title: Antisense inhibition of surfactant protein A decreases tubular myelin formation in human fetal lung in vitro.
abstract: 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.
authors.affiliation: Departments of Pediatrics, University of Iowa, Iowa City, Iowa 52242-1083, USA. jonathan-klein@uiowa.edu
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Klein
authors.forename: Troy A
authors.initials: TA
authors.lastname: McCarthy
authors.forename: John M
authors.initials: JM
authors.lastname: Dagle
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Snyder
mesh_terms: D002411:Cation Exchange Resins / Q000494:pharmacology; D005314:Embryonic and Fetal Development / Q000187:drug effects; D005333:Fetus / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008055:Lipids / Q000494:pharmacology; D008168:Lung / Q000196:embryology*; D009186:Myelin Sheath / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D011510:Proteolipids / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D002411:Cation Exchange Resins; D008055:Lipids; C086724:Lipofectamine; D016376:Oligonucleotides, Antisense; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D012333:RNA, Messenger; D007770:L-Lactate Dehydrogenase