Ferroptosis initiates membrane oxidative damage through lipid peroxidation and iron accumulation, and accumulates reactive oxygen species (ROS) during aplastic anemia (AA). Ferroptosis induces damage and apoptosis of hematopoietic stem/progenitor cells, mesenchymal stem cells, blood cells, and T lymphocytes through various pathways, inhibits bone marrow hematopoiesis, damages bone marrow microenvironment, exacerbates immune imbalance, leading to bone marrow failure and disease progression. Therefore, further exploring the ferroptosis mechanism in AA can help clarify the pathogenesis of disease and provide new research ideas and directions for the treatment of AA.
Anemia, Aplastic/metabolism* ; Humans ; Ferroptosis ; Reactive Oxygen Species/metabolism* ; Lipid Peroxidation ; Hematopoietic Stem Cells ; Apoptosis

OBJECTIVE: To investigate the effect of miR-125b on T cell activation in patients with aplastic anemia (AA) and its molecular mechanism. METHODS: A total of 30 AA patients were enrolled in department of hematology, Binzhou Medical University Hospital from January 2018 to October 2021, as well as 15 healthy individuals as healthy control (HC) group. Peripheral blood mononuclear cells (PBMCs) were isolated, in which the levels of miR-125b and B7-H4 mRNA were detected by RT-qPCR. Immunomagnetic beads were used to separate naive T cells and non-naive T cells from AA patients and healthy people to detect the levels of miR-125b and B7-H4 mRNA. Lentivirus LV-NC inhibitor and LV-miR-125b inhibitor were transfected into cells, and T cell activation was detected by flow cytometry. The dual-luciferase reporter gene assay was used to detect the targetting relationship between miR-125b and B7-H4. RT-qPCR and Western blot were used to detect the levels of miR-125b, CD40L, ICOS, IL-10 mRNA and B7-H4 protein. RESULTS: Compared with HC group, the expression of miR-125b was up-regulated but B7-H4 mRNA was down-regulated in PBMCs of AA patients (P <0.05), and the proportions of CD4⁺CD69⁺ T cells and CD8⁺CD69⁺ T cells in PBMCs of AA patients were higher (P <0.05). The expression of miR-125b was significantly up-regulated but B7-H4 mRNA was down-regulated in both naive T cells and non-naive T cells of AA patients (P <0.05), and non-naive T cells was more significant than naive T cells (P <0.05). Compared with NC inhibitor group, the expression of miR-125b was significantly decreased, the expression level of CD69 on CD4⁺ and CD8⁺ T cells in PBMCs was also significantly decreased, while the luciferase activity was significantly increased after co-transfection of miR-125b inhibitor and B7-H4-3'UTR-WT in the miR-125b inhibitor group (P <0.05). Compared with NC inhibitor group, the mRNA and protein levels of B7-H4 were significantly increased in the miR-125b inhibitor group (P <0.05). Compared with miR-125b inhibitor+shRNA group, the expression levels of CD69 on CD4⁺ and CD8⁺ T cells were significantly increased, and the levels of CD40L, ICOS and IL-10 mRNA were also significantly increased in the miR-125b inhibitor+sh-B7-H4 group (P <0.05). CONCLUSION MiR-125b may promote T cell activation by targetting B7-H4 in AA patients.
Humans ; Anemia, Aplastic/genetics* ; CD40 Ligand/metabolism* ; Interleukin-10 ; Leukocytes, Mononuclear/metabolism* ; Luciferases ; MicroRNAs/genetics* ; RNA, Messenger/metabolism* ; Lymphocyte Activation ; T-Lymphocytes/metabolism*

OBJECTIVE: To explore the improvement effect of CXC chemokine receptor 4 (Cxcr4) gene-modified bone marrow mesenchymal stem cell (BMSC)-derived exosomes on aplastic anemia (AA), and make a preliminary exploration of the mechanism. METHODS: Mouse BMSCs were isolated and cultured, then infected by recombinant lentivirus carrying Cxcr4 gene. The expression of green fluorescence was observed through fluorescence microscope, the expression of Cxcr4 mRNA was detected by real-time fluorescence quantitative PCR, and the BMSC-derived exosomes modified with Cxcr4 gene were extracted. Mouse models of AA were constructed, and control group, model group (AA), AA+BMSC group, AA+NC-BMSC group, AA+Cxcr4-BMSC group were set up. Except control group and model group, the other three groups of mice were injected 400 μl exosomes from different sources via the tail vein, after 2 weeks, the routine blood indices and the number of bone marrow nucleated cells were detected, the pathological changes of bone marrow were observed by HE staining, and the expression level of Treg cells was detected by flow cytometry. RESULTS: Mouse BMSCs were successfully isolated, and BMSCs with high expression of Cxcr4 and their exosomes were obtained. Compared with the control group, the number of red blood cell (RBC), white blood cell (WBC), and platelet (PLT), the hemoglobin (Hb) content and proportion of Treg cells in the peripheral blood of mice in the model group significantly decreased (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01). The proliferation level of nucleated cells was low, and the medullary cavity was filled with a large number of fat cells. Compared with the model group, the number of RBC, WBC, PLT, the Hb content and proportion of Treg cells in the peripheral blood of mice in the AA+BMSC group, AA+NC-BMSC group, and AA+Cxcr4-BMSC group significantly increased (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01), and pathological changes of bone marrow were improved. In addition, the number of RBC, WBC, PLT, the Hb content and proportion of Treg cells in the peripheral blood of mice in the AA+Cxcr4-BMSC group were significantly higher than those in the AA+BMSC group (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01). CONCLUSION Injection of Cxcr4 gene-modified BMSC-derived exosomes has a certain improvement effect on AA mice, and the mechanism may be related to an increase of the proportion of Treg cells.
Anemia, Aplastic/metabolism* ; Animals ; Bone Marrow Cells ; Exosomes/metabolism* ; Humans ; Mesenchymal Stem Cells ; Mice ; Receptors, CXCR4

No abstract available.
Adolescent ; Anemia, Aplastic/*diagnosis/pathology ; Bone Marrow/pathology ; Child ; Child, Preschool ; Diagnosis, Differential ; Female ; Half-Life ; Humans ; Immunohistochemistry ; Male ; Mutation ; Myelodysplastic Syndromes/*diagnosis/pathology ; Retrospective Studies ; Tumor Suppressor Protein p53/genetics/*metabolism

This study was purposed to investigate the role of regulatory T cells (Treg) in the immune unbalance for patients with acquired severe aplastic anemia (SAA). The flow cytometry was used to detect the quantity of CD4(+) CD25(+) CD127(dim) Tregs, T cell subset (CD4(+)/CD8(+) ratio), dendritic cell(DC) subset(mDC/pDC ratio) in 44 SAA patients(25 untreated patients and 19 recovery patients) and 23 normal controls. The correlation between Tregs and T cell subset, DC subset and hemogram were analyzed. The results showed that the percentage of CD4(+) CD25(+) CD127(dim) Tregs in peripheral blood lymphocyte(PBL) of untreated patients was (0.83 ± 0.44) %, which was obviously lower than that in recovery patients (2.91 ± 1.24)% and normal controls (2.18 ± 0.55)% (P < 0.05), but the difference was not statistically significant between latter two groups. The ratio of CD4(+)/CD8(+) was (0.5 ± 0.3) in untreated patients, which was obviously lower than that in recovery patients (1.2 ± 0.4) and normal controls (1.11 ± 0.24) (P < 0.05). The ratio of mDC/pDC was (3.08 ± 0.72) in untreated patients, which was significantly higher than that in recovery patients(1.61 ± 0.49) and normal controls (1.39 ± 0.36) (P < 0.05). The percentage of CD4(+) CD25(+)CD127(dim) Tregs in PBL positively correlated with CD4(+)/CD8(+) ratio (r = 0.695, P < 0.01), and that negatively correlated with mDC/pDC ratio (r = -0.796, P < 0.01). There were significant positive correlations between CD4(+)CD25(+)CD127(dim) Tregs/PBL and WBC, Ret% (r = 0.761, 0.749 respectively, P < 0.01). It is concluded that the decrease of CD4(+)CD25(+)CD127(dim) Tregs quantity in SAA may be one of mechanisms underlying bone marrow failure resulting from the deterioration of immune tolerance and hyperfunction of T-cells.
Adolescent ; Adult ; Anemia, Aplastic ; blood ; Case-Control Studies ; Child ; Female ; Flow Cytometry ; Humans ; Lymphocyte Count ; Male ; Middle Aged ; T-Lymphocytes, Regulatory ; cytology ; metabolism ; Young Adult

This study was aimed to compare the expressions of specific transcription factors of CD4(+) T cell subset ( T-bet, GATA-3, RORγt and FoxP3 mRNA) in peripheral blood of patients with aplastic anemia(AA), myelodysplastic syndrome(MDS), and acute myeloid leukemia(AML), and investigate their immune status and pathogenesis, so as to provide experimental basis for the choice of clinical treatment. The expression of T-box (T-bet), GATA-3, ROR-γt and Foxp3 mRNA in PBMNC were examined by RT-PCR in 42 cases of MDS, including 22 refractory anemia(MDS-RA) and 20 refractory anemia with excess blasts (MDS-RAEB), in 23 cases of AA, 17 cases of AML patients and 16 healthy volunteers respectively. The results indicated that, compared with normal control group, expressions of T-bet and RORγt mRNA in AA patient group were significantly higher (P < 0.01), expression levels of GATA3 Foxp3 mRNA were lower (both P < 0.01). There was no significant difference in expression of T-bet and GATA3 mRNA between MDS group and normal control group, but the expression levels of Foxp3 and RORγt mRNA were higher than those in normal controls (P < 0.05); T-bet and RORγt in MDS-RA group were higher than those in the normal controls(P < 0.01), and GATA3 expression significantly reduced (P < 0.05), however, there was no significant difference in expression of Foxp3 between MDS-RA and the controls. Expression levels of T-bet and RORγt mRNA in patients with MDS-RAEB and AML were lower than those in normal controls (P < 0.05), but the expression levels of GATA3 and Foxp3 mRNA were significantly higher than those in normal controls (P < 0.01). It is concluded that the transcription factor expressions are different in PBMNC of patients among these three diseases. Immune-mediated excessive apoptosis may play an important role in pathogenesis, bone marrow failure in patients with AA and MDS-RA, and abnormal clones of immature cells may be one of main reasons for bone marrow failure in AML and late stage of MDS.
Adolescent ; Adult ; Aged ; Anemia, Aplastic ; blood ; CD4-Positive T-Lymphocytes ; metabolism ; Case-Control Studies ; Female ; Forkhead Transcription Factors ; metabolism ; GATA3 Transcription Factor ; metabolism ; Humans ; Leukemia, Myeloid, Acute ; blood ; Male ; Middle Aged ; Myelodysplastic Syndromes ; blood ; Nuclear Receptor Subfamily 1, Group F, Member 3 ; metabolism ; T-Box Domain Proteins ; metabolism ; Young Adult

This study was aimed to investigate the effects of rapamycin on biological function and autophagy of bone marrow mesenchymal stem cells (BM-MSC) from patients with aplastic anemia so as to provide experimental basis for the clinical treatment of aplastic anemia (AA) with rapamycin. BM-MSC were treated with different concentrations of rapamycin (0, 10, 50, 100 nmol/L) for 48 h, the expression of LC3B protein was detected by Western blot to observe the effect of rapamycin on cell autophagy; cell apoptosis and cell cycles were detected by flow cytometry; the proliferation of BM-MSC of AA patients was measured by cell counting kit-8; the adipogenic differentiation of BM-MSC were tested by oil red O staining after adipogenic induction for 2 weeks; the adipogenic related genes (LPL, CFD, PPARγ) were detected by real-time PCR. The results showed that the proliferation and adipogenesis of BM-MSC of AA patients were inhibited by rapamycin. Moreover, the autophagy and apoptosis of BM-MSC were increased by rapamycin in a dose-dependent way.Rapamycin arrested the BM-MSC in G0/G1 phase and prevented them into S phase (P < 0.05). It is concluded that rapamycin plays an critical role in inhibiting cell proliferation, cell cycles, and adipogenesis, these effects may be related with the autophagy activation and mTOR inhibition resulting from rapamycin.
Anemia, Aplastic ; metabolism ; Apoptosis ; drug effects ; Autophagy ; Bone Marrow Cells ; cytology ; drug effects ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Humans ; Mesenchymal Stromal Cells ; cytology ; drug effects ; Signal Transduction ; Sirolimus ; pharmacology

Aplastic anemia(AA) is mostly considered as an immune-mediated bone marrow failure syndrome, characterized by pancytopenia and bone marrow hypoplasia. The pathogenesis of AA is complicated, until now it is not fully understood. Further study on the pathological mechanism will be helpful for the diagnosis and treatment of AA. CD8(+) T cells and their secreted cytokines play important roles in the abnormal immunity during the process of AA. Thus, this review focuses on the role of CD8(+) T cells and their secreted cytokines in the pathogenesis of AA.
Anemia, Aplastic ; immunology ; metabolism ; pathology ; CD8-Positive T-Lymphocytes ; immunology ; metabolism ; secretion ; Cytokines ; metabolism ; Humans ; Immunity, Cellular

Hemochromatosis is an inherited genetic disorder of iron metabolism which can also occur as a secondary result of iron-overload. It leads to organ damage such as cardiomyopathy, liver cirrhosis, hypogonadism, and diabetes. This paper discusses a case of secondary hemochromatosis associated with repeated transfusions, presenting as asymptomatic hypoparathyroidism and subclinical hypothyroidism with multiple organ involvement. The 29-year-old female, who had severe aplastic anemia, received multiple transfusions totaling approximately 1,400 units of red blood cells over 15 years. During her routine laboratory examination, hypocalcemia was detected with decreased intact parathyroid hormone and increased thyroid stimulating hormone. Serum ferritin, iron, and total iron binding capacity had increased to 27,583.03 ng/mL, 291 microg/dL, and 389 microg/dL, respectively. She had unusually bronze skin and computed tomography revealed iron deposition in the thyroid, liver, and heart. Multiorgan involvement as seen in this case is rare in hemochromatosis associated with secondary transfusions. To the best of the author's knowledge, this is the first case report in Korea of hypoparathyroidism and subclinical hypothyroidism due to iron deposition in the parathyroid and thyroid gland.
Adult ; Anemia, Aplastic ; Cardiomyopathies ; Erythrocytes ; Female ; Ferritins ; Heart ; Hemochromatosis* ; Humans ; Hypocalcemia ; Hypogonadism ; Hypoparathyroidism* ; Hypothyroidism* ; Iron ; Korea ; Liver ; Liver Cirrhosis ; Metabolism ; Parathyroid Hormone ; Skin ; Thyroid Gland ; Thyrotropin

OBJECTIVETo investigate the change in telomere length and TERC and TERT mutations in peripheral blood leukocytes of children with chronic aplastic anemia (CAA).

METHODSSixty-nine children with CAA were divided into untreated group (n=24) who did not receive immunosuppressive therapy (IST), response group (n=36) who showed response to IST, and non-response group (n=9) who showed no response to IST; another 35 healthy children matched for age and sex were selected as the control group. The telomere-to-single copy gene (T/S) ratio in peripheral blood leukocytes was measured by real-time PCR in all groups. PCR was performed to detect TERC and TERT mutations in all children with CAA.

RESULTSThe untreated and non-response groups had significantly lower T/S ratios than the control and response groups (P<0.01), whereas there was no significant difference in T/S ratio between the response and control groups (P>0.05). TERC and TERT mutations were not found in all children with CAA.

CONCLUSIONSThe change in telomere length in children with CAA may be related to the development and progression of disease. Telomere length measurement may be used as a prognostic indicator in children with CAA.

Adolescent ; Anemia, Aplastic ; drug therapy ; genetics ; Child ; Child, Preschool ; Chronic Disease ; Humans ; Immunosuppressive Agents ; therapeutic use ; Infant ; Leukocytes ; metabolism ; Male ; Mutation ; Telomerase ; genetics ; Telomere