Related Experiment Video
Updated: Aug 11, 2026
10:00
In Vitro Culture of Epithelial Cells from Different Anatomical Regions of the Human Amniotic Membrane
Published on: November 28, 2019
Epithelial Na(+) channel (ENaC) expression in the developing normal and abnormal human perinatal lung
D E Smith1, G Otulakowski, H Yeger
1Lung Biology Programme of the Hospital for Sick Children and Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada.
American Journal of Respiratory and Critical Care Medicine
|April 14, 2000
Summary
Impaired lung epithelial sodium channel (ENaC) activity causes respiratory distress at birth. This study reveals alphaENaC mRNA expression throughout human fetal lung development, suggesting complex regulation beyond transcription.
Area of Science:
- Pulmonary Medicine
- Developmental Biology
- Molecular Genetics
Background:
- Impaired lung epithelial sodium channel (ENaC) activity at birth leads to respiratory distress.
- Understanding the developmental expression of ENaC is crucial for identifying mechanisms of neonatal respiratory issues.
Purpose of the Study:
- To investigate the ontogeny and cellular distribution of alphaENaC subunit mRNA in human fetal lungs.
- To explore potential mechanisms underlying ENaC regulation in lung development and disease.
Main Methods:
- Nonradioisotopic in situ hybridization was used to study alphaENaC mRNA expression.
- Analysis was performed on normal, immature, and abnormal (hypoplastic) human fetal lungs.
Main Results:
- AlphaENaC mRNA was detected early in embryonic development (4-5 weeks gestation) in the lung bud epithelium.
- By late gestation, ENaC expression was observed in airway epithelium, serous cells, and distal lung units (ATII-like distribution).
- Significant alphaENaC expression was noted in newborns with lung diseases causing respiratory distress.
Conclusions:
- AlphaENaC mRNA expression occurs throughout human lung development, starting from embryonic stages.
- Regulation of ENaC activity may involve post-transcriptional mechanisms, as mRNA appears constitutively expressed.
- Impairments in other ENaC subunits or alternative transporters could contribute to neonatal respiratory distress.
