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1.
BMC Pediatr ; 24(1): 244, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38580952

RESUMO

BACKGROUND: ß-Thalassemia major (BTM) is one of the most common hereditary anemias worldwide. Patients suffer from iron overload that results from repeated blood transfusion This in turn leads to multiple organ damage and endocrinopathies. This study aims to assess the prevalence of growth retardation, hypothyroidism, and diabetes mellitus in children and adolescents with BTM treated at Dubai Thalassemia Centre. METHODS: A total of 105 children and adolescents were included in this retrospective observational study. RESULTS: 39 children and 66 adolescents' data were analyzed. Females composed 51.3% (n = 20) of children and 53.0% (n = 35) of adolescents. Pretransfusion hemoglobin below 9 gm/dl was observed in 10.8% (n = 4) and 10.6% (n = 7) in children and adolescents, respectively. The mean age of menarche was 13.5 years. Among all study participants, 22.6% (n = 14) had normal height velocity whereas 37.1% (n = 23) had reduced height velocity in one year and 40.3% (n = 25) had reduced height velocity in two consecutive years. The proportion of children and adolescents showing reduced height velocity was significantly higher in females compared to the males (90.6% versus 63.3%, respectively, Chi-square = 6.597, p-value = 0.010). Although none of the study participants had diabetes mellitus, 26.1% (n = 12/46) had pre-diabetes. Elevated TSH was observed in 14.7% (n = 5) children and 8.1% (n = 5) adolescents while low FT4 was reported in one child and one adolescent. CONCLUSION: Of all endocrinopathies seen among children and adolescents with BTM, growth delay remains the main concern for this group of patients. Effective treatment is key to further reducing endocrinopathies. Although the sample size is limited, we postulate that the low percentage of endocrinopathies among children with BTM treated at Dubai thalassemia center and the low level of pretransfusion anemia reflect the effective transfusion and chelation at the center.


Assuntos
Diabetes Mellitus , Hipotireoidismo , Sobrecarga de Ferro , Talassemia beta , Masculino , Criança , Feminino , Adolescente , Humanos , Talassemia beta/complicações , Talassemia beta/epidemiologia , Talassemia beta/terapia , Quelantes de Ferro/efeitos adversos , Hipotireoidismo/epidemiologia , Hipotireoidismo/etiologia
2.
J Vis Exp ; (205)2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38557954

RESUMO

Pseudomonas aeruginosa (P. aeruginosa) is known for its production of a diverse range of virulence factors to establish infections in the host. One such mechanism is the scavenging of iron through siderophore production. P. aeruginosa produces two different siderophores: pyochelin, which has lower iron-chelating affinity, and pyoverdine, which has higher iron-chelating affinity. This report demonstrates that pyoverdine can be directly quantified from bacterial supernatants, while pyochelin needs to be extracted from supernatants before quantification. The primary method for qualitatively analyzing siderophore production is the Chrome Azurol Sulfonate (CAS) agar plate assay. In this assay, the release of CAS dye from the Fe3+-Dye complex leads to a color change from blue to orange, indicating siderophore production. For the quantification of total siderophores, bacterial supernatants were mixed in equal proportions with CAS dye in a microtiter plate, followed by spectrophotometric analysis at 630 nm. Pyoverdine was directly quantified from the bacterial supernatant by mixing it in equal proportions with 50 mM Tris-HCl, followed by spectrophotometric analysis. A peak at 380 nm confirmed the presence of pyoverdine. As for Pyochelin, direct quantification from the bacterial supernatant was not possible, so it had to be extracted first. Subsequent spectrophotometric analysis revealed the presence of pyochelin, with a peak at 313 nm.


Assuntos
Infecções por Pseudomonas , Sideróforos , Tiazóis , Humanos , Pseudomonas aeruginosa , Fenóis , Quelantes de Ferro , Infecções por Pseudomonas/microbiologia
3.
Metallomics ; 16(4)2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38449344

RESUMO

Iron is a vital metal for most biological functions in tissues, and its concentration is exquisitely regulated at the cellular level. During the process of differentiation, keratinocytes in the epidermis undergo a noticeable reduction in iron content. Conversely, psoriatic lesions, characterized by disruptions in epidermal differentiation, frequently reveal an excessive accumulation of iron within keratinocytes that have undergone differentiation. In this study, we clarified the significance of attenuated cellular iron content in the intricate course of epidermal differentiation. We illustrated this phenomenon through the utilization of hinokitiol, an iron chelator derived from the heartwood of Taiwanese hinoki, which forcibly delivers iron into cells independent of the intrinsic iron-regulation systems. While primary cultured keratinocytes readily succumbed to necrotic cell death by this iron chelator, mild administration of the hinokitiol-iron complex modestly disrupts the process of differentiation in these cells. Notably, keratinocyte model cells HaCaT and anaplastic skin rudiments exhibit remarkable resilience against the cytotoxic impact of hinokitiol, and the potent artificial influx of iron explains a suppressive effect selectively on epidermal differentiation. Moreover, the augmentation of iron content induced by the overexpression of divalent metal transporter 1 culminates in the inhibition of differentiation in HaCaT cells. Consequently, the diminution in cellular iron content emerges as an important determinant influencing the trajectory of keratinocyte differentiation.


Assuntos
Ferro , Queratinócitos , Tropolona/análogos & derivados , Ferro/metabolismo , Queratinócitos/metabolismo , Monoterpenos/metabolismo , Epiderme/fisiologia , Diferenciação Celular/fisiologia , Quelantes de Ferro/metabolismo
4.
J Vis Exp ; (204)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38465932

RESUMO

Cancer cells require large amounts of iron to maintain their proliferation. Iron metabolism is considered a hallmark of cancer, making iron a valid target for anti-cancer approaches. The development of novel compounds and the identification of leads for further modification requires that proof of mechanism assays be carried out. There are many assays to evaluate the impact on proliferation; however, the ability to chelate iron is an important and sometimes overlooked end-point measure due to the high costs of equipment and the challenge to quickly and reproducibly quantify the strength of chelation. Here, we describe a quantifiable and inexpensive cell-free fluorescent method to confirm the ability of novel compounds to chelate iron. Our assay relies on the commercially available inexpensive fluorescent dye Calcein, whose fluorescence can be quantified on most fluorescent microtiter plate readers. Calcein is a weak iron chelator, and its fluorescence is quenched when it binds Fe2+/3+; fluorescence is restored when a novel chelator outcompetes Calcein for bound Fe2+/3+. The removal of fluorescent quenching and the resulting increase in fluorescence allows the chelation ability of a novel putative chelator to be determined. Therefore, we offer an inexpensive, high-throughput assay that allows the rapid screening of novel candidate chelator compounds.


Assuntos
Quelantes de Ferro , Ferro , Quelantes de Ferro/farmacologia , Quelantes de Ferro/metabolismo , Ferro/metabolismo , Fluoresceínas/metabolismo , Corantes Fluorescentes
5.
Health Qual Life Outcomes ; 22(1): 14, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38302961

RESUMO

Understanding consequences of poor chelation compliance is crucial given the enormous burden of post-transfusional iron overload complications. We systematically reviewed iron-chelation therapy (ICT) compliance, and the relationship between compliance with health outcome and health-related quality of life (HRQoL) in thalassaemia patients. Several reviewers performed systematic search strategy of literature through PubMed, Scopus, and EBSCOhost. The preferred reporting items of systematic reviews and meta-analyses (PRISMA) guidelines were followed. Of 4917 studies, 20 publications were included. The ICT compliance rate ranges from 20.93 to 75.3%. It also varied per agent, ranging from 48.84 to 85.1% for desferioxamine, 87.2-92.2% for deferiprone and 90-100% for deferasirox. Majority of studies (N = 10/11, 90.91%) demonstrated significantly negative correlation between compliance and serum ferritin, while numerous studies revealed poor ICT compliance linked with increased risk of liver disease (N = 4/7, 57.14%) and cardiac disease (N = 6/8, 75%), endocrinologic morbidity (N = 4/5, 90%), and lower HRQoL (N = 4/6, 66.67%). Inadequate compliance to ICT therapy is common. Higher compliance is correlated with lower serum ferritin, lower risk of complications, and higher HRQoL. These findings should be interpreted with caution given the few numbers of evidence.


Assuntos
Quelantes de Ferro , Talassemia , Humanos , Quelantes de Ferro/uso terapêutico , Deferasirox , Deferiprona , Desferroxamina/uso terapêutico , Qualidade de Vida , Piridonas/efeitos adversos , Benzoatos/efeitos adversos , Triazóis/efeitos adversos , Talassemia/tratamento farmacológico , Terapia por Quelação , Ferritinas , Avaliação de Resultados em Cuidados de Saúde
6.
Microbiol Spectr ; 12(3): e0369323, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38311809

RESUMO

The multidrug-resistant pathogen Pseudomonas aeruginosa is a common nosocomial respiratory pathogen that continues to threaten the lives of patients with mechanical ventilation in intensive care units and those with underlying comorbidities such as cystic fibrosis or chronic obstructive pulmonary disease. For over 20 years, studies have repeatedly demonstrated that the major siderophore pyoverdine is an important virulence factor for P. aeruginosa in invertebrate and mammalian hosts in vivo. Despite its physiological significance, an in vitro, mammalian cell culture model that can be used to characterize the impact and molecular mechanisms of pyoverdine-mediated virulence has only been developed very recently. In this study, we adapt a previously-established, murine macrophage-based model to use human bronchial epithelial (16HBE) cells. We demonstrate that conditioned medium from P. aeruginosa induced rapid 16HBE cell death through the pyoverdine-dependent secretion of cytotoxic rhamnolipids. Genetic or chemical disruption of pyoverdine biosynthesis decreased rhamnolipid production and mitigated cell death. Consistent with these observations, chemical depletion of lipids or genetic disruption of rhamnolipid biosynthesis abrogated the toxicity of the conditioned medium. Furthermore, we also examine the effects of exposure to purified pyoverdine on 16HBE cells. While pyoverdine accumulated within cells, it was largely sequestered within early endosomes, resulting in minimal cytotoxicity. More membrane-permeable iron chelators, such as the siderophore pyochelin, decreased epithelial cell viability and upregulated several pro-inflammatory genes. However, pyoverdine potentiated these iron chelators in activating pro-inflammatory pathways. Altogether, these findings suggest that the siderophores pyoverdine and pyochelin play distinct roles in virulence during acute P. aeruginosa lung infection. IMPORTANCE: Multidrug-resistant Pseudomonas aeruginosa is a versatile bacterium that frequently causes lung infections. This pathogen is life-threatening to mechanically-ventilated patients in intensive care units and is a debilitating burden for individuals with cystic fibrosis. However, the role of P. aeruginosa virulence factors and their regulation during infection are not fully understood. Previous murine lung infection studies have demonstrated that the production of siderophores (e.g., pyoverdine and pyochelin) is necessary for full P. aeruginosa virulence. In this report, we provide further mechanistic insight into this phenomenon. We characterize distinct and novel ways these siderophores contribute to virulence using an in vitro human lung epithelial cell culture model.


Assuntos
Fibrose Cística , Fenóis , Infecções por Pseudomonas , Tiazóis , Humanos , Animais , Camundongos , Sideróforos/metabolismo , Pseudomonas aeruginosa/genética , Ferro/metabolismo , Meios de Cultivo Condicionados/metabolismo , Fibrose Cística/microbiologia , Quelantes de Ferro , Infecções por Pseudomonas/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Células Epiteliais/metabolismo , Pulmão/metabolismo , Mamíferos
7.
Int J Biol Macromol ; 263(Pt 2): 130387, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38401586

RESUMO

Alzheimer's disease (AD) is a prevalent form of neurodegenerative disease with a complex pathophysiology that remains not fully understood, and the exact mechanism of neurodegeneration is uncertain. Ferroptosis has been linked to the progression of degenerative diseases observed in AD models. The present study is designed to investigate the protective effects of spermidine, a potent antioxidant and iron chelator, and its synergistic interactions with ciprofloxacin, another iron chelator, in modulating ferroptosis and mitigating AD progression in rats. This study investigated AD-related biomarkers like neurotoxic amyloid beta (Aß), arginase I, and serotonin. Spermidine demonstrated an anti-ferroptotic effect in the AD model, evident from the modulation of ferroptosis parameters such as hippocampus iron levels, reduced protein expression of transferrin receptor 1 (TFR1), and arachidonate 15-lipoxygenase (ALOX15). Additionally, the administration of spermidine led to a significant increase in protein expression of phosphorylated nuclear factor erythroid 2-related factor 2 (p-Nrf2) and upregulation of Cystine/glutamate transporter (SLC7A11) gene expression. Moreover, spermidine notably decreased p53 protein levels, acrolein, and gene expression of spermidine/spermine N1-acetyltransferase 1 (SAT1). Overall, our findings suggest that spermidine and/or ciprofloxacin may offer potential benefits against AD by modulating ferroptosis. Furthermore, spermidine enhanced the antioxidant efficacy of ciprofloxacin and reduced its toxic effects.


Assuntos
Doença de Alzheimer , Ferroptose , Doenças Neurodegenerativas , Ratos , Masculino , Animais , Doença de Alzheimer/tratamento farmacológico , Espermidina/farmacologia , Espermidina/metabolismo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Peptídeos beta-Amiloides/metabolismo , Estresse Oxidativo , Ciprofloxacina/farmacologia , Quelantes de Ferro/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo
8.
CNS Neurosci Ther ; 30(2): e14607, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38334258

RESUMO

INTRODUCTION: Several studies have reported iron accumulation in the basal ganglia to be associated with the development of Parkinson's Disease (PD). Recently, a few trials have examined the efficacy of using the iron-chelating agent Deferiprone (DFP) for patients with PD. We conducted this meta-analysis to summarize and synthesize evidence from published randomized controlled trials about the efficacy of DFP for PD patients. METHODS: A comprehensive literature search of four electronic databases was performed, spanning until February 2023. Relevant RCTs were selected, and their data were extracted and analyzed using the RevMan software. The primary outcome was the change in the Unified Parkinson's Disease Rating Scale (UPDRS-III). RESULTS: Three RCTs with 431 patients were included in this analysis. DFP did not significantly improve UPDRS-III score compared to placebo (Standardized mean difference -0.06, 95% CI [-0.69, 0.58], low certainty evidence). However, it significantly reduced iron accumulation in the substantia nigra, putamen, and caudate as measured by T2*-weighted MRI (with high certainty evidence). CONCLUSION: Current evidence does not support the use of DFP in PD patients. Future disease-modification trials with better population selection, adjustment for concomitant medications, and long-term follow up are recommended.


Assuntos
Doença de Parkinson , Humanos , Deferiprona/uso terapêutico , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/tratamento farmacológico , Quelantes de Ferro/uso terapêutico , Ferro , Substância Negra
9.
Int J Mol Sci ; 25(4)2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38396940

RESUMO

Organometallic drug development is still in its early stage, but recent studies show that organometallics having iron as the central atom have the possibility of becoming good drug candidates because iron is an important micro-nutrient, and it is compatible with many biological systems, including the human body. Being an eco-friendly Lewis acid, iron can accept the lone pair of electrons from imino(sp2)-nitrogen, and the resultant iron-imine complexes with iron as a central atom have the possibility of interacting with several proteins and enzymes in humans. Iron-imine complexes have demonstrated significant potential with anticancer, bactericidal, fungicidal, and other medicinal activities in recent years. This article systematically discusses major synthetic methods and pharmacological potentials of iron-imine complexes having in vitro activity to significant clinical performance from 2016 to date. In a nutshell, this manuscript offers a simplistic view of iron complexes in medicinal inorganic chemistry: for instance, iron is presented as an "eco-friendly non-toxic" metal (as opposed to platinum) that will lead to non-toxic pharmaceuticals. The abundant literature on iron chelators shows that many iron complexes, particularly if redox-active in cells, can be quite cytotoxic, which can be beneficial for future targeted therapies. While we made every effort to include all the related papers, any omission is purely unintentional.


Assuntos
Antineoplásicos , Complexos de Coordenação , Humanos , Iminas , Ferro , Quelantes de Ferro , Oxirredução , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/metabolismo , Complexos de Coordenação/farmacologia , Ligantes
10.
Drug Dev Ind Pharm ; 50(3): 223-235, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38305197

RESUMO

BACKGROUND: Breast cancer (BC) stands as the second-leading cause of mortality among women worldwide. Many chemotherapeutic treatments for BC come with significant adverse effects. Additionally, BC is recognized as one of the most resistant forms of malignancy to treatment. Consequently, there exists a critical need for innovative therapeutic agents that are both highly effective and exhibit reduced toxicity and side effects for patients. Deferasirox (DFX), an iron-chelating drug approved by the FDA for oral use, emerges as a promising contender in the fight against BC proliferation. DFX, primarily administered orally, is utilized to address chronic iron excess resulting from blood transfusions, and it is the inaugural treatment for chronic iron overload syndrome. However, DFX encounters limitations due to its poor water solubility. AIM: This study aimed at incorporating DFX into lipid nanocapsules (DFX-LNCs) followed by investigating the anticancer effect of the DFX nanoform as compared to free DFX in-vitro and on an orthotopic BC mouse model in-vivo. METHODS: The DFX-LNCs was prepared and imaged using TEM and also characterized in terms of particle size (PS), zeta potential (ZP), and polydispersity index (PDI) using DLS. Moreover, drug release, cytotoxicity, and anticancer effect were assessed in-vitro, and in-vivo. RESULTS: The results revealed that DFX-LNCs are more cytotoxic than free DFX with IC50 of 4.417 µg/ml and 16.114 µg/ml, respectively, while the plain LNCs didn't show any cytotoxic effect on the 4T1 cell line (IC50 = 122.797 µg/ml). Besides, the apoptotic effect of DFX-LNCs was more pronounced than that of free DFX, as evidenced by Annexin V/PI staining, increased BAX expression, and decreased expression of BcL-2. Moreover, DFX-LNCs showed a superior antitumor effect in-vivo with potent antioxidant and anti-proliferative effects. CONCLUSION: The newly developed DFX nanoform demonstrated a high potential as a promising therapeutic agent for BC treatment.


Assuntos
Neoplasias da Mama , Sobrecarga de Ferro , Humanos , Feminino , Camundongos , Animais , Deferasirox/farmacologia , Deferasirox/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Quelantes de Ferro/efeitos adversos , Ferro/uso terapêutico , Sobrecarga de Ferro/induzido quimicamente , Sobrecarga de Ferro/tratamento farmacológico
11.
Artigo em Inglês | MEDLINE | ID: mdl-38423705

RESUMO

Deferasirox is an iron-chelating drug developed by Novartis company for treatment of diseases accompanied by chronic iron overload; such as ß-thalassemia or sickle cell diseases. Owing to its advantages such as high affinity, specificity and wide therapeutic window, it is considered as first line treatment. The current chapter describes the physicochemical characteristics, mode of action, pharmacokinetics, therapeutic applications and synthetic methods for deferasirox. Moreover, it includes Fourier transform infrared spectrometry (FTIR) and nuclear magnetic resonance spectroscopy (NMR) analysis for its functional groups. In addition, the selected analytical methods are summarized to aid the analysts in their routine analysis of deferasirox.


Assuntos
Benzoatos , Sobrecarga de Ferro , Humanos , Deferasirox/farmacologia , Deferasirox/uso terapêutico , Benzoatos/farmacologia , Benzoatos/uso terapêutico , Benzoatos/metabolismo , Triazóis/uso terapêutico , Triazóis/farmacocinética , Quelantes de Ferro/farmacologia , Quelantes de Ferro/uso terapêutico , Quelantes de Ferro/metabolismo , Sobrecarga de Ferro/tratamento farmacológico , Ferro/metabolismo , Ferro/uso terapêutico
12.
BMJ Open ; 14(2): e077342, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38331857

RESUMO

INTRODUCTION: Despite the improvement in medical management, many patients with transfusion-dependent ß-thalassaemia die prematurely due to transfusion-related iron overload. As per the current guidelines, the optimal chelation of iron cannot be achieved in many patients, even with two iron chelators at their maximum therapeutic doses. Here, we evaluate the efficacy and safety of triple combination treatment with deferoxamine, deferasirox and deferiprone over dual combination of deferoxamine and deferasirox on iron chelation in patients with transfusion-dependent ß-thalassaemia with very high iron overload. METHODS AND ANALYSIS: This is a single-centre, open-label, randomised, controlled clinical trial conducted at the Adult and Adolescent Thalassaemia Centre of Colombo North Teaching Hospital, Ragama, Sri Lanka. Patients with haematologically and genetically confirmed transfusion-dependent ß-thalassaemia are enrolled and randomised into intervention or control groups. The intervention arm will receive a combination of oral deferasirox, oral deferiprone and subcutaneous deferoxamine for 6 months. The control arm will receive the combination of oral deferasirox and subcutaneous deferoxamine for 6 months. Reduction in iron overload, as measured by a reduction in the serum ferritin after completion of the treatment, will be the primary outcome measure. Reduction in liver and cardiac iron content as measured by T2* MRI and the side effect profile of trial medications are the secondary outcome measures. ETHICS AND DISSEMINATION: Ethical approval for the study has been obtained from the Ethics Committee of the Faculty of Medicine, University of Kelaniya (Ref. P/06/02/2023). The trial results will be disseminated in scientific publications in reputed journals. TRIAL REGISTRATION NUMBER: The trial is registered in the Sri Lanka Clinical Trials Registry (Ref: SLCTR/2023/010).


Assuntos
Sobrecarga de Ferro , Talassemia beta , Adulto , Adolescente , Humanos , Deferasirox/uso terapêutico , Deferiprona/uso terapêutico , Desferroxamina/uso terapêutico , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico , Benzoatos/uso terapêutico , Benzoatos/efeitos adversos , Triazóis/efeitos adversos , Piridonas , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Quelantes de Ferro/efeitos adversos , Ferro/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto
13.
Biomolecules ; 14(1)2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38254692

RESUMO

Because of their capacity to bind metals, metal chelators are primarily employed for therapeutic purposes, but they can also find applications as colorimetric reagents and cleaning solutions as well as in soil remediation, electroplating, waste treatment, and so on. For instance, iron-chelation therapy, which is used to treat iron-overload disorders, involves removing excess iron from the blood through the use of particular molecules, like deferoxamine, that have the ability to chelate the metal. The creation of bioinspired and biodegradable chelating agents is a crucial objective that draws inspiration from natural products. In this context, starting from bioavailable molecules such as maltol and pyrogallol, new molecules have been synthetized and characterized by potentiometry, infrared spectroscopy and cyclic voltammetry. Finally, the ability of these to bind iron has been investigated, and the stability constants of ferric complexes are measured using spectrophotometry. These compounds offer intriguing scaffolds for an innovative class of versatile, multipurpose chelating agents.


Assuntos
Produtos Biológicos , Quelantes de Ferro , Ferro , Terapia por Quelação , Colorimetria , Ligantes
14.
Inorg Chem ; 63(5): 2401-2417, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38265361

RESUMO

As cancer cells exhibit an increased uptake of iron, targeting the interaction with iron has become a straightforward strategy in the fight against cancer. This work comprehensively characterizes the chemical properties of 6-methyl-3-{(2E)-2-[1-(2-pyridinyl)ethylidene]hydrazino}-5H-[1,2,4]triazino[5,6-b]indole (VLX600), a clinically investigated iron chelator, in solution. Its protonation processes, lipophilicity, and membrane permeability as well as its complexation with essential metal ions were investigated using UV-visible, electron paramagnetic resonance, and NMR spectroscopic and computational methods. Formation constants revealed the following order of metal binding affinity at pH 7.4: Cu(II) > Fe(II) > Zn(II). The structures of VLX600 (denoted as HL) and the coordination modes in its metal complexes [Cu(II)(LH)Cl2], [Cu(II)(L)(CH3OH)Cl], [Zn(II)(LH)Cl2], and [Fe(II)(LH)2](NO3)2 were elucidated by single-crystal X-ray diffraction. Redox properties of the iron complexes characterized by cyclic voltammetry showed strong preference of VLX600 toward Fe(II) over Fe(III). In vitro cytotoxicity of VLX600 was determined in six different human cancer cell lines, with IC50 values ranging from 0.039 to 0.51 µM. Premixing VLX600 with Fe(III), Zn(II), and Cu(II) salts in stoichiometric ratios had a rather little effect overall, thus neither potentiating nor abolishing cytotoxicity. Together, although clinically investigated as an iron chelator, this is the first comprehensive solution study of VLX600 and its interaction with physiologically essential metal ions.


Assuntos
Complexos de Coordenação , Compostos Férricos , Hidrazonas , Triazóis , Humanos , Cobre/farmacologia , Cobre/química , Metais/química , Ferro/química , Íons , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Quelantes de Ferro/farmacologia , Compostos Ferrosos
15.
Appl Environ Microbiol ; 90(2): e0146823, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38193675

RESUMO

Bacillus spp., a class of aerobic bacteria, is widely used as a biocontrol microbe in the world. However, the reactive oxygen species (ROS) will accumulate once the aerobic bacteria are exposed to environmental stresses, which can decrease cell activity or lead to cell death. Hydroxyl radical (·OH), the strongest oxide in the ROS, can damage DNA directly, which is generated through Fenton Reaction by H2O2 and free iron. Here, we proved that the synthesis of pulcherriminic acid (PA), an iron chelator produced by Bacillus spp., could reduce DNA damage to protect cells from oxidative stress by sequestrating excess free iron, which enhanced the cell survival rates in stressful conditions (salt, antibiotic, and high temperature). It was worth noting that the synthesis of PA was found to be increased under oxidative stress. Thus, we demonstrated that the YvmB, a direct negative regulator of PA synthesis cluster yvmC-cypX, could be oxidized at cysteine residue (C57) to form a dimer losing the DNA-binding activity, which led to an improvement in PA production. Collectively, our findings highlight that YvmB senses ROS to regulate PA synthesis is one of the evolved proactive defense systems in bacteria against adverse environments.IMPORTANCEUnder environment stress, the electron transfer chain will be perturbed resulting in the accumulation of H2O2 and rapidly transform to ·OH through Fenton Reaction. How do bacteria deal with oxidative stress? At present, several iron chelators have been reported to decrease the ·OH generation by sequestrating iron, while how bacteria control the synthesis of iron chelators to resist oxidative stress is still unclear. Our study found that the synthesis of iron chelator PA is induced by reactive oxygen species (ROS), which means that the synthesis of iron chelator is a proactive defense mechanism against environment stress. Importantly, YvmB is the first response factor found to protect cells by reducing the ROS generation, which present a new perspective in antioxidation studies.


Assuntos
Bacillus licheniformis , Bacillus , Espécies Reativas de Oxigênio/metabolismo , Bacillus licheniformis/metabolismo , Peróxido de Hidrogênio , Estresse Oxidativo , Ferro/metabolismo , Quelantes de Ferro , Bacillus/metabolismo , DNA/metabolismo
16.
PLoS One ; 19(1): e0284267, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38215162

RESUMO

BACKGROUND AND AIM: Hypozincemia is a prevalent adverse consequence in diabetes mellitus (DM) and ß-Thalassemia patients. We aimed to evaluate the level of serum zinc in ß-thalassemia patients with DM and a risk assessment for hypozincemia. METHODS: The study population included transfusion-dependent thalassemia (TDT) and non-transfusion-dependent thalassemia (NTDT) with overt DM (fasting plasma glucose (FPG) ≥126 mg/dL, and/or 2-h plasma glucose≥200 mg/dL). Serum zinc concentration was measured by the colorimetric method, and the values below 70 µg/dL were defined as hypozincemia. Myocardial and liver T2*-weighted magnetic resonance imaging (MRI T2*, millisecond [ms]) were valued by a free contrast MRI. The demographic, clinical, paraclinical, and laboratory data were also recorded. The data belonged to the period from December 2018 until December 2020. RESULTS: Of 64 diabetic ß-thalassemia patients, 41 cases had zinc data in their medical files (aged 38 ± 9 years, 48.8% female). 78.05% of patients (n = 32) were TDT, and 21.95% were NTDT (n = 9). The mean ± standard deviation of zinc level was 110.2 ± 127.6 µg/dL. The prevalence of hypozincemia was 9.76%, 95% confidence interval [CI] 0.27 to 19.24 (four cases). After controlling age, the odds of hypozincemia for using deferasirox (DFX) was 8.77, 95% CI 0.60 to 127.1. In ß-thalassemia patients, the age-adjusted risk of hypozincemia was calculated at 15.85, 95% CI 0.47 to 529.3 for hepatitis C. The adjusted risk of hypozincemia based on age for antacid use was 6.34, 95% CI 0.39 to 102.7. CONCLUSION: In light of this study, as well as hepatitis C, using DFX and antacids is associated with a high risk of hypozincemia amid diabetic ß-thalassemia cases. However, upward bias should be taken into consideration.


Assuntos
Diabetes Mellitus , Hepatite C , Sobrecarga de Ferro , Talassemia , Talassemia beta , Humanos , Feminino , Masculino , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico , Deferasirox/uso terapêutico , Sobrecarga de Ferro/complicações , Glicemia , Fatores de Risco , Talassemia/epidemiologia , Hepatite C/complicações , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/induzido quimicamente , Zinco , Quelantes de Ferro/uso terapêutico
17.
Neuropharmacology ; 246: 109837, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38184274

RESUMO

BACKGROUND: Current antidepressants have limitations due to insufficient efficacy and delay before improvement in symptoms. Polymorphisms of the serotonin transporter (5-HTT) gene have been linked to depression (when combined with stressful life events) and altered response to selective serotonergic reuptake inhibitors. We have previously revealed the antidepressant-like properties of the iron chelator deferiprone in the 5-HTT knock-out (KO) mouse model of depression. Furthermore, deferiprone was found to alter neural activity in the prefrontal cortex of both wild-type (WT) and 5-HTT KO mice. METHODS: In the current study, we examined the molecular effects of acute deferiprone treatment in the prefrontal cortex of both genotypes via phosphoproteomics analysis. RESULTS: In WT mice treated with deferiprone, there were 22 differentially expressed phosphosites, with gene ontology analysis implicating cytoskeletal proteins. In 5-HTT KO mice treated with deferiprone, we found 33 differentially expressed phosphosites. Gene ontology analyses revealed phosphoproteins that were predominantly involved in synaptic and glutamatergic signalling. In a drug-naïve cohort (without deferiprone administration), the analysis revealed 21 differentially expressed phosphosites in 5-HTT KO compared to WT mice. We confirmed the deferiprone-induced increase in tyrosine hydroxylase serine 40 residue phosphorylation (pTH-Ser40) (initially revealed in our phosphoproteomics study) by Western blot analysis, with deferiprone increasing pTH-Ser40 expression in WT and 5-HTT KO mice. CONCLUSION: As glutamatergic and synaptic signalling are dysfunctional in 5-HTT KO mice (and are the target of fast-acting antidepressant drugs such as ketamine), these molecular effects may underpin deferiprone's antidepressant-like properties. Furthermore, dopaminergic signalling may also be involved in deferiprone's antidepressant-like properties.


Assuntos
Antidepressivos , Ferro , Humanos , Animais , Camundongos , Deferiprona , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Transdução de Sinais , Quelantes de Ferro/farmacologia , Camundongos Knockout
18.
Environ Microbiol Rep ; 16(1): e13234, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38240404

RESUMO

We investigated the ability of four plant and soil-associated fungi to modify or degrade siderophore structures leading to reduced siderophore iron-affinity in iron-limited and iron-replete cultures. Pyrenophora biseptata, a melanized fungus from wheat roots, was effective in inactivating siderophore iron-chelating moieties. In the supernatant solution, the tris-hydroxamate siderophore desferrioxamine B (DFOB) underwent a stepwise reduction of the three hydroxamate groups in DFOB to amides leading to a progressive loss in iron affinity. A mechanism is suggested based on the formation of transient ferrous iron followed by reduction of the siderophore hydroxamate groups during fungal high-affinity reductive iron uptake. P. biseptata also produced its own tris-hydroxamate siderophores (neocoprogen I and II, coprogen and dimerum acid) in iron-limited media and we observed loss of hydroxamate chelating groups during incubation in a manner analogous to DFOB. A redox-based reaction was also involved with the tris-catecholate siderophore protochelin in which oxidation of the catechol groups to quinones was observed. The new siderophore inactivating activity of the wheat symbiont P. biseptata is potentially widespread among fungi with implications for the availability of iron to plants and the surrounding microbiome in siderophore-rich environments.


Assuntos
Ascomicetos , Sideróforos , Triticum , Sideróforos/metabolismo , Quelantes de Ferro , Ferro/metabolismo
19.
ACS Infect Dis ; 10(2): 676-687, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38287902

RESUMO

Iron, as an essential micronutrient, plays a crucial role in host-pathogen interactions. In order to limit the growth of the pathogen, a common strategy of innate immunity includes withdrawing available iron to interfere with the cellular processes of the microorganism. Against that, unicellular parasites have developed powerful strategies to scavenge iron, despite the effort of the host. Iron-sequestering compounds, such as the approved and potent chelator deferoxamine (DFO), are considered a viable option for therapeutic intervention. Since iron is heavily utilized in the mitochondrion, targeting iron chelators in this organelle could constitute an effective therapeutic strategy. This work presents mitochondrially targeted DFO, mitoDFO, as a candidate against a range of unicellular parasites with promising in vitro efficiency. Intracellular Leishmania infection can be cleared by this compound, and experimentation with Trypanosoma brucei 427 elucidates its possible mode of action. The compound not only affects iron homeostasis but also alters the physiochemical properties of the inner mitochondrial membrane, resulting in a loss of function. Furthermore, investigating the virulence factors of pathogenic yeasts confirms that mitoDFO is a viable candidate for therapeutic intervention against a wide spectrum of microbe-associated diseases.


Assuntos
Anti-Infecciosos , Ferro , Desferroxamina/química , Antiparasitários/farmacologia , Quelantes de Ferro/farmacologia , Quelantes de Ferro/uso terapêutico , Mitocôndrias
20.
Ann N Y Acad Sci ; 1532(1): 50-62, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38270933

RESUMO

Health-related quality of life (HRQOL) is a patient-reported outcome that assesses the impact of a disease or illness on different domains of a patient's life. Different general and disease-specific measures can be used to evaluate HRQOL. This article aimed to summarize the evidence for HRQOL among patients with transfusion-dependent (TDT) and non-transfusion-dependent thalassemia (NTDT). We included HRQOL data related to standard therapy with blood transfusions, iron chelation, and/or luspatercept in TDT and NTDT, as well as curative therapies for TDT, including hematopoietic stem cell transplant (HSCT) and gene therapy. Patients with thalassemia had worse HRQOL scores compared to the general population, and chronic pain was seen to increase in frequency and severity over time with age. NTDT patients reported worse physical health and functioning, mental health, general health, and vitality than TDT patients. However, TDT patients reported worse pain, change in health, and social support than NTDT. Most therapies improved overall HRQOL among thalassemia patients. Deferasirox, an oral iron chelator, was associated with more HRQOL benefits compared to deferoxamine, an intravenous iron chelator. Luspatercept showed clinically meaningful improvement in physical functioning among TDT and NTDT. Furthermore, HSCT and gene therapy were associated with better physical, emotional, and mental domains scores.


Assuntos
Dor Crônica , Sobrecarga de Ferro , Talassemia , Humanos , Qualidade de Vida , Talassemia/terapia , Talassemia/complicações , Quelantes de Ferro/uso terapêutico , Transfusão de Sangue , Sobrecarga de Ferro/complicações
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