Effect of ethanol on chondroitin sulfate proteoglycans: relevance to FASD

酒精对发育中的大脑有深远的影响，从结构异常到 功能异常，导致胎儿酒精特有的认知和行为功能受损 谱系障碍(FASD)。神经元的成熟是神经发育过程中必不可少的过程。 系统。脑特异性硫酸软骨素蛋白多糖(CSPGs)、神经多糖和短链蛋白聚糖构成抑制作用 防止神经突起向不正确方向延伸的线索，因此有助于正确的形成 神经细胞的结构。Neurocan和Brivican抑制神经突起的生长，并由胶质细胞高度产生 细胞，特别是星形胶质细胞，在体外和体内。CSPG是由核心蛋白组成的糖蛋白 附着在称为硫酸软骨素(CS)的糖胺多聚糖(GAG)的线性链上，它包含在 软骨素-4硫酸盐(C4S)和软骨素-6硫酸盐(C6S)；CSPG的抑制性能取决于它们的 核心蛋白和它们的封口链。几种酶参与GAG的生物合成和降解。 链；芳基硫酸酯酶B(ARSB)和半乳糖-6-硫酸酯酶(GALN)从C4S和C6S中去除硫酸盐基团 分别是降解CS-GAG所需的。蒸馏器中CSPG的意外增加 大脑发育可能导致大脑连通性改变和神经元可塑性过早下降。在这 我们假设乙醇处理的星形胶质细胞通过增加CSPG来抑制神经发生。更多 具体地说，我们假设乙醇通过抑制星形胶质细胞中ARSB和GALNS的活性， 增加这些细胞中CS-GAG和CSPG核心蛋白Neurcan和Brivican的水平，导致抑制 海马神经元神经发生的研究。具体目标1将研究乙醇对ARSB和ARSB的影响 GALNS的活性和表达，在CS-GAG、NeuroCan和Brivican水平上，以及ARSB和 GALNS对乙醇抑制星形胶质细胞介导的体外海马神经元再生的调节作用。 特定目的2将研究体内新生儿酒精暴露对ARSB和GALNS活性的影响以及 蛋白质和mRNA的表达，CS-GAG，C4S-GAG，以及神经钙素和短链淀粉结合的SGAG水平，以及 神经钙素和短蛋白在海马区的蛋白和mRNA表达。

Ethanol exerts profound effects on the developing brain, which range from structural abnormalities to functional anomalies, resulting in compromised cognitive and behavioral functions characteristic of fetal alcohol spectrum disorders (FASD). Neuronal maturation is an essential process in the development of the nervous system. Brain-specific chondroitin sulfate proteoglycans (CSPGs) neurocan and brevican constitute inhibitory cues that prevent the extension of neurites in improper directions therefore contributing to the proper formation of neuronal architecture. Neurocan and brevican inhibit neurite outgrowth and are highly produced by glial cells, and astrocytes in particular, both in vitro and in vivo. CSPG are glycoproteins consisting of core-proteins attached to linear chains of glycosaminoglycans (GAGs) called chondroitin sulfates (CS), which consists in chondroitin-4 sulfate (C4S) and chondroitin-6 sulfate (C6S); the inhibitory properties of CSPGs depend on their core-protein and their GAG chains. Several enzymes are involved in the biosynthesis and degradation of GAG chains; 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. An unscheduled increase in CSPGs in the still developing brain may lead to altered brain connectivity and to premature decrease in neuronal plasticity. In this proposal we hypothesize that ethanol-treated astrocytes inhibits neuritogenesis by increasing CSPGs. More specifically, we hypothesize that ethanol, through the inhibition of ARSB and GALNS activity in astrocytes, increases CS-GAG and CSPG core-protein neurocan and brevican levels in these cells leading to the inhibition of hippocampal neuron neuritogenesis. Specific aim 1 will investigate the effect of ethanol on ARSB and GALNS activity and expression, on CS-GAG, neurocan, and brevican levels, and on the role of ARSB and GALNS in modulating ethanol-induced inhibition of astrocyte-mediated hippocampal neuritogenesis in vitro. Specific Aim 2 will investigate the effect of in vivo neonatal alcohol exposure on ARSB and GALNS activity and protein and mRNA expression, CS-GAG, C4S-GAG, and neurocan- and brevican-bound sGAG levels, and neurocan and brevican protein and mRNA expression in the hippocampus.