Temporal changes in expression of TGF-beta isoforms in mouse lung exposed to oxygen.
Oxygen-induced pulmonary injury is associated with cell death and a significant inflammatory response. Because transforming growth factor (TGF)-beta is a potent modulator of the immune response, changes in expression of the three TGF-beta (beta 1, beta 2, beta 3) isoforms was determined in lungs of adult mice exposed to > 95% oxygen. TGF-beta 1 immunostaining within cuboidal nonciliated bronchiolar epithelial cells was increased within 3 h of oxygen exposure and continued to increase for 48 h before decreasing to control levels by 72 h. A similar but less marked change that was morphologically consistent with alveolar type II cells was observed in granulated cells. Immunostaining for TGF-beta 2 and TGF-beta 3 revealed a similar change in bronchiolar epithelium with little change observed in the alveolar epithelium. Immunohistochemical changes in TGF-beta expression were not observed in any other pulmonary cells. Northern blot analysis of total lung RNA revealed that expression of the TGF-beta mRNA was not markedly altered over the 72-h exposure period. Exposure to > 95% oxygen resulted in cell type-specific posttranscriptional changes in TGF-beta isoforms in the lung.
O'Reilly
M A
MA
Department of Pediatrics, Children's Hospital at Strong, University of Rochester, New York 14642, USA. OReillyM@envmed.rochester.edu
Staversky
R J
RJ
Flanders
K C
KC
Johnston
C J
CJ
Finkelstein
J N
JN
D000818:Animals; D015152:Blotting, Northern; D007150:Immunohistochemistry; D007536:Isomerism; D008168:Lung / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010100:Oxygen / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014018:Tissue Distribution; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D010100:Oxygen