大鼠模型中分析抗精神病药物反应， 抗精神病药物治疗的行为。了解抗精神病药物功能选择性的相关性 可以提供具有更少副作用、更大治疗选择性和增强疗效的新靶点， 治疗精神分裂症患者我们的项目#3有三个具体目标。 艾姆岛多巴胺能亢进在DAT-KO小鼠对抗精神病化合物反应中的作用。 A.比较DAT-KO小鼠对不同抗精神病药物的行为反应。 B。将MFSTP应用于不同的脑区，以确定高多巴胺能表型并分析 抗精神病药物的反应 Aim II. NR 1-KD小鼠中NMDA受体表达减少在对抗精神病药的反应中的作用。 A.比较不同抗精神病药物对NR 1低形态小鼠的行为反应。 B。将MFSTP应用于不同的脑区域，以确定NMDA受体亚型的表型。 小鼠并分析对抗精神病化合物的反应。 Aim III.药物诱导的多巴胺能亢进或多巴胺能减退在对多巴胺的反应中的作用 抗精神病化合物在C57 BU 6小鼠中的作用。 A.比较AMPH或PCP处理的小鼠对不同抗精神病药物的行为反应。 B。将MFSTP应用于不同的脑区，以确定药理学诱导的多巴胺能亢进或 并分析对抗精神病化合物的反应。

SPECIFIC AIMS In classical pharmacology, an agonist activates a single linear signal transduction pathway, whereas an antagonist blocks the action of the agonist and possesses no intrinsic activity. Over the past few years, it has become clear that signal transduction pathways are not merely linear cascades for signaling. Instead, they are organized into complex signaling networks that require high levels of regulation to generate precise and unique cellular responses. Hence, a given receptor, through various ligand-induced functional conformations, can engage multiple modalities through interaction with different signaling partners. In this way, a given ligand can bind a receptor and act as an antagonist for one signaling pathway while serving as an agonist at another or the converse. This property is established for several G protein-coupled receptors (GPCRs) - the most important targets for therapeutic intervention. Importantly, none of the drugs in clinical use have been developed with these multiple signaling considerations in mind. Additionally, agonists and antagonists are rarely completely selective and, for a given receptor, may alter signaling by influencing various receptor-mediated processes such as interaction with G proteins, desensitization, internalization, down-regulation, and receptor-mediated scaffolding of non-G protein signaling components. Unfortunately, the physiological relevance of these properties is not fully appreciated. Thus, identifying the functional selectivity of compounds may help reveal not only distinct biological processes, but also specific functional outcomes. Currently, the relevance of functional selectivity to psychiatry is unknown. This is particularly important for antipsychotic drugs, where dopamine (DA) D2 receptor (D2R) antagonism is essentially a prerequisite for all these drugs; however, their other intrinsic activities are obscure. The overall goal of the proposed research is to examine behavioral responses to antipsychotic compounds and to elucidate signal transduction mechanisms that are essential for antipsychotic efficacy in preclinical genetic and pharmacological mouse models of schizophrenia-like behaviors. For behavior, effects of antipsychotic compounds on motor activity, prepulse inhibition (PPI), latent inhibition (LI), and social behavior in DA transporter (DAT) knockout (KO), N-methyl-D-aspartate (NMDA) receptor NR1-subunit knockdown (KD), and C57BL/6 mice treated with amphetamine (AMPH) or phencyclidine (PCP) to reproduce schizophrenia-like states. Molecular fingerprinting of signal transduction pathways (MFSTP) will be performed to analyze effects of antipsychotic compounds on various signal transduction modalities that include the protein kinase A (PKA) and DA and cAMP-regulated phosphoprotein 32 (DARPP- 32), Akt/protein kinase B (PKB or Akt) and glycogen synthase kinase 33 (GSK3), phospholipase C (PLC), and extracellular signal-regulated mitogen activated protein kinase (ERK) pathways. The experiments in the present Project #3 will complement those in Projects #1 and #2 by providing preclinical models to test the in vivo selectivities and efficacies of various antipsychotic compounds on amelioration of schizophrenia-like behaviors and will correlate these responses to alterations in signal transduction. Our Project #3 will complement also the Core Project from Wyeth where antipsychotic responses will be analyzed in rat models of schizophrenia-like and antipsychotic-treated behaviors. Understanding the relevance of functional selectivity of antipsychotic drugs may provide novel targets with fewer side-effects, greater therapeutic selectivity, and enhanced efficacy for treating individuals with schizophrenia. Our Project #3 has three Specific Aims. Aim I. Role of hyperdopaminergia in responses to antipsychotic compounds in DAT-KO mice. A. To compare behavioral responses of DAT-KO mice to different antipsychotic compounds. B. To apply MFSTP to various brain regions to define the hyperdopaminergic phenotype and analyze responses to antipsychotic compounds. Aim II. Role of reduced NMD A receptor expression in responses to antipsychotics in NR1-KD mice. A. To compare behavioral responses of NR1 hypomorphic mice to different antipsychotic compounds. B. To apply MFSTP to various brain regions to define the phenotype of the NMDA receptor hypomorphic mice and analyze responses to antipsychotic compounds. Aim III. Roles of pharmacologically-induced hyperdopaminergia or hypoglutamatergia in responses to antipsychotic compounds in C57BU6 mice. A. To compare behavioral responses of mice treated with AMPH or PCP to different antipsychotics. B. To apply MFSTP to various brain regions to define pharmacologically-induced hyperdopaminergic or hypoglutamatergic states and analyze responses to antipsychotic compounds.