Abnormal Ferroptosis in Myelodysplastic Syndrome.
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ABSTRACT: Background
Ferroptosis is a form of iron-dependent non-apoptotic cell death, with characteristics of loss of the activity of the lipid repair enzyme, glutathione (GSH) peroxidase 4 (GPX4), and accumulation of lethal reactive lipid oxygen species. The mechanism of ferroptosis in myelodysplastic syndrome (MDS) is unclear.Methods
Cell viability assay, reactive oxygen species (ROS) assay, GSH assay, and GPX activity assay were performed to study the regulation of ferroptosis in MDS cells obtained from MDS patients, the iron overload model mice, and cell lines.Results
The growth-inhibitory effect of decitabine could be partially reversed by ferrostatin-1 and iron-chelating agent [desferrioxamine (DFO)] in MDS cell lines. Erastin could increase the cytotoxicity of decitabine on MDS cells. The level of GSH and the activity of GPX4 decreased, whereas the ROS level increased in MDS cells upon treatment with decitabine, which could be reversed by ferrostatin-1. The concentration of hemoglobin in peripheral blood of iron overload mice was negatively correlated with intracellular Fe2+ level and ferritin concentration. Iron overload (IO) led to decreased viability of bone marrow mononuclear cells (BMMNCs), which was negatively correlated with intracellular Fe2+ level. Ferrostatin-1 partially reversed the decline of cell viability in IO groups. The level of GSH and the activity of GPX4 decreased, whereas the ROS level increased in BMMNCs of IO mice. DFO could increase the level of GSH. Ferrostatin-1 and DFO could increase the GPX4 activity of BMMNCs in IO mice. Ferrostatin-1 could significantly reverse the growth-inhibitory effect of decitabine in MDS patients. Decitabine could significantly increase the ROS level in MDS groups, which could be inhibited by ferrostatin-1 or promoted by erastin. Ferrostatin-1 could significantly reverse the inhibitory effect of decitabine on GSH levels in MDS patients. Erastin combined with decitabine could further reduce the GSH level. Erastin could further decrease the activity of GPX4 compared with the decitabine group.Conclusion
Ferroptosis may account for the main mechanisms of how decitabine induced death of MDS cells. Decitabine-induced ROS raise leads to ferroptosis in MDS cells by decreasing GSH level and GPX4 activity.
SUBMITTER: Lv Q
PROVIDER: S-EPMC7492296 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundThis study is aimed at assessing the subsets of bone marrow macrophages in patients with myelodysplastic syndrome (MDS) and exploring the role of macrophages in the pathogenesis of MDS.MethodsThirty-eight newly diagnosed MDS patients were enrolled in the Department of Hematology of General Hospital of Tianjin Medical University from June 2015 to June 2016. Bone marrow monocytes and macrophage subsets (M1/M2) were detected in patients with MDS and normal controls by flow cytometry. M1 macrophages were cultured in vitro, and the expression of IL-1β and TNF-α mRNA was measured using real-time polymerase chain reaction.ResultsCompared with the normal control group, the proportion of bone marrow monocytes was higher (2.11 ± 0.93% vs. 3.66 ± 3.38%), and the mean fluorescence intensity of surface molecule CD14 was lower in the higher-risk (HR) MDS group (639.05 ± 359.78 vs. 458.26 ± 306.72, p < 0.05). The ratio of M2 macrophages to monocytes was higher in patients with HR-MDS (1.82 ± 2.47% vs. 3.93 ± 3.81%, p < 0.05). The ratio of M1 to M2 macrophages was lower in the HR-MDS group (3.50 ± 3.22 vs. 1.80 ± 0.88, p < 0.05). The expression of IL-1β and TNF-α mRNA in M1 macrophages was significantly lower in the MDS group (p < 0.05).ConclusionsPatients with MDS had abnormal macrophage polarization, which may be involved in the alteration of bone marrow microenvironments.
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Project description:Myelodysplastic syndrome (MDS) is a spectrum of diseases, characterized by debilitating cytopenias and a propensity of developing acute myeloid leukemia. Comprehensive sequencing efforts have revealed a range of mutations characteristic, but not specific, of MDS. Epidemiologically, autoimmune diseases are common in patients with MDS, fueling hypotheses of common etiological mechanisms. Both innate and adaptive immune pathways are overly active in the hematopoietic niche of MDS. Although supportive care, growth factors, and hypomethylating agents are the mainstay of MDS treatment, some patients-especially younger low-risk patients with HLA-DR15 tissue type-demonstrate impressive response rates after immunosuppressive therapy. This is in contrast to higher-risk MDS patients, where several immune activating treatments, such as immune checkpoint inhibitors, are in the pipeline. Thus, the dual role of immune mechanisms in MDS is challenging, and rigorous translational studies are needed to establish the value of immune manipulation as a treatment of MDS.
| S-EPMC4926477 | biostudies-literature
Project description:Supplemental Digital Content is available in the text.
| S-EPMC7000478 | biostudies-literature
Project description:This article describes three rare syndromes in which the presence of ?-thalassemia provided an important clue to the molecular basis of the underlying condition. It exemplifies how rare diseases allied with careful clinical observation can lead to important biological principles. Two of the syndromes, ATR-16 and ATR-X, are characterized by ?-thalassemia in association with multiple developmental abnormalities including mental retardation. The third condition, ATMDS, is an acquired disorder in which ?-thalassemia arises in the context of myelodysplasia. Intriguingly, mutations in the chromatin remodeling factor, ATRX, are common to both ATR-X syndrome and ATMDS.
| S-EPMC3475406 | biostudies-literature
Project description:BackgroundMyelodysplastic syndromes (MDS) are a diverse group of clonal hematopoietic stem cell malignancies that primarily affect the elderly. Although the incidence of MDS in western countries has been well investigated, little is known about the incidence in Asian populations.MethodsTo identify the incidence of MDS in Japan, we used population-based registry data from 1993 to 2008. The data represented 33.1% of the Japanese population. A total of 7995 patients were reported to the registry with newly diagnosed MDS during the study period.ResultsMedian age at diagnosis was 76 years. Incidence sharply increased with age, particularly in those aged over 70 years. The most recent crude incidence rate of MDS was 3.8 (95% CI 3.6-4.1) cases per 100 000 for men and 2.4 (95% CI 2.2-2.6) cases per 100 000 for women in 2008. Age-adjusted incidences of MDS in 2008, standardized by the world standard population, were 1.6 and 0.8 cases per 100 000 for men and women, respectively, while incidences standardized by the 1985 Japanese population were 2.5 and 1.2 cases per 100 000 for men and women, respectively.ConclusionsOur study reveals that some elderly patients suffer from MDS in Japan, but the incidence is lower than in Western countries. In current clinical practice, many elderly MDS patients are treated with supportive therapy based on an incomplete diagnosis, suggesting that the incidence estimated in this study might still be substantially underestimated. Accurate evaluation of the health impact of MDS requires evaluation of the mortality of the disease, continued surveillance, and improvement in the quality of cancer registry data.
| S-EPMC4213221 | biostudies-literature
Project description:Myelodysplastic syndromes (MDS) are a group of clonal disorders of hematopoietic stem cells. Mesenchymal stem cells (MSC) are the progenitors of the Bone Marrow (BM) stroma and have been involved in the physiopathology of MDS. The presence of cytogenetic aberrations on MSC from MDS patients is controversial. The aim of the study is to characterize BM derived MSC from patients with MDS using: kinetic studies, immunophenotyping, fluorescent in situ hybridisation (FISH) analysis and genetic changes by array based comparative genomic hybridization (array-CGH). 32 cases of untreated MDS were included in the study. MSC from MDS achieved confluence at a slower rate than donor-MSC, and the antigenic expression of CD105 and CD104 was also lower. Array-CGH studies showed DNA genomic changes that were proved not to be somatic, and gains were more frequent than looses. The results of array-CGH were confirmed by FISH. When an unsupervised hierarchical cluster analysis was performed two clusters were identified: one of them included the 5q- syndrome patients, while the other incorporated the rest of the MDS patients. Our results shows, for the first time, that MSC from MDS display genomic aberrations, assessed by array-CGH and FISH, some of them specially linked to particular MDS subtypes. Keywords: Genomic comparison between mesenchymal cells 32 BM cells from âde novoâ MDS, corresponding to 29 patients, were included in the study. Male/female ratio was 14/15 and median age was 70 years (range 34-89). MDS diagnosis was established by peripheral blood counts and morphology, BM morphology and cytogenetic analyses and classified according to the WHO proposals. 12 Patientsâ characteristics are summarized in table 1. Three patients were included twice in the study: at the diagnosis of one RA (case 2) and two Unclassifiable MDS (cases 29,30), and at the progression into RAEB-2 (cases 16, 20 and 18). None of them had received treatment during this period of time, other than supportive therapy. Normal BM samples were obtained from 15 healthy donors, 8 males and 7 females, with a median age of 57 (range 37-88). Written informed consent was obtained from all patients and donors according to ethical guidelines of our institution. Genomic-wide analysis of DNA copy number changes of MSC from 13 cases was performed using array-CGH. Slides containing 3032 BACs were produced in âCentro de Investigación del Cáncerâ (Salamanca, Spain). The particular BAC and P-1 derived artificial chromosome set used to produce this array is distributed to academic institutions by the Welcome Trust Sanger Institute (Cambridge, United Kingdom) and contains targets spaced at ï» 1 Mb density over full genome, a set of subtelomeric sequences for each chromosome arm, and a few hundred probes selected for their involvement in oncogenesis. The clone content is available in the âCytoviewâ windows of the Sanger Institute mapping database site, Ensembl (http://www.ensembl.org/). According to this database, clones were ordered along the chromosomes. These clones were isolated from their bacterial cultures with the relevant antibiotics and the DNA was extracted with standard protocol Welcome Trust Sanger Institute (Cambridge, UK). 10 ng of DNA (BAC/PAC) was used as a template for three DOP-PC. 22;23 These products were ethanol precipitated and dissolved in distilled water. A minimum of three replicates per clone were printed by Microgrid II (Biorobotics) on each slide (Ultragaps Coated Slides, Corning) using the aqueous dimethylsulfoxide buffer as spotting solution. Briefly, for labelling reactions, 1 μg of nonamplified genomic DNA, test and reference were digested separately with DpnII restriction enzyme (New England Biolabs, Beverly, MA). For microarray hybridization, the digested DNAs were separately labelled using random primers (Bioprimer labelling kit, Invitrogen) and cyanine dye-3-dCTP and cyanine dye-5-dCTP fluorescent dye to paired hybridisation samples (Amersham Biosciences). The incorporated of the label nucleotide was quantified using the Nanodrop spectrophotometer. Labelled test and reference DNAs were mixed equitably, co-precipitated in presence of Cot-1 human DNA (Roche, Indianapolis, IN) with ethanol, washed, and resuspended in hybridization solution (50% Formamide, 10% Dextran sulfate, 2X standard saline citrate, 10 mM Tris pH 7.6, 2.7% sodium dodecyl sulfate and 10 μg/ μl of yeast tRNA). DNA mixtures were hybridized to the arrays in the TECAN HS4800 Pro according to the manufacturerâs recommended protocol. Images and signal intensities were acquired using GenePix4000B (Axon Instruments, Burlingame, CA) dual laser scanner in combination with GenePixPro4.0 (Axon Instruments) imaging software. Image and Data analysis. Spot intensities measured by the GenePix Pro 4.1 software (Axon Instruments, Wetsbur BV, Leuden, The Netherland). Pixel intensities for each feature were integrated and median values were determined, and the local background was calculated. For each spot the intensities were corrected by subtracting the local background for both wavelengths, and only spots with signal intensities al least threefold above background signal intensities were included in the analysis. The median of the ratios of all spots was calculated and used to normalize all data points. From each feature, the log2 value of the average of the normalization ratios of the spots was calculated and used to display the data. In addition, fluorescence ratios were normalized for each microarray using the print-tip loess method and the background subtraction with the Diagnosis and Normalization Arrays Data tool. 24 The cut-off level was determined for each individual experiment after avering the ratios from the two color-swith hybridizations and subsequent for normalization, and calculate the mean and Standard derivations to define the cut-off level as means plus/minus two times the standard derivations. The clones that showed possible changes were submitted to the Database of Genomics Variants (http://projects.tcag.ca/variation/) and chromosomal Imbalances and Phenotype in Humans using Ensembl Resources (DECIPCHER: http: www sanger. ac.uk /PostGenomics/decipher/. Clustering Unsupervised clustering We converted the relative ratio value for each BAC clones in each sample to score of 1 (gain/amplified), 0 (no change), or -1 (loss) based on the 2 SD standards described above and analyzed with Cluster and TreeView) 25 (Cluster and TreeView software) based on the average linkage method with the centered correlation metric was used (or Pearson Uncentered). Supervised Sam analysis was used http://www-stat.stanford.edu/ tibs/SAM) 26 to identify BACs that segregate subgroups on MSC. BACs with an SD of zero across the data set before analysis were removed.
2010-05-25 | E-GEOD-10822 | biostudies-arrayexpress
Project description:Delineating key HSC regulators is of significant interest for informing the treatment of hematologic malignancy. While HSC activity is enhanced by overexpression of SKI, the transforming growth factor-beta (TGFβ) signaling antagonist corepressor, its requirement in HSC is unknown. Here we reveal a profound defect in Ski-/- HSC fitness but not specification. Transcriptionally, Ski-/- HSC exhibited striking upregulation of TGFb superfamily signaling and splicing alterations. As these are both common aspects of myelodysplastic-syndrome (MDS) pathobiology with prognostic value, we investigated the role of SKI in MDS. A SKI-correlated gene signature defines a subset of low-risk MDS patients with active TGFβ signaling and deregulated RNA splicing (e.g. CSF3R). The apparent paradox of Ski-/- HSC sharing molecular aspects of MDS with elevated SKI-mRNA is resolved by miR-21 targeting of SKI in MDS. We conclude that miR-21-mediated loss of SKI contributes to early stage MDS pathogenesis by activating TGFβ signaling and alternative splicing while hindering HSC fitness.
2018-11-28 | GSE115903 | GEO
Project description:BackgroundWe sought to enhance the cytometric analysis of myelodysplastic syndromes (MDS) by performing a pilot study of a single cell mass cytometry (MCM) assay to more comprehensively analyze patterns of surface marker expression in patients with MDS.MethodsTwenty-three MDS and five healthy donor bone marrow samples were studied using a 34-parameter mass cytometry panel utilizing barcoding and internal reference standards. The resulting data were analyzed by both traditional gating and high-dimensional clustering.ResultsThis high-dimensional assay provided three major benefits relative to traditional cytometry approaches: First, MCM enabled detection of aberrant surface maker at high resolution, detecting aberrancies in 27/31 surface markers, encompassing almost every previously reported MDS surface marker aberrancy. Additionally, three previously unrecognized aberrancies in MDS were detected in multiple samples at least one developmental stage: increased CD321 and CD99; and decreased CD47. Second, analysis of the stem and progenitor cell compartment (HSPCs), demonstrated aberrant expression in 21 of the 23 MDS samples, which were not detected in three samples from patients with idiopathic cytopenia of undetermined significance. These immunophenotypically abnormal HSPCs were also the single most significant distinguishing feature between clinical risk groups. Third, unsupervised clustering of high-parameter MCM data allowed identification of abnormal differentiation patterns associated with immunophenotypically aberrant myeloid cells similar to myeloid derived suppressor cells.ConclusionsThese results demonstrate that high-parameter cytometry methods that enable simultaneous analysis of all bone marrow cell types could enhance the diagnostic utility of immunophenotypic analysis in MDS.
| S-EPMC9292828 | biostudies-literature
Project description:BACKGROUND:Allogeneic hematopoietic stem-cell transplantation is the only curative treatment for patients with myelodysplastic syndrome (MDS). The molecular predictors of disease progression after transplantation are unclear. METHODS:We sequenced bone marrow and skin samples from 90 adults with MDS who underwent allogeneic hematopoietic stem-cell transplantation after a myeloablative or reduced-intensity conditioning regimen. We detected mutations before transplantation using enhanced exome sequencing, and we evaluated mutation clearance by using error-corrected sequencing to genotype mutations in bone marrow samples obtained 30 days after transplantation. In this exploratory study, we evaluated the association of a mutation detected after transplantation with disease progression and survival. RESULTS:Sequencing identified at least one validated somatic mutation before transplantation in 86 of 90 patients (96%); 32 of these patients (37%) had at least one mutation with a maximum variant allele frequency of at least 0.5% (equivalent to 1 heterozygous mutant cell in 100 cells) 30 days after transplantation. Patients with disease progression had mutations with a higher maximum variant allele frequency at 30 days than those who did not (median maximum variant allele frequency, 0.9% vs. 0%; P<0.001). The presence of at least one mutation with a variant allele frequency of at least 0.5% at day 30 was associated with a higher risk of progression (53.1% vs. 13.0%; conditioning regimen-adjusted hazard ratio, 3.86; 95% confidence interval [CI], 1.96 to 7.62; P<0.001) and a lower 1-year rate of progression-free survival than the absence of such a mutation (31.3% vs. 59.3%; conditioning regimen-adjusted hazard ratio for progression or death, 2.22; 95% CI, 1.32 to 3.73; P=0.005). The rate of progression-free survival was lower among patients who had received a reduced-intensity conditioning regimen and had at least one persistent mutation with a variant allele frequency of at least 0.5% at day 30 than among patients with other combinations of conditioning regimen and mutation status (P?0.001). Multivariate analysis confirmed that patients who had a mutation with a variant allele frequency of at least 0.5% detected at day 30 had a higher risk of progression (hazard ratio, 4.48; 95% CI, 2.21 to 9.08; P<0.001) and a lower 1-year rate of progression-free survival than those who did not (hazard ratio for progression or death, 2.39; 95% CI, 1.40 to 4.09; P=0.002). CONCLUSIONS:The risk of disease progression was higher among patients with MDS in whom persistent disease-associated mutations were detected in the bone marrow 30 days after transplantation than among those in whom these mutations were not detected. (Funded by the Leukemia and Lymphoma Society and others.).
| S-EPMC6309244 | biostudies-literature
Project description:Myelodysplastic syndrome (MDS) is a malignant hematopoietic stem cell disorder that frequently evolves into acute myeloid leukemia (AML). Patients with MDS are prone to infectious complications, in part due to the presence of severe neutropenia and/or neutrophil dysfunction. However, not all patients with neutropenia become infected, suggesting that other immune cells may compensate in these patients. Monocytes are also integral to immunologic defense; however, much less is known about monocyte function in patients with MDS. In the current study, we monitor the composition of peripheral blood monocytes and several aspects of monocyte function in MDS patients, including HLA-DR expression, LPS-induced inflammatory cytokine production, and phagocytosis. We find that monocytes from MDS patients exhibit relatively normal innate immune functions compared to monocytes from healthy control subjects. We also find that HLA-DR expression is moderately increased in monocytes from MDS patients. These results suggest that monocytes could compensate for other immune deficits in MDS patients to help fight infection. We also find that the range of immune functions in monocytes from MDS patients correlates with several key clinical parameters, including blast cell count, monocyte count, and revised International Prognostic Scoring System score, suggesting that disease severity impacts monocyte function in MDS patients.
| S-EPMC6113098 | biostudies-literature