Changes in Expression of Platelet-Derived Growth Factor and Its Receptors in the Lungs of Newborn Rats Exposed to Air or 60% O2

Article · October 2000with119 Reads
DOI: 10.1203/00006450-200010000-00003
Abstract
PDGF-related gene expression has been well characterized during fetal rat lung development and adult rat lung injury, but not during normal postnatal lung growth or injury. Lung expression of the mRNA for PDGF-A, -B, -αR, and -βR and immunoreactive PDGF-AA, -BB, -αR, and -βR were assessed in rat pups raised in air or 60% O2 for up to 14 d after birth. Expression of mRNA and immunoreactive ligand did not correlate for pups raised in air. Immunoreactive PDGF-αR and -βR, but not PDGF-AA and -BB, were evident throughout the lung at birth. Both PDGF-AA and -BB were evident in airway epithelium, PDGF-BB in alveolar epithelial cells and PDGF-AA was widely distributed in parenchymal tissue at 4 d. PDGF-αR was localized to airway epithelium, and PDGF-βR to subendothelial perivascular regions and to airway and alveolar epithelium at 4 d. Immunoreactive PDGF ligands all declined after 4 d. Intraperitoneal injection of neutralizing antibodies or truncated soluble receptors to PDGF-BB reduced lung DNA synthesis in air. Exposure to 60% O2 significantly increased mRNA for PDGF-B, -βR, and -αR, but not PDGF-A, relative to air-exposed lung at various time points after birth. PDGF-A, -B, and -αR immunoreactivities in these lungs were reduced and delayed, consistent with a global inhibition of lung growth. Pups exposed to 60% O2 had a similar distribution of PDGF-βR to that seen in air, except that at 14 d PDGF-βR was distributed throughout the lung parenchyma. We conclude that PDGF ligands and receptors are important for normal postnatal lung growth and that their expression is delayed by O2 exposure.Abbreviations: BPD, bronchopulmonary dysplasia; IGF-IR, type I IGF receptor; PDGF, platelet-derived growth factor; PDGF-R, platelet-derived growth factor receptor
Project
T understand the regulatory mechanism of NETosis since NETs are involved in many inflammatory and autoimmune disease. This information and understanding would be helpful to clinically manifest thes…" [more]
Project
To understand the molecular mechanism of labour onset particularly the role of progesterone receptors PRA and PRB in this process.
Article
July 2002 · Pediatric Research · Impact Factor: 2.31
    Unilateral pneumonectomy leads to compensatory growth in the residual lung, the mediators of which are largely unknown. We hypothesized, based on its other known roles in lung cell growth, that platelet-derived growth factor (PDGF)-BB would be an essential mediator of postpneumonectomy compensatory lung growth. Left-sided pneumonectomies were performed on 21-d-old rats, for comparison with... [Show full abstract]
    Article
    October 2000 · Pediatric Research · Impact Factor: 2.31
      We hypothesized that reactive O2 species, or their intermediary products, generated during exposure to elevated O2 lead to pathologic endothelin-1 expression in the newborn lung. Endothelin-1 expression and 8-isoprostane content (an in vivo marker of lipid peroxidation) were examined and found to be elevated (p < 0.05) in the lungs of newborn rats with abnormal lung morphology and pulmonary... [Show full abstract]
      Article
      July 2003 · American Journal of Respiratory and Critical Care Medicine · Impact Factor: 13.00
        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... [Show full abstract]
        Discover more