This revised application proposes to study effects and mechanisms of insulin action on surfactant protein A of human fetal lung. The fetus of the diabetic mother is at increased risk for newborn lung disease and it has been proposed that high levels of insulin delay human lung maturation. The previous studies by the applicant indicated that insulin treatment of human fetal lung explants did not affect surfactant phospholipid synthesis or composition but did decrease accumulation of surfactant protein A and its mRNA. Also, concentrations of SP-A in amniotic fluid were found to be lower in diabetic vs. non-diabetic women. In this proposal it is hypothesized that hyperinsulinemia may predispose infants of diabetic mothers to develop respiratory distress by inhibiting the synthesis of surfactant associated proteins, in particular SP-A, thereby altering the composition and function of surfactant. Experiments are proposed using cultured human fetal lung and the H-441 adenocarcinoma cell line to explore the mechanism of insulin effects.
The first aim will determine insulin regulation of the two human SP-A genes in cultured tissue and use in situ hybridization to localize the two SP-A transcripts in human lung tissue. The second Specific Aim will examine molecular mechanisms for insulin regulation of SP-A using nuclear run-on assays, studies of SP-A mRNA stability, and inhibitors. The third specific aim will investigate the role of 3' untranslated portion of SP-A mRNA which is predicted to mediate the inhibitory effects of insulin. Transient transfection studies with chimeric genes will identify sequences involved in the proposed destabilizing effect of insulin. In the fourth specific aim, mechanisms involved in the interaction between insulin and glucocorticoid in gene expression will be examined including transcription rate, transcript stability and possible induction of new gene products using differential PCR. These studies will provide new information on the role and mechanism of insulin effects and interaction with glucocorticoids in human fetal lung development.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL050050-01A2
Application #
2226149
Study Section
Human Embryology and Development Subcommittee 1 (HED)
Project Start
1995-09-01
Project End
1999-08-31
Budget Start
1995-09-01
Budget End
1996-08-31
Support Year
1
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of Iowa
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Fischer, Anthony J; Goss, Kelli L; Scheetz, Todd E et al. (2009) Differential gene expression in human conducting airway surface epithelia and submucosal glands. Am J Respir Cell Mol Biol 40:189-99
Snyder, Gary D; Oberley-Deegan, Rebecca E; Goss, Kelli L et al. (2008) Surfactant protein D is expressed and modulates inflammatory responses in human coronary artery smooth muscle cells. Am J Physiol Heart Circ Physiol 294:H2053-9
Oberley, Rebecca E; Goss, Kelli L; Hoffmann, Darren S et al. (2007) Regulation of surfactant protein D in the mouse female reproductive tract in vivo. Mol Hum Reprod 13:863-8
Oberley, Rebecca E; Goss, Kelli L; Quintar, Amado A et al. (2007) Regulation of surfactant protein D in the rodent prostate. Reprod Biol Endocrinol 5:42
Garbrecht, Mark R; Klein, Jonathan M; McCarthy, Troy A et al. (2007) 11-Beta hydroxysteroid dehydrogenase type 2 in human adult and fetal lung and its regulation by sex steroids. Pediatr Res 62:26-31
Garbrecht, Mark R; Klein, Jonathan M; Schmidt, Thomas J et al. (2006) Glucocorticoid metabolism in the human fetal lung: implications for lung development and the pulmonary surfactant system. Biol Neonate 89:109-19
George, Caroline L S; White, Misty L; Kulhankova, Katarina et al. (2006) Early exposure to a nonhygienic environment alters pulmonary immunity and allergic responses. Am J Physiol Lung Cell Mol Physiol 291:L512-22
Garbrecht, Mark R; Schmidt, Thomas J; Krozowski, Zygmunt S et al. (2006) 11Beta-hydroxysteroid dehydrogenase type 2 and the regulation of surfactant protein A by dexamethasone metabolites. Am J Physiol Endocrinol Metab 290:E653-60
Garbrecht, Mark R; Krozowski, Zygmunt S; Snyder, Jeanne M et al. (2006) Reduction of glucocorticoid receptor ligand binding by the 11-beta hydroxysteroid dehydrogenase type 2 inhibitor, Thiram. Steroids 71:895-901
Oberley, Rebecca E; Goss, Kelli L; Dahmoush, Laila et al. (2005) A role for surfactant protein D in innate immunity of the human prostate. Prostate 65:241-51

Showing the most recent 10 out of 27 publications