Legros Hélène, Launay Séverine, Roussel Benoit Denis, Marcou-Labarre Aurélie, Calbo Sébastien, Catteau Julie, Leroux Philippe, Boyer Olivier, Ali Carine, Marret Stéphane, Vivien Denis, Laudenbach Vincent
EA 4309 Neovasc Microvascular Endothelium and Neonatal Brain Lesions, IHURBM, IFRMP 23, School of Medicine and Pharmacy, University of Rouen, Rouen, France.
J Cereb Blood Flow Metab. 2009 Jun;29(6):1146-58. doi: 10.1038/jcbfm.2009.39. Epub 2009 Apr 15.
Few data are available on the involvement of brain microvascular endothelial cells (BMECs) in excitotoxic neonatal brain lesions. Therefore, we developed an original approach for investigating mouse-derived BMECs in vitro. We hypothesized that newborn and adult BMEC cultures would show age-related differences in phenotype and sensitivity to glutamate. Expression of the monocarboxylate transporter, MCT1, was higher in neonatal than in adult BMECs, whereas expression of the glucose transporter, GLUT1, was higher in adult than in neonatal BMECs that overexpressed the N-methyl-D-aspartate receptor NR1 subunit (NMDAR1) compared with adult BMECs. The ability of neonatal and adult BMECs to be activated by glutamate was confirmed through intracellular calcium ([Ca2+]i) recording. The glutamate-induced [Ca2+]i increase was blocked by the selective NMDAR antagonist, MK-801. Significant glutamate-evoked concentration-dependent release of tissue-type plasminogen activator (t-PA) and matrix metalloproteinases (MMPs) activities was found in supernatants of neonatal, but not in adult BMECs. The glutamate-mediated release of t-PA, MMP-2, and MMP-9 proteolytic activities in neonatal BMECs was blocked by MK-801. Conceivably, this protease release from neonatal BMECs may participate in neonatal brain lesions.
关于脑微血管内皮细胞（BMECs）在兴奋性毒性新生儿脑损伤中的作用，目前可用的数据很少。因此，我们开发了一种原创方法来体外研究源自小鼠的BMECs。我们假设新生和成年BMEC培养物在表型和对谷氨酸的敏感性方面会表现出与年龄相关的差异。单羧酸转运体MCT1在新生BMECs中的表达高于成年BMECs，而葡萄糖转运体GLUT1在成年BMECs中的表达高于新生BMECs，与成年BMECs相比，过表达N-甲基-D-天冬氨酸受体NR1亚基（NMDAR1）的新生BMECs中GLUT1的表达更高。通过细胞内钙（[Ca2+]i）记录证实了新生和成年BMECs被谷氨酸激活的能力。谷氨酸诱导的[Ca2+]i增加被选择性NMDAR拮抗剂MK-801阻断。在新生BMECs的上清液中发现了显著的谷氨酸诱发的浓度依赖性组织型纤溶酶原激活剂（t-PA）释放和基质金属蛋白酶（MMPs）活性，但在成年BMECs中未发现。MK-801阻断了新生BMECs中谷氨酸介导的t-PA、MMP-2和MMP-9蛋白水解活性的释放。可以想象，新生BMECs释放的这种蛋白酶可能参与新生儿脑损伤。
