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Cincinnati, OH, United States

Sundaram N.,Cincinnati Childrens Hospital Medical Center | Tailor A.,U.S. National Institutes of Health | Mendelsohn L.,U.S. National Institutes of Health | Wansapura J.,Cincinnati Childrens Hospital Medical Center | And 9 more authors.
Blood | Year: 2010

Pulmonary hypertension is associated with reduced nitric oxide bioavailability and early mortality in sickle cell disease (SCD). We previously demonstrated that placenta growth factor (PlGF), an angiogenic factor produced by erythroid cells, induces hypoxia-independent expression of the pulmonary vasoconstrictor endothelin-1 in pulmonary endothelial cells. Using a lentivirus vector, we simulated erythroid expression of PlGF in normal mice up to the levels seen in sickle mice. Consequently, endothelin-1 production increased, right ventricle pressures increased, and right ventricle hypertrophy and pulmonary changes occurred in the mice within 8 weeks. These findings were corroborated in 123 patients with SCD, inwhom plasma PlGF levels were significantly associated with anemia, endothelin-1, and tricuspid regurgitant velocity; the latter is reflective of peak pulmonary artery pressure. These results illuminate a novel mechanistic pathway linking hemolysis and erythroid hyperplasia to increased PlGF, endothelin-1, and pulmonary hypertension in SCD, and suggest that strategies that block PlGF signaling may be therapeutically beneficial. This trial was registered at http://clinicaltrials.gov as #NCT00011648. Source


Mpollo M.-S.E.M.,Burnet Institute | Mpollo M.-S.E.M.,University of Cincinnati | Brandt E.B.,University of Cincinnati | Shanmukhappa S.K.,CCHMC | And 16 more authors.
Journal of Clinical Investigation | Year: 2016

Airway hyperresponsiveness (AHR) affects 55%-77% of children with sickle cell disease (SCD) and occurs even in the absence of asthma. While asthma increases SCD morbidity and mortality, the mechanisms underlying the high AHR prevalence in a hemoglobinopathy remain unknown. We hypothesized that placenta growth factor (PlGF), an erythroblast-secreted factor that is elevated in SCD, mediates AHR. In allergen-exposed mice, loss of Plgf dampened AHR, reduced inflammation and eosinophilia, and decreased expression of the Th2 cytokine IL-13 and the leukotriene-synthesizing enzymes 5-lipoxygenase and leukotriene-C4-synthase. Plgf-/- mice treated with leukotrienes phenocopied the WT response to allergen exposure; conversely, anti-PlGF Ab administration in WT animals blunted the AHR. Notably, Th2-mediated STAT6 activation further increased PlGF expression from lung epithelium, eosinophils, and macrophages, creating a PlGF/leukotriene/Th2-response positive feedback loop. Similarly, we found that the Th2 response in asthma patients is associated with increased expression of PlGF and its downstream genes in respiratory epithelial cells. In an SCD mouse model, we observed increased AHR and higher leukotriene levels that were abrogated by anti-PlGF Ab or the 5-lipoxygenase inhibitor zileuton. Overall, our findings indicate that PlGF exacerbates AHR and uniquely links the leukotriene and Th2 pathways in asthma. These data also suggest that zileuton and anti-PlGF Ab could be promising therapies to reduce pulmonary morbidity in SCD. Source


Perumbeti A.,Cancer and Blood Institute | Malik P.,Cancer and Blood Institute
TheScientificWorldJournal | Year: 2010

Gene therapy for β-globinopathies, particularly β-thalassemia and sickle cell anemia, holds promise for the future as a definitive corrective approach for these common and debilitating disorders. Correction of the β-globinopathies using lentivirus vectors carrying the β- or γ-globin genes and elements of the locus control region has now been well established in murine models, and an understanding of "what is required to cure these diseases" has been developed in the first decade of the 21 st century. A clinical trial using one such vector has been initiated in France with intriguing results, while other trials are under development. Vector improvements to enhance the safety and efficiency of lentivirus vectors are being explored, while new strategies, including homologous recombination in induced pluripotent cells, for correction of sickle cell anemia have shown proof-of-concept in vitro. Here, a review is provided of the current substantial progress in genetic correction of β-globin disorders. ©2010 with author. Published by TheScientificWorld. Source


Perumbeti A.,Cancer and Blood Institute | Malik P.,Cancer and Blood Institute
Annals of the New York Academy of Sciences | Year: 2010

Gene therapy for β-globinopathies, particularly β-thalassemia and sickle cell anemia, hold much promise for the future, as a one time cure for these common and debilitating disorders. Correction of the β-globinopathies using lentivirus vectors (LV) carrying the β- or γ-globin genes and elements of the locus control region has been well established in murine models, and a good idea of "what it will take to cure these diseases" has been developed in the first decade of the twenty-first century. A clinical trial using one such vector has been initiated in France while other trials are in development. Vector improvements to enhance the safety and efficiency of LV are being explored, while newer strategies, like homologous recombination in induced pluripotent cells for correction of sickle cell anemia, has been shown as a proof-of-concept. Here we provide a review of current progress in genetic correction of β-globin disorders. © 2010 New York Academy of Sciences. Source

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