Aim of our study was to provide insight into the temporal and spatial expression of FGFR1, FGFR2 and CTGF during normal human lung development which may have an important impact on understanding occurrence of developmental lung anomalies. Morphological parameters were analysed using double immunofluorescence on human embryonal (6th and 7th developmental week-dw) and foetal (8th, 9th and 16th developmental week) human lung samples.

FGFR1 and FGFR2 was positive during all the dw in both the epithelium and mesenchyme. The highest number of FGFR1 positive cells was observed during the 6th dw (112/mm²) and 9th dw (87/mm²) in the epithelium compared to the 7th, 8th and 16th dw (Kruskal-Wallis test, p < 0.001, p < 0.0001). The highest number of FGFR1 positive cells in the mesenchyme was observed during the 8th dw (19/mm²) and 16th dw (13/mm²) compared to the 6th, 7th, and 9th dw (Kruskal-Wallis test, p < 0.001, p < 0.0001). The number of FGFR1 positive cells in the epithelium was higher for FGFR2 compared to number of positive cells (Mann-Whitney test, p < 0.0001). FGFR2 showed the highest number in the epithelium during the 7th dw (111/mm²) and 9th dw (87/mm²) compared to 6th, 8th and 16th dw (Kruskal-Wallis test, p < 0.001, p < 0.0001, p < 0.01 respectively). The highest number of FGFR2 positive cells in the mesenchyme was observed during the 9th dw (26/mm²), compared to the 6th, 7th,8th and 16th dw (Kruskal-Wallis test, p < 0.0001), while the number of FGFR2 positive cells in the epithelium was significantly higher than in the mesenchyme (Mann-Whitney test, p < 0.0001). CTGF was negative in both epithelium and mesenchyme during all except the 16th dw in the mesenchyme where it co-localized with FGFR2.

FGFR1 and FGFR2 might be essential for epithelial-mesenchymal interactions that determine epithelial branching and mesenchymal growth during early lung development. Sudden increase in FGF1 in the epithelium and FGF2 in the mesenchyme in the foetus at 9th dw could be associated with the onset of foetal breathing movements. CTGF first appear during the foetal lung development.

我们研究的目的是深入了解正常人肺发育过程中 FGFR1、FGFR2 和 CTGF 的时空表达，这可能对了解发育性肺异常的发生有重要影响。使用双重免疫荧光对人胚胎（第 6 和第 7 发育周-dw）和胎儿（第 8、第 9 和第 16 发育周）人肺样品进行形态学参数分析。

FGFR1和FGFR2在上皮和间充质的所有dw期间均为阳性。^{与第 7 天、第 8 天和第 16 天相比，在第 6 天 (112/mm 2} ) 和第 9 天 (87/mm ² )期间，上皮中的 FGFR1 阳性细胞数量最多（Kruskal-Wallis 检验，p < 0.001， p < 0.0001)。与第 6、7 和 9 dw 相比，在第8 dw (19/mm ² ) 和第 16 dw (13/mm ² )期间观察到间充质中 FGFR1 阳性细胞的数量最多（Kruskal-Wallis 检验，p < 0.001 , p < 0.0001)。与阳性细胞数相比，FGFR2 上皮中 FGFR1 阳性细胞的数量更高（Mann-Whitney 检验，p < 0.0001）。FGFR2 在第 7 天（111/mm ²) 和第 9 dw (87/mm ² ) 与第 6、8 和 16 dw 相比（Kruskal-Wallis 检验，分别为 p < 0.001、p < 0.0001、p < 0.01）。与第 6、7、8和 16 天（Kruskal-Wallis 检验，p < 0.0001）相比，在第9 天（26/mm ² ）观察到间充质中 FGFR2 阳性细胞的数量最多，而 FGFR2 的数量上皮中的阳性细胞显着高于间充质（Mann-Whitney 检验，p < 0.0001）。除了与 FGFR2 共定位的间质中的第 16 天外，CTGF 在上皮和间充质中均为阴性。

FGFR1 和 FGFR2 可能对决定早期肺发育过程中上皮分支和间充质生长的上皮间充质相互作用至关重要。胎儿第 9 天时上皮细胞中 FGF1 和间充质中 FGF2 的突然增加可能与胎儿呼吸运动的开始有关。CTGF首先出现在胎儿肺发育过程中。