Expression of transforming growth factor-alpha in mid-gestation human fetal lung.
Transforming growth factor-alpha (TGF-alpha), a member of the epidermal growth factor (EGF) family, is a potent mitogen for several cell types. To investigate the possible role of TGF-alpha in the development of midgestation human fetal lung, we studied its distribution with immunohistochemistry and determined levels of steady-state TGF-alpha mRNA by Northern analysis of cellular RNA isolates from lung. Lung was obtained from fetuses at 10 to 22 wk of gestation (n = 14) and immunostained for TGF-alpha. TGF-alpha was localized in epithelial cells at all gestational ages examined. Immunostaining was particularly prominent in bronchiolar epithelial cells. TGF-alpha immunoreactivity was also associated with arterial smooth muscle cells, as well as with nerves. Occasional chondrocytes were also associated with TGF-alpha immunoreactivity. Total cellular RNA was isolated from lung tissue obtained from additional fetuses at gestational ages 10 to 24 wk (n = 22). TGF-alpha mRNA was present in RNA extracts of all fetal lungs studied. We conclude that TGF-alpha is probably produced in human fetal lung during mid-gestation. The prominent immunostaining of bronchiolar epithelial cells for TGF-alpha is consistent with its playing a role in distal airway formation.
Strandjord
T P
TP
Department of Pediatrics, University of Washington, Seattle 98195.
Clark
J G
JG
Hodson
W A
WA
Schmidt
R A
RA
Madtes
D K
DK
D000911:Antibodies, Monoclonal; D015152:Blotting, Northern; D005260:Female; D005333:Fetus; D005865:Gestational Age; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000166:cytology / Q000196:embryology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D012313:RNA / Q000302:isolation & purification; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism*; D011994:Recombinant Proteins / Q000032:analysis / Q000276:immunology; D016211:Transforming Growth Factor alpha / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics
D000911:Antibodies, Monoclonal; D015347:RNA Probes; D012333:RNA, Messenger; D011994:Recombinant Proteins; D016211:Transforming Growth Factor alpha; D012313:RNA