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CNS Neuroscience & Therapeutics Feb 2024Disturbances in the circadian rhythm are positively correlated with the processes of aging and related neurodegenerative diseases, which are also associated with brain...
AIMS
Disturbances in the circadian rhythm are positively correlated with the processes of aging and related neurodegenerative diseases, which are also associated with brain iron accumulation. However, the role of brain iron in regulating the biological rhythm is poorly understood. In this study, we investigated the impact of brain iron levels on the spontaneous locomotor activity of mice with altered brain iron levels and further explored the potential mechanisms governing these effects in vitro.
RESULTS
Our results revealed that conditional knockout of ferroportin 1 (Fpn1) in cerebral microvascular endothelial cells led to brain iron deficiency, subsequently resulting in enhanced locomotor activity and increased expression of clock genes, including the circadian locomotor output cycles kaput protein (Clock) and brain and muscle ARNT-like 1 (Bmal1). Concomitantly, the levels of period circadian regulator 1 (PER1), which functions as a transcriptional repressor in regulating biological rhythm, were decreased. Conversely, the elevated brain iron levels in APP/PS1 mice inhibited autonomous rhythmic activity. Additionally, our findings demonstrate a significant decrease in serum melatonin levels in Fpn1 -CKO mice compared with the Fpn1 group. In contrast, APP/PS1 mice with brain iron deposition exhibited higher serum melatonin levels than the WT group. Furthermore, in the human glioma cell line, U251, we observed reduced PER1 expression upon iron limitation by deferoxamine (DFO; iron chelator) or endogenous overexpression of FPN1. When U251 cells were made iron-replete by supplementation with ferric ammonium citrate (FAC) or increased iron import through transferrin receptor 1 (TfR1) overexpression, PER1 protein levels were increased. Additionally, we obtained similar results to U251 cells in mouse cerebellar astrocytes (MA-c), where we collected cells at different time points to investigate the rhythmic expression of core clock genes and the impact of DFO or FAC treatment on PER1 protein levels.
CONCLUSION
These findings collectively suggest that altered iron levels influence the circadian rhythm by regulating PER1 expression and thereby modulating the molecular circadian clock. In conclusion, our study identifies the regulation of brain iron levels as a potential new target for treating age-related disruptions in the circadian rhythm.
Topics: Mice; Humans; Animals; Iron; Melatonin; Endothelial Cells; Brain; Circadian Rhythm; Period Circadian Proteins
PubMed: 38385622
DOI: 10.1111/cns.14592 -
Biomedicine & Pharmacotherapy =... Mar 2024Iron homeostasisis is integral to normal physiological and biochemical processes of lungs. The maintenance of iron homeostasis involves the process of intake, storage... (Review)
Review
Iron homeostasisis is integral to normal physiological and biochemical processes of lungs. The maintenance of iron homeostasis involves the process of intake, storage and output, dependening on iron-regulated protein/iron response element system to operate tightly metabolism-related genes, including TFR1, DMT1, Fth, and FPN. Dysregulation of iron can lead to iron overload, which increases the virulence of microbial colonisers and the occurrence of oxidative stress, causing alveolar epithelial cells to undergo necrosis and apoptosis, and form extracellular matrix. Accumulated iron drive iron-dependent ferroptosis to exacerbated pulmonary fibrosis. Notably, the iron chelator deferoxamine and the lipophilic antioxidant ferritin-1 have been shown to attenuate ferroptosis and inhibit lipid peroxidation in pulmonary fibrosis. The paper summarises the regulatory mechanisms of dysregulated iron metabolism and ferroptosis in the development of pulmonary fibrosis. Targeting iron metabolism may be a potential therapeutic strategy for the prevention and treatment of pulmonary fibrosis.
Topics: Humans; Pulmonary Fibrosis; Lipid Peroxidation; Oxidative Stress; Alveolar Epithelial Cells; Iron
PubMed: 38364737
DOI: 10.1016/j.biopha.2024.116270 -
Scientific Reports Feb 2024In this work, we present the synthesis and evaluation of magnetic resonance (MR) properties of novel phosphorus/iron-containing probes for dual P and H MR imaging and...
In this work, we present the synthesis and evaluation of magnetic resonance (MR) properties of novel phosphorus/iron-containing probes for dual P and H MR imaging and spectroscopy (MRI and MRS). The presented probes are composed of biocompatible semitelechelic and multivalent phospho-polymers based on poly(2-methacryloyloxyethyl phosphorylcholine) (pMPC) coordinated with small paramagnetic Fe ions or superparamagnetic maghemite (γ-FeO) nanoparticles via deferoxamine group linked to the end or along the polymer chains. All probes provided very short H T and T relaxation times even at low iron concentrations. The presence of iron had a significant impact on the shortening of P relaxation, with the effect being more pronounced for probes based on γ-FeO and multivalent polymer. While the water-soluble probe having one Fe ion per polymer chain was satisfactorily visualized by both P-MRS and P-MRI, the probe with multiple Fe ions could only be detected by P-MRS, and the probes consisting of γ-FeO nanoparticles could not be imaged by either technique due to their ultra-short P relaxations. In this proof-of-principle study performed on phantoms at a clinically relevant magnetic fields, we demonstrated how the different forms and concentrations of iron affect both the H MR signal of the surrounding water molecules and the P MR signal of the phospho-polymer probe. Thus, this double contrast can be exploited to simultaneously visualize body anatomy and monitor probe biodistribution.
Topics: Polymers; Tissue Distribution; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Iron; Water
PubMed: 38360883
DOI: 10.1038/s41598-024-54158-x -
EJNMMI Radiopharmacy and Chemistry Feb 2024Nanoparticles exhibit distinct behaviours within the body, depending on their physicochemical properties and administration routes. However, in vivo behaviour of...
BACKGROUND
Nanoparticles exhibit distinct behaviours within the body, depending on their physicochemical properties and administration routes. However, in vivo behaviour of poly(lactic-co-glycolic acid) (PLGA) nanoparticles, especially when administered nasally, remains unexplored; furthermore, there is a lack of comparative analysis of uptake efficiency among different administration routes. Therefore, here, we aimed to comprehensively investigate the real-time in vivo behaviour of PLGA nanoparticles across various administration routes. PLGA-NH nanoparticles of three sizes were synthesised using an oil-in-water single-emulsion method. We assessed their uptake by murine macrophage RAW264.7 cells using fluorescence microscopy. To enable real-time tracking, we conjugated p-SCN-Bn-deferoxamine to PLGA-NH nanoparticles and further radiolabelled them with Zr-oxalate before administration to mice via different routes. Nanoparticle internalisation by lung immune cells was monitored using fluorescence-activated cell sorting analysis.
RESULTS
The nanoparticle sizes were 294 ± 2.1 (small), 522.5 ± 5.58 (intermediate), and 850 ± 18.52 nm (large). Fluorescent labelling did not significantly alter the nanoparticle size and charge. The level of uptake of small and large nanoparticles by RAW264.7 cells was similar, with phagocytosis inhibition primarily reducing the internalisation of large particles. Positron emission tomography revealed that intranasal delivery resulted in the highest and most targeted pulmonary uptake, whereas intravenous administration led to accumulation mainly in the liver and spleen. Nasal delivery of large nanoparticles resulted in enhanced uptake by myeloid immune cells relative to lymphoid cells, whereas dendritic cell uptake initially peaked but declined over time.
CONCLUSIONS
Our study provides valuable insights into advancing nanomedicine and drug delivery, with the potential for expanding the clinical applications of nanoparticles.
PubMed: 38358577
DOI: 10.1186/s41181-023-00227-x -
Frontiers in Microbiology 2024Food-borne infections constitute serious threats to human health worldwide. Since antibiotic treatment is usually not indicated in infected immune-competent patients,...
Oral treatment of human gut microbiota associated IL-10 mice suffering from acute campylobacteriosis with carvacrol, deferoxamine, deoxycholic acid, and 2-fucosyl-lactose.
Food-borne infections constitute serious threats to human health worldwide. Since antibiotic treatment is usually not indicated in infected immune-competent patients, antibiotic-independent treatment approaches are needed to tackle campylobacteriosis. To address this, we orally applied carvacrol, deferoxamine, deoxycholate, and 2-fucosyl-lactose either alone or all in combination to human microbiota-associated IL-10 mice from day 2 until day 6 following oral infection. Neither treatment regimen affected loads in the colon, whereas carvacrol lowered the pathogen numbers in the ileum on day 6 post-infection (p.i.). The carvacrol and combination treatment regimens resulted in alleviated diarrheal symptoms, less distinct histopathological and apoptotic epithelial cell responses in the colon, as well as diminished numbers of colonic neutrophils and T lymphocytes on day 6 p.i., whereas the latter cells were also decreased upon deferoxamine, deoxycholate, or 2-fucosyl-lactose application. Remarkably, the carvacrol, deferoxamine, and combination treatment regimens dampened IFN-γ secretion in the colon, the kidneys, and even in the serum to basal concentrations on day 6 p.i. In conclusion, carvacrol alone and its combination with deferoxamine, deoxycholate, and 2-fucosyl-lactose constitute promising antibiotics-independent treatment options to fight acute campylobacteriosis.
PubMed: 38343716
DOI: 10.3389/fmicb.2024.1290490 -
BMJ Open Feb 2024Despite the improvement in medical management, many patients with transfusion-dependent β-thalassaemia die prematurely due to transfusion-related iron overload. As per...
Efficacy and safety of deferoxamine, deferasirox and deferiprone triple iron chelator combination therapy for transfusion-dependent β-thalassaemia with very high iron overload: a protocol for randomised controlled clinical trial.
INTRODUCTION
Despite the improvement in medical management, many patients with transfusion-dependent β-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 β-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 β-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).
Topics: Adult; Adolescent; Humans; Deferasirox; Deferiprone; Deferoxamine; beta-Thalassemia; Benzoates; Triazoles; Pyridones; Iron Overload; Iron Chelating Agents; Iron; Randomized Controlled Trials as Topic
PubMed: 38331857
DOI: 10.1136/bmjopen-2023-077342 -
Bioactive Materials May 2024Repair of large bone defects caused by severe trauma, non-union fractures, or tumor resection remains challenging because of limited regenerative ability. Typically,...
Repair of large bone defects caused by severe trauma, non-union fractures, or tumor resection remains challenging because of limited regenerative ability. Typically, these defects heal through mixed routines, including intramembranous ossification (IMO) and endochondral ossification (ECO), with ECO considered more efficient. Current strategies to promote large bone healing via ECO are unstable and require high-dose growth factors or complex cell therapy that cause side effects and raise expense while providing only limited benefit. Herein, we report a bio-integrated scaffold capable of initiating an early hypoxia microenvironment with controllable release of low-dose recombinant bone morphogenetic protein-2 (rhBMP-2), aiming to induce ECO-dominated repair. Specifically, we apply a mesoporous structure to accelerate iron chelation, this promoting early chondrogenesis via deferoxamine (DFO)-induced hypoxia-inducible factor-1α (HIF-1α). Through the delicate segmentation of click-crosslinked PEGylated Poly (glycerol sebacate) (PEGS) layers, we achieve programmed release of low-dose rhBMP-2, which can facilitate cartilage-to-bone transformation while reducing side effect risks. We demonstrate this system can strengthen the ECO healing and convert mixed or mixed or IMO-guided routes to ECO-dominated approach in large-size models with clinical relevance. Collectively, these findings demonstrate a biomaterial-based strategy for driving ECO-dominated healing, paving a promising pave towards its clinical use in addressing large bone defects.
PubMed: 38327823
DOI: 10.1016/j.bioactmat.2024.01.019 -
Applied and Environmental Microbiology Mar 2024Iron is essential to many biological processes but its poor solubility in aerobic environments restricts its bioavailability. To overcome this limitation, bacteria have...
Iron is essential to many biological processes but its poor solubility in aerobic environments restricts its bioavailability. To overcome this limitation, bacteria have evolved a variety of strategies, including the production and secretion of iron-chelating siderophores. Here, we describe the discovery of four series of siderophores from ATCC23877, three of which are unprecedented. MS/MS-based molecular networking revealed that one of these series corresponds to acylated desferrioxamines (acyl-DFOs) recently identified from . The remaining sets include tetra- and penta-hydroxamate acyl-DFO derivatives, all of which incorporate a previously undescribed building block. Stable isotope labeling and gene deletion experiments provide evidence that biosynthesis of the acyl-DFO congeners requires unprecedented crosstalk between two separate non-ribosomal peptide synthetase (NRPS)-independent siderophore (NIS) pathways in the producing organism. Although the biological role(s) of these new derivatives remain to be elucidated, they may confer advantages in terms of metal chelation in the competitive soil environment due to the additional bidentate hydroxamic functional groups. The metabolites may also find application in various fields including biotechnology, bioremediation, and immuno-PET imaging.IMPORTANCEIron-chelating siderophores play important roles for their bacterial producers in the environment, but they have also found application in human medicine both in iron chelation therapy to prevent iron overload and in diagnostic imaging, as well as in biotechnology, including as agents for biocontrol of pathogens and bioremediation. In this study, we report the discovery of three novel series of related siderophores, whose biosynthesis depends on the interplay between two NRPS-independent (NIS) pathways in the producing organism the first example to our knowledge of such functional cross-talk. We further reveal that two of these series correspond to acyl-desferrioxamines which incorporate four or five hydroxamate units. Although the biological importance of these novel derivatives is unknown, the increased chelating capacity of these metabolites may find utility in diagnostic imaging (for instance, Zr-based immuno-PET imaging) and other applications of metal chelators.
Topics: Humans; Siderophores; Deferoxamine; Tandem Mass Spectrometry; Iron; Hydroxamic Acids; Peptide Synthases
PubMed: 38323847
DOI: 10.1128/aem.02115-23 -
Heliyon Feb 2024Diabetic foot ulcer (DFU) is a chronic complication of diabetes. Wound healing in patients with DFU is generally very slow, with a high recurrence rate even after the... (Review)
Review
Diabetic foot ulcer (DFU) is a chronic complication of diabetes. Wound healing in patients with DFU is generally very slow, with a high recurrence rate even after the ulcer healed. The DFU remains a major clinical challenge due to a lack of understanding of its pathogenesis. Given the significant impact of DFU on patient health and medical costs, enhancing our understanding of pathophysiological alterations and wound healing in DFU is critical. A growing body of research has shown that impaired activation of the HIF-1 pathway in diabetics, which weakens HIF-1 mediated responses to hypoxia and leads to down-regulation of its downstream target genes, leading to incurable diabetic foot ulcers. By analyzing and summarizing the literature in recent years, this review summarizes the mechanism of HIF-1 signaling pathway damage in the development of DFU, analyzes and compares the application of PHD inhibitors, VHL inhibitors, biomaterials and stem cell therapy in chronic wounds of diabetes, and proposes a new treatment scheme mediated by participation in the HIF-1 signaling pathway, which provides new ideas for the treatment of DFU.
PubMed: 38318060
DOI: 10.1016/j.heliyon.2024.e24656