Tracheal ligation increases cell proliferation but decreases surfactant protein in fetal murine lungs in vitro

Gene expression analysis after prenatal tracheal ligation in fetal rat as a model of stimulated lung growth

“…Tracheal occlusion or ligation in rats increases lung volume, surface area, parenchyma volume, total saccular number as well as radial saccular count without an increase in airway branching, as we could see in our and other studies [4,5,14]. Similar effects have been observed after TL in rabbits and mice [15][16][17][18][19][20]. Although fetal TL accelerates lung growth in experimental animals, with or without congenital diaphragmatic hernia (CDH), it has failed to show a benefit when it has been performed in human fetuses with CDH, compared with expert postnatal treatment [21] in prospective randomized studies [21].…”

“…However, contradictory reports about thyroid transcription factor 1 and surfactant expression after TL have been published [18,19,[25][26][27]. In our study, CTGF is the growth factor that exhibits the most striking and robust increase after TL.…”

Tracheal occlusion increases the rate of epithelial branching of embryonic mouse lung via the FGF10-FGFR2b-Sprouty2 pathway

“…Several studies showed that the occlusion of the embryonic trachea increases lung internal pressure by approximately twofold, leading to an acceleration of lung growth and branching morphogenesis, while conversely drainage of this fluid decreases lung growth and development in the fetal sheep lung (Alcorn et al, 1977;Blewett et al, 1996;Moessinger et al, 1990). This effect has also been shown in murine whole-organ culture (Bullard et al, 1997), where an impact on developmental gene expression such as Parathyroid Hormone (Pth) has also been reported (Cilley et al, 2000).…”

Tracheal occlusion in fetal rats alters expression of mesenchymal nuclear transcription factors without affecting surfactant protein expression

“…This has been confirmed by studies in normal fetuses and fetuses with lung hypoplasia in a variety of species [3,[16][17][18][19]34 ]. It has been sugges ted that TO leads to a severe surfactant deficiency by 2 mechanisms: (1) stretchedinduced inhibition of the differentiation of undifferentiated epithelial cells into AE2 cells and (2) accelerated stimulation of the differentiation of AE2 cells into type 1 pneumocytes [18,35 ,36].…”