Growth factors gene expression in the developing lung.
OBJECTIVE
This is the first systematic study using quantitative real-time PCR to analyze and compare the expression profiles for critical members of the epidermal growth factor (EGF), transforming growth factor beta (TGFbeta), and vascular endothelial growth factor (VEGF) families in developing rat lungs.


METHODS
mRNA expression was quantified at embryonic (E) day 15, 17, 19, 21, and postnatal age 1 day, 2 weeks, 12 weeks.


RESULTS
EGF and EGFR increased during gestation and development, then decreased in adulthood, whereas TGFalpha was highest at birth and remained unchanged afterwards. All TGFbeta isoforms increased slightly during pregnancy, reached highest expression during development, and returned to neonatal levels in adulthood. TGFbetaRI and TGFbetaRII patterns were similar to TGFbeta2 and TGFbeta1 respectively, whereas TGFbetaRIII expression was lowest at the postnatal time points. VEGF(164) and VEGF(120) showed a steady increase up to 2 weeks and declined at 12 weeks, whereas highest VEGF(188) expression occurred at 12 weeks. VEGF-A receptors expression paralleled the summation of all three isoforms, increasing steadily with age.


CONCLUSIONS
Expression of growth factors in the developing lung is characterized by highly regulated distinctive patterns that may be critical to understand the early origin and progression of pulmonary diseases in childhood as well as in adulthood. Quantitative real-time PCR analysis revealed several differences compared to previously reported expression patterns defined with older methodologies.
Mager
Edward M
EM
Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA.
Renzetti
Gabriele
G
Auais
Alexander
A
Piedimonte
Giovanni
G
D000818:Animals; D000831:Animals, Newborn; D004815:Epidermal Growth Factor / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D020022:Genetic Predisposition to Disease; D008168:Lung / Q000196:embryology* / Q000502:physiology*; D008171:Lung Diseases / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods; D051381:Rats; D011916:Rats, Inbred F344; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D004815:Epidermal Growth Factor