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（由申请人提供）：自闭症谱系障碍 (ASD) 具有共同的核心症状，包括焦虑增加、重复行为以及社交能力降低。人们普遍认为，自闭症谱系障碍是由兴奋性和抑制性之间“平衡”的细微差异引起的。 GABA 能神经传递。电中性 K+/Cl- 协同转运蛋白 2（KCC2 或 SLC12A5）在出生后选择性地在 CNS 中表达，并允许神经元传递。维持低细胞内 Cl- 浓度是抑制性神经传递的出生后发育的重要先决条件，与其促进神经元抑制的作用一致，KCC2 表达缺陷在 ASD 患者和多种自闭症动物模型中很明显。分别通过丝氨酸 940 和苏氨酸残基 906 和 1007 的磷酸化进行正向和负向调节。在这里，我们将直接测试这些调节过程是否影响。 GABA 能抑制的出生后发育以及 ASD 的病理生理学为此，我们创建了通过磷酸化对 KCC2 活性进行正向调节的小鼠，其中 S940 突变为丙氨酸 (S940A)，并被磷酸化。 -无赖氨酸激酶（WNK），我们还获得了 WNK 活性缺陷的小鼠品系。使用这些新试剂的初步研究使我们能够提出一个新的假设，并将在此进行测试：S940 的相互磷酸化和 T906/1007 的去磷酸化促进了 KCC2 的出生后激活，损害这些过程会直接降低 GABAergic 的功效。有助于自闭症谱系障碍的病理生理学研究。我们将进行的实验用于检验我们的假设，具体目标如下。 1. 检验 KCC2 中 S940 的磷酸化是 GABA 能抑制的出生后发展的关键决定因素 2. 检验 KCC2 的 WNK 依赖性磷酸化减缓超极化 GABA 能抑制的出生后发展的假设。为了检验这一假设，即减缓 GABA 能抑制的出生后发育会重现 ASD 的核心行为缺陷。提供了关于 KCC2 磷酸依赖性调节的缺陷如何影响 ASD 病理生理学的关键机制见解。这些信息可能会导致针对 KCC2 活性的更有效疗法的开发，从而最终改善 ASD 患者的治疗结果。此类策略也可能与其他相关。神经精神疾病，例如癫痫、神经性疼痛和精神分裂症，KCC2 活性缺陷被认为在这些疾病中具有重要意义。