Adamson I Y, Bakowska J, McMillan E, King G M
Department of Pathology, University of Manitoba, Winnipeg, Canada.
In Vitro Cell Dev Biol. 1990 Aug;26(8):784-90. doi: 10.1007/BF02623620.
The role of epithelial-mesenchymal interactions in the stimulation of lung development by estrogen is now investigated using organ cultures of lung from male and female fetal rats taken from Days 17 to 21 of gestation. Estradiol at 1 microgram/ml was found to reduce cell proliferation in explants taken during a rapid growth phase (Day 18) and to stimulate surfactant synthesis in both males and females only in Day 20 explants when cell division is much slower. At this time more epithelial cells from estrogen-treated explants contained lamellar bodies, which were also secreted to fill the air sacs. These cultures also showed a significant increase in the frequency of cell-to-cell contacts between epithelial cells and fibroblasts. Uptake of tritiated estradiol by explants increased from Day 18 onward, and by autoradiography, labeling was located predominantly over fibroblasts. Using pure cultures of fetal and adult cells, uptake of labeled estradiol was significantly higher in fibroblasts than in corresponding epithelial cells, and estradiol did not directly enhance palmitate incorporation into epithelial cells. The results suggest that the earlier maturation and increased surfactant synthesis in female fetal lung is related at least in part to enhanced binding of estrogen by the fibroblast with subsequent transfer of a maturation factor to the fetal epithelium.
现在，利用取自妊娠第17至21天的雄性和雌性胎鼠的肺器官培养物，研究了上皮 - 间充质相互作用在雌激素刺激肺发育中的作用。发现1微克/毫升的雌二醇可减少快速生长阶段（第18天）取出的外植体中的细胞增殖，并且仅在细胞分裂慢得多的第20天的外植体中刺激雄性和雌性的表面活性剂合成。此时，来自雌激素处理的外植体的更多上皮细胞含有板层小体，这些板层小体也被分泌以填充气囊。这些培养物还显示上皮细胞与成纤维细胞之间细胞间接触的频率显著增加。从第18天起，外植体对氚标记雌二醇的摄取增加，通过放射自显影，标记主要位于成纤维细胞上。使用胎儿和成年细胞的纯培养物，成纤维细胞对标记雌二醇的摄取显著高于相应的上皮细胞，并且雌二醇不会直接增强上皮细胞中棕榈酸的掺入。结果表明，雌性胎儿肺中较早的成熟和表面活性剂合成增加至少部分与成纤维细胞对雌激素的结合增强有关，随后成熟因子转移至胎儿上皮。
