title: Maternal protein restriction alters VEGF signaling and decreases pulmonary alveolar in fetal rats.
abstract: Epidemiological studies have demonstrated that intrauterine growth restriction (IUGR) increases the risk for respiratory morbidity from infancy, throughout childhood and into adulthood. Chronic restriction of nutrients causes abnormalities in the airways and lungs of offspring, but whether IUGR adversely impacts fetal pulmonary vascular development and underlying mechanisms remain under investigation. In this study, we investigated the effects of protein malnutrition in utero on pulmonary alveolarization and vascular growth of the fetal lung and placentae. Pregnant rats were feed with an isocaloric low-protein diet (8% protein) until delivery. Placenta and fetal lungs were harvested on 20th day of gestation (term 21 days of gestation). Lung index (lung weight as a percentage of body weight), total DNA and protein, radial alveolar count, arteriolar wall thickness, lung maturity and angiogenic factor VEGF were assessed. The lung was hypoplastic in IUGR fetus, evidenced by reduction in lung weight, DNA and protein content. Protein restriction in utero led to higher glycogen levels, but reduced number of alveoli as confirmed by the measurement of radial alveolar counts. IUGR fetus had significantly reduced VEGF, Flk-1 levels in lung but no changes in Flt-1 mRNA. Furthermore, IUGR was associated with increased lung miR-126-3p levels, which modulated the expression of angiogenic factor. In contrast, with regard to the placenta, IUGR fetus presented with decreased expression of VEGF, with no changes in VEGF receptors and expression-regulating miRNAs. This work suggested that VEGF signaling defect plays an important role in the defective lung development, which may explain the increased incidence of respiratory infections in IUGR patients.
authors.affiliation: Key Laboratory of Health Ministry for Congenital Malformations, Shengjing Hospital of China Medical University ShenYang, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Internal Medicine, Shengjing Hospital of China Medical University ShenYang, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Pathology, Shengjing Hospital of China Medical University ShenYang, China.
authors.forename: Baoling
authors.initials: B
authors.lastname: Tian
authors.affiliation: Key Laboratory of Health Ministry for Congenital Malformations, Shengjing Hospital of China Medical University ShenYang, China.
authors.forename: Jianing
authors.initials: J
authors.lastname: Miao
authors.affiliation: Department of Pediatrics, Shengjing Hospital of China Medical University ShenYang, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Xi
authors.affiliation: Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University ShenYang, China.
authors.forename: Caixia
authors.initials: C
authors.lastname: Liu
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005317:Fetal Growth Retardation / Q000378:metabolism* / Q000473:pathology*; D048070:Fetal Nutrition Disorders / Q000378:metabolism / Q000473:pathology; D005333:Fetus; D015151:Immunoblotting; D008168:Lung / Q000098:blood supply / Q000196:embryology / Q000378:metabolism; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011650:Pulmonary Alveoli / Q000098:blood supply* / Q000196:embryology* / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat
keywords: IUGR; VEGF; miRNA; placenta; pulmonary