Programmed cell death contributes to postnatal lung development

Schittny, Johannes C.; Djonov, Valentin; Fine, Alan; Burri, Peter H. (1998). Programmed cell death contributes to postnatal lung development. American journal of respiratory cell and molecular biology, 18(6), pp. 786-793. American Lung Association 10.1165/ajrcmb.18.6.3031

Preview

Text ajrcmb%2E18%2E6%2E3031.pdf - Published Version Available under License Publisher holds Copyright. Sherpa/Romeo: Publisher's version/PDF may be used in institutional repository only Download (440kB) | Preview

The rat lung undergoes the phase of maturation of the alveolar septa and of the parenchymal microvascular network mainly during the third postnatal week. Speculating that programmed cell death may contribute to the thinning of the alveolar septa, we searched for the presence of DNA fragmentation in rat lungs between postnatal days 6 and 36 using the TUNEL procedure. The number of positive nuclei was compared at different days. We observed an 8-fold increase of programmed cell death toward the end of the third week as compared to the days before and after this time point. The precise timing of the appearance of the peak depended on the size of the litter. Double-labeling for DNA fragmentation (TUNEL) and for type I and type II epithelial cells (antibodies E11 and MNF-116), as well as morphologic studies at electron microscopic level, revealed that during the peak of programmed cell death mainly fibroblasts and type II epithelial cells were dying. While both dying cell types were TUNEL-positive, nuclear fragments and apoptotic bodies were exclusively observed in the dying fibroblasts. We conclude that programmed cell death is involved in the structural maturation of the lung by reducing the number of fibroblasts and type II epithelial cells in the third postnatal week. We observed that the dying fibroblasts are cleared by neighboring fibroblasts in a later stage of apoptosis, and we hypothesize that type II epithelial cells are cleared by alveolar macrophages in early stages of the programmed cell death process.

Interest & Impact

Downloads

500 since deposited on 25 Aug 2014
42 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item