Effect of nitric oxide on fibroblast growth factor-10 and bone morphogenetic protein 4 expressions in the branching morphogenesis of fetal rat lung explants.
OBJECTIVE
Nitric oxide (NO) can accelerate branching morphogenesis of fetal rat lung explants in vitro, whereas its exact mechanism remains unclear. In this study, we investigate the effect of NO on the expression of fibroblast growth factor-10 (FGF10) and bone morphogenetic protein-4 (BMP4), which plays an important role in bud formation.


METHODS
Fetal rat lungs harvested on day 13.5 of gestation were cultured in serum-free medium for 72 hours with 0, 50, 100, and 200 micromol/L of an NO donor, DETA NONOate (DETA/NO) (n = 4, 3, 6, and 5). The ratio of bud increment of each cultured lung was calculated, and the FGF10 and BMP4 mRNA expression levels were analyzed by real-time reverse transcription polymerase chain reaction.


RESULTS
Bud increment ratio was significantly increased in 50, 100, and 200 micromol/L DETA/NO (3.3 +/- 0.2, 3.0 +/- 0.3, and 3.5 +/- 0.5) compared to controls (1.9 +/- 0.3) (P < .05). There was a significant increase in BMP4 mRNA expression in 100 micromol/L DETA/NO (190% +/- 20%) compared to controls (100% +/- 30%) (P < .05), whereas FGF10 mRNA expression was not significantly different between each DETA/NO group and controls.


CONCLUSIONS
The NO donor not only promotes branching of fetal lung explants but also upregulates expression of BMP4, which is an important regulator of branching morphogenesis.
Shinkai
Masato
M
Children's Research Centre, Our Lady's Hospital for Sick Children, University College Dublin, Dublin 12, Ireland.
Shinkai
Toko
T
Pirker
Martina A
MA
Montedonico
Sandra
S
Puri
Prem
P
D000818:Animals; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005333:Fetus; D051526:Fibroblast Growth Factor 10 / Q000378:metabolism*; D008168:Lung / Q000187:drug effects / Q000196:embryology*; D008970:Molecular Weight; D009024:Morphogenesis / Q000187:drug effects; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009603:Nitroso Compounds / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
C525811:Bmp4 protein, rat; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D051526:Fibroblast Growth Factor 10; D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; D012333:RNA, Messenger; C094210:2,2'-(hydroxynitrosohydrazono)bis-ethanamine