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

OBJECTIVETo investigate the quantitative and qualitative changes of TCRVα24(+)Vβ11(+) natural killer T (NKT) cells from bone marrow (BM) of aplastic anemia (AA) after in vitro stimulation of α-galactosylceramide (α-Galcer).

METHODSNKT cells in the bone marrow mononuclear cells (BMMNCs) from either AA patients or healthy controls were enumerated with flow cytometry. BMMNCs were cultured in RPMI1640 medium supplemented with either α-Galcer and rhIL-2 or α-Galcer, rhIL-2 and rhG-CSF. The proliferative capacity of NKT cells was determined by NKT cell numbers before and after in vitro culture. Expression of intracellular IFNγ and IL-4 in activated NKT cells was analyzed with flow cytometry.

RESULTSIn AA group, the percentage of NKT cells in BMMNCs was (0.19 ± 0.09)%. Addition of rhG-CSF into the α-Galcer/rhIL-2 culture medium resulted in significantly reduced expansion of NKT cells (67.45 ± 29.42-fold vs 79.91 ± 40.56 fold, P < 0.05). Meanwhile, addition of rhG-CSF reduced IFNγ positive NKT cells \[(37.45 ± 7.89)% vs (62.31 ± 14.67)%, P < 0.01\] and increased IL-4 positive NKT cells \[(55.11 ± 12.13)% vs (27.03 ± 9.88)%, P < 0.01\]. In healthy control group, the percentage of NKT cells in BMMNCs was (0.25 ± 0.12)%. Addition of rhG-CSF into the α-Galcer/rhIL-2 culture medium also significantly reduced expansion of NKT cells (97.91 ± 53.22-fold vs 119.58 ± 60.49-fold, P < 0.05), reduced IFNγ positive NKT cells \[(28.65 ± 10.63)% vs (50.87 ± 12.66)%, P < 0.01\], and increased IL-4 positive NKT cells \[(66.53 ± 14.96)% vs (31.11 ± 10.07)%, P < 0.01\].

CONCLUSIONCompared to those from healthy controls, BMMNCs from AA patiants have a reduced fraction of NKT cells, which possesses a decreased potential to expand in vitro in response to α-Galcer stimulation, and produce more IFNγ(+) NKT1 cells. rhG-CSF, in combination with α-Galcer, confers polarization of NKT cells towards IL-4(+) NKT2 subpopulation.

Anemia, Aplastic ; metabolism ; Bone Marrow ; metabolism ; Humans ; Interleukin-4 ; metabolism ; Killer Cells, Natural ; cytology ; Natural Killer T-Cells

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

Anemia, Aplastic ; metabolism ; Animals ; Bone Marrow Cells ; metabolism ; Disease Models, Animal ; Female ; Mice ; Mice, Inbred BALB C ; PPAR gamma ; metabolism

OBJECTIVETo investigate the expression of CD133 in the bone marrow of patients with myelodysplastic syndrome (MDS) and explore its clinical significance.

METHODSThe expression of CD133 and CD34/CD38 in the bone marrow was detected using flow cytometry in 31 cases of refractory anemia with excess blasts (RAEB), 10 cases of refractory cytopenia with multilineage dysplasia (RCMD) and 11 cases of aplastic anemia (AA).

RESULTSThe percentage of CD133-expressing cells was 6.75% in patients with RAEB, significantly higher than that in patients with RCMD (1.41%) and AA (2.70%) (P<0.05); the percentage of CD133-positive cells were similar between the latter two patient groups (P>0.05). The percentage of CD34(+)/CD38- cells was similar in the 3 groups (P>0.05), all lower than 1%.

CONCLUSIONSAdvanced MDS patients are characterized by an increase of CD133-expressing cells, suggesting the value of CD133 in the diagnosis of RAEB. CD34(+)/CD38- cells do not show a significant value in the diagnosis of MDS.

AC133 Antigen ; Anemia, Aplastic ; metabolism ; Antigens, CD ; metabolism ; Antigens, CD34 ; metabolism ; Female ; Flow Cytometry ; Glycoproteins ; metabolism ; Humans ; Male ; Middle Aged ; Myelodysplastic Syndromes ; diagnosis ; metabolism ; Peptides ; metabolism

OBJECTIVETo investigate the abnormalities of iron metabolism, the prevalence and risk factors of iron overload and clinical characteristics of patients with aplastic anemia (AA).

METHODSA cross-sectional study was conducted on 520 newly diagnosed AA patients.

RESULTSIron overload was observed in 66(13%) of 520 AA patients,in which a higher prevalence of iron overload was seen not only in patients with infections(19/86, 22%)than those without infections (47/434, 11%, P<0.01), but also in patients with hepatitis associated AA(HAAA) (6/22, 19%) than the idiopathic cases (60/488, 12%, P>0.05). Excluded the patients with infections and/or HAAA, 43 of 405(11%)cases had iron overload, including 14 of 248(6%) cases without history of blood transfusion and 29 of 157 patients (18%, P<0.01) with transfusion. In univariate analysis, higher levels of serum ferritin (SF), serum iron (SI) and transferrin saturation (TS) were mainly observed in adult male patients with severe AA (SAA) and significantly upward with increasing blood transfusion (P<0.01). No differences of soluble transferrin receptor (sTfR) were observed between adults and children, males and females, hepatitis and idiopathic AA. However, patients with infections had significantly lower level of sTfR (0.50 mg/L) than cases without infections (0.79 mg/L, P<0.01). The level of sTfR in SAA patients (0.70 mg/L) was only half of that in non-SAA (NSAA) (1.36 mg/L, P<0.01). Patients with increasing blood transfusion had significantly downward levels of sTfR (P<0.01). In multivariate analysis, more than 8 U blood transfusion (OR=10.52, P<0.01), adults (OR=3.48, P<0.01), males (OR=3.32, P<0.01) and infections (OR=2.09, P<0.01) were independent risk factors.

CONCLUSIONAA patients had higher iron burden and were high-risk populations occurring iron overload. The iron overload occurred in 18% of patients with blood transfusion and in 6% of patients without transfusion.

Anemia, Aplastic ; complications ; physiopathology ; Blood Transfusion ; Ferritins ; blood ; Hepatitis ; complications ; Humans ; Iron ; blood ; metabolism ; Iron Overload ; physiopathology ; Risk Factors

This study was aimed to explore the gene expression profile characteristics of T lymphocytes involved in pathogenesis of severe aplastic anemia (SAA) and to predict putative curative drugs for SAA by using biological principle of similarity contrast of gene expression profiles between drugs and diseases. SAA and T lymphocyte were used as key words to search gene expression datasets related to pathogenesis of SAA in public Gene Expression Omnibus (GEO) of NCBI. After significance test, gene expression profiling involved in pathogenesis of SAA were screened and applied to cluster analysis. And then SAA-related gene expression profiles were thrown into pharmacological gene expression datasets of 3000 candidate drugs for similarity analysis and significantly negative correlation was used as a screening criterion for selecting putative curative drugs of SAA. The results showed that only one gene expression dataset was found out, i.e. GSE3807. Computational bioanalysis identified a total of 515 candidate genes of T lymphocyte involved in pathogenesis of SAA, whose expression level exceeded more than 2-fold. Among them, 202 genes were upregulated and 313 genes were downregulated. Cluster analysis showed that those genes belonged to different pathways, including nucleic acid metabolic process, ubiquitin-dependent protein catabolic process, Golgi apparatus protein transport, protein phosphorylation and immunoglobin/major histocompatibility complex. Similarity analysis of gene expression profiles of SAA and drugs showed that hydroxycamptothecin and metformin might have a potential therapeutic efficacy on SAA. It is concluded that by means of novel bioinformatics method, gene expression profiling combined with similarity analysis between disease-related gene expression and pharmacological gene expression profiles may be a novel way of drug screening for SAA.
Anemia, Aplastic ; genetics ; Computational Biology ; Drug Evaluation, Preclinical ; Gene Expression Profiling ; Humans ; Oligonucleotide Array Sequence Analysis ; T-Lymphocytes ; metabolism

In thirty patients with acute leukemia and severe aplastic anemia receiving random single donor platelet transfusions, the development of refractoriness by consecutive platelet transfusions with cytapheresis and its relationship to the appearance of anti-platelet antibodies were investigated. The median number of platelet transfusions inducing refractoriness was 13 times, and 20% of the patients remained unrefractory despite of the repeated multiple platelet transfusions up to 20 to 25 times. The results of anti-platelet antibody tasts by the enzyme-linked immunosorbent assay(ELISA) and immunofluorescent techniques(IFT) showed no statistically significant relationship with the refractoriness (p greater than 0.1). Although there was significant correlation between the results of ELISA and IFT, both tests were insufficient to find out refractoriness even with the use of pooled platelets from multiple donors as target cells. This study shows that 13 single donor platelet transfusions result in refractoriness, that both ELISA and IFT are insufficient to detect refractoriness despite of their significant correlation, and that other methods than these are needed in order to detect alloimmunization.
Adolescent ; Adult ; Aged ; Anemia, Aplastic/therapy ; Anemia, Refractory/*etiology ; Antibodies/metabolism ; *Blood Platelets/immunology ; *Blood Transfusion ; Female ; Humans ; Leukemia/therapy ; Male ; Middle Aged

The purpose of this study was to investigate the influence of immunosuppressive therapy on the expression of TNF-α/IFN-γ in cytoplasm of peripheral blood lymphocytes of patients with aplastic anemia (AA). The expression of TNF-α and IFN-γ in cytoplasm of peripheral CD3(+) lymphocytes were measured by flow cytometry in 25 cases of de novo AA patients and 20 cases of AA after immunosuppressive therapy. The results showed that the positive rates of CD3(+)/TNF-α(+) and CD3(+)/IFN-γ(+) in de novo AA patients were (5.97 ± 6.78)% and (15.20 ± 11.28)% respectively, and (1.56 ± 0.87)% and (1.76 ± 0.87)% in normal controls respectively. There was significant difference between de novo AA patients and normal controls (p < 0.05). The positive rates of CD3(+)/TNF-α(+) and CD3(+)/IFN-γ(+) in immunosuppressive therapy group were (1.67 ± 1.26)% and (4.35 ± 4.33)% respectively. The difference between immunosuppressive therapy group and de novo AA group was statistically significant (p < 0.05). It is concluded that the levels of intracellular TNF-α and IFN-γ in AA patients are higher than those in normal controls. Immunosuppressive therapy significantly reduces the expression of intracellular TNF-α and IFN-γ. Its relationship with the clinical treatment is worth further observing.
Adolescent ; Adult ; Anemia, Aplastic ; blood ; metabolism ; therapy ; Female ; Humans ; Immunosuppression ; Interferon-gamma ; metabolism ; Lymphocytes ; metabolism ; Middle Aged ; Tumor Necrosis Factor-alpha ; metabolism ; Young Adult

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*