Vascular endothelial growth factor gene expression in human fetal lung in vitro
Vascular endothelial growth factor gene expression in human fetal lung in vitro
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DOI：
10.1165/ajrcmb.20.1.3251
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发表时间：
1999-01-01
影响因子：
6.4
通讯作者：
Snyder, JM
中科院分区：
文献类型：
--
作者：
Acarregui, MJ;Penisten, ST;Snyder, JM
新生儿的呼吸功能取决于发育良好的肺毛细血管床。血管内皮生长因子（VEGF）是内皮细胞生长和血管生成的有效诱导剂。在发育中的肺中检测到高水平的 VEGF 蛋白和信使 RNA (mRNA)，表明 VEGF 在肺毛细血管床的发育中发挥作用。为了开始了解 VEGF 在人肺发育中的作用，我们探索了 VEGF 基因表达的调节以及 VEGF 蛋白和 mRNA 在发育中的人肺模型中的定位。在妊娠中期人胎儿肺组织中检测到 VEGF 蛋白和 mRNA，其水平随着外植体培养时间的延长而增加。与 20% O-2 环境相比，在 2% O-2 环境中维持人胎肺外植体可增加 VEGF 蛋白和 mRNA。研究发现，在 20% O-2 中培养的外植体中，环磷酸腺苷 (cAMP) 会增加 VEGF mRNA 水平，但在 2% O-2 中培养的外植体中，VEGF mRNA 水平不会增加。 VEGF 蛋白的免疫染色显示其主要定位于妊娠中期人胎儿肺组织的气道上皮细胞中。 VEGF 的免疫染色随着人胎肺外植体在 2% 和 20% O-2 中的孵育而增加。有趣的是，在 20% O-2 中孵育 4 天后，VEGF 蛋白主要定位于气道上皮细胞下方的基底膜中。在二丁酰 cAMP 存在的情况下孵育组织会导致 VEGF 免疫染色增加，主要是在 20% O-2 处理的组织中的前肺泡管基底膜中。原位杂交研究表明 VEGF mRNA 存在于间充质细胞和气道上皮细胞中。这些数据表明，在发育中的人肺中，VEGF 基因表达受到氧和 cAMP 的调节。远端气道上皮细胞中VEGF mRNA和蛋白的检测以及气道上皮细胞下方基底膜中VEGF蛋白的检测表明VEGF蛋白在上皮中合成后发生易位。 VEGF 定位于气道上皮细胞的基底膜，对于指导人肺毛细血管的发育可能很重要。
Neonatal respiratory function depends on the development of a well-formed pulmonary capillary bed. Vascular endothelial growth factor (VEGF) is a potent inducer of endothelial cell growth and angiogenesis. High levels of VEGF protein and messenger RNA (mRNA) have been detected in the developing lung, suggesting that VEGF plays a role in the development of the pulmonary capillary bed. To begin to understand the role of VEGF in human lung development, we explored the regulation of VEGF gene expression and the localization of VEGF protein and mRNA in a model of the developing human lung. VEGF protein and mRNA were detected in midtrimester human fetal lung tissue, and their levels increased with time in explant culture. VEGF protein and mRNA were increased by the maintenance of human fetal lung explants in 2% O-2 environments compared with 20% O-2 environments. VEGF mRNA levels were found to be increased by cyclic adenosine monophosphate (cAMP) in explants that were incubated in 20% O-2, but not in those incubated in 2% O-2. Immunostaining for VEGF protein demonstrated localization primarily in airway epithelial cells in midtrimester human fetal lung tissue. Immunostaining for VEGF increased with incubation of human fetal lung explants in 2% and 20% O-2. Interestingly, VEGF protein was localized primarily in the basement membrane subjacent to airway epithelial cells after 4 d of incubation in 20% O-2. Incubation of tissues in the presence of dibutyryl cAMP resulted in an increase in immunostaining for VEGF, primarily in the basement membranes of prealveolar ducts in 20% O-2-treated tissues. In Situ hybridization studies indicated that VEGF mRNA was present in both mesenchymal cells and airway epithelial cells. These data suggest that VEGF gene expression is regulated by both oxygen and cAMP in the developing human lung. The detection of VEGF mRNA and protein in distal airway epithelial cells and the detection of VEGF protein in the basement membrane subjacent to the airway epithelial cells suggest that translocation of VEGF protein occurs after its synthesis in the epithelium. Localization of VEGF to the basement membrane of airway epithelial cells may be important for directing capillary development in the human lung.