Lung transcriptome analysis of mice with lung mesechyme specific deletion of Pbx transcription factors

Two critical events that are required for normal transition from fetal to extrauterine life are development of the alveoli that allow for efficient gas exchange in the lung and relaxation of the pulmonary vascular smooth muscle. Patients with congenital diaphragmatic hernia (CDH) have abnormal lung and pulmonary vascular development that results in a lethal combination of lung hypoplasia and pulmonary hypertension. To better understand the mechanisms responsible for abnormal lung and pulmonary vascular development and function we generated Pbx1/2 conditional knockout mice that lack Pbx1 and Pbx2 expression in the lung mesenchyme. Pbx1 has previously been shown to be required for normal diaphragm development, however its role in alveologenesis, and the mechanisms responsible for pulmonary hypertension, has not been studied. We found that Pbx1/2 CKO mice have failure of alveologenesis and die of severe pulmonary hypertension by 2 to 3 weeks of age. In order to better understand the downstream genetic mis-regulation caused by deletion of Pbx1/2, and identify their potential transcriptional targets, we carried out transcriptional profiling of Pbx1/2 CKO and control mice starting at postnatal day 3 (P3), when a histological phenotype first becomes apparent, and then working back to the time of birth (P0), and embryonic day 14 (E14) when the pulmonary vascular smooth muscle is developing.

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McCulley DJ, Wienhold MD, Hines EA, Hacker TA, Rogers A, Pewowaruk RJ, Zewdu R, Chesler NC, Selleri L, Sun X