OBJECTIVE: To investigate the effect of iron overload on the expression of programmed death-1 (PD-1) on the surface of T lymphocyte in mice, in order to analyze the mechanism of iron overload inhibiting T cell function. METHODS: Flow cytometry was used to detect the labile iron pool (LIP), reactive oxygen species (ROS), and the expression of PD-1 in peripheral blood T cells in mice with iron overload. RESULTS: The mean fluorescence intensity of calcein in T cells of mice in iron overload group was 2 492±311.1, which was significantly lower than 3 136±537.3 in the control group ( P <0.01), suggesting that increased LIP in iron overload group. Compared with the control group, the ratio of CD4/CD8 of peripheral blood T cells was normal or increased in iron overload group. The level of ROS in T cells was 2 452±393.3 in iron overload group, which was significantly increased compared to 1 874±121.8 in the control group ( P <0.001). The expression of PD-1 on the surface of T cells was significantly increased. The percentage of PD-1⁺ cells in CD8⁺T cells was (12.97±6.92)% and (6.18±2.95)% in iron overload group and control group, respectively ( P <0.05), and that in CD8^-T cells was (33.55±15.69)% and (12.51±4.11)% ( P <0.001). CONCLUSION The expression of PD-1 on peripheral blood T cells in mice with iron overload is significantly increased, which may be involved in inhibiting T cell effector function.
Animals ; Mice ; Programmed Cell Death 1 Receptor/metabolism* ; Iron Overload/metabolism* ; Reactive Oxygen Species/metabolism* ; T-Lymphocytes/metabolism* ; Flow Cytometry ; Iron ; CD8-Positive T-Lymphocytes/metabolism*

OBJECTIVES: To observe the evolution of intrahepatic macrophage polarization in mice with liver fibrosis induced by iron overload. METHODS: Thirty-two C57BL/6 mice (6-8 weeks) were randomized into control group (n=8) and liver fibrosis model group (n=24) induced by aidly intraperitoneal injection of iron dextran. At the 3rd, 5th, and 7th weeks of modeling, 8 mice in the model group were sacrificed for observing liver fibrosis using Masson, Sirius Red and immunohistochemical staining and detecting serum levels of ALT, AST and the levels of serum iron, ferritin, liver total Fe and ferrous Fe. iNOS⁺/F4/80⁺ cells and CD206⁺/F4/80⁺ cells were detected by double immunofluorescence assay to observe the proportion and distribution of M1 and M2 macrophages. The hepatic expressions of Arg-1, iNOS, IL-6, IL-10, and TNF‑α proteins were detected using Western blotting or ELISA, and the expression of CD206 mRNA was detected using RT-PCR. RESULTS: The mice in the model group showed gradual increase of fibrous tissue hyperplasia in the portal area over time, structural destruction of the hepatic lobules and formation of pseudolobules. With the passage of time during modeling, the rat models showed significantly increased hepatic expressions of α-SMA and COL-1, elevated serum levels of ALT, AST, Fe, ferritin, and increased liver total Fe and ferrous Fe levels. The expressions of M1 polarization markers IL-6, TNF‑α, and iNOS all increased with time and reached their peak levels at the 3rd week; The expressions of M2 polarization markers (IL-10 and Arg-1 proteins and CD206 mRNA) significantly increased in the 3rd week and but decreased in the 5th and 7th weeks. CONCLUSIONS Iron overload promotes M1 polarization of macrophages in mice. Liver fibrosis in the early stage promotes M2 polarization of macrophages but negatively regulate M2 polarization at later stages.
Animals ; Mice ; Mice, Inbred C57BL ; Iron Overload/pathology* ; Macrophages/metabolism* ; Male ; Liver Cirrhosis/etiology* ; Nitric Oxide Synthase Type II/metabolism* ; Interleukin-10/metabolism* ; Liver/pathology* ; Interleukin-6/metabolism* ; Mannose Receptor ; Tumor Necrosis Factor-alpha/metabolism* ; Mannose-Binding Lectins/metabolism* ; Arginase

It is reported that iron metabolism and ferroptosis can influence the occurrence and development of myeloid tumors, which can serve as therapeutic targets. Dysregulation of iron metabolism is present in a variety of myeloid neoplasms. The prognosis of acute myeloid leukemia is related to differential expression of molecules related to iron metabolism. The prognosis of myelodysplastic syndrome patients with iron overload is poor. Myeloproliferative neoplasms are often characterized by the coexistence of iron deficiency and erythrocytosis, which can be treated by targeting hepcidin. Myeloid tumor cells are susceptible to oxidative damage caused by the accumulation of reactive oxygen species and are sensitive to ferroptosis. Ferroptosis has anti-tumor effect in acute myeloid leukemia and myelodysplastic syndrome. Targeting ferroptosis can reverse imatinib resistance in chronic myeloid leukemia. This article reviews the characteristics of iron metabolism in the development and progression of myeloid neoplasms, as well as the mechanism of ferroptosis, to provide a basis for the development of new therapeutic strategies.
Ferroptosis ; Humans ; Iron/metabolism* ; Myelodysplastic Syndromes/pathology* ; Reactive Oxygen Species/metabolism* ; Leukemia, Myeloid, Acute/pathology* ; Hepcidins/metabolism* ; Iron Overload/metabolism* ; Myeloproliferative Disorders/metabolism* ; Prognosis

Ex vivo culture-amplified mesenchymal stem cells (MSCs) have been studied because of their capacity for healing tissue injury. MSC transplantation is a valid approach for promoting the repair of damaged tissues and replacement of lost cells or to safeguard surviving cells, but currently the efficiency of MSC transplantation is constrained by the extensive loss of MSCs during the short post-transplantation period. Hence, strategies to increase the efficacy of MSC treatment are urgently needed. Iron overload, reactive oxygen species deposition, and decreased antioxidant capacity suppress the proliferation and regeneration of MSCs, thereby hastening cell death. Notably, oxidative stress (OS) and deficient antioxidant defense induced by iron overload can result in ferroptosis. Ferroptosis may inhibit cell survival after MSC transplantation, thereby reducing clinical efficacy. In this review, we explore the role of ferroptosis in MSC performance. Given that little research has focused on ferroptosis in transplanted MSCs, further study is urgently needed to enhance the in vivo implantation, function, and duration of MSCs.
Humans ; Antioxidants/metabolism* ; Ferroptosis ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stem Cells ; Iron Overload/metabolism*

Objective: To analyze the influencing factors of iron metabolism assessment in patients with myelodysplastic syndrome. Methods: MRI and/or DECT were used to detect liver and cardiac iron content in 181 patients with MDS, among whom, 41 received regular iron chelation therapy during two examinations. The adjusted ferritin (ASF) , erythropoietin (EPO) , cardiac function, liver transaminase, hepatitis antibody, and peripheral blood T cell polarization were detected and the results of myelofibrosis, splenomegaly, and cyclosporine were collected and comparative analyzed in patients. Results: We observed a positive correlation between liver iron concentration and ASF both in the MRI group and DECT groups (r=0.512 and 0.606, respectively, P<0.001) , only a weak correlation between the heart iron concentration and ASF in the MRI group (r=0.303, P<0.001) , and no significant correlation between cardiac iron concentration and ASF in the DECT group (r=0.231, P=0.053) . Moreover, transfusion dependence in liver and cardiac [MRI group was significantly associated with the concentration of iron in: LIC: (28.370±10.706) mg/g vs (7.593±3.508) mg/g, t=24.30, P<0.001; MIC: 1.81 vs 0.95, z=2.625, P<0.05; DECT group: liver VIC: (4.269±1.258) g/L vs (1.078±0.383) g/L, t=23.14, P<0.001: cardiac VIC: 1.69 vs 0.68, z=3.142, P<0.05]. The concentration of EPO in the severe iron overload group was significantly higher than that in the mild to moderate iron overload group and normal group (P<0.001) . Compared to the low-risk MDS group, the liver iron concentration in patients with MDS with cyclic sideroblasts (MDS-RS) was significantly elevated [DECT group: 3.80 (1.97, 5.51) g/L vs 1.66 (0.67, 2.94) g/L, P=0.004; MRI group: 13.7 (8.1,29.1) mg/g vs 11.6 (7.1,21.1) mg/g, P=0.032]. Factors including age, bone marrow fibrosis, splenomegaly, T cell polarization, use of cyclosporine A, liver aminotransferase, and hepatitis antibody positive had no obvious effect on iron metabolism. Conclusion: There was a positive correlation between liver iron concentration and ASF in patients with MDS, whereas there was no significant correlation between cardiac iron concentration and ASF. Iron metabolism was affected by transfusion dependence, EPO concentration, and RS.
Ferritins ; Humans ; Iron ; Iron Overload ; Liver/metabolism* ; Myelodysplastic Syndromes/therapy* ; Primary Myelofibrosis ; Retrospective Studies ; Splenomegaly

β-thalassemia is a type of inherited hemolytic anemia caused by decreased globin production due to defect of the HBB gene. The pathogenesis of the disease is imbalance of α/β globin chains. The excess of α-globin chains will form hemichromes which can damage red blood cell membranes and lead to hemolysis, ineffective erythropoiesis, and secondary iron overload. Iron overload in turn can cause complications such as growth retardation, liver cirrhosis, cardiac insufficiency, and aggravate the disease phenotype. In recent decades, genes participating in iron metabolism have been discovered, and the mechanism of iron metabolism in the development of thalassemia has gradually been elucidated. Subsequently, by manipulating the expression of key genes in iron metabolism such as hepcidin and transferrin receptor, researchers have revealed that iron restriction can improve ineffective hematopoiesis and iron overload, which may provide a potential approach for the treatment of thalassemia. This article reviews the progress of research on iron metabolism-related genes and related pathways in β-thalassemia.
Humans ; Iron/metabolism* ; Iron Overload/genetics* ; Phenotype ; Research/trends* ; beta-Thalassemia/physiopathology*

The aim of the present study was to investigate the role of ferroptosis in acute lung injury (ALI) mouse model induced by oleic acid (OA). ALI was induced in the mice via the lateral tail vein injection of pure OA. The histopathological score of lung, lung wet-dry weight ratio and the protein content of bronchoalveolar lavage fluid (BALF) were used as the evaluation indexes of ALI. Iron concentration, glutathione (GSH) and malondialdehyde (MDA) contents in the lung tissues were measured using corresponding assay kits. The ultrastructure of pulmonary cells was observed by transmission electron microscope (TEM), and the expression level of prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA was detected by quantitative polymerase chain reaction (q-PCR). Protein expression levels of glutathione peroxidase 4 (GPX4), ferritin and transferrin receptor 1 (TfR1) in lung tissues were determined by Western blot. The results showed that histopathological scores of lung tissues, lung wet-dry weight ratio and protein in BALF in the OA group were higher than those of the control group. In the OA group, the mitochondria of pulmonary cells were shrunken, and the mitochondrial membrane was ruptured. The expression level of PTGS2 mRNA in the OA group was seven folds over that in the control group. Iron overload, GSH depletion and accumulation of MDA were observed in the OA group. Compared with the control group, the protein expression levels of GPX4 and ferritin in lung tissue were down-regulated in the OA group. These results suggest that ferroptosis plays a potential role in the pathogenesis of ALI in our mouse model, which may provide new insights for development of new drugs for ALI.
Acute Lung Injury ; chemically induced ; pathology ; Animals ; Apoptosis ; Bronchoalveolar Lavage Fluid ; chemistry ; Cyclooxygenase 2 ; metabolism ; Ferritins ; metabolism ; Glutathione ; analysis ; Glutathione Peroxidase ; metabolism ; Iron ; analysis ; Iron Overload ; physiopathology ; Lung ; cytology ; pathology ; Malondialdehyde ; analysis ; Mice ; Microscopy, Electron, Transmission ; Mitochondrial Membranes ; ultrastructure ; Oleic Acid

OBJECTIVEThe aim of this study was to summarize the interactions between hepatitis C virus (HCV) infection and iron overload, and to understand the mechanisms of iron overload in chronic hepatitis C (CHC) and the role iron plays in HCV life cycle.

DATA SOURCESThis review was based on data in articles published in the PubMed databases up to January 28, 2017, with the keywords "hepatitis C virus", "iron overload", "iron metabolism", "hepcidin", "translation", and "replication".

STUDY SELECTIONArticles related to iron metabolism, iron overload in patients with CHC, or the effects of iron on HCV life cycle were selected for the review.

RESULTSIron overload is common in patients with CHC. The mechanisms involve decreased hepcidin levels caused by HCV through signal transducer and activator of transcription 3, mitogen-activated protein kinase, or bone morphogenetic protein/SMAD signaling pathways, and the altered expression of other iron-metabolism-related genes. Some studies found that iron increases HCV replication, while other studies found the opposite result. Most of the studies suggest the positive role of iron on HCV translation, the mechanisms of which involve increased expression levels of factors associated with HCV internal ribosome entry site-dependent translation, such as eukaryotic initiation factor 3 and La protein.

CONCLUSIONThe growing literature demonstrates that CHC leads to iron overload, and iron affects the HCV life cycle in turn. Further research should be conducted to clarify the mechanism involved in the complicated interaction between iron and HCV.

Female ; Hepacivirus ; pathogenicity ; Hepatitis C ; complications ; metabolism ; Hepcidins ; metabolism ; Humans ; Iron Overload ; etiology ; metabolism ; virology ; Male ; Signal Transduction

OBJECTIVETo investigate the effects of iron overload on apoptosis and function of splenic CD8+ T cells in mice.

METHODSForty C57BL/6 mice were randomly divided into control groups, Iron overload (IO), IO+NAC and IO+DFX groups. The iron overload model was established by intraperitoneal injection of iron dextran, and saline was injected as the control. The levels of intracellular reactive oxygen species (ROS) and labile iron pool (LIP) were analyzed by measuring the mean fluorescence intensity (MFI) of 2-7 dichlorofluorescein (DCF) or calcein. The ratio of CD8+ T cells and the levels of IFN-γ, TNF-α, Granzyme-B, and perforin in CD8+ T cells were detected by flow cytometry. The CD8+ T cell apoptosis was determined by flow cytometry with Annexin V/PI double staining. Real-time PCR was used to detect the expression of IFN-γ, TNF-α, Granzyme-B, perforin, BCL-2, and bax at mRNA level in CD8+ T cells.

RESULTSIron overload was found by spleen iron staining and flow cytometry. The level of intracellular ROS in iron overload (IO) groups was higher than that of the control groups (P<0.01). The percentage of CD8+ T cells in spleen from mice with IO was lower than that in control groups (P<0.05). The expression of IFN-γ and Granzyme-B in CD8+ T cells in IO group were lower than that in control group, the expression of IFN-γ and Granzyme-B at mRNA level in CD8+ T cells was lower than that of control group (P<0.05). CD8+ T cell apoptosis in iron overload group was significantly higher than that in control groups (P<0.01); the expression of BCL-2 at mRNA level was lower than that in control group, but the expression of BAX at mRNA level was higher than that in control group (P<0.05). These effects could be reversed after treating iron-overloaded mice with DFX or NAC.

CONCLUSIONIron overload can inhibit the ratio of CD8+ T cells of splenic cells in mice, decrease the expression of IFN-γ, Granzyme-B, increase the apoptosis of CD3+ CD8+/CD8-. These effects may be regulated through increasing the intracellular ROS level, and can be partially reversed after treating iron-overloaded mice with DFX or NAC.

Animals ; Apoptosis ; CD8-Positive T-Lymphocytes ; cytology ; pathology ; Granzymes ; metabolism ; Interferon-gamma ; metabolism ; Iron ; metabolism ; Iron Overload ; physiopathology ; Mice ; Mice, Inbred C57BL ; Perforin ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Random Allocation ; Reactive Oxygen Species ; metabolism ; Spleen ; cytology ; Tumor Necrosis Factor-alpha ; metabolism ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo observe the status of iron deposition in patient with β thalassemia major, and to formulate appropriate treatment strategies.

METHODThe data of status of transfusion and chelation in 135 patients aged from 6 years and 4 months to 17 years and 11 months with β thalassemia major were collected and analyzed. Serum ferritin levels were determined and cardiac and hepatic iron deposition was determined using MRI T2(*) technology.

RESULTOf the 135 cases studied, 66 were male, and 69 were female, their average age was 12.1 years. Serum ferritin (SF) was determined for 111 cases, it varied from 1 086.8 µg/L to 15 011.5 µg/L. Among them, 16 cases had SF level <2 000 µg/L (14.5%) , in 41 cases SF were between 2 000 and 4 000 µg/L (36.0%) ;in 54 cases SF >4 000 µg/L (48.7%) . Liver MRI T2(*) results showed that in only 8 cases (5.9%) iron content in the liver was in normal range, 19 cases (14.9%) showed mild liver iron deposition;34 (25.2%) moderate and 74 (54.8%, the youngest one was only 6 years and 4 months of age) had severe iron deposition respectively. Cardiac MRI T2(*) showed that in 89 cases (65.9%) iron content in the heart was in normal range;19 cases (14.1%) had mild cardiac iron deposition and 27 (20.0%) presented severe iron deposition (the youngest one was only 9 years and 3 months of age) . SF level was obviously related to liver and cardiac iron deposition (MRI T2(*)) r and P value were -0.284, 0.003 and -0.374, 0.000 respectively. In 108 cases regular transfusion and chelation were delayed due to financial problem. The late and insufficient dosage administered and irregular chelation caused the higher SF level and the severe iron deposition.

CONCLUSIONThe survival status of β thalassemia major in China is worrisome. Majority of them had not received regular transfusion and chelation. Liver and cardiac iron deposition occur early and had a high incidence.

Adolescent ; Child ; Female ; Ferritins ; blood ; Humans ; Iron ; metabolism ; Iron Chelating Agents ; adverse effects ; therapeutic use ; Iron Overload ; epidemiology ; etiology ; Liver ; metabolism ; Magnetic Resonance Imaging ; Male ; Myocardium ; metabolism ; Radiography ; Retrospective Studies ; Transfusion Reaction ; beta-Thalassemia ; diagnostic imaging ; metabolism ; therapy