Astrocyte-neuron interactions and sulfatases in Fetal Alcohol Spectrum Disorders

胎儿酒精谱系障碍中的星形胶质细胞-神经元相互作用和硫酸酯酶

• 批准号: 9297181
• 负责人: Marina Guizzetti
• 金额: $ 28.74万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-05 至 2020-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9297181
• 关键词: Affect; Antioxidants; Architecture; Arylsulfatase B; Astrocytes; Axon; Behavior; Behavioral; Biological; Brain; CSPG3 gene; Chondroitin Sulfate A; Chondroitin Sulfate C; Chondroitin Sulfate Proteoglycan; Clinical Research; Coculture Techniques; Cognitive; Communication; Core Protein; Cues; Dendrites; Development; Disaccharides; Enzyme Activation; Enzymes; Ethanol; Experimental Models; Family; Fetal Alcohol Spectrum Disorder; GAG Gene; Galactose; Generations; Hippocampus (Brain); Hypoxia; In Vitro; Injection of therapeutic agent; Investigation; Learning; Length; Link; Measures; Memory; Memory impairment; Messenger RNA; National Institute on Alcohol Abuse and Alcoholism; Neonatal; Neonatal Alcohol Exposure; Neurites; Neuronal Plasticity; Neurons; Oxidative Stress; Performance; Prevention; Property; Proteoglycan; Rattus; Reactive Oxygen Species; Recombinants; Reporting; Research; Role; Side; Signal Transduction; Small Interfering RNA; Sulfatases; Supplementation; Testing; Unspecified or Sulfate Ion Sulfates; Vertebral column; Work; alcohol abuse therapy; alcohol effect; alcohol exposure; brain abnormalities; brevican; chondroitin sulfate glycosaminoglycan; density; effective therapy; hippocampal pyramidal neuron; in vivo; innovation; insight; liquid chromatography mass spectrometry; molecular targeted therapies; morris water maze; neuron development; novel; novel therapeutic intervention; permissiveness; postnatal; preclinical study; prevent; public health relevance; versican

 DESCRIPTION (provided by applicant): Fetal Alcohol Spectrum Disorders (FASD) are characterized by structural brain abnormalities and compromised cognitive and behavioral functions. Neuronal connectivity and plasticity are affected by developmental alcohol exposure. The exposure of astrocytes to ethanol inhibits neuritogenesis in hippocampal neurons co-cultured with ethanol-treated astrocytes. However, a lack of understanding of the mechanisms by which ethanol affects neuronal structural plasticity in the developing brain persists. Filling tis gap will open the path to the identification of highly effective treatments to prevent or ameliorat the developmental effects of ethanol. Lecticans are inhibitory proteoglycans that, in the brain, prevent the extension of axons and dendrites. Lecticans consist of a core-protein moiety covalently bound to linear chains of disaccharides, chondroitin sulfates glycosaminoglycans (CS-GAGs), which are comprised mostly of chondroitin-4 sulfate (C4S) and chondroitin-6 sulfate (C6S); the inhibitory properties of lecticans depend on their core-protein and their sGAG side-chains. Two sulfatase enzymes, arylsulfatase B (ARSB) and galactose-6-sulfatase (GALNS) remove sulfate groups from C4S and C6S respectively and are required for the degradation of CS-GAGs. We find that ethanol inhibits the activity of ARSB and GALNS and that ethanol and ARSB silencing increase the expression of the lectican neurocan and C4S-GAG content in astrocytes in vitro. ARSB activity is inhibited, neurocan and sGAG levels are upregulated, and pyramidal neuron dendritic arborization is reduced also in the hippocampus of neonatal rats after in vivo ethanol exposure. Reduced ARSB activity and dendritic arborization persist up to post-natal day 36 and is correlated with reduced performance in spatial learning and memory tasks. In this proposal we hypothesize that the inhibition of ARSB and GALNS activity by ethanol in the developing hippocampus induces an unscheduled increase in lectican (neurocan, brevican, and versican) core-protein and CS-GAG levels leading to decreased in neuronal structural plasticity; these effects are long-lasting and causally linked to reduced performance in learning and memory tasks and are rescued by recombinant (r)ARSB. We plan to test our hypothesis by pursuing the following three specific aims: 1) To investigate the mechanisms of ethanol-induced sulfatase inhibition and the consequences on lectican core-proteins and sGAG levels and on CS disaccharide levels and composition in astrocytes. 2) To investigate the role of: sulfatases, SUMF1, lecticans, and oxidative stress on ethanol-treated astrocyte inhibition of neurite outgrowth. 3) To investigate the effects of in vivo neonatal ethanol exposure and of rARSB injections on sulfatase activity, lectican expression, sGAG levels and CS disaccharide levels, and dendritic arborization in the hippocampus and on spatial learning and memory. The proposed work is innovative and significant as it explores a novel mechanism underlying ethanol-induced inhibition of neuronal plasticity and will yield strategies aimed at sulfatase enzyme activation for the treatment of alcohol teratogenesis therefore advancing FASD research.

 描述（由申请人提供）：胎儿酒精谱系障碍（FASD）的特征是大脑结构异常和认知和行为功能受损。神经元的连接性和可塑性受到酒精暴露的影响。星形胶质细胞暴露于乙醇抑制与乙醇处理的星形胶质细胞共培养的海马神经元的轴突发生。然而，乙醇影响发育中大脑神经元结构可塑性的机制仍然缺乏了解。填补这一空白将开辟一条道路，以确定高效的治疗，以防止或改善乙醇的发展影响。凝集素是抑制性蛋白聚糖，在大脑中，阻止轴突和树突的延伸。凝集素由与二糖、硫酸软骨素糖胺聚糖（CS-GAG）的线性链共价结合的核心蛋白部分组成，硫酸软骨素糖胺聚糖（CS-GAG）主要由4硫酸软骨素（C4 S）和6硫酸软骨素（C6 S）组成;凝集素的抑制特性取决于其核心蛋白及其sGAG侧链。两种硫酸酯酶，芳基硫酸酯酶B（ARSB）和半乳糖-6-硫酸酯酶（GALNS）分别从C4 S和C6 S去除硫酸酯基团，并且是CS-GAG降解所需的。我们发现乙醇抑制ARSB和GALNS的活性，并且乙醇和ARSB沉默增加体外星形胶质细胞中凝集素神经聚糖的表达和C4 S-GAG含量。在体内乙醇暴露后，新生大鼠海马中的ARSB活性被抑制，神经聚糖和sGAG水平上调，锥体神经元树突分支也减少。减少ARSB活动和树突树枝化持续到出生后第36天，并与空间学习和记忆任务的性能下降。在该提议中，我们假设在发育中的海马中乙醇对ARSB和GALNS活性的抑制诱导凝集素蛋白聚糖（神经聚糖、短蛋白聚糖和多功能蛋白聚糖）核心蛋白和CS-GAG水平的非计划性增加，导致神经元结构可塑性降低;这些影响是持久的，并且与神经元的表现降低有因果关系。 学习和记忆任务，并通过重组（r）ARSB拯救。我们计划通过追求以下三个具体目标来测试我们的假设：1）研究乙醇诱导的硫酸酯酶抑制的机制以及对凝集素核心蛋白和sGAG水平以及对星形胶质细胞中CS二糖水平和组成的影响。2)研究硫酸酯酶、SUMF 1、凝集素和氧化应激对乙醇处理的星形胶质细胞抑制神经突生长的作用。3)研究体内新生儿乙醇暴露和rARSB注射对硫酸酯酶活性、凝集素表达、sGAG水平和CS二糖水平、海马中树突状分支以及空间学习和记忆的影响。这项工作具有创新性和重要意义，因为它探索了乙醇诱导的神经元可塑性抑制的新机制，并将产生旨在激活硫酸酯酶治疗酒精致畸的策略，从而推进FASD研究。