Fibroblast growth factor receptor-1 and neonatal compensatory lung growth after exposure to 95% oxygen.
Neonatal rats exposed to 95% oxygen (O2) for 7 days from birth had inhibited lung growth, DNA synthesis, and secondary septation. These parameters were rapidly restored by a period of recovery in air. Northern and Western blot analysis and immunohistochemistry were used to screen for the fibroblast growth factor receptor-1 (FGF-R1) and its high affinity ligand, basic fibroblast growth factor (bFGF), which could have a role in this recovery process. Expression of bFGF in the lung was significantly reduced at the end of the 7-day exposure to 95% O2 and was increased after 3 days of recovery in air. Expression of FGF-R1 was not affected by exposure to 95% O2 or recovery in air. We hypothesized that the increase in bFGF after removal from 95% O2, acting through the FGF-R1, would be critical for compensatory growth. Intraperitoneal injection of soluble truncated FGF-R1 at the onset of the recovery phase arrested compensatory lung DNA synthesis and secondary septation seen in control animals after 3 days of recovery, confirming a role for FGF-R1 in this model of compensatory neonatal lung growth.
Jankov
Robert P
RP
Division of Neonatology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8 Canada.
Luo
Xiaoping
X
Campbell
Ann
A
Belcastro
Rosetta
R
Cabacungan
Judy
J
Johnstone
Leslie
L
Frndova
Helena
H
Lye
Stephen J
SJ
Tanswell
A Keith
AK
D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern; D015153:Blotting, Western; D001997:Bronchopulmonary Dysplasia / Q000209:etiology; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D008168:Lung / Q000254:growth & development*; D010100:Oxygen; D051381:Rats; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism / Q000502:physiology*; D015854:Up-Regulation
D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; D010100:Oxygen