ABSTRACT
Cryopreservation of hematopoietic stem/progenitor cells (HSPCs) is associated with oxidative stress-mediatedcryodamage, hence compromising the therapeutic potency. The roles of N-acetyl cysteine (NAC) on the oxidativestress-mediated cryodamage and repopulation capacity of HSPCs into myeloid, erythroid, and pre-B lymphoidprogenitors were investigated. Mice bone marrow-derived HSPCs were cultured for 24 hours, followed bycryopreservation at 1 × 106/ml cells in cryomedium containing 10% dimethyl sulfoxide with NAC (0.25, 0.5, or 2.0µM) or without for 48 hours, 2 weeks, and 4 weeks at −80°C. Cryopreservation significantly reduced cell viability atpost-thawed (p < 0.05) with long-term cryopreservation conferred a greater cell recovery. NAC improved the bonemarrow-derived HSPC viability (p < 0.05) at 0.5 and 2.0 µM after 48 hours of cryopreservation. Cryopreservationlowered the malondialdehyde level (p < 0.05) although glutathione, superoxide dismutase, and protein carbonyl levelswere not significantly affected. Repopulation capacity of HSPCs into myeloid–erythroid progenitors was greatlyreduced (p < 0.05) after 4 weeks of cryopreservation as compared to precryopreservation group. Meanwhile, NACsupplementation showed no remarkable effect on oxidative stress-mediated cryodamage and repopulation capacity ofHSPCs. Conclusively, the cryoprotective role of NAC on the cryopreservation of HSPCs deserves further investigation
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Objective To establish Ad-LIF-OSM transgenic feeder cells for the expansion of CD34+ hematopoietic stem/progenitor cell and tentatively study its effect in expansion and differentiation of cord blood hematopoietic stem cell(HSC) in vitro.Methods In the foundation of pAdTrack-CMV-LIF-polyA+promoterΔ,the OSM gene was inserted to the vector plasmid.Then we structure the transfer plasmid pAdTrack-CMV-LIF-polyA+promoterΔ-OSM.The transfer vector and backbone vector were further cotransfected for homologous recombination. The result pAdEasy-1-pAdTrack-CMV-LIF-polyA + promoterΔ-OSM homologous recombination plasmid were transfected into the human embryonic kidney 293 (QBI-293A) cells,leading to formation of the recombinant adenviruses Ad-LIF-OSM which co-expressing LIF and OSM.Infect the feeder layer cells with groups of Adenovirus,detection the expressing of LIF and OSM in WI-38 cells by RT-PCR and ELISA.Compares the stem cells differentiation and proliferation of the different experimental groups in vitro by transwell and cell counting.Results The sequencing results show that the OSM genes were anastomotic in Ad-LIF-OSM.LIF and OSM gene could be detected in feeder layer cells which infected by Ad-LIF-OSM.Exogenetic LIF and OSM have special effect in culturing HSC in vitro.Conclusion The adenoviral vector co-expressing LIF and OSM (Ad-LIF-OSM) were successfully constructed.Ad-LIF-OSM transgenic feeder cells can effectively proliferate umbilical cord blood CD34+ HSPC in vitro and delay it differentiate.
ABSTRACT
Objective To explore the effect of stroma cell-derived factor receptor CXCR4 on the homing of the hematopoietic stem/progenitor cells in utero transplantation. Methods CD34~+ cells were collected by Ficoil density gradient centrifugation and MiniMACS and then stimulated for 48 h by SCF and IL-6 cytokines prior to transplantation. CD184(CXCR4) expressions and transmigrate rates of the CD34~+ cells were analysed by flow cytometer. Cells pre-treated with different treatment were transplanted into the abdominal cavity of the fetal BALB/c mouse in the pregnant days 13～14. Human CD45 cells as the marker of graft were detected by flow cytometry after 1 month the fetus born. Results Expression changes of CD184 on CD34~+ cells were from 9. 58%±1. 56% to 19. 32%±3. 64% after SCF and IL-6 stimulation. The CD34~+/CXCR4~(high) cells exhibited significant increases in SDF-1 mediated chemotaxis compared with the CD34~+/CXCR4~(low) cells. Transmigration of CD34~+ /CXCR4~(high) was inhibited by pretreatment with an-tiCXCR4mAb and PTX. The positive rates of human CD45 cells detected in the fetal mouse were significantly higher in the SCF and IL-6 pretreatment group. This effects were significantly abrogated after the addition of antiCXCR4mAb or PTX. Conclusion Up-regulation of CXCR4 expression may be useful for improving hematopoietic stem/progenitor cells homing in utero transplantation. This homing process is mediated and depends on the CXCR4 receptors. The signal transduction is mediated by PTX-sensitive Gi protein.
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Objective To establish Ad-hLIF transgenic feeder cells for the expansion of umbilical cord blood CD34+ HSPC in vitro and study the SCID mice model of hematopoietic stem/progenitor cell (HSPC) transplantation. Methods The expression of objective gene in Ad-hLIF transgenic feeder cells was detected by RT-PCR and ELISA. The purity of umbilical cord blood CD34+ HSPC separated by magnetic-activated cell sorting(MACS) was detected by the flow cytometry. After expanded with various combinant of cytokines and transgenic feeder layer cells for 28 d, the quantity of mono-nuclear cell (MNC) and CD34+ cells rate was detected in different time. MNC after expansion stained by CFDA SE was injected to the sublethally irradiated SCID mice. Humanize gene Alu was detected by RT-PCR and fluorescence microscope. Results The green fluorescence was observed in the transgenic cells infected with 50MOI( multiplicity of infection) Ad-hLIF, and the objective gene was confirmed by RT-PCR and ELISA. The purity of umbilical cord blood CD34+ HSPC separated by MACS could reach 95.60% ±2.58%, Ad-hLIF transgenic feeder cells and various cytokines system increased MNC by 356.95±0.87 fold, and maximal expansion of CD34+ cells was observed during 0-14 d of culture, then down-expansion gradually. Four weeks after transplanted in SCID mice, fluorescently-labeled humanize cells still can be observed. The existence of the humanized gene Alu was confirmed by RT-PCR. Conclusion Ad-hLIF transgenic feeder cells can effectively proliferate umbilical cord blood CD34+ HSPC in vitro and delay it differentiate, what's more, it has high transplant efficacy and haematogenesis activity.
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Hematopoietic stem/progenitor cells have the potential of self-renewal,proliferation and multidirectional differentiation,which maintain the normal haematopoiesis of bnmml body.Alterations in the number and function of mature blood cells in the peripheral blood commonly observed in humans exposed to microgravity (μ-g)are results of many reasons.The change of biological characteristic of hematopoietic stem/progenitor cells is one of the important ressons.Migration,proliferation,and differentiation of hematopoietic stem/progenitor cells under microgravity are summarized in this article.
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Objective To explore the effect of stroma cell-derived factor receptor CXCR4 on the homing of the hematopoietic stem/progenitor cells in utero transplantation. Methods CD34+ cells were collected by Ficoll density gradient centrifugation and MiniMACS and then stimulated for 48 h by SCF and IL-6 cytokines prior to transplantation. CD184(CXCR4) expressions and transmigrate rates of the CD34+ cells were analysed by flow cytometer. Cells pretreated with different treatment were transplanted into the abdominal cavity of the fetal BALB/c mouse in the pregnant days 13～14. Human CD45 cells as the marker of graft were detected by flow cytometry after 1 month the fetus born. Results Expression changes of CD184 on CD34+ cells were from 9.58%?1.56% to 19.32%?3.64% after SCF and IL-6 stimulation. The CD34+/CXCR4high cells exhibited significant increases in SDF-1 mediated chemotaxis compared with the CD34+/CXCR4low cells. Transmigration of CD34+/CXCR4high was inhibited by pretreatment with antiCXCR4mAb and PTX. The positive rates of human CD45 cells detected in the fetal mouse were significantly higher in the SCF and IL-6 pretreatment group. This effects were significantly abrogated after the addition of antiCXCR4mAbor PTX. Conclusion Up-regulation of CXCR4 expression may be useful for improving hematopoietic stem/progenitor cells homing in utero transplantation. This homing process is mediated and depends on the CXCR4 receptors. The signal transduction is mediated by PTX-sensitive Gi protein.
ABSTRACT
In order to investigate the influence of angiotensin Ⅱ on hematopoietic system, CD34+cells in cord blood were purified, and the effects of angiotensin Ⅱ in combination with various cytokines on their growth and differentiation were studied by cell culture in vitro. It was found that angiotensin Ⅱ in suspending medium could stimulate both BFU-E and CFU-GM expansion. The number of BFU-E and CFU-GM was increased with the increases of angiotensin Ⅱ concentrations during a certain range. In addition, the expansion fold of CFU-GM was increased from 2.3±0.8 times to 7.8±2.3 times when angiotensin Ⅱ was added in the presence of SCF+G-CSF+GM-CSF+IL-3 cytokines mixture. Similarly, the expansion fold of BFU-E was increased from 3.1 ±1.8 times to 9.2±2.3 times with angiotensin Ⅱ in the presence of SCF+EPO+TPO+IL-3. In the semi-solid medium, angiotensin Ⅱ could stimulate CFU-GM expansion but had no effect on the growth of BFU-E. In conclusion, angiotensin Ⅱ had some stimulating effects on cord blood hematopoietic progenitors expansion in vitro in the presence of other cytokines.
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Objective:To study the mobilizable effect of ginseng polysaccharide(GPS)on murine hematopoietic stem/ progenitor cells and provide experimental evidences for mobilizable preparation of hematopoietic stem cell from plant polysaccharide.Methods:The changes of the numbers of WBC and MNC,the percentage of CD34+ cell and the yields of CFU-Mix in peripheral blood were examined by means of WBC and MNC counts,immunocytochemistry,flow cytometry and hematopoietic cell culture in vitro.Results:4 hours after injection of GPS into mice with a dosage of 2 mg/kg,the numbers of WBC and MNC reached the maximum,which were 3 times and 3.5 times that of the NS group respectively.The percentage of CD34+ cell and the yields of CFU-Mix in vitro in peripheral blood(0.0079?0.0011 and(25.0?9.1)cfu/2?105MNC respectively)after the mobilization by GPS were obviously higher than those of the NS group.The effect of mobilization by combination of GPS and G-CSF was much better than that mobilized by single administration of GPS.Conclusion:GPS alone or in combination with G-CSF could significantly mobilize murine hematopoietic stem/progenitor cells from bone marrow into peripheral blood.
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Objective:To study the hematopoietic reconstruction for bone marrow depression mice with mobilized peripheral blood stem/proginiter cells by ginseng polysaccharide.Methods: Establish hematopoiesis failure model of mouse and transplant murine peripheral blood mononuclear cells mobilized by GPS.To observe the survival time,WBC,the weight of spleen,the number of CFU-S of recipient mice and chromosome chimerism.Results: After PBMNCs(1?105)mobilized by GPS from mice(male) were injected to the lethality irradiated mice,it can reduce the time of WBC recovery obviously;prolong the time of murine survival,increase the number of WBC of the recipient mice;it can also increase the number of CFU-S,the weight of spleen;Evaluating the Y chromosome by PCR,the result showed that 581bp Y chromosome sequence was examined in peripheral blood of the recipient mice.Conclusion: There are a lot of hematopoietic stem/ proginiter cells in peripheral blood of the mice mobilized by GPS,so it can obviously reconstruct the hematopoiesis of the bone marrow depression mice by transplantation.