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Expression of transforming growth factor-alpha and epidermal growth factor receptor is increased following bleomycin-induced lung injury in rats.
- Source :
-
American journal of respiratory cell and molecular biology [Am J Respir Cell Mol Biol] 1994 Nov; Vol. 11 (5), pp. 540-51. - Publication Year :
- 1994
-
Abstract
- To investigate the potential role of transforming growth factor-alpha (TGF-alpha) and the epidermal growth factor receptor (EGF-R) in the fibroproliferative response to acute lung injury, we determined lung steady-state TGF-alpha and EGF-R mRNA levels, TGF-alpha protein levels, and the distribution of TGF-alpha and EGF-R immunoreactive protein of bleomycin-injured and control rat lungs. At 2 and 4 days after a single intratracheal injection of bleomycin, TGF-alpha mRNA levels increased to 159% and 184% of control values, respectively. EGF-R mRNA levels increased to 163%, 314%, and 170% of control values at 1, 7, and 14 days after bleomycin instillation. TGF-alpha protein levels in whole lung extracts increased to 230% of control values at 4 days after bleomycin administration. TGF-alpha and EGF-R immunoreactivity was detected in macrophages, alveolar septal cells, and airway epithelium of control and bleomycin-injured animals with an apparent increase in the intensity and number of specifically immunostained cells following lung injury. TGF-alpha and EGF-R immunoreactive proteins were detected in foci of cellular proliferation and in areas of intraalveolar fibrosis. We conclude that TGF-alpha and the EGF-R are present in normal and bleomycin-injured rat lung and that the expression of this growth factor and its receptor are up-regulated following lung injury. These results suggest that increased expression of TGF-alpha and the EGF-R may be an important mechanism that modulates the fibroproliferative response to acute lung injury.
- Subjects :
- Amino Acid Sequence
Animals
Antibody Specificity
Base Sequence
Bleomycin administration & dosage
Cell Division
ErbB Receptors analysis
Lung drug effects
Lung immunology
Lung pathology
Macrophages, Alveolar chemistry
Male
Molecular Sequence Data
Proliferating Cell Nuclear Antigen analysis
Pulmonary Alveoli chemistry
Pulmonary Alveoli cytology
Pulmonary Fibrosis metabolism
RNA, Messenger biosynthesis
Rats
Rats, Sprague-Dawley
Respiratory Distress Syndrome chemically induced
Respiratory Distress Syndrome immunology
Specific Pathogen-Free Organisms
Transforming Growth Factor alpha analysis
ErbB Receptors biosynthesis
Lung metabolism
Respiratory Distress Syndrome metabolism
Transforming Growth Factor alpha biosynthesis
Subjects
Details
- Language :
- English
- ISSN :
- 1044-1549
- Volume :
- 11
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- American journal of respiratory cell and molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 7524566
- Full Text :
- https://doi.org/10.1165/ajrcmb.11.5.7524566