Reduced bone morphogenetic protein receptor 2 (BMPR2) expression in patients with pulmonary arterial hypertension (PAH) can impair pulmonary arterial EC (PAEC) function. This can adversely affect EC survival and promote SMC proliferation. We hypothesized that interventions to normalize expression of genes that are targets of BMPR2 signaling could restore PAEC function and prevent or reverse PAH. Here we have characterized, in human PAECs, a BMPR2-mediated transcriptional complex between PPARγ and β-catenin and shown that disruption of this complex impaired BMP-mediated PAEC survival. Using whole genome-wide ChIP-Chip promoter analysis and gene expression microarrays, we delineated PPARγ/β-catenin-dependent transcription of target genes including APLN, which encodes apelin. We documented reduced PAEC expression of apelin in PAH patients versus controls. In cell culture experiments, we showed that apelin-deficient PAECs were prone to apoptosis and promoted pulmonary arterial SMC (PASMC) proliferation. Conversely, we established that apelin, like BMPR2 ligands, suppressed proliferation and induced apoptosis of PASMCs. Consistent with these functions, administration of apelin reversed PAH in mice with reduced production of apelin resulting from deletion of PPARγ in ECs. Taken together, our findings suggest that apelin could be effective in treating PAH by rescuing BMPR2 and PAEC dysfunction.
The importance of genetic predisposition, inflammation, and autoimmune mechanisms in the development of pulmonary arterial hypertension (PAH) is becoming increasingly clear. We hypothesized that the analysis of gene expression profiles from peripheral blood mononuclear cells would distinguish patients with PAH from normal volunteers. We also hypothesized that a subset of genes would discriminate between patients with idiopathic PAH and pulmonary hypertension related to secondary causes. Mononuclear cells were isolated from 15 patients diagnosed with PAH and 6 normal control subjects. Microarray expression was performed, and the expression profiles were analyzed for consistent and predictive differences in gene expression. We identified a signature set of 106 genes that discriminated with high certainty (p < or = 0.002) between patients with PAH and normal individuals. The results of the microarray analysis were retrospectively and prospectively confirmed by quantitative polymerase chain reaction for 2 of the 106 genes. Supervised clustering analysis generated a list of differentially expressed genes between patients with idiopathic and secondary causes of pulmonary hypertension. Microarray expression profiling of peripheral blood cells can discriminate between patients with PAH and normal volunteers. These findings may have important implications toward diagnosis, screening, and pathogenesis of this disease.
ESD requires the endoscopist to perform a surgical dissection. Until now, development of these skills required intensive training on porcine models that are not widely available. We were able to create a method using the excised portion from sleeve gastrectomy patients, providing a more accessible and cost-effective model for ESD training and potentially other endoscopic therapeutic modalities.
Burn injury in children can cause severe and chronic physical and mental sequelae. Opioids are a mainstay in burn pain management but increasing utilization in this country has led to concern for their continued use and potential for dependence. Methadone is a long-acting analgesic that targets the N-methyl-D-aspartate (NMDA) receptor in addition to the mu opioid receptor and has benefit in adult burn patients. However, its use in the pediatric burn population has been less robustly studied. This is a retrospective cohort study at a single Level 1 Burn Center whose primary aim is to compare opioid utilization 36 hours postoperatively between pediatric burn patients who received intraoperative, intravenous methadone and those who did not. Secondary aim was to describe differences in methadone-related complications between the cohorts. There was decreased opioid utilization measured by median morphine equivalents per kilogram (ME/kg) postoperatively in the methadone cohort compared to the control cohort (0.54mg/kg v. 0.77mg/kg, p = 0.18). No adverse events were noted upon chart review. The data suggests methadone use is beneficial in pediatric burn patients, but further prospective studies are warranted on a larger population.
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