VEGFA、VEGFC及其受体和angiopoietin-1/angiopoietin-2及其受体在人胚胎卵黄囊血岛、AGM区的表达

本研究观察VEGFA、VEGFC及其受体和angiopoietin-1、angiopoietin-2及其受体在发育第3-12周人胚胎卵黄囊血岛、主动脉-生殖腺-中肾(AGM)区的表达。在征得意外流产孕妇同意并签字后，收集其意外流产的受精龄第3-12周的人胚胎，用4％多聚甲醛固定，石蜡包埋切片，HE和免疫组织化学染色，光镜观察。结果表明：第21-25天人胚卵黄囊血岛血管内皮细胞和造血细胞强表达VEGFA及其受体flt1和flk-1，VEGFC及其受体fit4，anglopomtin-2及其受体Tie-2蛋白；弱表达angiopoietin-1蛋白。背主动脉和中肾于发育第4周开始表达上述各种因子及其受体，免疫阳性反应物集中在大而圆、有核的造血细胞。阳性细胞的数量到第7周到达高峰。8周以后，阳性细胞数量显著减少，到12周几乎所有的血细胞为免疫阴性反应。生殖腺主要在第6—8周表达VEGFA，flt1，flt4，angiopoietin-1，angiopoietin-2和Tie-2蛋白，但不表达VEGFC和flk-1。在AGM区的血管内皮细胞未检测到上述各因子的表达。结论：人胚胎卵黄囊血岛造血细胞和内皮细胞以及背主动脉和中肾共表达多种与血管发生和血液发生相关的因子。人胚内造血发生于第4周。

Expression of VEGFA,VEGFC,Angiopoietin-1,Angiopoietin-2 and Their Receptors on Yolk Sac Blood Island,Aorta-Gonad-Mesonephros(AGM)Region of Human Embryo

The study was to investigate the expression of VEGFA, VEGFC, angiopoietin-1, angiopoietin-2 and their receptors on yolk sac blood island, AGM region during gestation of 3th-12th weeks of human embryo. Human embryo contingently aborted at 3 - 12 weeks of gestation were collected with signed agreements of the pregnant women suffered from accidental abortions. The specimens were fixed by 4% paraformaldehyde and embedded by paraffin. 5 micro m serial sections were made. HE and immunohistochemistry method (SABC) and light-microscope were employed. The results showed that VEGFA and its receptors flt1/flk-1, VEGFC and its receptor flt-4, angiopoietin-2 and its receptor tie-2 proteins were expressed strongly and angiopoietin-1 was weakly expressed by hematopoietic cells and vascular endothelial cells of blood island at 21 and 25 days of gestation. In the 4th week of gestation, immuno-positive reaction of these factors and their receptors appeared in the aorta and mesonephros deposited in larger, rounded and nucleated cells which represented hematopoietic cells. Up to 7th week, positive hematopoietic cells in the regions were much abundant. The number of positive cells decreased at 8th week. Up to 12th week, almost all blood cells were immuno-negative. VEGFA, flt-1, flt-4, angiopoietin-1, angiopoietin-2 and Tie-2 protein were expressed mainly by gonad at 6 - 8 weeks, but it did not express VEGFC and flk-1. The immuno-reaction of the factors and their receptors could not detected in vascular endothelial cells during 3-12th weeks of gestation. It is concluded that hematopoietic cells and endothelial cells in blood island of yolk sac, mesonephros and dorsal aorta co-expressed some factors and their receptors in relation to vasculogenesis and hematopoiesis. Intraembryonic hematopoiesis began in the 4th week of gestation.