Iron deficiency in pulmonary arterial hypertension: perspectives.
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ABSTRACT:
SUBMITTER: Quatredeniers M
PROVIDER: S-EPMC8207285 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Iron deficiency augments hypoxic pulmonary arterial pressure in healthy individuals and exacerbates pulmonary arterial hypertension (PAH) in patients, even without anemia. Conversely, iron supplementation has been shown to be beneficial in both settings. The mechanisms underlying the effects of iron availability are not known, due to lack of understanding of how cells of the pulmonary vasculature respond to changes in iron levels. The iron export protein ferroportin (FPN) and its antagonist peptide hepcidin control systemic iron levels by regulating release from the gut and spleen, the sites of absorption and recycling, respectively. We found FPN to be present in pulmonary arterial smooth muscle cells (PASMCs) and regulated by hepcidin cell autonomously. To interrogate the importance of this regulation, we generated mice with smooth muscle-specific knock in of the hepcidin-resistant isoform fpn C326Y. While retaining normal systemic iron levels, this model developed PAH and right heart failure as a consequence of intracellular iron deficiency and increased expression of the vasoconstrictor endothelin-1 (ET-1) within PASMCs. PAH was prevented and reversed by i.v. iron and by the ET receptor antagonist BQ-123. The regulation of ET-1 by iron was also demonstrated in healthy humans exposed to hypoxia and in PASMCs from PAH patients with mutations in bone morphogenetic protein receptor type II. Such mutations were further associated with dysregulation of the HAMP/FPN axis in PASMCs. This study presents evidence that intracellular iron deficiency specifically within PASMCs alters pulmonary vascular function. It offers a mechanistic underpinning for the known effects of iron availability in humans.
| S-EPMC6600981 | biostudies-literature
Project description:UnlabelledIn patients with idiopathic pulmonary arterial hypertension (iPAH), iron deficiency is common and has been associated with reduced exercise capacity and worse survival. Previous studies have shown beneficial effects of intravenous iron administration. In this study, we investigated the use of intravenous iron therapy in iron-deficient iPAH patients in terms of safety and effects on exercise capacity, and we studied whether altered exercise capacity resulted from changes in right ventricular (RV) function and skeletal muscle oxygen handling. Fifteen patients with iPAH and iron deficiency were included. Patients underwent a 6-minute walk test, cardiopulmonary exercise tests, cardiac magnetic resonance imaging, and a quadriceps muscle biopsy and completed a quality-of-life questionnaire before and 12 weeks after receiving a high dose of intravenous iron. The primary end point, 6-minute walk distance, was not significantly changed after 12 weeks (409 ± 110 m before vs. 428 ± 94 m after; P = 0.07). Secondary end points showed that intravenous iron administration was well tolerated and increased body iron stores in all patients. In addition, exercise endurance time (P < 0.001) and aerobic capacity (P < 0.001) increased significantly after iron therapy. This coincided with improved oxygen handling in quadriceps muscle cells, although cardiac function at rest and maximal [Formula: see text] were unchanged. Furthermore, iron treatment was associated with improved quality of life (P < 0.05). In conclusion, intravenous iron therapy in iron-deficient iPAH patients improves exercise endurance capacity. This could not be explained by improved RV function; however, increased quadriceps muscle oxygen handling may play a role. (Trial registrationClinicalTrials.gov identifier NCT01288651).
| S-EPMC4556497 | biostudies-literature
Project description:Pulmonary arterial hypertension (PAH) is a severe cardiovascular disease that is caused by the progressive occlusion of the distal pulmonary arteries, eventually leading to right heart failure and death. Almost 40% of patients with PAH are iron deficient. Although widely studied, the mechanisms linking between PAH and iron deficiency remain unclear. Here we review the mechanisms regulating iron homeostasis and the preclinical and clinical data available on iron deficiency in PAH. Then we discuss the potential implications of iron deficiency on the development and management of PAH.
| S-EPMC7926484 | biostudies-literature
Project description:While there have been advances in the field of pulmonary arterial hypertension (PAH), disease management remains suboptimal for many patients. The development of novel treatments and strategies can provide opportunities to target other mechanisms that play a role in the complex pathobiology of PAH outside of the three main pathophysiological pathways. In this review, we highlight some of the potential PAH therapies or techniques that are being, or have been, investigated in phase II clinical trials. This review also discusses potential points for consideration in the development of novel therapies that target putative disease mediators or modifiers.
| S-EPMC9487553 | biostudies-literature
Project description:BackgroundPulmonary arterial hypertension (PAH) is a progressive disease with limited survival. Iron deficiency (ID) correlates with disease severity and mortality. While oral iron supplementation was shown to be insufficient in such patients, the potential impact of parenteral iron on clinical measures warrants further investigation.MethodsWe retrospectively analysed the long-term effects of intravenous ferric carboxymaltose (FCM) on iron status and clinical measures in patients with PAH and ID [ferritin < 100 μg/L or ferritin 100-300 μg/L and transferrin saturation (TSAT) < 20%] who were on stable targeted PAH therapy, compared with matched controls without ID. Patients with ID received a single infusion of FCM (500 to 1000 mg). Clinical measures monitored included exercise capacity, World Health Organization (WHO) functional class, ESC/ERS risk status, and hospitalizations. The observation period was up to 18 months.ResultsOne hundred and seventeen patients (mean age 60.9 ± 16.1 years; 64.1% females) with confirmed PAH and on stable targeted therapy for ≥3 months were included (58 with and 59 patients without ID who did not receive FCM). In patients with ID, iron supplementation with FCM resulted in an immediate and sustained improvement of iron status for up to 18 months (serum iron, ferritin, TSAT, all P < 0.01). Fourteen patients in the FCM group received a second FCM infusion after 9.6 ± 4.8 months due to recurrent ID. At 6 and 18 months after FCM infusion, 6 min walk distance improved from 377.5 ± 15.9 at baseline to 412.5 ± 15.1 and 400.8 ± 14.5 m, respectively (both P < 0.05). WHO functional class (P < 0.05) and ESC/ERS risk status also improved, and there was a reduction of hospitalizations for worsening PAH in the 12 months post vs. prior to iron repletion (P = 0.029). No significant changes were observed in the control group. FCM was well tolerated in all patients, with no severe adverse events.ConclusionsIn addition to targeted therapy, correction of ID by parenteral iron supplementation with FCM appears feasible and safe, has sustained effects on iron status, and may improve the clinical status and hospitalization rates in patients with PAH. Larger controlled studies are required to confirm this finding.
| S-EPMC8718050 | biostudies-literature
Project description:Pulmonary arterial hypertension (PAH) is a chronic and progressive disease characterized by pulmonary vasculopathy with elevation of pulmonary artery pressure, often culminating in right ventricular failure. GATA-6, a member of the GATA family of zinc-finger transcription factors, is highly expressed in quiescent vasculature and is frequently lost during vascular injury. We hypothesized that endothelial GATA-6 may play a critical role in the molecular mechanisms underlying endothelial cell (EC) dysfunction in PAH. Here we report that GATA-6 is markedly reduced in pulmonary ECs lining both occluded and nonoccluded vessels in patients with idiopathic and systemic sclerosis-associated PAH. GATA-6 transcripts are also rapidly decreased in rodent PAH models. Endothelial GATA-6 is a direct transcriptional regulator of genes controlling vascular tone [endothelin-1, endothelin-1 receptor type A, and endothelial nitric oxide synthase (eNOS)], pro-inflammatory genes, CX3CL1 (fractalkine), 5-lipoxygenease-activating protein, and markers of vascular remodeling, including PAI-1 and RhoB. Mice with the genetic deletion of GATA-6 in ECs (Gata6-KO) spontaneously develop elevated pulmonary artery pressure and increased vessel muscularization, and these features are further exacerbated in response to hypoxia. Furthermore, innate immune cells including macrophages (CD11b(+)/F4/80(+)), granulocytes (Ly6G(+)/CD45(+)), and dendritic cells (CD11b(+)/CD11c(+)) are significantly increased in normoxic Gata6-KO mice. Together, our findings suggest a critical role of endothelial GATA-6 deficiency in development and disease progression in PAH.
| S-EPMC3668018 | biostudies-literature
Project description:Microarray analysis of peripheral blood mononuclear (PBMC) cells in pulmonary arterial hypertension. Keywords = mononuclear cells Keywords = gene microarray Keywords = pulmonary arterial hypertension Keywords = Herpesvirus Keywords = biomarker Keywords: other
2003-11-15 | GSE703 | GEO
Project description:Pulmonary arterial hypertension (PAH), is a fatal disease characterized by a pseudo-malignant phenotype. We investigated the expression and the role of the receptor tyrosine kinase Axl in experimental (i.e., monocrotaline and Su5416/hypoxia treated rats) and clinical PAH. In vitro Axl inhibition by R428 and Axl knock-down inhibited growth factor-driven proliferation and migration of non-PAH and PAH PASMCs. Conversely, Axl overexpression conferred a growth advantage. Axl declined in PAECs of PAH patients. Axl blockage inhibited BMP9 signaling and increased PAEC apoptosis, while BMP9 induced Axl phosphorylation. Gas6 induced SMAD1/5/8 phosphorylation and ID1/ID2 increase were blunted by BMP signaling obstruction. Axl association with BMPR2 was facilitated by Gas6/BMP9 stimulation and diminished by R428. In vivo R428 aggravated right ventricular hypertrophy and dysfunction, abrogated BMPR2 signaling, elevated pulmonary endothelial cell apoptosis and loss. Together, Axl is a key regulator of endothelial BMPR2 signaling and potential determinant of PAH.
| S-EPMC8385080 | biostudies-literature
Project description:NFU1 deficiency is a rare metabolic disorder affecting iron-sulfur cluster synthesis, an essential pathway for lipoic acid-dependent enzymatic activities and mitochondrial respiratory chain complexes. It is a little-known cause of pulmonary arterial hypertension (PAH), while PAH is a prominent feature of the disease. We herein report on a female infant diagnosed as having idiopathic PAH since 1 month of age, who did not respond to bosentan plus sildenafil. NFU1 deficiency was only suggested and confirmed at 10 months of age when she demonstrated neurological deterioration along with high glycine levels in body fluids. Unexplained PAH in early infancy should prompt clinicians to perform amino acid chromatography searching for high glycine levels. Early recognition will avoid further invasive procedures and enable appropriate genetic counseling to be offered. No effective treatment is currently able to prevent the fatal course of this metabolic condition.
| S-EPMC6716310 | biostudies-literature
Project description:Rationale: Iron deficiency, in the absence of anemia, is common in patients with idiopathic and heritable pulmonary arterial hypertension (PAH) and is associated with a worse clinical outcome. Oral iron absorption may be impeded by elevated circulating hepcidin concentrations. The safety and benefit of parenteral iron replacement in this patient population is unclear. Objectives: To evaluate the safety and efficacy of parenteral iron replacement in PAH. Methods: In two randomized, double-blind, placebo-controlled 12-week crossover studies, 39 patients in Europe received a single infusion of ferric carboxymaltose (Ferinject) (1,000 mg or 15 mg/kg if weight <66.7 kg) or saline as placebo, and 17 patients in China received iron dextran (Cosmofer) (20 mg iron/kg body weight) or saline placebo. All patients had idiopathic or heritable PAH and iron deficiency at entry as defined by a serum ferritin <37 μg/L or iron <10.3 μmol/L or transferrin saturations <16.4%. Results: Both iron treatments were well tolerated and improved iron status. Analyzed separately and combined, there was no effect on any measure of exercise capacity (using cardiopulmonary exercise testing or 6-minute walk test) or cardiopulmonary hemodynamics, as assessed by right heart catheterization, cardiac magnetic resonance, or plasma NT-proBNP (N-terminal-pro hormone brain natriuretic peptide) at 12 weeks. Conclusions: Iron repletion by administration of a slow-release iron preparation as a single infusion to patients with PAH with iron deficiency without overt anemia was well tolerated but provided no significant clinical benefit at 12 weeks. Clinical trial registered with ClinicalTrials.gov (NCT01447628).
| S-EPMC8456720 | biostudies-literature