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Expression of transforming growth factor-alpha and epidermal growth factor receptor is increased following bleomycin-induced lung injury in rats.

Authors :
Madtes DK
Busby HK
Strandjord TP
Clark JG
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.

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