Deficits in KCC2 activity and the pathophysiology of Autism spectrum disorders

KCC2 活性缺陷和自闭症谱系障碍的病理生理学

基本信息

批准号：
9149319
负责人：
Stephen J Moss
金额：
$ 20.63万
依托单位：
TUFTS UNIVERSITY BOSTON
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-25 至 2018-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9149319
关键词：
Adult Affect Alanine Animal Model Anxiety Autistic Disorder Behavior Behavioral Behavioral Paradigm Birth Brain Bumetanide Child Cognitive deficits Common Core Development Epilepsy Equilibrium Exhibits Functional disorder Gated Ion Channel Glutamates Health Hippocampus (Brain)Human Knockout Mice Lead Ligands Lysine Measures Mediating Mediator of activation protein Membrane Modeling Modification Mus Mutation Neurons Patient-Focused Outcomes Patients Phospho-Specific Antibodies Phosphorylation Phosphotransferases Play Process Protein Dephosphorylation Reagent Rodent Rodent Model Role Schizophrenia Serine Signal Transduction Social Interaction Symptoms Synapses Testing Threonine anxiety symptoms autism spectrum disorder effective therapy gamma-Aminobutyric Acid improved inhibitor/antagonist insight neuropsychiatric disorder neurotransmission novel painful neuropathy postnatal prevent receptor repetitive behavior research study selective expression symporter synaptic inhibition uptake

项目摘要

DESCRIPTION (provided by applicant): Autism spectrum disorders (ASD) have common core symptoms which include increases in anxiety, and repetitive behaviors, with reduced sociability. It is widely believed that ASDs arise from subtle differences in the "equilibrium" between excitatory and inhibitory GABAergic neurotransmission. The electroneutral K+/Cl- co- transporter 2 (KCC2, or SLC12A5) is selectively expressed in the CNS after birth and allows neurons to maintain low intracellular Cl- concentrations an essential pre-requisite for the postnatal development of inhibitory neurotransmission. Consistent with its role in facilitating neuronal inhibition, deficits in KCC2 expression are evident in patients with ASDs and multiple autism animal models. KCC2 activity is subject to both positive and negative modulation via phosphorylation of serine's 940 and threonine residues 906 and 1007 respectively. Here, we will directly test if these regulatory processes influence the postnatal development of GABAergic inhibition, and the pathophysiology of ASDs. To do so we have created mice in which positive modulation of KCC2 activity by phosphorylation has been ablated via mutation of S940 to an alanine (S940A). T906/1007 are phosphorylated by with with-no-lysine kinases (WNKs), and we have also obtained line mouse lines with deficits in WNK activity. Preliminary studies using these new reagents have allowed us to formulate a novel hypothesis that will be tested here: The postnatal activation of KCC2 is facilitated by the reciprocal phosphorylation of S940 and dephosphorylation of T906/1007. Compromising these processes decreases the efficacy of GABAergic and directly contributes to the pathophysiology of ASDs. The experiments we will perform to test our hypothesis are detailed in the following aims. Specific Aim 1. To test the hypothesis that phosphorylation of S940 in KCC2 is a critical determinant for the postnatal development of GABAergic inhibition. Specific Aim 2. To test the hypothesis that WNK dependent phosphorylation of KCC2 slows the postnatal development of hyperpolarizing GABAergic inhibition. Specific Aim 3. To test the hypothesis that slowing the postnatal development of GABAergic inhibition reproduces the core behavioral deficits of ASDs. Collectively, these experiments will provide key mechanistic insights into how deficits in KCC2 phospho-dependent modulation contribute to the pathophysiology of ASD. This information may lead to the development of more effective therapies targeting KCC2 activity to ultimately improve patient outcomes for ASDs. Such strategies may also be relevant for other neuropsychiatric disorders, such as epilepsy, neuropathic pain, and schizophrenia in which deficits of KCC2 activity are believed to be of significance.

描述（由适用提供）：自闭症谱系障碍（ASD）具有共同的核心症状，包括焦虑症和重复行为的增加，社交性降低。人们普遍认为，ASD源于兴奋性和抑制性GABA能神经传递之间“平衡”的细微差异。出生后，在中枢神经系统中选择性表达了电荷的K+/Cl- co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-Co-转运蛋白，并允许神经元保持低细胞内CL浓缩，这是抑制性神经传递产后发展的必不可少的必需前抑制性神经传递的必要前。与其在支持神经抑制作用中的作用一致，KCC2表达中的定义是ASD和多种自闭症动物模型患者的证据。 KCC2活性分别通过丝氨酸的940和苏氨酸残留906和1007的磷酸化进行正调节和负调节。在这里，我们将直接测试这些调节过程是否影响GABA能抑制的产后发展以及ASD的病理生理学。为此，我们创建了小鼠，其中通过磷酸化对KCC2活性的阳性调节已通过S940向丙氨酸（S940A）的突变消化。 T906/1007被与非赖氨酸激酶（WNK）磷酸化，我们还获得了WNK活性定义的线小鼠线。使用这些新试剂的初步研究使我们能够在此处进行新的假设：KCC2的产后激活得到了S940的相互磷酸化和T906/1007的去磷酸化的支持。损害这些过程会降低GABA能的有效性，并直接有助于ASD的病理生理学。我们将进行测试假设的实验在以下目的中详细介绍了。具体目的1。检验以下假设：KCC2中S940的磷酸化是产后发育GABA能抑制的关键确定剂。具体目的2。为了检验以下假设：KCC2的依赖性磷酸化会减慢过度溶解GABA能抑制的产后发展。具体目的3。为了检验以下假设：降低了加巴能抑制后产后发展的核心行为定义了ASD的核心行为。总的来说，这些实验将提供关键的机械见解，以了解如何定义KCC2磷酸化的调节，从而有助于ASD的病理生理。这些信息可能会导致针对KCC2活动的更有效的疗法的发展，以最终改善ASD的患者预后。这种策略也可能与其他神经精神疾病有关，例如癫痫，神经性疼痛和精神分裂症，其中定义KCC2活性的定义具有重要意义。