Heterozygous deficiency of hypoxia-inducible factor-2alpha protects mice against pulmonary hypertension and right ventricular dysfunction during prolonged hypoxia.
J Clin Invest
Chronic hypoxia induces pulmonary vascular remodeling, leading to pulmonary hypertension, right ventricular hypertrophy, and heart failure. Heterozygous deficiency of hypoxia-inducible factor-1alpha (HIF-1alpha), which mediates the cellular response to hypoxia by increasing expression of genes involved in erythropoiesis and angiogenesis, has been previously shown to delay hypoxia-induced pulmonary hypertension. HIF-2alpha is a homologue of HIF-1alpha and is abundantly expressed in the lung, but its role in pulmonary hypertension remains unknown. Therefore, we analyzed the pulmonary response of WT and viable heterozygous HIF-2alpha-deficient (Hif2alpha(+/-)) mice after exposure to 10% O(2) for 4 weeks. In contrast to WT mice, Hif2alpha(+/-) mice were fully protected against pulmonary hypertension and right ventricular hypertrophy, unveiling a critical role of HIF-2alpha in hypoxia-induced pulmonary vascular remodeling. Pulmonary expression levels of endothelin-1 and plasma catecholamine levels were increased threefold and 12-fold respectively in WT but not in Hif2alpha(+/-) mice after hypoxia, suggesting that HIF-2alpha-mediated upregulation of these vasoconstrictors contributes to the development of hypoxic pulmonary vascular remodeling.
|Title:||Heterozygous deficiency of hypoxia-inducible factor-2alpha protects mice against pulmonary hypertension and right ventricular dysfunction during prolonged hypoxia.|
|Keywords:||Animals, Anoxia, Atmosphere Exposure Chambers, Basic Helix-Loop-Helix Transcription Factors, Catecholamines, Endothelin-1, Fetal Viability, Hematocrit, Heterozygote, Hypertension, Pulmonary, Lung, Mice, Mice, Transgenic, Phenotype, Pulmonary Artery, RNA, Messenger, Time, Trans-Activators, Up-Regulation, Ventricular Dysfunction, Right|
|UCL classification:||UCL > School of Life and Medical Sciences
UCL > School of Life and Medical Sciences > Faculty of Medical Sciences
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