Antisense inhibition of surfactant protein A decreases tubular myelin formation in human fetal lung in vitro

• Published in: American journal of physiology. Lung cellular and molecular physiology 2002-03, Vol.282 (3), p.L386-L393
• Main Authors: Klein, Jonathan M, McCarthy, Troy A, Dagle, John M, Snyder, Jeanne M
• Format: Article
• Language: English
• Subjects: Cation Exchange Resins - pharmacology; Embryonic and Fetal Development - drug effects; Fetus - metabolism; Homeostasis; Humans; Immunohistochemistry; In Vitro Techniques; L-Lactate Dehydrogenase - metabolism; Lipids - pharmacology; Lung - embryology; Myelin Sheath - metabolism; Oligonucleotides, Antisense - pharmacology; Proteolipids - antagonists & inhibitors; Proteolipids - genetics; Proteolipids - metabolism; Pulmonary Surfactant-Associated Protein A; Pulmonary Surfactant-Associated Proteins; Pulmonary Surfactants - antagonists & inhibitors; Pulmonary Surfactants - genetics; Pulmonary Surfactants - metabolism; RNA, Messenger - metabolism
• ISSN: 1040-0605; 1522-1504
• DOI: 10.1152/ajplung.00410.2000

Surfactant protein A (SP-A) is the most abundant of the surfactant-associated proteins. SP-A is involved in the formation of tubular myelin, the modulation of the surface tension-reducing properties of surfactant phospholipids, the metabolism of surfactant phospholipids, and local pulmonary host defense. We hypothesized that elimination of SP-A would alter the regulation of SP-B gene expression and the formation of tubular myelin. Midtrimester human fetal lung explants were cultured for 3-5 days in the presence or absence of an antisense 18-mer phosphorothioate oligonucleotide (ON) complementary to SP-A mRNA. After 3 days in culture, SP-A mRNA was undetectable in antisense ON-treated explants. After 5 days in culture, levels of SP-A protein were also decreased by antisense treatment. SP-B mRNA levels were not affected by the antisense SP-A ON treatment. However, there was decreased tubular myelin formation in the antisense SP-A ON-treated tissue. We conclude that selective elimination of SP-A mRNA and protein results in a decrease in tubular myelin formation in human fetal lung without affecting SP-B mRNA. We speculate that SP-A is critical to the formation of tubular myelin during human lung development and that the regulation of SP-B gene expression is independent of SP-A gene expression.