Related Experiment Videos
Hemoglobin is expressed by alveolar epithelial cells.
Danforth A Newton1, K Murali Krishna Rao, Richard A Dluhy
1Division of Neonatology, Department of Pediatrics, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425, USA.
The Journal of Biological Chemistry
|January 13, 2006
Summary
This study reveals that lung alveolar epithelial cells express hemoglobin, a protein typically found in red blood cells. This unexpected finding in pulmonary surfactant-producing cells may impact lung physiology and disease.
Area of Science:
- Pulmonary biology
- Molecular genetics
- Cell biology
Background:
- Hemoglobin gene expression is known in activated macrophages and lens cells.
- Alveolar epithelial cells, including alveolar type II (ATII) cells, are crucial for lung immunity and surfactant production.
- ATII cells serve as stem cells differentiating into alveolar type I cells.
Purpose of the Study:
- To investigate hemoglobin gene expression in pulmonary epithelial cells.
- To determine if alveolar type II cells and Clara cells express hemoglobin.
- To explore the potential implications of this novel finding in lung physiology and pathology.
Main Methods:
- Reverse transcriptase-PCR was used to detect alpha- and beta-globin gene transcripts.
- DNA sequencing confirmed the specificity of PCR amplification.
- Western blotting and tandem mass spectrometry identified hemoglobin protein subunits.
Main Results:
- Hemoglobin gene transcripts (alpha- and beta-globin mRNAs) were detected in human (A549, H441) and rodent (MLE-15, primary ATII) pulmonary epithelial cells.
- DNA sequencing verified the globin gene cDNAs.
- Hemoglobin protein subunits (alpha- and beta-globin) were confirmed in rat primary ATII cells via Western blotting and mass spectrometry.
Conclusions:
- Pulmonary epithelial cells, specifically alveolar type II cells and Clara cells, express hemoglobin.
- This discovery challenges the traditional understanding of hemoglobin's role and location.
- Further research is needed to elucidate the function of hemoglobin in the pulmonary epithelium and its relevance to lung health and disease.