Connexin 26 expression in human and ferret airways and lung during development.
Coordinated microscopic and molecular biological studies were used to document gap junction expression during postnatal development in ferret tracheal epithelium and lung and in fetal and adult human airway and lung. Expression of connexin 26 (Cx26) in the ferret airways was limited to the epithelial layer and was observed only during the newborn interval. In contrast, we found Cx26 expressed in the alveolar epithelium of the ferret lung by in situ hybridization, Northern blotting, RT-PCR amplification, and immunocytochemical labeling at all ages examined. This finding was further confirmed by documentation of gap junctional plaques upon ultrastructural examination of freeze-fracture replicas of adult ferret lung tissue. Parallel studies of developing human fetal lung and airway suggested connexin expression in the airways only in the first trimester but, as in the ferret, persistent expression was observed in both fetal and adult lung. These studies suggest that the transient expression of Cx26 is a reliable early indicator of airway epithelial development and differentiation in the airways. In contrast, Cx26 expression persists throughout life in the lung, suggesting that gap junctions serve more perennial intercellular communication functions in the peripheral lung.
Carson
J L
JL
The Department of Pediatrics, and Frank Porter Graham Child Development Center, The University of North Carolina at Chapel Hill, 27599-7310, USA. jcarson@med.unc.edu
Reed
W
W
Moats-Staats
B M
BM
Brighton
L E
LE
Gambling
T M
TM
Hu
S C
SC
Collier
A M
AM
D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D004848:Epithelium / Q000196:embryology / Q000254:growth & development / Q000648:ultrastructure; D005289:Ferrets; D005614:Freeze Fracturing; D017629:Gap Junctions / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008168:Lung / Q000196:embryology / Q000254:growth & development* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D016133:Polymerase Chain Reaction; D012194:RNA-Directed DNA Polymerase; D014132:Trachea / Q000196:embryology / Q000254:growth & development* / Q000648:ultrastructure
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26; D012194:RNA-Directed DNA Polymerase