Prenatal Origins of Neurometabolic Consequences

 描述（由申请人提供）：儿童发育迟缓的发生率占美国人口的18%，男孩多于女孩。环境因素（如胎儿生长发育异常和低血糖）和遗传畸变起病因作用。发育迟缓和自闭症谱系障碍（ASD）与12号染色体上Slc 2A 3基因的拷贝数变异（CNV）、缺失或重复有关。ASD是终身神经发育障碍（NDD），具有脑突触连接断开。Slc 2A 3基因翻译产物Glut 3蛋白是神经元促进性葡萄糖转运蛋白，其为神经细胞增殖和分化、突触形成/可塑性和功能/神经传递所必需的氧化代谢提供燃料。随着新的遗传技术的出现，在儿童中描述了与CNVs相关的表型独特的人类GLUT 3缺陷。我们以前观察到，在经典的单等位基因Slc 2A 3缺失小鼠与胎儿生长受限（FGR），男性表达ASD症状。为了区分FGR对异常脑器官发生和发病的影响，我们假设大脑皮层和海马神经元中缺乏Glut 3将揭示从自闭症到智力残疾的表型，从而揭示筛查和干预的可能性，即帮助具有这些表现特征的个体并预防一些NDD及其相关的合并症。为了验证这一假设，我们提出了以下具体目标，通过破坏条件性神经元NCL 3无效缺失小鼠系（NCL 3loxP/loxP/nestinCre+）中的神经元特异性Slc 2A 3，来研究对以下的影响：1. a.不同妊娠期（G13、G19）胎盘和胎儿脑Slc 2A 3表达和功能和B.胎儿生长受限（FGR）对胎盘和胎脑Slc 2A 3表达和功能的作用。2.产后的，产后的代谢状态，其包括具有代偿机制的血浆、脑脊液和脑（神经元和神经胶质）代谢概况，B.脑形态学和免疫组织化学检测不同的细胞类型和过程中的畸变。3.成人和成人A。神经行为表型包括活动、癫痫发作、认知、工作记忆、焦虑、社会化、发声和刻板，具有B。在膜片钳神经元的电生理学中检测功能损伤，以及生酮饮食逆转的可能性。我们提出的研究结果将告诉我们，ASD 3缺乏对ASD的贡献和影响，为未来的内表型人类研究在多因素ASD/NDD中检测ASD 3基因变异奠定基础。这将使随后的治疗发现成为可能。所获得的见解将在预防和治疗与早期发育期间遇到的神经元葡萄糖供应不足（例如FGR）相关的其他疾病中推广，并导致具有ASD临床特征的NDD，有时表现为EEG癫痫发作和婴儿小头畸形。

 DESCRIPTION (provided by applicant): The incidence of developmental delays in children is 18% of the US population, with boys outnumbering girls. Environmental factors (e.g. fetal growth deviations and hypoglycemia) and genetic aberrations play etiological roles. Developmental delays and autism spectrum disorders (ASDs) have been associated with copy number variations (CNVs), deletion or duplication of the Slc2A3 gene on chromosome 12. ASDs are life-long neurodevelopmental disorders (NDD) with brain synaptic disconnectivity. Slc2A3 gene translation product, Glut3 protein is the neuronal facilitative glucose transporter that fuels oxidative metabolism necessary for neural cell proliferation and differentiation, synaptic formation/plasticity and function/neurotransmission. The phenotypically distinct human GLUT3 deficiency associated with CNVs is being described in children with the advent of newer genetic technologies. We previously observed that in the classical mono-allelic Slc2A3 deletion mouse with fetal growth restriction (FGR), males expressed ASD symptoms. To separate the impact of FGR on aberrant brain organogenesis and the advent of morbidities, we hypothesize that lack of Glut3 in cerebral cortical and hippocampal neurons will reveal a phenotype ranging from autism to intellectual disability, thereby unraveling possibilities for screening and interventions, that an aid individuals with these presenting features and prevent some NDDs and their associated co-morbidities. To test this hypothesis, we propose the following specific aims by disrupting neuron-specific Slc2A3 in a conditional neuronal glut3 null deletion mouse line (glut3loxP/loxP/nestinCre+), to study the impact on: 1. a. Placental and fetal brain Slc2A3 expression and function at different gestational stages (G13, G19) and b. the role of fetal growth restriction (FGR) on placental and fetal brain Slc2A3 expression and function. 2. Postnatal a. metabolic status which includes plasma, cerebro-spinal fluid and brain (neuronal and glial) metabolic profile with compensatory mechanisms, b. brain morphology and immunohistochemistry to detect different cell types and aberrations in processes. 3. Postnatal and adult a. neurobehavioral phenotype including activity, seizures, cognition, working memory, anxiety, socialization, vocalization and stereotypies, with b. electrophysiology in patch-clamped neurons to detect functional impairments, and possibility of reversal with a ketogenic diet. The results of our proposed studies will inform us about the contribution and impact of glut3 deficiency on ASDs, setting the stage for future endophenotype human studies in detecting glut3 gene variations in the multifactorial ASD/NDDs. This will enable subsequent therapeutic discovery. The insights gained will be generalizable in preventing and treating other conditions related to deficient neuronal glucose supply (e.g. FGR) encountered during early development and resulting in NDDs with clinical features of ASDs, sometimes presenting with EEG seizures and infantile microcephaly.