CHANGES IN THE VASCULAR EXTRACELLULAR-MATRIX DURING EMBRYONIC VASCULOGENESIS AND ANGIOGENESIS
CHANGES IN THE VASCULAR EXTRACELLULAR-MATRIX DURING EMBRYONIC VASCULOGENESIS AND ANGIOGENESIS
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DOI：
10.1016/0012-1606(88)90225-4
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发表时间：
1988-02-01
影响因子：
2.7
通讯作者：
LEMMON, V
中科院分区：
文献类型：
--
作者：
RISAU, W;LEMMON, V
我们之前已经鉴定了针对鸡脑细胞的单克隆抗体。其中一种方法（14-2B2）对小鸡大脑冷冻切片的所有毛细血管进行了明亮的染色。这里我们展示了这种抗体是针对鸡纤维连接蛋白的。利用该抗体和抗层粘连蛋白的多克隆抗体，我们研究了血管细胞外基质的发育。研究了卵黄囊、血岛和胚胎内背主动脉内皮细胞原位分化形成毛细血管的血管发生过程。血岛产生高水平的纤维连接蛋白，但不产生层粘连蛋白。早期胚胎内毛细血管均表达纤维连接蛋白，但几乎不表达层粘连蛋白。6日龄小鸡胚胎的背主动脉有几层产生纤维连接蛋白的细胞，但缺乏层粘连蛋白。第8天开始表达层粘连蛋白，第10天在主动脉血管壁发现成人样分布。在大脑发育过程中研究了血管生成，即先前存在的血管形成毛细血管。在胚胎第4天侵入神经外胚层的毛细血管芽在缺乏层粘连蛋白的富含纤维连接蛋白的基质中迁移。超微结构免疫定位显示纤维连接蛋白仅存在于内皮细胞的腔内部位。从第6天开始，层粘连蛋白与纤维连接蛋白在脑毛细血管中共分布。我们得出结论，未成熟的毛细血管在富含纤维连接蛋白的细胞外基质中迁移和增殖，随后被重塑获得基底膜样特征。我们认为层粘连蛋白的表达是血管成熟的早期迹象。
We have previously characterized monoclonal antibodies against chick brain cells. One of them (14-2B2) brightly stained all capillaries in frozen sections of chick brain. Here we show that this antibody is directed against chick fibronectin. Using this antibody and polyclonal antibodies against laminin, we have studied the development of the vascular extracellular matrix. Vasculogenesis, the development of capillaries from in situ differentiating endothelial cells, was studied in yolk sac blood islands and intraembryonic dorsal aorta. Blood islands produced high levels of fibronectin but not laminin. Early intraembryonic capillaries all expressed fibronectin but little if any laminin. The dorsal aorta of a 6-day-old chick embryo has several layers of fibronectin-producing cells, but is devoid of laminin. Laminin expression commenced at Day 8 and by Day 10 an adult-like distribution was found in the aortic vascular wall. Angiogenesis, the formation of capillaries from preexisting vessels, was studied during brain development. Capillary sprouts invading the neuroectoderm at Embryonic Day 4 migrated in a fibronectin-rich matrix devoid of laminin. Ultrastructural immunolocalization demonstrated the presence of fibronectin exclusively on the abluminal site of the endothelial cells. Beginning on Day 6, laminin codistributed with fibronectin in brain capillaries. We conclude that immature capillaries migrate and proliferate in a fibronectin-rich extracellular matrix, which is subsequently remodeled acquiring basement membrane-like characteristics. We suggest that laminin expression is an early indication of vascular maturation.