【摘要】 目的通过观察血管内皮生长因子A(VEGFA)、血管内皮生长因子C(VEGFC)及其受体flt-1、flk-1、flt-4在人胚胎肝发育过程中的表达,了解血管内皮细胞和造血细胞与人胚胎肝干细胞发育的关系。方法运用E3~12周胚胎,石蜡切片,免疫组织化学染色,光镜下观察人肝干细胞的发育、与血管内皮细胞和造血细胞的关系及其表达VEGFA、VEGFC等生长因子及其受体的情况。结果E3~5周人胚肝细胞具有幼稚细胞的形态特点,并呈c-Met阳性反应。E10~12周,c-Met阳性的肝干细胞主要分布于汇管区周围。E4~6周胚,少数肝干细胞呈VEGFA免疫反应阳性,E7周以后阳性反应消失。VEGFC、flt-1、flk-1、flt-4阳性肝细胞在4~12周胚胎肝内都可检测到。E4~6周,靠近肝芽的横隔间充质中可见较多的血管内皮细胞,并正在形成血管,而在远离肝芽处的内皮细胞和毛细血管较少。E4、5周时,靠近原始肝的横隔间充质组织中血管内皮细胞呈VEGFA、VEGFC、flt-1、flk-1和flt-4阳性,肝内的血管内皮细胞为VEGFA、flt-1、flk-1、VEGFC和flt-4免疫反应阴性。E4~12周胚胎,造血细胞呈VEGFA和flt-4阳性反应,而VEGFC和flt-1、flk-1免疫反应阴性。结论肝干细胞的发育受肝外间充质血管产生的VEGFA、VEGFC的诱导和调节。造血细胞分泌的VEGFA可以通过旁分泌途径调节肝干细胞的发育,而造血细胞的发育依赖于肝干细胞产生的VEGFC。更多还原

【Abstract】 Objective To understand the reciprocity of hepatic stem cells and endothelial cells, hematopoietic cells, we observed the expression of VEGFA, VEGFC and their receptors flt-1、 flk-1、 flt-4 during the early liver development. Methods A series of 5?μm sections were made from 47 cases of human embryos aged 3-12 weeks. The hematoxylin-eosin and immunohistochemistry stains were performed. The development of endothelial cells and hematopoietic cells, the expression of c-Met and CD34, VEGFA, VEGFC and their receptors, flt-1, flk-1, flt-4, were studied. Results The formation, proliferation and differentiation of hepatic stem cells have a close relationship with hematopoietic cells and endothelial cells inside or outside of liver. The hepatocytes of E3-5 weeks displayed the typical characteristic of immature cells:small in size, round or ovoid nuclei with dark color, scant cytoplasm with slight blue and a high ratio of nuclei/cytoplasm. They were positive for c-Met. At E10-12weeks, the c-Met positive cells mainly located at the periportal region. VEGFA was expressed by a few hepatocytes of E4-6weeks, and the expression disappeared after E7 weeks. At E4-12weeks, VEGFC, flt-1, flk-1, flt-4 were expressed by hepatocytes. Hematopoietic cells were positive for VEGFA and flt-4, and negative for VEGFC, flt-1, flk-1. Endothelial cells inside liver were negative for VEGFA and their receptor flt-1, flk-1, VEGFC and its receptor flt-4. VEGFA and VEGFC were expressed by the endothelial cells in STM adjacent liver at E4-5weeks.Conclusion Our results suggest the following conclusions: the development of hepatic stem cells was affected by endothelial cells of STM and the endothelial cells of liver sinusoids were induced by the hepatic stem cells. VEGFA secreted by hematopoietic cells could regulate the development of hepatic stem cells by para-secretion. Meanwhile, the development of hematopoietic cells is depended on the VEGFC produced by hematopoietic cells.更多还原