Expression of epidermal growth factor and surfactant proteins during postnatal and compensatory lung growth.
We examined whether lung growth after pneumonectomy (PNX) invokes normal signaling pathways of postnatal development. We qualitatively and quantitatively assessed the immunoexpression of epidermal growth factor (EGF), its receptor (EGFR), surfactant proteins (SP) [SP-A and -D and surfactant proproteins (proSP)-B and -C] and proliferating cell nuclear antigen (PCNA) in immature and mature dog lung. We also assayed these proteins in lungs of immature dogs 3 wk or 10 mo after they underwent right PNX compared with simultaneous matched sham controls. During maturation, alveolar cell proliferation is regionally regulated in parallel with EGF and EGFR levels and inversely correlated with SP-A and proSP-C levels. In contrast, post-PNX lung growth is not associated with EGF or EGFR upregulation but with markedly increased SP-A level and moderately increased SP-D level; proSP-B and proSP-C levels did not change. We conclude that 1) signaling of EGF axis and differential regulation of SPs persist during postnatal lung development, 2) post-PNX lung growth is not a simple recapitulation of maturational responses, and 3) SP-A and SP-D may modulate post-PNX lung growth.
Foster
David J
DJ
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9034, USA.
Yan
Xiao
X
Bellotto
Dennis J
DJ
Moe
Orson W
OW
Hagler
Herbert K
HK
Estrera
Aaron S
AS
Hsia
Connie C W
CC
D000375:Aging; D000818:Animals; D004285:Dogs; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D008168:Lung / Q000166:cytology / Q000254:growth & development*; D011013:Pneumonectomy; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011498:Protein Precursors / Q000378:metabolism; D011510:Proteolipids / Q000378:metabolism; D037662:Pulmonary Surfactant-Associated Protein A / Q000378:metabolism*; D037663:Pulmonary Surfactant-Associated Protein D / Q000378:metabolism*; D012038:Regeneration
D018809:Proliferating Cell Nuclear Antigen; D011498:Protein Precursors; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; C105511:surfactant protein B propeptide; D004815:Epidermal Growth Factor; D066246:ErbB Receptors