Different expression of surfactant protein B mature peptide and proprotein at 21 weeks'' gestation in human fetal pulmonary epithelial cells |
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Authors: | Kazuhiro Mori Kazushige Ikeda Mamoru Tanaka |
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Affiliation: | Division of Neonatology, Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan. kazuiked@sc.itc.keio.ac.jp |
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Abstract: | AIM: The aim of this study is to evaluate the maturation of pulmonary epithelial cells in human fetal lungs at 21 weeks' gestation. METHODS: Eight fetuses at 21 weeks' gestation were evaluated. The maturation of pulmonary epithelial cells was assessed by immunohistochemical examination for surfactant proteins and by electron microscopy. RESULTS: Surfactant protein B mature peptide was detected slightly in the epithelial lining of the bronchioles, but was totally absent in the terminal airways. Surfactant protein B proprotein was clearly detected in the epithelial lining of both bronchioles and terminal airways. Transmission electron microscopy of terminal airway cells showed abundant glycogen granules and few intracellular organelles. CONCLUSIONS: The production of mature surfactant protein B in terminal airways is scarce at 21 weeks' gestation, which is associated with the immature mechanism of proprotein processing in the cytoplasm. |
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Keywords: | human fetus lung maturation pulmonary epithelial cells surfactant protein |
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