AJP - Lung Cellular and Molecular Physiology, Vol 268, Issue 2 309-L320, Copyright © 1995 by American Physiological Society
Ontogeny of type I procollagen expression during human fetal lung development
R. M. Davila, D. deMello and E. C. Crouch
Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110.
The cellular sites of type I procollagen (PCI) production were investigated
during fetal and early postnatal human lung development. PCI-synthesizing
cells and sites of recent collagen deposition were visualized by
immunoperoxidase staining of lung tissue with monoclonal antibodies to
human PCI. In selected cases, serial sections were also examined by in situ
hybridization to establish the cellular sites of PCI gene expression and
mRNA accumulation. PCI cytoplasmic immunostaining generally correlated with
sites of mRNA accumulation and with known sites of interstitial collagen
deposition, including the adventitial and muscular layers of large blood
vessels, submesothelial and peribronchial connective tissue, perichondrium,
and interstitial matrix. However, we also observed developmental changes in
relative PCI expression for each of these compartments, heterogeneity in
the level of PCI expression by cells within individual anatomic
subcompartments, and variations in the level of PCI expression along the
length of pulmonary blood vessels and airways. These studies emphasize the
complexity of developmentally regulated alterations in procollagen
production during lung development.
