iron accumulation Dotaz Zobrazit nápovědu
PURPOSE OF REVIEW: Recent years have witnessed the discoveries of several genes causing neurodegeneration with brain iron accumulation (NBIA) and subsequently their novel classification scheme was suggested. The first results of treatments with modern chelating drugs are also being published. RECENT FINDINGS: Most recently, mutations in the c19orf12 gene encoding a mitochondrial protein of unknown function were identified in patients suffering from hitherto unknown NBIA presenting with a clinical phenotype similar to pantothenate kinase-associated neurodegeneration (PKAN) but with a slightly later onset. A case study has shown that mutations in the fatty-acid 2-hydroxylase gene may lead to various phenotypes combining the features of leukodystrophy and NBIA, supporting that abnormal metabolism of myelin and iron accumulation may have a common cause. A phase-II pilot study did not find any clinical improvement after chelating treatment in a group of PKAN patients. However, benefits of chelating treatment have been observed in individual patients with PKAN and idiopathic NBIA in another study. SUMMARY: This review gives an outline of the clinical presentations of recently discovered NBIA syndromes and summarizes the clues to their differential diagnosis. While chelating treatment still remains experimental, advances have been made regarding the indications of deep brain stimulation in symptomatic treatment of NBIAs manifesting with generalized dystonia.
- MeSH
- chelátory železa terapeutické užití MeSH
- diferenciální diagnóza MeSH
- lidé MeSH
- mitochondriální proteiny genetika MeSH
- mozek účinky léků metabolismus MeSH
- mutace genetika MeSH
- neurodegenerativní nemoci farmakoterapie patologie MeSH
- železo metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- C19orf12 protein, human MeSH Prohlížeč
- chelátory železa MeSH
- mitochondriální proteiny MeSH
- železo MeSH
Disruption of cerebral iron regulation appears to have a role in aging and in the pathogenesis of various neurodegenerative disorders. Possible unfavorable impacts of iron accumulation include reactive oxygen species generation, induction of ferroptosis, and acceleration of inflammatory changes. Whole-brain iron-sensitive magnetic resonance imaging (MRI) techniques allow the examination of macroscopic patterns of brain iron deposits in vivo, while modern analytical methods ex vivo enable the determination of metal-specific content inside individual cell-types, sometimes also within specific cellular compartments. The present review summarizes the whole brain, cellular, and subcellular patterns of iron accumulation in neurodegenerative diseases of genetic and sporadic origin. We also provide an update on mechanisms, biomarkers, and effects of brain iron accumulation in these disorders, focusing on recent publications. In Parkinson's disease, Friedreich's disease, and several disorders within the neurodegeneration with brain iron accumulation group, there is a focal siderosis, typically in regions with the most pronounced neuropathological changes. The second group of disorders including multiple sclerosis, Alzheimer's disease, and amyotrophic lateral sclerosis shows iron accumulation in the globus pallidus, caudate, and putamen, and in specific cortical regions. Yet, other disorders such as aceruloplasminemia, neuroferritinopathy, or Wilson disease manifest with diffuse iron accumulation in the deep gray matter in a pattern comparable to or even more extensive than that observed during normal aging. On the microscopic level, brain iron deposits are present mostly in dystrophic microglia variably accompanied by iron-laden macrophages and in astrocytes, implicating a role of inflammatory changes and blood-brain barrier disturbance in iron accumulation. Options and potential benefits of iron reducing strategies in neurodegeneration are discussed. Future research investigating whether genetic predispositions play a role in brain Fe accumulation is necessary. If confirmed, the prevention of further brain Fe uptake in individuals at risk may be key for preventing neurodegenerative disorders.
- Klíčová slova
- MRI, NBIA, chelation, ferroptosis, iron accumulation, neurodegeneration, siderosis,
- MeSH
- lidé MeSH
- mozek patologie MeSH
- neuroaxonální dystrofie * patologie MeSH
- neurodegenerativní nemoci * patologie MeSH
- poruchy metabolismu železa * patologie MeSH
- železo farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- železo MeSH
AIMS: In Wilson disease (WD), T2/T2*-weighted (T2*w) MRI frequently shows hypointensity in the basal ganglia that is suggestive of paramagnetic deposits. It is currently unknown whether this hypointensity is related to copper or iron deposition. We examined the neuropathological correlates of this MRI pattern, particularly in relation to iron and copper concentrations. METHODS: Brain slices from nine WD and six control cases were investigated using a 7T-MRI system. High-resolution T2*w images were acquired and R2* parametric maps were reconstructed using a multigradient recalled echo sequence. R2* was measured in the globus pallidus (GP) and the putamen. Corresponding histopathological sections containing the lentiform nucleus were examined using Turnbull iron staining, and double staining combining Turnbull with immunohistochemistry for macrophages or astrocytes. Quantitative densitometry of the iron staining as well as copper and iron concentrations were measured in the GP and putamen and correlated with R2* values. RESULTS: T2*w hypointensity in the GP and/or putamen was apparent in WD cases and R2* values correlated with quantitative densitometry of iron staining. In WD, iron and copper concentrations were increased in the putamen compared to controls. R2* was correlated with the iron concentration in the GP and putamen, whereas no correlation was observed for the copper concentration. Patients with more pronounced pathological severity in the putamen displayed increased iron concentration, which correlated with an elevated number of iron-containing macrophages. CONCLUSIONS: T2/T2*w hypointensity observed in vivo in the basal ganglia of WD patients is related to iron rather than copper deposits.
- Klíčová slova
- Wilson disease, brain, iron accumulation, pathology, post mortem 7T MRI,
- MeSH
- astrocyty MeSH
- bazální ganglia diagnostické zobrazování metabolismus patologie MeSH
- corpus striatum metabolismus patologie MeSH
- dospělí MeSH
- hepatolentikulární degenerace diagnostické zobrazování metabolismus patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- makrofágy MeSH
- měď metabolismus MeSH
- mladý dospělý MeSH
- železo metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- měď MeSH
- železo MeSH
BACKGROUND: Neurodegeneration with brain iron accumulation (NBIA) are a group of clinically and genetically heterogeneous diseases characterized by iron overload in basal ganglia and progressive neurodegeneration. Little is known about the epidemiology of NBIA disorders. In the absence of large-scale population-based studies, obtaining reliable epidemiological data requires innovative approaches. METHODS: All pathogenic variants were collected from the 13 genes associated with autosomal recessive NBIA (PLA2G6, PANK2, COASY, ATP13A2, CP, AP4M1, FA2H, CRAT, SCP2, C19orf12, DCAF17, GTPBP2, REPS1). The allele frequencies of these disease-causing variants were assessed in exome/genome collections: the Genome Aggregation Database (gnomAD) and our in-house database. Lifetime risks were calculated from the sum of allele frequencies in the respective genes under assumption of Hardy-Weinberg equilibrium. FINDINGS: The combined estimated lifetime risk of all 13 investigated NBIA disorders is 0.88 (95% confidence interval 0.70-1.10) per 100,000 based on the global gnomAD dataset (n = 282,912 alleles), 0.92 (0.65-1.29) per 100,000 in the European gnomAD dataset (n = 129,206), and 0.90 (0.48-1.62) per 100,000 in our in-house database (n = 44,324). Individually, the highest lifetime risks (>0.15 per 100,000) are found for disorders caused by variants in PLA2G6, PANK2 and COASY. INTERPRETATION: This population-genetic estimation on lifetime risks of recessive NBIA disorders reveals frequencies far exceeding previous population-based numbers. Importantly, our approach represents lifetime risks from conception, thus including prenatal deaths. Understanding the true lifetime risk of NBIA disorders is important in estimating disease burden, allocating resources and targeting specific interventions. FUNDING: This work was carried out in the framework of TIRCON ("Treat Iron-Related Childhood-Onset Neurodegeneration").
- Klíčová slova
- Autosomal recessive NBIA disorders, CoPAN, Lifetime risk, Neurodegeneration, PKAN, PLAN,
- MeSH
- databáze genetické MeSH
- dítě MeSH
- jaderné proteiny MeSH
- komplexy ubikvitinligas MeSH
- lidé MeSH
- mitochondriální proteiny genetika MeSH
- mozek patologie MeSH
- neuroaxonální dystrofie * epidemiologie genetika patologie MeSH
- neurodegenerativní nemoci * epidemiologie genetika patologie MeSH
- poruchy metabolismu železa * genetika patologie MeSH
- proteiny vázající vápník MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- C19orf12 protein, human MeSH Prohlížeč
- DCAF17 protein, human MeSH Prohlížeč
- jaderné proteiny MeSH
- komplexy ubikvitinligas MeSH
- mitochondriální proteiny MeSH
- proteiny vázající vápník MeSH
- REPS1 protein, human MeSH Prohlížeč
Isolated REM sleep behavior disorder (iRBD) is an early stage of synucleinopathy with most patients progressing to Parkinson's disease (PD) or related conditions. Quantitative susceptibility mapping (QSM) in PD has identified pathological iron accumulation in the substantia nigra (SN) and variably also in basal ganglia and cortex. Analyzing whole-brain QSM across iRBD, PD, and healthy controls (HC) may help to ascertain the extent of neurodegeneration in prodromal synucleinopathy. 70 de novo PD patients, 70 iRBD patients, and 60 HCs underwent 3 T MRI. T1 and susceptibility-weighted images were acquired and processed to space standardized QSM. Voxel-based analyses of grey matter magnetic susceptibility differences comparing all groups were performed on the whole brain and upper brainstem levels with the statistical threshold set at family-wise error-corrected p-values <.05. Whole-brain analysis showed increased susceptibility in the bilateral fronto-parietal cortex of iRBD patients compared to both PD and HC. This was not associated with cortical thinning according to the cortical thickness analysis. Compared to iRBD, PD patients had increased susceptibility in the left amygdala and hippocampal region. Upper brainstem analysis revealed increased susceptibility within the bilateral SN for both PD and iRBD compared to HC; changes were located predominantly in nigrosome 1 in the former and nigrosome 2 in the latter group. In the iRBD group, abnormal dopamine transporter SPECT was associated with increased susceptibility in nigrosome 1. iRBD patients display greater fronto-parietal cortex involvement than incidental early-stage PD cohort indicating more widespread subclinical neuropathology. Dopaminergic degeneration in the substantia nigra is paralleled by susceptibility increase, mainly in nigrosome 1.
- Klíčová slova
- Parkinson disease, QSM, REM sleep behavioral disorder, iron, whole brain,
- MeSH
- lidé MeSH
- mozek diagnostické zobrazování patologie MeSH
- Parkinsonova nemoc * komplikace MeSH
- porucha chování v REM spánku * diagnostické zobrazování MeSH
- substantia nigra diagnostické zobrazování patologie MeSH
- synukleinopatie * komplikace patologie MeSH
- železo MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- železo MeSH
The liver secretes hepcidin (Hepc) into the bloodstream to reduce blood iron levels. Hepc accomplishes this by triggering degradation of the only known cellular iron exporter ferroportin in the gut, macrophages, and liver. We previously demonstrated that systemic Hepc knockout (HepcKO) mice, which have high serum iron, develop retinal iron overload and degeneration. However, it was unclear whether this is caused by high blood iron levels or, alternatively, retinal iron influx that would normally be regulated by retina-produced Hepc. To address this question, retinas of liver-specific and retina-specific HepcKO mice were studied. Liver-specific HepcKO mice had elevated blood and retinal pigment epithelium (RPE) iron levels and increased free (labile) iron levels in the retina, despite an intact blood-retinal barrier. This led to RPE hypertrophy associated with lipofuscin-laden lysosome accumulation. Photoreceptors also degenerated focally. In contrast, there was no change in retinal or RPE iron levels or degeneration in the retina-specific HepcKO mice. These data indicate that high blood iron levels can lead to retinal iron accumulation and degeneration. High blood iron levels can occur in patients with hereditary hemochromatosis or result from use of iron supplements or multiple blood transfusions. Our results suggest that high blood iron levels may cause or exacerbate retinal disease.
- MeSH
- degenerace retiny etiologie metabolismus patologie MeSH
- hematoretinální bariéra MeSH
- hepcidiny fyziologie MeSH
- játra metabolismus patologie MeSH
- myši inbrední C57BL MeSH
- myši knockoutované MeSH
- myši MeSH
- přetížení železem etiologie metabolismus patologie MeSH
- retina metabolismus patologie MeSH
- železo metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- Hamp protein, mouse MeSH Prohlížeč
- hepcidiny MeSH
- železo MeSH
The aim of this work was to quantify the accumulation of iron in the basal ganglia in multiple sclerosis (MS) patients and in a control group, and to investigate the relationship between iron accumulation and other parameters assessed in MS, i.e. lesion load (LL) and brain parenchymal fraction (BPF). Magnetic resonance imaging T(2) relaxometry was used for the measurement. 970 patients with clinically definite MS and 117 controls were examined. Patients were divided into three subgroups according to LL and BPF. This work provides quantitative evidence of increased iron accumulation in the basal ganglia in MS patients in comparison to healthy controls. We also found that in the subgroup with small LL value, iron accumulation is higher than in the subgroup with large LL value. The hypothesis of a neurodegenerative component of MS is supported by the changes in iron content in the brain.
- MeSH
- bazální ganglia chemie patologie MeSH
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mozek - chemie MeSH
- roztroušená skleróza patologie MeSH
- senioři MeSH
- železo analýza MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- železo MeSH
Epidemiological studies have established that a high level of iron body stores is associated with increased risk of acute coronary heart disease. To explain this association, it has been proposed that iron catalyzes the production of highly reactive forms of free oxygen species, and thus, promotes low-density lipoprotein (LDL) oxidation, a lipoprotein that plays a critical role in atherogenesis. However, few studies have provided evidence to support this hypothesis. In the present study, we determined the effect of iron loading of THP-1 mononuclear phagocytes on LDL metabolism. We demonstrated that iron loading of THP-1 cells stimulated conjugated diene formation in LDL in the culture medium. In addition, iron loading of THP-1 cells significantly increased cholesteryl ester accumulation in cells exposed to native LDL, suggesting that during the incubation of the cells with native LDL, the LDL became oxidized and was taken up by the cells. We further demonstrated that the degradation of 125I-oxidized LDL was significantly increased in iron-loaded THP-1 cells. Lastly, we demonstrated that iron loading of THP-1 cells stimulated scavenger receptor expression in these cells. In conclusion, this study demonstrates that loading of mononuclear phagocytes with iron leads to oxidization of LDL, increased cellular cholesterol accumulation and scavenger receptor expression, and supports the hypothesis that increased macrophage iron levels promote atherogenesis.
- MeSH
- arterioskleróza etiologie MeSH
- buněčné linie MeSH
- cholesterol metabolismus MeSH
- estery cholesterolu metabolismus MeSH
- fagocyty chemie účinky léků metabolismus MeSH
- lipoproteiny LDL metabolismus MeSH
- peroxidace lipidů účinky léků MeSH
- receptory imunologické analýza MeSH
- scavengerové receptory MeSH
- železo aplikace a dávkování MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Research Support, U.S. Gov't, P.H.S. MeSH
- Názvy látek
- cholesterol MeSH
- estery cholesterolu MeSH
- lipoproteiny LDL MeSH
- oxidized low density lipoprotein MeSH Prohlížeč
- receptory imunologické MeSH
- scavengerové receptory MeSH
- železo MeSH
An important issue in the context of both potenial toxicity of iron oxide nanoparticles (IONP) and their medical applications is tracking of the internalization process of these nanomaterials into living cells, as well as their localization and fate within them. The typical methods used for this purpose are transmission electron microscopy, confocal fluorescence microscopy as well as light-scattering techniques including dark-field microscopy and flow cytometry. All the techniques mentioned have their advantages and disadvantages. Among the problems it is necessary to mention complicated sample preparation, difficult interpretation of experimental data requiring qualified and experienced personnel, different behavior of fluorescently labeled IONP comparing to those label-free or finally the lack of possibility of chemical composition characteristics of nanomaterials. The purpose of the present investigation was the assessment of the usefulness of Raman microscopy for the tracking of the internalization of IONP into cells, as well as the optimization of this process. Moreover, the study focused on identification of the potential differences in the cellular fate of superparamagnetic nanoparticles having magnetite and maghemite core. The Raman spectra of U87MG cells which internalized IONP presented additional bands which position depended on the used laser wavelength. They occurred at the wavenumber range 1700-2400 cm-1 for laser 488 nm and below the wavenumber of 800 cm-1 in case of laser 532 nm. The intensity of the mentioned Raman bands was higher for the green laser (532 nm) and their position, was independent and not characteristic on the primary core material of IONP (magnetite, maghemite). The obtained results showed that Raman microscopy is an excellent, non-destructive and objective technique that allows monitoring the process of internalization of IONP into cells and visualizing such nanoparticles and/or their metabolism products within them at low exposure levels. What is more, the process of tracking IONP using the technique may be further improved by using appropriate wavelength and power of the laser source.
- Klíčová slova
- Internalization into cells, Iron oxide nanoparticles, Magnetite and maghemite core, Multivariate methods, Raman spectroscopy and imaging,
- MeSH
- lidé MeSH
- magnetické nanočástice oxidů železa * chemie MeSH
- mikroskopie metody MeSH
- nádorové buněčné linie MeSH
- Ramanova spektroskopie * metody MeSH
- železité sloučeniny chemie analýza metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- železité sloučeniny MeSH
Background Abnormal findings at brain MRI in patients with neurologic Wilson disease (WD) are characterized by signal intensity changes and cerebral atrophy. T2 signal hypointensities and atrophy are largely irreversible with treatment; their relationship with permanent disability has not been systematically investigated. Purpose To investigate associations of regional brain atrophy and iron accumulation at MRI with clinical severity in participants with neurologic WD who are undergoing long-term anti-copper treatment. Materials and Methods Participants with WD and controls were compared in a prospective study performed from 2015 to 2019. MRI at 3.0 T included three-dimensional T1-weighted and six-echo multigradient-echo pulse sequences for morphometry and quantitative susceptibility mapping, respectively. Neurologic severity was assessed with the Unified WD Rating Scale (UWDRS). Automated multi-atlas segmentation pipeline with dual contrast (susceptibility and T1) was used for the calculation of volumes and mean susceptibilities in deep gray matter nuclei. Additionally, whole-brain analysis using deformation and surface-based morphometry was performed. Least absolute shrinkage and selection operator regression was used to assess the association of regional volumes and susceptibilities with the UWDRS score. Results Twenty-nine participants with WD (mean age, 47 years ± 9 [standard deviation]; 15 women) and 26 controls (mean age, 45 years ± 12; 14 women) were evaluated. Whole-brain analysis demonstrated atrophy of the deep gray matter nuclei, brainstem, internal capsule, motor cortex and corticospinal pathway, and visual cortex and optic radiation in participants with WD (P < .05 at voxel level, corrected for family-wise error). The UWDRS score was negatively correlated with volumes of putamen (r = -0.63, P < .001), red nucleus (r = -0.58, P = .001), globus pallidus (r = -0.53, P = .003), and substantia nigra (r = -0.50, P = .006) but not with susceptibilities. Only the putaminal volume was identified as a stable factor associated with the UWDRS score (R2 = 0.38, P < .001) using least absolute shrinkage and selection operator regression. Conclusion Individuals with Wilson disease (WD) had widespread brain atrophy most pronounced in the central structures. The putaminal volume was associated with the Unified WD Rating Scale score and can be used as a surrogate imaging marker of clinical severity. © RSNA, 2021 Supplemental material is available for this article. See also the editorial by Du and Bydder in this issue.
- MeSH
- atrofie MeSH
- hepatolentikulární degenerace diagnostické zobrazování farmakoterapie metabolismus patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie metody MeSH
- mozek diagnostické zobrazování metabolismus patologie MeSH
- prospektivní studie MeSH
- studie případů a kontrol MeSH
- stupeň závažnosti nemoci MeSH
- železo metabolismus MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- železo MeSH