Expression analysis of platelet-derived growth factor receptor alpha and its ligands in the developing mouse lung.

Activation of the platelet-derived growth factor receptor- (PDGFR) signaling pathway is critically important during lung alveogenesis, the process in lung development during which alveoli are formed from the terminal alveolar sacs. Several studies have aimed to characterize the expression patterns of PDGFR and its two ligands (PDGF-A and -C) in the lung, but published analyses have been limited to embryonic and/or perinatal time points, and no attempts have been made to characterize both receptor and ligand expression simultaneously. In this study, we present a detailed map of the expression patterns of PDGFR, PDGF-A and PDGF-C during the entire period of lung development, that is, from early embryogenesis until adulthood. Three different reporter mice were analyzed ( , , and ), in which either or were expressed under the respective promoter in gene-targeted alleles. A spatiotemporal dynamic expression was identified for both ligands and receptor. PDGF-A and PDGF-C were located to distinct populations of epithelial and smooth muscle cells, whereas PDGFR expression was located to different mesenchymal cell populations. The detailed characterization of gene expression provides a comprehensive map of PDGFR signaling in lung cells, opening up for a better understanding of the role of PDGF signaling during lung development.