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This Article Full Text Full Text (PDF) All Versions of this Article: 295/1/L86    most recent 00534.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Ambalavanan, N. Articles by Chen, Y.-F. PubMed PubMed Citation Articles by Ambalavanan, N. Articles by Chen, Y.-F.

Transforming growth factor-β signaling mediates hypoxia-induced pulmonary arterial remodeling and inhibition of alveolar development in newborn mouse lung

Departments of ¹Pediatrics, ²Cell Biology, ³Medicine, and ⁴Pathology, University of Alabama at Birmingham, Birmingham, Alabama

Submitted 26 December 2007 ; accepted in final form 11 May 2008

Hypoxia causes abnormal neonatal pulmonary artery remodeling (PAR) and inhibition of alveolar development (IAD). Transforming growth factor (TGF)-β is an important regulator of lung development and repair from injury. We tested the hypothesis that inhibition of TGF-β signaling attenuates hypoxia-induced PAR and IAD. Mice with an inducible dominant-negative mutation of the TGF-β type II receptor (DNTGFβRII) and nontransgenic wild-type (WT) mice were exposed to hypoxia (12% O₂) or air from birth to 14 days of age. Expression of DNTGFβRII was induced by 20 µg/g ZnSO₄ given intraperitoneally daily from birth. PAR, IAD, cell proliferation, and expression of extracellular matrix (ECM) proteins were assessed. In WT mice, hypoxia led to thicker, more muscularized resistance pulmonary arteries and impaired alveolarization, accompanied by increases in active TGF-β and phosphorylated Smad2. Hypoxia-induced PAR and IAD were greatly attenuated in DNTGFβRII mice given ZnSO₄ compared with WT control mice and DNTGFβRII mice not given ZnSO₄. The stimulatory effects of hypoxic exposure on pulmonary arterial cell proliferation and lung ECM proteins were abrogated in DNTGFβRII mice given ZnSO₄. These data support the conclusion that TGF-β plays an important role in hypoxia-induced pulmonary vascular adaptation and IAD in the newborn animal model.

lung development; infant; persistent pulmonary hypertension of the newborn