Morphometric analysis of the immunohistochemical expression of Clara cell 10-kDa protein and surfactant apoproteins A and B in the developing bronchi and bronchioles of human fetuses and neonates

Abstract

Morphometric analyses of the immunohistochemical expression of the Clara cell secretory 10-kDa protein (CC10) and surfactant apoproteins A and B (SP-A and -B) were carried out on the developing bronchi and bronchioles of human fetuses and neonates. We analysed the ratio of the number of CC10-positive cells per subepithelial length of the bronchial or bronchiolar basement membrane and found that both the bronchial and the bronchiolar population of CC10-positive cells was significantly higher than that of either SP-A or SP-B. In addition, CC10 was found to be distributed mainly in the bronchiole. CC10-positive cells began to be recognized in the late pseudoglandular phase (15 weeks of gestation) and thereafter gradually increased in the canalicular and terminal sac phases, which correspond to the active development period of the acini or peripheral airways. The earliest expression of SP-A was also noted at 15 weeks of gestation, but its positive epithelial cells were present mainly in the larger bronchi. Double immunohistochemical staining for CC10 and SP-A revealed that the CC10-positive cells lining both the bronchi and bronchioles were different from the SP-A-positive cells. This finding suggests that CC10-positive cells are functionally and developmentally heterogeneous in both fetal and neonatal lungs in humans.

c-Jun NH2-Terminal Kinase Is Required for Lineage-Specific Differentiation but Not Stem Cell Self-Renewal

“…Paraformaldehyde-fixed tissue was processed, embedded in paraffin, and 4-m sections were stained with hematoxylin and eosin (H&E). Sections were also stained with antibodies to insulin (Dako), ␣-fetoprotein (Meridian Life Science), troponin I (Santa Cruz), keratin 5/8 (Lab Vision), desmin (Dako), Nestin (Chemicon), and the cytokeratin Endo-A (TROMA-1; Developmental Studies Hybridoma Bank, University of Iowa) using indirect immunoperoxidase detection (58). Alkaline phosphatase activity was measured using cells fixed with 4% paraformaldehyde at room temperature (1 h) using the Red Alkaline phosphatase substrate kit I (Vector).…”

Identification of tumor markers and differentiation markers for molecular diagnosis of lung adenocarcinoma

“…SFTPB mRNA is known to be expressed in both type II alveolar epithelial cells and bronchiolar epithelial cells, whereas SCGB1A1 mRNA is known to be expressed in Clara cells in bronchiolar and bronchial epithelia but not in type II alveolar epithelial cells (Broers et al, 1992;Xu et al, 1998;Barth et al, 2000;Borczuk et al, 2003). As expected, SFTPB specific PCR products were detected in both type II alveolar epithelial cells and bronchiolar epithelial cells, and SCGB1A1 specific products were detected in both bronchiolar and bronchial epithelial cells (Figure 2a).…”

Distribution of Clara cell secretory protein expression in the tracheobronchial airways of rhesus monkeys

“…The distribution of CCSP we found in the monkey lung is similar to that of the human as reported by Singh in 1992 (29) and Engelhardt in 1994 (12), increasing proximally with the highest levels in the cartilaginous bronchioles. Unlike in the rat, where submucosal glands are rare and contain no CCSP, several investigators have previously reported CCSP in the epithelial cells of the submucosal glands (19) and gland ducts (3,30,32) of humans. In looking at newborn human infant lungs, Asabe et al (3) found CCSP in the bronchioles and the bronchi, as we did in monkeys.…”