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Published on: June 30, 2010
KL-6, a human MUC1 mucin, is expressed early in premature lung
1Department of Pathology, Kochi Medical School, Nankoku, Kochi 783-8505, Japan.
Insights
This study reveals that KL-6, a marker for MUC1 antigens, is present in developing lungs, suggesting its role in lung morphogenesis and function in premature infants.
Area of Science:
- Pulmonology
- Developmental Biology
- Biochemistry
Background:
- KL-6 is a MUC1 antigen expressed on type II pneumocytes, with serum levels correlating to interstitial pneumonia activity.
- MUC1 expression is linked to epithelial and glandular formation during embryonic development.
Purpose of the Study:
- To investigate the role of KL-6 in lung morphogenesis in premature infants.
- To examine KL-6 expression in developing lung tissue.
Main Methods:
- Immunohistochemistry was used to analyze KL-6 expression in 35 neonatal and infant lung tissue specimens (23-40 weeks gestational age).
- Antibody against surfactant protein A (SP-A) was used as a marker for type II pneumocytes.
- Hyaline membranes (HMs) were assessed in the specimens.
Main Results:
- KL-6 staining was strongly positive in alveolar epithelial cells and HMs in infants with gestational age >23 weeks.
- KL-6 was detected in hyaline membranes in 13 out of 35 cases.
- PE10 immunoreaction varied with gestational age and postnatal survival.
Conclusions:
- KL-6 is expressed early in premature lungs.
- KL-6 may play a significant role in the morphogenesis and function of the developing lung during early gestation.
Abstract:
KL-6, one of the MUC1 antigens, is a mucin-like high-molecular-weight glycoprotein, which is strongly expressed on type II pneumocytes. Serum levels of KL-6 have been shown to correlate with activity of interstitial pneumonia (IP). During embryonic development, MUC1 expression coincides with the onset of epithelial sheet and glandular formation. To investigate the potential role of KL-6 in lung morphogenesis, we examined KL-6 expression by immunohistochemistry on autopsied lung tissue specimens of 35 neonates and infants with gestational age from 23 to 40 weeks. Hyaline membranes (HMs) were detected in 13 of 35 cases. Simultaneously, antibody against surfactant protein A (SP-A) was employed in the study which is a distinct marker for type II pneumocytes. In all cases studied with gestational age above 23 weeks, staining for KL-6 was strongly positive in alveolar epithelial cells and in HMs found in 13 cases, whereas immunoreaction for PE10 varied depending on gestational age and duration of postnatal survival. Our findings suggest that KL-6 is expressed earlier in premature lung and may act as an important factor contributing to morphogenesis and function of developing lung in early gestation.
