Table 2.
Composition of interalveolar septa.
| Group | 2 Weeks | 8 Weeks | 12 Weeks | Two-Way ANOVA | |||||
|---|---|---|---|---|---|---|---|---|---|
| Parameter | ctrl | Nedd4-2 −/− | ctrl | Nedd4-2 −/− | ctrl | Nedd4-2 −/− | G | T | Inter |
| V(AE1,sep) mm³ | 30.88 (5.96) | 30.43 (4.02) | 31.16 (2.89) | 33.93 (3.15) | 35.40 (4.92) | 24.73 (6.24) | n.s. | 0.004 | n.s. |
| V(AE2,sep) mm³ | 14.07 (0.98) | 12.85 (4.71) | 14.19 (3.60) | 15.29 (6.74) | 13.75 (1.62) | 29.64 (15.59) | n.s. | 0.014 | 0.020 |
| V(Endo,sep) mm³ | 36.78 (10.80) | 34.80 (6.63) | 34.50 (4.83) | 46.72 (3.35) | 42.61 (10.07) | 35.88 (8.54) | n.s. | 0.016 | n.s. |
| V(capl,sep) mm³ | 21.49 (2.50) | 23.05 (5.61) | 20.72 (3.92) | 24.18 (5.21) | 35.42 (5.74) | 26.94 (6.98) | n.s. | 0.018 | <0.001 |
| V(recm,sep) mm³ | 5.81 (1.84) | 6.89 (2.10) | 6.75 (2.15) | 7.46 (1.53) | 5.33 (1.70) | 9.30 (6.43) | n.s. | n.s. | n.s. |
| V(col,sep) mm³ | 3.68 (1.64) | 4.13 (1.42) | 4.10 (0.98) | 5.57 (1.59) | 4.76 (0.60) | 19.33 (16.56) | <0.001 | <0.001 | 0.004 |
| V(IC,sep) mm³ | 15.29 (5.14) | 12.78 (2.67) | 22.58 (4.42) | 25.67 (3.11) | 21.35 (5.44) | 70.19 (30.47) | <0.001 | <0.001 | <0.001 |
| V(LB,sep) mm³ | 2.65 (0.57) | 2.27 (1.14) | 2.52 (0.84) | 2.63 (1.45) | 2.40 (0.63) | 5.97 (2.92) | 0.034 | 0.013 | 0.005 |
| νV(LB) µm3 | 0.35 (0.16) | 0.36 (0.20) | 0.20 (0.03) | 0.17 (0.04) | 0.22 (0.07) | 0.51 (0.20) | n.s. | 0.004 | 0.018 |
| S(epi_air,sep) cm² | 1322 (181) | 1305 (205) | 1386 (210) | 1622 (150) | 2232 (191) | 1518 (501) | <0.001 | n.s. | <0.001 |
| τ(bg) µm | 0.48 (0.04) | 0.46 (0.05) | 0.48 (0.05) | 0.48 (0.05) | 0.83 (0.10) | 1.29 (0.41) | 0.0027 | <0.001 | 0.002 |
Summarized electron microscopic data are provided as mean (standard deviation). Parameters are defined in the text and in the methods section. Statistical analysis was based on a two-way ANOVA taking the factors genetics (G: ctrl vs. Nedd4-2−/−) and time (T: weeks) as well as the interaction (Inter) of these factors into account. p-values below 0.05 were considered as statistically significant. Abbreviations: V: volume; νV: volume-weighted mean volume; S: surface area; τ: arithmetic mean thickness; AE1: alveolar epithelial type I cell; AE2: alveolar epithelial type II cell; Endo: endothelium; recm: residual extracellular matrix; col: collagen fibrils; IC: interstitial cell; LB: lamellar body; epi_air: epithelium covered by air; bg: blood–gas barrier; sep: interalveolar septa.