Clinical significance of anti-rheumatoid arthritis 33 antibody in patients with systemic lupus erythematosus.

Although anti-rheumatoid arthritis (RA) 33 antibodies have been reported to be present in various connective tissue diseases (CTDs), the clinical significance of anti-RA33 in CTDs is still obscure. This study was performed to explore the clinical significance of anti-RA33 in CTDs, especially systemic lupus erythematosus (SLE). A total of 565 patients with positive anti-nuclear antibodies who had been tested for anti-RA33 were included in this study and were further classified into RA33-positive and RA33-negative groups. The association between anti-RA33 and the clinical features of CTDs was examined. Receiver operating characteristic (ROC) analysis was performed to explore the diagnostic value of anti-RA33 in SLE and SLE-related organ involvement. The results showed that SLE was the most common disease in CTD patients positive for anti-RA33 (48.8%). Compared with the RA33-negative group, higher proportions of SLE-associated antibodies and SLE patients with a high disease activity as well as lower levels of serum complement components were observed in the RA33-positive group (all p < 0.05). Furthermore, CTD patients with positive anti-RA33 were more likely to suffer from mucocutaneous and hematological involvement as well as interstitial lung disease (all p < 0.05). ROC analysis revealed an area under the curve value of 0.634 (95% confidence interval: 0.587-0.681) for anti-RA33 in the diagnosis of SLE, with a specificity and sensitivity of 92.9% and 13.5%, respectively. Taken together, this study reveals a significant association between anti-RA33 and the clinical features of CTDs, especially SLE, indicating a potential clinical significance of anti-RA33 in the management of SLE.

[Effect and Involved Mechanism of RSL3-induced Ferroptosis in Acute Leukemia Cells MOLM13 and Drug-resistant Cell Lines].

OBJECTIVE: To investigate the effect and involved mechanism of RSL3 on ferroptosis action in acute leukemia cells MOLM13 and its drug-resistant cells. METHODS: After MOLM13 treated with RSL3, CCK-8 assay was performed to detect cell viability, flow cytometry was used to detect the reactive oxygen species (ROS) level of the cells, RT-qPCR and Western blot were used to detect the expression of glutathione peroxidase 4 (GPX4). After MOLM13/IDA and MOLM13/Ara-C, the drug-resistant cell lines were constructed, the ferroptosis induced by RSL3 was observed. Bone marrow samples were collected from patients with acute monocytic leukemia. RT-qPCR and Western blot were performed to detect the expression of related genes and proteins involved in ferroptosis pathway. RESULTS: RSL3 significantly inhibited the cell viability of MOLM13 and increased the intracellular ROS level, which were partially reversed by ferrostatin-1. The mRNA and protein expression of GPX4 decreased in MOLM13 treated with RSL3. RSL3 inhibited the viability of MOLM13/IDA and MOLM13/Ara-C cells more strongly than that of non-drug resistant cells, also increased the intracellular ROS level . The cytotoxic effects were partially reversed by ferrostatin-1. The mRNA and protein expressions of GPX4 in MOLM13/IDA and MOLM13/Ara-C cells were higher than those in non-drug resistant cells. The mRNA and protein levels of GPX4 in bone marrow of relapsed/refractory acute mononuclear leukemia patients were higher than those of ordinary acute mononuclear leukemia patients. CONCLUSION: RSL3 can induce non-drug resistant cells MOLM13 ferroptosis by inhibiting GPX4 activity. MOLM13/IDA and MOLM13/Ara-C are more sensitive to RSL3 compared with non-drug resistant cells MOLM13, which may be caused by the differences in GPX4 expression. The expressions of GPX4 mRNA and protein in relapsed/refractory acute mononuclear leukemia are higher than those in ordinary acute mononuclear leukemia.

Noninvasive tools based on immune biomarkers for the diagnosis of central nervous system graft-vs-host disease: Two case reports and a review of the literature.

BACKGROUND: Central nervous system graft-vs-host disease (CNS-GVHD) is a rare cause of CNS disorders after allogeneic hematopoietic stem cell transplantation. Currently, establishing a diagnosis of CNS-GVHD is challenging because the diagnostic criteria and diagnostic methods are not well defined and many confounding factors need to be ruled out. CASE SUMMARY: Here, we present two patients with CNS-GVHD. Both patients with a history of acute GVHD or chronic GVHD developed neurological symptoms that could not be explained by other causes, and had abnormal cerebrospinal fluid (CSF) studies as determined by CSF and blood immune biomarker examinations, suggestive of suspected CNS-GVHD. Due to the lack of specific magnetic resonance imaging abnormalities and the rapid clinical deterioration of the patients, we did not attempt to perform a brain biopsy, but prompted the initiation of empirical immunosuppressive therapy. In view of the rapid and favorable response to local and systematic immunosuppressive treatment and the aforementioned neurologic manifestations together with CSF abnormalities and other negative findings, a final diagnosis of CNS-GVHD was made. CONCLUSION: CSF and blood immune biomarker examinations facilitated the diagnosis of CNS-GVHD, which are particularly suitable for patients who are critically ill and require urgent treatment and for those who are unsuitable for invasive diagnostic procedures.

[Effects of Combined Infusion of Mesenchymal Stem Cells and Endothelial Progenitor Cells on Lung Injury after Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To investigate the effects of combined infusion of mesenchymal stem cells (MSC) and endothelial progenitor cells (EPC) on lung injury after hematopoietic stem cell transplantation (HSCT). METHODS: The experiment was divided into normal control group, irradiation group, bone marrow cell transplantation group (BMT group), BMT+EPC group, BMT+MSC group and BMT+EPC+MSC group. The model of HSCT was established, on the 30th day after transplantation, the mice were sacrificed. Then lung tissue was taken for testing. The mRNA expression levels of VEGF, IL-18, IL-12b were detected by RT-PCR, and protein expression level of NLRP3 was detected by Western blot. The expression of MPO and CD146 was observed by immunohistochemistry assay. RESULTS: The expression level of VEGF gene in BMT+EPC+MSC group was significantly higher than that in other groups (P＜0.01). The expression level of IL-18 and IL-12b gene was the highest in BMT group and the lowest in BMT+EPC+MSC group, and the difference was statistically significant (P＜0.05). HSCT could increase the expression of NLRP3 protein, and the BMT+EPC+MSC could significantly reduce the level of NLRP3 protein in lung cells, tending to normal. Compared with normal tissues, the BMT+EPC+MSC could improve the lung tissue structure more effectively, the expression of MPO positive cells was lower, and the expression of VEGF positive cells was higher. CONCLUSIONS: The combined infusion of MSC and EPC can promote capillary regeneration, alleviate inflammation and promote lung repair after HSCT, which is superior to single EPC or MSC infusion.

Feasibility study and reference values of FibroScan 502 with M probe in healthy preschool children aged 5 years.

BACKGROUND: Transient elastography (TE) using FibroScan with M probe has been widely used in adults for controlled attenuation parameter (CAP) and liver stiffness measurement (LSM). In this study, we aimed to assess the feasibility of this approach and reference values of CAP and LSM in healthy preschool children aged 5 years. METHODS: FibroScan-502 with M probe (Echosens, Paris, France) and bioelectrical impedance analysis (InBody 720, Biospace, South Korea) were prospectively conducted in healthy children aged 5 years from the Shanghai Prenatal Cohort Study. Linear regression models and piece-wise linear regression models were used to explore the factors associated with CAP and LSM. RESULTS: The success rate of a valid TE measurement was 96.5% in 452 healthy preschool children aged 5 years, and 436 children with 236 boys were included for further study. The median, inter quartile range (IQR) and the 5th-95th percentiles of CAP values were 171.50, 162.07-188.13 and 154.21-214.53 dB/m, respectively. The median, mean ± standard deviation and the 5th-95th percentiles of LSM were 3.20, 3.28 ± 0.86 and 2.00-4.78 kPa, respectively. In multivariate linear regression analyses, the CAP but not the LSM value was significantly positively correlated with such anthropometric index as body weight, body mass index, waist circumference, body fat content and body fat percentage. CONCLUSIONS: FibroScan-502 with M-probe can be used to measure CAP and LSM in preschool children aged 5 years. The 95th percentiles of CAP values and LSM were 214.53 dB/m and 4.78 kPa, respectively. Further study should be performed to explore the cut-off values of CAP and LSM for diagnosis of hepatic steatosis and fibrosis in children.

S100A16 suppresses the growth and survival of leukaemia cells and correlates with relapse and relapse free survival in adults with Philadelphia chromosome-negative B-cell acute lymphoblastic leukaemia.

Refinement of risk stratification in Philadelphia chromosome (Ph)-negative B-cell acute lymphoblastic leukaemia (ALL) might aid the identification of patients who are likely to relapse. Abnormal S100 calcium binding protein A16 (S100A16) has been implicated in various cancers, but its function remains unclear. We found S100A16 transcript levels were higher in 130 adults with newly-diagnosed Ph-negative B-cell ALL compared with 33 healthy controls. In 115 of 130 patients who achieved first complete remission, those with high S100A16 transcript levels displayed a lower 3-year cumulative incidence of relapse (CIR; 34% [21, 47%] vs. 40% [48, 72%]; P = 0·012) and higher 3-year relapse-free survival (RFS; 65% [53, 78%] vs. 35% [23, 46%]; P = 0·012), especially when receiving chemotherapy only. In multivariate analysis a low S100A16 transcript level was independently-associated with a higher CIR (Hazard ratio [HR] = 3·74 [1·01-13·82]; P = 0·048) and inferior RFS (HR = 5·78 [1·91, 17·84]; P < 0·001). Function analysis indicated that knockdown of S100A16 promoted proliferation and anti-apoptosis and reduced chemosensitivity. S100A16 over-expression revealed an opposite trend, especially in a xeno-transplant mouse model. Western blotting analysis showed upregulation of PI3K/AKT and ERK1/2 in S100A16-knockdown and S100A16-overexpression B-cell ALL cell lines respectively. Inhibition assays suggested these two signalling pathways participated in the S100A16-mediated proliferation and survival effects in B-cell ALL cell lines. Trial Registration: Registered in the Chinese Clinical Trial Registry [ChiCTR-OCH-10000940]; http://www.chictr.org.cn.

[Establishment and Identification of MDS Mouse Model with Irom Overload].

OBJECTIVE: To establish a MDS mouse model with iron overload and to study the effect of iron overload on MDS. METHODS: The exogenous mutant gene RUNX1-S291fs was inserted into the mice bone marrow mononuclear cell's genome in mice by retrovirus and transplanted into C57BL/6 mice irradiated by 60 Co γ-ray. After 8 weeks,intraperitoneal injection of iron was performed to establish an MDS mouse model with iron overload. After 24 weeks of transplantation, the peripheral blood, bone marrow, femur, liver and spleen of mice were taken, then the morphological characteristics of peripheral blood and bone marrow cells were observed by Wright's staining; the liver, spleen and bone marrow were stained with Prussian blue to observe the iron deposition. The surface antigens of bone marrow cells were detected by flow cytometry. Bone marrow mononuclear cells and spleen tissue proteins were detected by Western blot to confirm the transfection of RUNX1-S291fs gene and expression of protein. The blood routine and transplanted cell chimeric rate of mice were monitored periodically. RESULTS: Compared with the empty plasmid control mice, levels of leukocyte and hemoglobin as well as platelet were decreased in RUNX1-S291fs mutant mice; the peripheral blood cells and bone marrow cells showed pathological hematopoiesis; the liver and spleen enlarged significantly; the tissue structure of femur, liver and spleen was abnormal; the expression of bone marrow cell surface antigens was abnormal. Bone marrow cells and spleen tissue expressed the RUNX1-S291fs protein. Compared with the controlled mice injected with normal saline, iron deposition occurred in the bone marrow, liver and spleen stained with Prussian blue in the mice injected with iron agent. CONCLUSION: Mice engineered to carry exogenous mutant gene RUNX1-S291fs and injected with iron showed pathologic features of MDS and iron overload, resulting in establishing MDS iron overloaded mouse model successfully, which lays a foundation for studying the effect of iron overload on MDS.

[Effects of Cyclin A1 on the Proliferation of SKM-1 Cells and Its Potential Role in Myelodysplastic Syndrome].

OBJECTIVE: To investigate the effects of Cyclin A1 on the proliferation of SKM-1 cells and its underlying role in myelodysplastic syndrome (MDS). METHODS: Cyclin A1 was knocked down with its small interfering RNA (siRNA). The efficiency of siRNA transfection was measured by Western blot and RT-PCR. Then the proliferation of SKM-1 cells and the expression of CDK2,RUNX1 and SRSF2 with and without knockdown of Cyclin A1 recorded and analysed respectively. RESULTS: Cyclin A1 was knocked down by siRNA after transfected for 48 h. The kncokdown of Cyclin A1 inhibited the proliferation of SKM-1 cells and down-regulated the expression of CDK2, RUNX1 and SRSF2, and these effects were at least partially mediated through RUNX1 and SRSF2 signaling pathway. CONCLUSION: Cyclin A1 plays an important role in the proliferation of SKM-1 cells. These findings provide new insights into the pathogenesis of MDS, and it may be a potential target in the treatment of MDS.

Adiponectin receptor agonist AdipoRon suppresses adipogenesis in C3H10T1/2 cells through the adenosine monophosphate­activated protein kinase signaling pathway.

The aim of the present study was to investigate the effects of AdipoRon, an adiponectin receptor agonist, on adipogenesis in C3H10T1/2 cells and to explore the underlying mechanisms. C3H10T1/2 cells were treated with increasing doses of AdipoRon for 8 days, and Oil Red O staining was used to assess lipid accumulation. The protein and mRNA expression levels of adipogenic transcription factors and adipocyte­specific genes were examined by western blotting and reverse transcription quantitative polymerase chain reaction, respectively. AdipoRon treatment inhibited lipid accumulation in C3H10T1/2 cells in a dose­dependent manner and significantly suppressed the expression of adipogenic transcription factors, including peroxisome proliferator­activated receptor Î³, CAAT/enhancer binding protein (C/EBP)­ß and C/EBPα. In addition, cells treated with AdipoRon exhibited a significant decrease in the expression of adipocyte­specific genes, including fatty acid binding protein 4, fatty acid synthase, leptin, adiponectin, and stearoyl­CoA desaturase­1. Notably, AdipoRon significantly increased the phosphorylation of adenosine monophosphate­activated protein kinase (AMPK) and acetyl­CoA carboxylase (ACC). The results indicated that AdipoRon exerted an inhibitory effect on adipogenesis in C3H10T1/2 cells by downregulating the expression of adipogenic transcription factors and adipocyte­specific genes and by promoting the phosphorylation of AMPK and ACC, which suggested that AdipoRon may be a potential drug to prevent and treat diseases caused by abnormal adipogenesis, such as obesity.

Reactive oxygen species mediated T lymphocyte abnormalities in an iron-overloaded mouse model and iron-overloaded patients with myelodysplastic syndromes.

The adverse effects of iron overload have raised more concerns as a growing number of studies reported its association with immune disorders. This study aimed to investigate alterations in the immune system by iron overload in patients with myelodysplastic syndrome (MDS) and an iron-overloaded mouse model. The peripheral blood from patients was harvested to test the effect of iron overload on the subsets of T lymphocytes, and the level of reactive oxygen species (ROS) was also evaluated. The data showed that iron-overloaded patients had a lower percentage of CD3+ T cells and disrupted T cell subsets, concomitant with higher ROS level in lymphocytes. In order to explore the mechanism, male C57Bl/6 mice were intraperitoneally injected with iron dextran at a dose of 250 mg/kg every 3 days for 4 weeks to establish an iron-overloaded mouse model and the blood of each mouse was collected for the analysis of the T lymphocyte subsets and T cell apoptosis. The results showed that iron overload could reduce the percentage of CD3+ T cells and the ratio of Th1/Th2 and Tc1/Tc2 but increase the percentage of regulatory T (Treg) cells and the ratio of CD4/CD8. We also found that iron overload induced the apoptosis of T lymphocytes and increased its ROS level. Furthermore, these effects could be partially recovered after treating with antioxidant N-acetyl-L-cysteine (NAC) or iron chelator deferasirox (DFX). Taken together, these observations indicated that iron overload could selectively affect peripheral T lymphocytes and induce an impaired cellular immunity by increasing ROS level.

Multiple cytotoxic factors involved in IL-21 enhanced antitumor function of CIK cells signaled through STAT-3 and STAT5b pathways.

BACKGROUND/OBJECTIVES: Maintenance of cellular function in culture is vital for transfer and development following adoptive immunotherapy. Dual properties of IL-21 in activating T cells and reducing activation induced cell death led us to explore the mechanism of action of IL-21 enhanced proliferation and cytotoxic potential of CIK cells. METHOD: CIK cells cultured from PBMCs of healthy subjects were stimulated with IL-21 and cellular viability and cytotoxicity to K562 cells were measured. To elucidate the mechanism of action of IL-21, mRNA expression of cytotoxic factors was assessed by RT-PCR and protein expression of significantly important cytotoxic factors and cytokine secretion were determined through flow cytometry and ELISA. Western blotting was performed to check the involvement of the JAK/STAT pathway following stimulation. RESULTS: We found that IL-21 did not enhance in vitro proliferation of CIK cells, but did increase the number of cells expressing the CD3+/ CD56+ phenotype. Cytotoxic potential was increased with corresponding increase in perforin (0.9831±0.1265 to 0.7592±0.1457), granzyme B (0.4084±0.1589 to 0.7319±0.1639) and FasL (0.4015±0.2842 to 0.7381±0.2568). Interferon gamma and TNF-alpha were noted to increase (25.8±6.1 ng/L to 56.0±2.3 ng/L; and 5.64±0.61 µg/L to 15.14±0.93 µg/L, respectively) while no significant differences were observed in the expression of granzyme A, TNF-alpha and NKG2D, and NKG2D. We further affirmed that IL-21 signals through the STAT-3 and STAT- 5b signaling pathway in the CIK cell pool. CONCLUSION: IL-21 enhances cytotoxic potential of CIK cells through increasing expression of perforin, granzyme B, IFN-gamma and TNF-alpha. The effect is brought about by the activation of STAT-3 and STAT-5b proteins.

[Establishment of an mouse model of iron-overload and its impact on bone marrow hematopoiesis].

OBJECTIVE: To establish a mouse model of iron overload by intraperitoneal injection of iron dextran and investigate the impact of iron overload on bone marrow hematopoiesis. METHODS: A total of 40 C57BL/6 mice were divided into control group, low-dose iron group (12.5 mg/ml), middle-dose iron group (25 mg/ml), and high-dose iron group (50 mg/ml). The control group received normal saline (0.2 ml), and the rest were injected with intraperitoneal iron dextran every three days for six weeks. Iron overload was confirmed by observing the bone marrow, hepatic, and splenic iron deposits and the bone marrow labile iron pool. In addition, peripheral blood and bone marrow mononuclear cells were counted and the hematopoietic function was assessed. RESULTS: Iron deposits in bone marrow, liver, and spleen were markedly increased in the mouse models. Bone marrow iron was deposited mostly within the matrix with no significant difference in expression of labile iron pool.Compared with control group, the ability of hematopoietic colony-forming in three interventional groups were decreased significantly (P<0.05). Bone marrow mononuclear cells counts showed no significant difference. The amounts of peripheral blood cells (white blood cells, red blood cells, platelets, and hemoglobin) in different iron groups showed no significant difference among these groups;although the platelets were decreased slightly in low-dose iron group [(780.7±39.60)×10(9)/L], middle dose iron group [(676.2±21.43)×10(9)/L], and high-dose iron group [(587.3±19.67)×10(9)/L] when compared with the control group [(926.0±28.23)×10(9)/L], there was no significant difference(P>0.05). CONCLUSIONS: The iron-overloaded mouse model was successfully established by intraperitoneal administration of iron dextran. Iron overload can damage the hepatic, splenic, and bone marrow hematopoietic function, although no significant difference was observed in peripheral blood count.

[Reactive oxygen species mediate the injury and deficient hematopoietic supportive capacity of umbilical cord derived mesenchymal stem cells induced by iron overload].

OBJECTIVE: To explore the effects of iron overload on umbilical cord derived mesenchymal stem cells (UC-MSC) and elucidate the involvement of reactive oxygen species (ROS) in this process. METHODS: The iron overload model of MSC was established by in vitro addition of ferric ammonium citrate (FAC) into culture medium. Cell proliferation and apoptosis were determined by Annexin V/PI double staining and population doubling time (DT) respectively. Co-culture system was used to assess the hematopoietic support capacity of UC-MSC in different groups. Thereafter the ROS level was detected with fluorescent probe 2', 7'-dichlorofluorescin diacetate (DCFH-DA). And the ROS related signaling factors of p-p38MAPK, p38 MAPK, P53 were measured by Western blot. RESULTS: (1) The DT of UC-MSC in iron overload group was significantly longer than that of control ((24.43 ± 2.72) h vs (16.03 ± 2.31) h, P < 0.05). But the difference was insignificant after two passages (P > 0.05). (2) Apoptosis in iron overload group was higher than that of control (12.75% ± 0.32% vs 3.63% ± 0.80%, P < 0.05). (3) The colony forming capacity of mononuclear cell (MNC) co-cultured with UC-MSC of iron overload group for 1/2 weeks significantly decreased. (4) The ROS level of UC-MSC with iron overload was higher than that of control in time and concentration-dependent fashions and it peaked at 400 µmol/L of FAC for 12 h (1499 ± 86 vs 548 ± 97, P < 0.05). (5) The expressions of p-p38MAPK and P53 increased in response to FAC compared with control. But such an effect was partially inhibited after the use of antioxidants. CONCLUSIONS: Iron overload may impair the proliferation, survival and hematopoiesis supportive function of UC-MSC by enhancing the generation of ROS. And ROS stimulates the signaling pathways of p-p38MAPK and P53.

[Effects and mechanism on anti-leukemic activity of cytokine-induced killer cells with an endogenous expression of interleukin-21].

OBJECTIVE: To explore the effects and mechanism on anti-leukemic activity of cytokine inducing killer (CIK) cells with an endogenous expression of interleukin-21 (IL-21). METHODS: Mononuclear cells were isolated from peripheral blood and cultured with cytokines to generate CIK cells. IL-21 lentiviral vector was constructed and used to transfect 293T cells. Then the culture supernatant with virus infected CIK cells was identified. Proliferation of CIK cells and their cytotoxic activity against K562 cells were measured by methyl thiazolyl tetrazolium (MTT). The expressions of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), tumor necrosis factor-ß (TNF-ß), perforin, granzyme A, granzyme B, FasL and NKG2D mRNA were measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). Immunophenotypes of CIK cells, IL-21 receptor (IL-21R) and FasL on the surface of CIK cells, intra-cellular perforin and granzyme B of CIK cells were measured by flow cytometry. And the concentrations of IFN-γ and TNF-α in cultured supernatant were measured by enzyme immunoassay. RESULTS: By restriction enzyme digestion and sequencing, IL-21 lentiviral vector was identified, after transfecting virus supernatant into CIK cells, the expression of IL-21 was detected in CIK cells. Compared to control, (1) the total number of cells remained unchanged, but the proportion of cells expressing CD3(+)/CD56(+) phenotype increased from 16.95% ± 4.70% to 24.60% ± 2.10%. (2) Cytotoxic activity against K562 cells by CIK cells increased from 23.3% ± 2.8% to 58.4% ± 8.3% and stayed at 61.2% ± 6.2% after 5 days. It was stronger and longer compared to the exogenous effect of IL-21 (from 22.8% ± 2.8% to 44.6% ± 8.3%). (3) The expression of IL-21R increased around 2 folds. (4) The mRNA expressions of IFN-γ and TNF-α increased almost 1.5 folds, perforin, granzyme B, FasL rose almost 2 folds, the expressions of granzyme A, TNF-ß and NKG2D were similar with those of controls. (5) Detected by flow cytometry, the expression of FasL of CIK cells was higher than that of control (0.56% ± 0.37% vs 0.06% ± 0.02%), the expression of perforin increased from 12.23% ± 2.35% to 25.86% ± 6.13%, the expression of granzyme B rose from 14.56% ± 1.36% to 37.58% ± 2.30%, the concentration of IFN-γ in culture supernatant spiked from (23.2 ± 5.6) to (55.3 ± 3.5) ng/L and TNF-α jumped from (5.6 ± 0.6) to (15.6 ± 0.6) µg/L. CONCLUSIONS: CIK cells with an endogenous expression of IL-21 have stronger anti-leukemic activity through an up-regulation of IL-21R, perforin, granzyme B, FasL, IFN-γ and TNF-α. Thus IL-21 may potentially enhance the anti-leukemic immunotherapy.

[Effect and mechanism of iron-catalyzed oxidative stress on mesenchymal stem cells].

OBJECTIVE: To explore effect of iron overload on the proliferation and apoptosis of mesenchymal stem cell(MSCs) and the possible mechanism. METHODS: Iron overload model of MSCs was established by adding ferric ammonium citrae (FAC) into the culture medium at different concentrations (100, 200, 400 Μmol/L) and incubated for different lengths of time (12, 24, 48 h). The levels of labile iron pool (LIP) and reactive oxygen species (ROS) were measured to confirm oxidative stress state in the model. Changes in cell proliferation and apoptosis after iron overload were measured through population double time(DT)and annexin V-PI assay. Finally, the expressions of phosphorylated p38 mitogen activated protein kinase (P-p38MAPK), p38MAPK, protein kinase B (AKT), and p53 were determined through Western blot analysis to investigate which ROS-mediated signaling pathway was involved in this process. RESULTS: The LIP level of MSCs was significantly increased by FAC treatment at 400 Μmol/L (mean fluorescence intensity 482.49±20.96 vs. 303.88±23.37, P<0.05). The level of intracellular ROS was positively correlated with the concentration of FAC and reached a peak level when cultured with 400 Μmol/L FAC (P<0.05).After treatment with 400 Μmol/L FAC at different time points (12 h, 24 h, and 48 h), the DT of MSCs was (1.47± 0.11) d, (1.80±0.13) d, and (2.04±0.14) d, respectively, which was signifcantly longer than that of the control, which was(1.20±0.05)d (P<0.05).The apoptosis rate was also significantly higher in iron overload group[(3.51±1.17)% vs.(0.66±0.62)%, P<0.05]with consequent increase in the expressions of P-p38MAPK, p38MAPK, and p53 proteins in iron overload group, while no significant difference was found in the expression of AKT. CONCLUSION: Iron overload can inhibit the proliferation of MSCs and induce their apoptosis through the generation of ROS, which is probably due to the stimulation of p38MAPK- p53 signaling pathway.

[Effect of oxidative stress on bone marrow mesenchymal stem cells].

Bone marrow mesenchymal stem cells (MSCs) are somatic stem cells that can differentiate into progenies of multiple lineages. They play an important role in hematopoiesis and stem cell therapy due to their multi-lineage potentials and immunomodulatory properties. Oxidative stress is a disturbed redox state caused by accumulation of reactive oxygen species. It can induce the senescence and apoptosis of MSCs via phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and p53 pathways, and inhibit the proliferation and differentiation of MSCs through apurinic/apyrimidinic endonuclease/redox factor 1 (APE/REF-1) and extracellular signal-regulated kinase (ERK) pathways. Furthermore, using anti-stress medication and hypoxic preconditioning, the functions of MSCs can be further enhanced. Accordingly, further studies on the effect of oxidative stress on MSCs and its signaling pathways may be meaningful for the treatment of hematologic diseases and for improving stem cell therapy.

[Effects of humanized interleukin 21 on anti-leukemic activity of cytokine induced killer cells and the mechanism].

OBJECTIVE: To explore the effects of humanized interleukin 21 (IL-21) on anti-leukemic activity of cytokine induced killer(CIK) cells derived from peripheral blood(PB) and the mechanism. METHODS: Mononuclear cells were separated from peripheral blood and cultured with cytokines to induce CIK cells. Proliferation of CIK cells with or without IL-21 stimulation and their cytotoxic activity against K562 cells was measured by MTT method. IL-21 receptor (IL-21R) and immunophenotypes of CIK cells were measured by flow cytometry. The expression of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), tumor necrosis factor-ß (TNF-ß), perforin, granzyme A, granzyme B, FasL and NKG2D mRNA were measured by semi-quantitative RT-PCR. FasL on the surface of CIK cells and intra-cellular perforin and granzyme B of CIK cells were measured by flow cytometry. The concentration of IFN-γ and TNF-α in the cultured supernatant were measured by enzyme immunoassay. JAK-STAT signalling pathway of CIK cells were measured by Western-blot. RESULTS: After IL-21 stimulation, the proportion of CIK cells increased from (17.5 ± 4.7)% to (26.5 ± 2.1)%. Cytotoxic activity against K562 cells by CIK cells increased from (22.8 ± 2.8)% to(44.6 ± 8.3)%. The expression of IL-21R increased about 2 folds. The mRNA expression of IFN-γ increased almost 2 folds from (0.3760 ± 0.2358) to (0.7786 ± 0.2493), TNF-α increased almost 2 folds from (0.6557 ± 0.1598) to (1.3145 ± 0.2136), perforin increased almost 1.5 folds from (0.6361 ± 0.1457) to (0.9831 ± 0.1265), granzyme B increased almost 2 folds from (0.4084 ± 0.1589) to (0.7319 ± 0.1639), FasL increased almost 2 folds from (0.4015 ± 0.2842) to (0.7381 ± 0.2568), the expression of granzyme A, TNF-ß and NKG2D were similar with control. Flow cytometry analysis showed that the expression of FasL of CIK cells was higher than that of control (0.19% vs 0.04%), the expression of perforin increased from 35.28% to 53.16%, and the expression of granzyme B increased from 43.16% to 78.82%. The concentration of IFN-γ in the culture supernatant increased almost 2 folds from (25.8 ± 6.1) ng/L to (56.0 ± 2.3) ng/L, and TNF-α increased almost 3 folds from (5.64 ± 0.61) µg/L to (15.14 ± 0.93) µg/L. Western blot showed that the expression of STAT1 and STAT5a had no significant differences, but the expression of STAT3 and STAT5b were higher than that of control. CONCLUSION: Humanized IL-21 could enhance the anti-leukemic activity of CIK cells via increasing IL-21R, perforin, granzyme B, FasL, IFN-γ and TNF-α, as well as activating JAK-STAT signaling pathway. These data indicate that IL-21 has a potential clinical value in the enhancement of anti-leukemic immunotherapy.

[Effects of oxidative stress on hematopoiesis of hematopoietic stem and progenitor cells with iron overload].

OBJECTIVE: To establish a model of hematopoietic stem and progenitor cells with iron overload derived from umbilical cord blood (UCB) cells and explore the effects of reactive oxygen species (ROS) on the hematopoiesis of hematopoietic stem and progenitor cells with iron overload. METHODS: The model was established by adding different concentrations (50, 100, 200, 400 µmol/L)of ferric citrate (FAC) into mononuclear cells from UCB and culturing for different times (6, 12, 24 h). The UCB cells were divided into 4 groups: control group, group FAC, group FAC+N-acetyl-L-cysteine (NAC) and group FAC+ L-Glutathione (GSH). Then the changes of ROS, labile iron pool (LIP), apoptosis, the capacity of hematopoietic colony forming (CFU-E, BFU-E, CFU-GM, CFU-mix) and the percentage and the numbers of CD34(+), CD33(+), GlyA(+) cells were detected. And the changes of these indices were tested after the treatment of iron overload UCB with antioxidants (NAC and GSH). RESULTS: UCB cells were cultured with the addition of FAC at different concentrations for different times. The level of total ROS increased in time and concentration-dependent manners. The intracellular level of ROS peaked when cultured at 200 µmol/L of FAC for 24 hours. Cells were treated with antioxidants NAC or GSH after cultured with 200 µmol/L FAC for 24 hours. Then the ROS levels of total cells, myeloid cells and erythroid cells decreased markedly versus normal controls. The LIP of total cells, myeloid cells and erythroid cells increased markedly when cells were cultured at 200 µmol/L of FAC for 24 hours versus normal controls (P < 0.05). NAC and GSH had no effect on the level of LIP. The apoptotic rates of FAC-treated cells [(20.90 ± 3.45)%] increased significantly versus normal controls [(9.20 ± 1.29)%] (P < 0.05). The capacity of hematopoietic colony forming in FAC treated cells decreased markedly versus normal controls. The percentage and numbers of CD34(+), CD33(+), GlyA(+) cells of FAC-treated cells also decreased significantly versus normal controls (P < 0.05). And these changes could be recovered by the addition of NAC or GSH. CONCLUSION: Oxidative stress plays an important role in the injuries of hematopoiesis of hematopoietic stem and progenitor cells with iron overload by inducing the generation of ROS. These findings may help us find a specific target and improve the therapeutic efficacy of ineffective hematopoiesis in patients with iron overload.