Comparative efficacy of deferiprone, deferoxamine and combination of deferiprone and deferoxamine on serum ferritin value in Beta-Thalassemia patients

Background: Iron overload is a predictable and life-threatening complication in patients with thalassemia. Effective and convenient iron chelation remains one of the main targets of clinical management of thalassemia major. The development of a safe and effective chelator has been the goal for many years. Aims and Objective: It was aimed to compare the effect of deferiprone, deferoxamine and combination of deferiprone and deferoxamine on serum ferritin value in beta-thalassemia patients. Material and Methods: This controlled clinical trial was conducted on 46 major beta-thalassemic patients. Fifteen patients in deferiprone group received deferiprone 75mg/kg/day three times a day orally. Nineteen patients in deferoxamine group received deferoxamine 30-50 mg/kg/day subcutaneously for 8-12 hours/day and 5 days per week. Twelve patients in combined therapy group received deferiprone 75 mg/kg/day three times a day orally with deferoxamine 30–50 mg/kg subcutaneously every other day. Serum ferritin value was measured at the beginning and at the end of 6th and 12th months of study. Results: The mean of serum ferritin value in deferiprone group insignificantly increased from 2731± 1398.5 μg/L at the beginning to 2788.5 ± 978.6 μg/L and to 3331.8 ± 1833.9 μg/L at the end of 6th and 12th months of study, respectively. The mean of serum ferritin value in deferoxamine group insignificantly increased from 2883.5 ± 1598.1 μg/L at the beginning to 2935.3 ± 1258.2 μg/L at the end of 6th month of study and decreased to 2773.8 ± 1216.1 μg/L and 12th month of study. The mean of serum ferritin level in combined therapy group significantly decreased from 7498.7 ± 3512.9 μg/L at the beginning to 4839.9 ± 2698.2 μg/L (P < 0.001) and to 4298.2 ± 2288.7 μg/L (P < 0.001) at the end of 6th and 12th months of study, respectively. Conclusion: Combined therapy significantly decreases serum ferritin level. Study suggests deferiprone as a significant addition to support therapy in patients with betathalassemia major on regular transfusion regimens. © 2015 Journal of Krishna Institute of Medical Sciences University

Neuropilin-1 Controls Endothelial Homeostasis by Regulating Mitochondrial Function and Iron-Dependent Oxidative Stress.

The transmembrane protein neuropilin-1 (NRP1) promotes vascular endothelial growth factor (VEGF) and extracellular matrix signaling in endothelial cells (ECs). Although it is established that NRP1 is essential for angiogenesis, little is known about its role in EC homeostasis. Here, we report that NRP1 promotes mitochondrial function in ECs by preventing iron accumulation and iron-induced oxidative stress through a VEGF-independent mechanism in non-angiogenic ECs. Furthermore, NRP1-deficient ECs have reduced growth and show the hallmarks of cellular senescence. We show that a subcellular pool of NRP1 localizes in mitochondria and interacts with the mitochondrial transporter ATP-binding cassette B8 (ABCB8). NRP1 loss reduces ABCB8 levels, resulting in iron accumulation, iron-induced mitochondrial superoxide production, and iron-dependent EC senescence. Treatment of NRP1-deficient ECs with the mitochondria-targeted antioxidant compound mitoTEMPO or with the iron chelator deferoxamine restores mitochondrial activity, inhibits superoxide production, and protects from cellular senescence. This finding identifies an unexpected role of NRP1 in EC homeostasis

Perturbed angular correlation study of a haptenic molecule

The angular correlation of the 173-247 keV gamma-ray cascade after the electron-capture decay of (111)In is strongly perturbed when the I-p-nitrophenylethylenediaminetetraacetate chelate of (111)In(3+) is added to a solution containing rabbit antibody to dinitrophenyl groups. The radioactive chelate can be displaced by the addition of dinitrophenyllysine or unlabeled chelate. The average association constant between the antibody and the labeled chelate has been estimated from perturbed angular correlation measurements; this value is compared to the results of equilibrium dialysis. These experiments provide good evidence that information concerning macromolecular behavior can be obtained from perturbed angular correlation experiments that use chemically specific labels

Fob1 and Fob2 Proteins Are Virulence Determinants of Rhizopus oryzae via Facilitating Iron Uptake from Ferrioxamine.

Dialysis patients with chronic renal failure receiving deferoxamine for treating iron overload are uniquely predisposed for mucormycosis, which is most often caused by Rhizopus oryzae. Although the deferoxamine siderophore is not secreted by Mucorales, previous studies established that Rhizopus species utilize iron from ferrioxamine (iron-rich form of deferoxamine). Here we determined that the CBS domain proteins of Fob1 and Fob2 act as receptors on the cell surface of R. oryzae during iron uptake from ferrioxamine. Fob1 and Fob2 cell surface expression was induced in the presence of ferrioxamine and bound radiolabeled ferrioxamine. A R. oryzae strain with targeted reduced Fob1/Fob2 expression was impaired for iron uptake, germinating, and growing on medium with ferrioxamine as the sole source of iron. This strain also exhibited reduced virulence in a deferoxamine-treated, but not the diabetic ketoacidotic (DKA), mouse model of mucormycosis. The mechanism by which R. oryzae obtains iron from ferrioxamine involves the reductase/permease uptake system since the growth on ferrioxamine supplemented medium is associated with elevated reductase activity and the use of the ferrous chelator bathophenanthroline disulfonate abrogates iron uptake and growth on medium supplemented with ferrioxamine as a sole source of iron. Finally, R. oryzae mutants with reduced copies of the high affinity iron permease (FTR1) or with decreased FTR1 expression had an impaired iron uptake from ferrioxamine in vitro and reduced virulence in the deferoxamine-treated mouse model of mucormycosis. These two receptors appear to be conserved in Mucorales, and can be the subject of future novel therapy to maintain the use of deferoxamine for treating iron-overload

A yeast three-hybrid system that reconstitutes mammalian hypoxia inducible factor regulatory machinery

Background: Several human pathologies, including neoplasia and ischemic cardiovascular diseases, course with an unbalance between oxygen supply and demand ( hypoxia). Cells within hypoxic regions respond with the induction of a specific genetic program, under the control of the Hypoxia Inducible Factor (HIF), that mediates their adaptation to the lack of oxygen. The activity of HIF is mainly regulated by the EGL-nine homolog (EGLN) enzymes that hydroxylate the alpha subunit of this transcription factor in an oxygen-dependent reaction. Hydroxylated HIF is then recognized and ubiquitinilated by the product of the tumor suppressor gene, pVHL, leading to its proteosomal degradation. Under hypoxia, the hydroxylation of HIF by the EGLNs is compromised due to the lack of oxygen, which is a reaction cosubstrate. Thus, HIF escapes degradation and drives the transcription of its target genes. Since the progression of the aforementioned pathologies might be influenced by activation of HIF-target genes, development of small molecules with the ability to interfere with the HIF-regulatory machinery is of great interest.Results: Herein we describe a yeast three-hybrid system that reconstitutes mammalian HIF regulation by the EGLNs and VHL. In this system, yeast growth, under specific nutrient restrictions, is driven by the interaction between the beta domain of VHL and a hydroxyproline-containing HIF alpha peptide. In turn, this interaction is strictly dependent on EGLN activity that hydroxylates the HIFa peptide. Importantly, this system accurately preserves the specificity of the hydroxylation reaction toward specific substrates. We propose that this system, in combination with a matched control, can be used as a simple and inexpensive assay to identify molecules that specifically modulate EGLN activity. As a proof of principle we show that two known EGLN inhibitors, dimethyloxaloylglycine (DMOG) and 6-chlor-3-hydroxychinolin-2-carbonic acid-N-carboxymethylamide (S956711), have a profound and specific effect on the yeast HIF/EGLN/VHL system.Conclusion: The system described in this work accurately reconstitutes HIF regulation while preserving EGLN substrate specificity. Thus, it is a valuable tool to study HIF regulation, and particularly EGLN biochemistry, in a cellular context. In addition, we demonstrate that this system can be used to identify specific inhibitors of the EGLN enzymes

How early can myocardial iron overload occur in Beta thalassemia major?

BACKGROUND: Myocardial siderosis is the most common cause of death in patients with beta thalassemia major(TM). This study aimed at investigating the occurrence, prevalence and severity of cardiac iron overload in a young Chinese population with beta TM. METHODS AND RESULTS: We analyzed T2* cardiac magnetic resonance (CMR), left ventricular ejection fraction (LVEF) and serum ferritin (SF) in 201 beta TM patients. The median age was 9 years old. Patients received an average of 13 units of blood per year. The median SF level was 4536 ng/ml and 165 patients (82.1%) had SF>2500 ng/ml. Myocardial iron overload was detected in 68 patients (33.8%) and severe myocardial iron overload was detected in 26 patients (12.6%). Twenty-two patients ≤10 years old had myocardial iron overload, three of whom were only 6 years old. No myocardial iron overload was detected under the age of 6 years. Median LVEF was 64% (measured by CMR in 175 patients). Five of 6 patients with a LVEF<56% and 8 of 10 patients with cardiac disease had myocardial iron overload. CONCLUSIONS: The TM patients under follow-up at this regional centre in China patients are younger than other reported cohorts, more poorly-chelated, and have a high burden of iron overload. Myocardial siderosis occurred in patients younger than previously reported, and was strongly associated with impaired LVEF and cardiac disease. For such poorly-chelated TM patients, our data shows that the first assessment of cardiac T2* should be performed as early as 6 years old

Disease modifying therapy for multiple system atrophy – Parkinsonian Type

BACKGROUND: Multiple System Atrophy –Parkinsonian Type (MSA-P) is a rare, rapidly progressive neurodegenerative disease without any current treatment. Recent research has increased the understanding of brain iron accumulation and its association with neurodegenerative synucleinopathies, like MSA-P. Because of this improved understanding of the disease process, there is potential for new therapies that could benefit patients with MSA-P. Unfortunately, many attempts at finding a new and effective treatments for MSA-P have been unsuccessful. Two drugs that have shown potential in neurodegenerative synucleinopathies associated with brain iron accumulation are iron chelators (Deferiprone) and tyrosine kinase inhibitors (Nilotinib.) METHODS: The proposed study is a multicenter, double blind, randomized control study of Nilotinib and Deferiprone for the treatment of MSA-P. There will be two treatment arms; Nilotinib and a placebo group vs. Nilotinib and Deferiprone. There will be a 24 week treatment phase, followed by a 24 week wash-out phase. All patients will have a baseline evaluation including: a full neurological exam with rating scales (UMSARS, UPDRS, SCOPA, and MOCA) to assess motor and non-motor symptoms of MSA-P. Lab and imaging data will include CBC, CMP, serum iron panel, CSF iron panel and brain SWI-MR scans. Neurological exams and rating scales will be assessed every four weeks while imaging and laboratory data will be assessed at baseline (week 0) at the end of the intervention phase (week 24) and at the end of the follow-up phase (week 48). CONCLUSIONS: Deferiprone and Nilotinib when used together will have a synergistic impact on the symptoms of MSA-P and will be more effective when used together versus when they are used individually. SIGNIFICANCE: Patients with MSA-P have shortened life expectancy as well as severely diminished quality of life due to rapidly progressive neurodegeneration. This trial aims to implementing evidence based treatment for MSA-P that could potentially improve life expectancy as well as quality of life in this patient population

Antidote Stocking at Hospitals in North Palestine

Objective: The purpose of this study was to determine the availability and adequacy of antidote stocking at hospitals in north Palestine based on published guidelines for antidote stocking. Methodology: This study is a cross sectional survey of all hospitals at north Palestine (n=11) using a questionnaire which was completed by the director of the pharmacy department at each hospital. The questionnaire was divided into 2 parts. The first part contained a list of 25 antidotes while the second part contained a list of 12 antidotes. This classification is based on the guideline proposed by the British Association for Emergency Medicine (BAEM). The net antidote stock results were compared with the American guidelines as well. Result: The overall availability of each antidote in the first list varied widely from zero for glucagon to 100% for atropine. The number antidotes of the first list that were stocked in the 11 hospitals ranged from 5 to 12 antidotes but none of the hospitals stocked all the 25 antidotes. Additionally, availability of antidotes in the second list varied widely from zero for polyethylene glycol to 100% for dobutamine. The number of antidotes stocked ranged from 5 to 9 but none of the hospitals stocked all the 12 antidotes. Discussion and Conclusion: hospitals in north Palestine do not have adequate stock of antidotes. Raising awareness of the importance of antidotes by education, regular review of antidote storage, distribution plans, and appropriate legislation might provide solutions. Coordination between Palestinian hospitals and the PCDIC at An-Najah National University is also important

Drug-tolerant persister cancer cells are vulnerable to GPX4 inhibition.

Acquired drug resistance prevents cancer therapies from achieving stable and complete responses. Emerging evidence implicates a key role for non-mutational drug resistance mechanisms underlying the survival of residual cancer 'persister' cells. The persister cell pool constitutes a reservoir from which drug-resistant tumours may emerge. Targeting persister cells therefore presents a therapeutic opportunity to impede tumour relapse. We previously found that cancer cells in a high mesenchymal therapy-resistant cell state are dependent on the lipid hydroperoxidase GPX4 for survival. Here we show that a similar therapy-resistant cell state underlies the behaviour of persister cells derived from a wide range of cancers and drug treatments. Consequently, we demonstrate that persister cells acquire a dependency on GPX4. Loss of GPX4 function results in selective persister cell ferroptotic death in vitro and prevents tumour relapse in mice. These findings suggest that targeting of GPX4 may represent a therapeutic strategy to prevent acquired drug resistance