title: Effect of two models of intrauterine growth restriction on alveolarization in rat lungs: morphometric and gene expression analysis.
abstract: Intrauterine growth restriction (IUGR) in preterm infants increases the risk of bronchopulmonary dysplasia, characterized by arrested alveolarization. We evaluated the impact of two different rat models (nitric oxide synthase inhibition or protein deprivation) of IUGR on alveolarization, before, during, and at the end of this postnatal process. We studied IUGR rat pups of dams fed either a low protein (LPD) or a normal diet throughout gestation and pups of dams treated by continuous infusion of Nω-nitro-L-arginine methyl ester (L-NAME) or its diluent on the last four days of gestation. Morphometric parameters, alveolar surface (Svap), mean linear intercept (MLI) and radial alveolar count (RAC) and transcriptomic analysis were determined with special focus on genes involved in alveolarization. IUGR pups regained normal weight at day 21 in the two treated groups. In the LPD group, Svap, MLI and RAC were not different from those of controls at day 4, but were significantly decreased at day 21, indicating alveolarization arrest. In the L-NAME group, Svap and RAC were significantly decreased and MLI was increased at day 4 with complete correction at day 21. In the L-NAME model, several factors involved in alveolarization, VEGF, VEGF-R1 and -R2, MMP14, MMP16, FGFR3 and 4, FGF18 and 7, were significantly decreased at day 4 and/or day 10, while the various factors studied were not modified in the LPD group. These results demonstrate that only maternal protein deprivation leads to sustained impairment of alveolarization in rat pups, whereas L-NAME impairs lung development before alveolarization. Known growth factors involved in lung development do not seem to be involved in LPD-induced alveolarization disorders, raising the question of a possible programming of altered alveolarization.
authors.affiliation: Institut National de la Santé Et de la Recherche Médicale (INSERM) U767, Paris, France ; PremUp, Paris, France ; Service de Médecine et Réanimation néonatales de Port-Royal, Groupe hospitalier Cochin, Broca, Hôtel-Dieu, Assistance Publique - Hôpitaux de Paris, Paris, France ; Université Paris Descartes, Paris, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Zana-Taieb
authors.forename: Laura
authors.initials: L
authors.lastname: Butruille
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Franco-Montoya
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Lopez
authors.forename: Flore
authors.initials: F
authors.lastname: Vernier
authors.forename: Isabelle
authors.initials: I
authors.lastname: Grandvuillemin
authors.forename: Danièle
authors.initials: D
authors.lastname: Evain-Brion
authors.forename: Philippe
authors.initials: P
authors.lastname: Deruelle
authors.forename: Olivier
authors.initials: O
authors.lastname: Baud
authors.forename: Christophe
authors.initials: C
authors.lastname: Delacourt
authors.forename: Pierre-Henri
authors.initials: PH
authors.lastname: Jarreau
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D018753:Diet, Protein-Restricted / Q000009:adverse effects; D005260:Female; D005317:Fetal Growth Retardation / Q000209:etiology / Q000503:physiopathology*; D008168:Lung / Q000187:drug effects / Q000473:pathology*; D008297:Male; D011247:Pregnancy; D011650:Pulmonary Alveoli / Q000473:pathology / Q000503:physiopathology*; D051381:Rats
chemical_list: C026512:arginine methyl ester; D001120:Arginine