Normandie Univ, UNIROUEN, INSERM U1245 and Rouen University Hospital, Department of Neonatal Paediatrics and Intensive Care, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.
Department of Pathology, Morvan Hospital, Brest, France.
Neurobiol Dis. 2020 Nov;145:105074. doi: 10.1016/j.nbd.2020.105074. Epub 2020 Sep 3.
In utero alcohol exposure can induce severe neurodevelopmental disabilities leading to long-term behavioral deficits. Because alcohol induces brain defects, many studies have focused on nervous cells. However, recent reports have shown that alcohol markedly affects cortical angiogenesis in both animal models and infants with fetal alcohol spectrum disorder (FASD). In addition, the vascular system is known to contribute to controlling gamma-aminobutyric acid (GABA)ergic interneuron migration in the developing neocortex. Thus, alcohol-induced vascular dysfunction may contribute to the neurodevelopmental defects in FASD. The present study aimed at investigating the effects of alcohol on endothelial activity of pial microvessels. Ex vivo experiments on cortical slices from mouse neonates revealed that in endothelial cells from pial microvessels acute alcohol exposure inhibits both glutamate-induced calcium mobilization and activities of matrix metalloproteinase-9 (MMP-9) and tissue plasminogen activator (tPA). The inhibitory effect of alcohol on glutamate-induced MMP-9 activity was abrogated in tPA-knockout and Grin1/VeCad mice suggesting that alcohol interacts through the endothelial NMDAR/tPA/MMP-9 vascular pathway. Contrasting with the effects from acute alcohol exposure, in mouse neonates exposed to alcohol in utero during the last gestational week, glutamate exacerbated both calcium mobilization and endothelial protease activities from pial microvessels. This alcohol-induced vascular dysfunction was associated with strong overexpression of the N-methyl-d-aspartate receptor subunit GluN1 and mispositioning of the Gad67-GFP interneurons that normally populate the superficial cortical layers. By comparing several human control fetuses with a fetus chronically exposed to alcohol revealed that alcohol exposure led to mispositioning of the calretinin-positive interneurons, whose density was decreased in the superficial cortical layers II-III and increased in deepest layers. This study provides the first mechanistic and functional evidence that alcohol impairs glutamate-regulated activity of pial microvessels. Endothelial dysfunction is characterized by altered metalloproteinase activity and interneuron mispositioning, which was also observed in a fetus with fetal alcohol syndrome. These data suggest that alcohol-induced endothelial dysfunction may contribute in ectopic cortical GABAergic interneurons, that has previously been described in infants with FASD.
子宫内酒精暴露可导致严重的神经发育障碍，导致长期的行为缺陷。由于酒精会引起大脑缺陷，因此许多研究都集中在神经细胞上。然而，最近的报告显示，酒精在动物模型和胎儿酒精谱系障碍（FASD）的婴儿中均明显影响皮质血管生成。此外，已知血管系统有助于控制发育中的新皮层中γ-氨基丁酸（GABA）能中间神经元的迁移。因此，酒精引起的血管功能障碍可能导致 FASD 的神经发育缺陷。本研究旨在研究酒精对脑皮层微血管内皮细胞活性的影响。来自新生小鼠皮质切片的离体实验显示，在脑皮层微血管内皮细胞中，急性酒精暴露抑制了谷氨酸诱导的钙动员以及基质金属蛋白酶-9（MMP-9）和组织纤溶酶原激活物（tPA）的活性。在 tPA 基因敲除和 Grin1/VeCad 小鼠中，酒精对谷氨酸诱导的 MMP-9 活性的抑制作用被消除，这表明酒精通过内皮 NMDAR/tPA/MMP-9 血管途径相互作用。与急性酒精暴露的作用相反，在最后一个妊娠期暴露于酒精的新生小鼠中，谷氨酸加剧了脑皮层微血管的钙动员和内皮蛋白酶活性。这种酒精引起的血管功能障碍与 N-甲基-D-天冬氨酸受体亚基 GluN1 的强烈过表达以及 Gad67-GFP 中间神经元的错位有关，这些中间神经元通常存在于浅层皮质层中。通过比较几个慢性暴露于酒精的人类胎儿与一个胎儿，发现酒精暴露导致 calretinin 阳性中间神经元的错位，其在浅层皮质层 II-III 中的密度降低，在最深层中的密度增加。这项研究首次提供了机制和功能证据，证明酒精会损害脑皮层微血管的谷氨酸调节活性。内皮功能障碍的特征是金属蛋白酶活性和中间神经元错位改变，在胎儿酒精综合征的胎儿中也观察到了这种改变。这些数据表明，酒精引起的内皮功能障碍可能导致皮层 GABA 能中间神经元的异位，这在 FASD 婴儿中已有描述。
