Division of Neonatology, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland.
Birth Defects Res. 2020 Apr 1;112(6):480-489. doi: 10.1002/bdr2.1657. Epub 2020 Feb 13.
Exposure to ethanol during pregnancy is the cause of fetal alcohol spectrum disorder. The function of L1 cell adhesion molecule (L1), critical for proper brain development, is dependent on detergent-resistant membrane microdomains (DRM). Ethanol at low concentrations disrupts L1 function measured by inhibition of downstream signaling and alterations in L1-DRM distribution in cerebellum in vivo and in cerebellar granule neurons (CGN) in vitro. We have previously shown that choline pretreatment of CGN partially prevents ethanol toxicity through improving L1 function in vitro. Here we show that choline supplementation reduces the impact of ethanol on L1 in cerebellum in vivo.
Pregnant rat dams were placed on choline free diet on gestational Day 5 (G5). Pups were treated with saline or choline from postnatal day (P) 1-5. On P5, pups were intubated twice 2 hr apart with ethanol or Intralipid® for a total dose of 6 g/kg/d and sacrificed 1 hr after the last intubation. The cerebella were harvested and L1 phosphorylation/dephosphorylation status and distribution in DRM were analyzed.
Ethanol reduced L1 tyrosine phosphorylation and L1-Y1176 dephosphorylation in cerebella, and caused an increase in the percent of L1 in DRM. Choline supplementation of pups reduced the ethanol-induced changes in L1 phosphorylation status and ameliorated ethanol-induced redistribution of L1 into DRM.
Choline supplementation before an acute dose of ethanol ameliorates changes in L1 in vivo.
妊娠期间接触乙醇是胎儿酒精谱系障碍的原因。L1 细胞黏附分子(L1)的功能对于大脑的正常发育至关重要,而 L1 的功能依赖于去污剂抗性膜微区(DRM)。低浓度的乙醇通过抑制下游信号和改变小脑体内 L1-DRM 分布以及体外小脑颗粒神经元(CGN)中的 L1-DRM 分布来破坏 L1 的功能。我们之前的研究表明,CGN 中的胆碱预处理通过改善体外 L1 的功能部分预防了乙醇毒性。在这里,我们表明胆碱补充减少了乙醇对体内小脑 L1 的影响。
妊娠大鼠孕 5 天(G5)时开始给予不含胆碱的饮食。新生后第 1-5 天,幼鼠给予生理盐水或胆碱处理。在 P5 时,幼鼠通过管饲法每 2 小时接受一次乙醇或 Intralipid®处理,总剂量为 6 g/kg/d,并在最后一次管饲后 1 小时处死。收获小脑并分析 DRM 中 L1 的磷酸化/去磷酸化状态和分布。
乙醇降低了小脑内 L1 的酪氨酸磷酸化和 L1-Y1176 的去磷酸化,并增加了 L1 在 DRM 中的百分比。幼鼠给予胆碱补充减少了乙醇诱导的 L1 磷酸化状态的变化,并改善了乙醇诱导的 L1 向 DRM 的重新分布。
在急性乙醇剂量前给予胆碱补充可改善体内 L1 的变化。