Project description:Rationale: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal congenital disorder causing respiratory failure and pulmonary hypertension shortly after birth. There are no effective treatments for ACDMPV other than lung transplant, and new therapeutic approaches are urgently needed. Although ACDMPV is linked to mutations in the FOXF1 gene, molecular mechanisms through which FOXF1 mutations cause ACDMPV are unknown.Objectives: To identify molecular mechanisms by which S52F FOXF1 mutations cause ACDMPV.Methods: We generated a clinically relevant mouse model of ACDMPV by introducing the S52F FOXF1 mutation into the mouse Foxf1 gene locus using CRISPR/Cas9 technology. Immunohistochemistry, whole-lung imaging, and biochemical methods were used to examine vasculature in Foxf1WT/S52F lungs and identify molecular mechanisms regulated by FOXF1.Measurements and Main Results: FOXF1 mutations were identified in 28 subjects with ACDMPV. Foxf1WT/S52F knock-in mice recapitulated histopathologic findings in ACDMPV infants. The S52F FOXF1 mutation disrupted STAT3-FOXF1 protein-protein interactions and inhibited transcription of Stat3, a critical transcriptional regulator of angiogenesis. STAT3 signaling and endothelial proliferation were reduced in Foxf1WT/S52F mice and human ACDMPV lungs. S52F FOXF1 mutant protein did not bind chromatin and was transcriptionally inactive. Furthermore, we have developed a novel formulation of highly efficient nanoparticles and demonstrated that nanoparticle delivery of STAT3 cDNA into the neonatal circulation restored endothelial proliferation and stimulated lung angiogenesis in Foxf1WT/S52F mice.Conclusions: FOXF1 acts through STAT3 to stimulate neonatal lung angiogenesis. Nanoparticle delivery of STAT3 is a promising strategy to treat ACDMPV associated with decreased STAT3 signaling.
Project description:Haploinsufficiency of FOXF1 causes an autosomal dominant neonatally lethal lung disorder, alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV). We identified novel 0.8-kb deletion within the 1.4-kb intron of FOXF1 in a deceased newborn diagnosed with ACDMPV. The deletion arose de novo on the maternal copy of the chromosome 16, and did not affect FOXF1 minigene splicing tested in lung fibroblasts. However, FOXF1 transcript level in the ACDMPV peripheral lung tissue was reduced by almost 40%. We found that, in an in vitro reporter assay, the FOXF1 intron exhibited moderate transcriptional enhancer activity, correlating with the presence of binding sites for expression regulators CTCF and CEBPB, whereas its truncated copy, which lost major CTCF and CEBPB-binding sites, inhibited the FOXF1 promoter. Our data further emphasize the importance of testing the non-protein coding regions of the genome currently not covered by diagnostic chromosomal microarray analyses or whole-exome sequencing.
Project description:BackgroundPulmonary hypertension (PH) is a common complication in patients with alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV), a severe congenital disorder associated with mutations in the FOXF1 gene. Although the loss of alveolar microvasculature causes PH in patients with ACDMPV, it is unknown whether increasing neonatal lung angiogenesis could prevent PH and right ventricular (RV) hypertrophy.MethodsWe used echocardiography, RV catheterization, immunostaining, and biochemical methods to examine lung and heart remodeling and RV output in Foxf1WT/S52F mice carrying the S52F Foxf1 mutation (identified in patients with ACDMPV). The ability of Foxf1WT/S52F mutant embryonic stem cells to differentiate into respiratory cell lineages in vivo was examined using blastocyst complementation. Intravascular delivery of nanoparticles with a nonintegrating Stat3 expression vector was used to improve neonatal pulmonary angiogenesis in Foxf1WT/S52F mice and determine its effects on PH and RV hypertrophy.ResultsFoxf1WT/S52F mice developed PH and RV hypertrophy after birth. The severity of PH in Foxf1WT/S52F mice directly correlated with mortality, low body weight, pulmonary artery muscularization, and increased collagen deposition in the lung tissue. Increased fibrotic remodeling was found in human ACDMPV lungs. Mouse embryonic stem cells carrying the S52F Foxf1 mutation were used to produce chimeras through blastocyst complementation and to demonstrate that Foxf1WT/S52F embryonic stem cells have a propensity to differentiate into pulmonary myofibroblasts. Intravascular delivery of nanoparticles carrying Stat3 cDNA protected Foxf1WT/S52F mice from RV hypertrophy and PH, improved survival, and decreased fibrotic lung remodeling.ConclusionsNanoparticle therapies increasing neonatal pulmonary angiogenesis may be considered to prevent PH in ACDMPV.
Project description:Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare and lethal developmental disorder of the lung that affect both acinar structure and the intrinsic pulmonary vasculature. We report prenatal and postnatal imaging with histopathological findings of this rare condition. We, first, describe MR imaging features and discuss its role in prenatal imaging.
Project description:Analysis of genes dysregulated in the lungs of neonates with ACDMPV neonate lungs compared to control lungs Total RNA extracted by eight ACDMPV lungs compared to total RNA extracted from five control lungs
Project description:Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal lung developmental disorder caused by heterozygous point mutations or genomic deletion copy-number variants (CNVs) of FOXF1 or its upstream enhancer involving fetal lung-expressed long noncoding RNA genes LINC01081 and LINC01082. Using custom-designed array comparative genomic hybridization, Sanger sequencing, whole exome sequencing (WES), and bioinformatic analyses, we studied 22 new unrelated families (20 postnatal and two prenatal) with clinically diagnosed ACDMPV. We describe novel deletion CNVs at the FOXF1 locus in 13 unrelated ACDMPV patients. Together with the previously reported cases, all 31 genomic deletions in 16q24.1, pathogenic for ACDMPV, for which parental origin was determined, arose de novo with 30 of them occurring on the maternally inherited chromosome 16, strongly implicating genomic imprinting of the FOXF1 locus in human lungs. Surprisingly, we have also identified four ACDMPV families with the pathogenic variants in the FOXF1 locus that arose on paternal chromosome 16. Interestingly, a combination of the severe cardiac defects, including hypoplastic left heart, and single umbilical artery were observed only in children with deletion CNVs involving FOXF1 and its upstream enhancer. Our data demonstrate that genomic imprinting at 16q24.1 plays an important role in variable ACDMPV manifestation likely through long-range regulation of FOXF1 expression, and may be also responsible for key phenotypic features of maternal uniparental disomy 16. Moreover, in one family, WES revealed a de novo missense variant in ESRP1, potentially implicating FGF signaling in the etiology of ACDMPV.
Project description:Alveolar capillary dysplasia (ACD) is a congenital, lethal disorder of the pulmonary vasculature. Phosphatase and tensin homologue deleted from chromosome 10 (Pten) encodes a lipid phosphatase controlling key cellular functions, including stem/progenitor cell proliferation and differentiation; however, the role of PTEN in mesodermal lung cell lineage formation remains unexamined. To determine the role of mesodermal PTEN in the ontogeny of various mesenchymal cell lineages during lung development, we specifically deleted Pten in early embryonic lung mesenchyme in mice. Pups lacking Pten died at birth, with evidence of failure in blood oxygenation. Analysis at the cellular level showed defects in angioblast differentiation to endothelial cells and an accompanying accumulation of the angioblast cell population that was associated with disorganized capillary beds. We also found decreased expression of Forkhead box protein F1 (Foxf1), a gene associated with the ACD human phenotype. Analysis of human samples for ACD revealed a significant decrease in PTEN and increased activated protein kinase B (AKT). These studies demonstrate that mesodermal PTEN has a key role in controlling the amplification of angioblasts as well as their differentiation into endothelial cells, thereby directing the establishment of a functional gas exchange interface. Additionally, these mice could serve as a murine model of ACD.
Project description:BackgroundAlveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a lethal neonatal lung disorder characterized by the decrease of the alveolar units, abnormalities in the air-blood barrier of the lung, and impaired gas exchange. Typically, it affects a full-term newborn; the symptoms usually start within a few hours after birth, resulting in severe respiratory distress and pulmonary hypertension. In most of the cases, this disorder is refractory to conventional pulmonary support.Case presentationWe report a case of a newborn male of 29 weeks gestational age, with birth weight of 850 g and intrauterine growth restriction. Severe respiratory distress appeared a few minutes after birth; non-invasive ventilatory support was provided in the delivery room and, as a consequence of persistent respiratory failure, he was admitted to the neonatal intensive care unit (NICU) where mechanical ventilation was required. Due to the symptoms and pulmonary ultrasound pattern suggestive of respiratory distress syndrome, surfactant treatment was administered. Lung ultrasound (LU) was used for monitoring the responsiveness to surfactant; severe pulmonary hypertension ensued, followed by respiratory failure, refractory shock, and death within 48 h. Owing to the poor response to the established therapy, ACD/MPV was suspected. The diagnosis was confirmed through autopsy. The main goal of this case report is to show the role of LU for monitoring the evolution of this disorder.ConclusionLU could provide essential information to help diagnose and follow-up the underlying cause of persistent pulmonary hypertension of the newborn in an earlier and more effective way than chest X-ray. LU is suitable for routine monitoring of lung disease in the NICU.
Project description:BACKGROUND:Alveolar capillary dysplasia (ACD) is a rare cause of severe pulmonary hypertension and respiratory failure in neonates. The onset of ACD is usually preceded by a short asymptomatic period. The condition is refractory to all available therapies as it irreversibly affects development of the capillary bed in the lungs. The diagnosis of ACD is based on histopathological evaluation of lung biopsy or autopsy tissue or genetic testing of FOXF1 on chromosome 16q24.1. Here, we describe the first two Polish patients with ACD confirmed by histopathological and genetic examination. CASE PRESENTATION:The patients were term neonates with high Apgar scores in the first minutes of life. They both were diagnosed prenatally with heart defects. Additionally, the first patient presented with omphalocele. The neonate slightly deteriorated around 12th hour of life, but underwent surgical repair of omphalocele followed by mechanical ventilation. Due to further deterioration, therapy included inhaled nitric oxide (iNO), inotropes and surfactant administration. The second patient was treated with prostaglandin E1 since birth due to suspicion of aortic coarctation (CoA). After ruling out CoA in the 3rd day of life, infusion of prostaglandin E1 was discountinued and immediately patient's condition worsened. Subsequent treatment included re-administration of prostaglandin E1, iNO and mechanical ventilation. Both patients presented with transient improvement after application of iNO, but died despite maximized therapy. They were histopathologically diagnosed post-mortem with ACD. Array comparative genomic hybridization in patient one and patient two revealed copy-number variant (CNV) deletions, respectively, ~ 1.45?Mb in size involving FOXF1 and an ~?0.7?Mb in size involving FOXF1 enhancer and leaving FOXF1 intact. CONCLUSIONS:Both patients presented with a distinct course of ACD, extra-pulmonary manifestations and response to medications. Surgery and ceasing of prostaglandin E1 infusion should be considered as potential causes of this variability. We further highlight the necessity of thorough genetic testing and histopathological examination and propose immunostaining for CD31 and CD34 to facilitate the diagnostic process for better management of infants with ACD.
Project description:Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a rare, lethal cause of neonatal respiratory failure and persistent pulmonary hypertension. We present a presumptive prenatal diagnosis of ACDMPV based on chorionic villus sampling of a FOXF1 mutation in a fetus with extra-pulmonary anomalies often associated with ACDMPV.