The effect of tracheal occlusion in congenital diaphragmatic hernia in the nitrofen rat lung explant model

Purpose: Here, we establish a tracheal occlusion (TO) model with rat lung explants in nitrofen-induced pulmonary hypoplasia in congenital diaphragmatic hernia (CDH). Methods: : We extracted lungs from rats on embryonic day 18. We mimicked TO in the lung explants by tying the trachea. We assessed lung weight, morphometry, and abundance of Ki-67, Active caspase-3, and Prosurfactant Protein C (proSP-C) with immunofluorescence. Results: : Lung weight was higher in TO+ than TO– on day 1. Abundance of Ki-67 was higher in TO+ than TO– (0.15 vs. 0.32, p =0.009 for day 1, 0.07 vs. 0.17, p =0.004 for day 2, 0.07 vs. 0.12, p =0.044 for day 3), and Active caspase-3 was higher in TO+ than TO– on day 2 and day 3 (0.04 vs. 0.03 p =0.669 for day 1, 0.03 vs. 0.13 p <0.001 for day 2, 0.04 vs. 0.17 p =0.008 for day3). However, proSP-C protein abundance was lower in TO+ than TO– (67.9 vs. 59.1 p =0.033 for day 1, 73.5 vs. 51.6 p =0.038 for day 2, 83.1 vs. 56.4 p =0.009 for day 3). Conclusions: : The TO model in lung explants mimics the outcomes of current surgical models of TO and further studies can reveal the cellular and molecular effects of TO in CDH lungs.