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Objective:To investigate the difference in the radiation sensitivity of hematopoietic stem and progenitor cells (HSPCs) derived from fetal liver and bone marrow.Methods:HSPCs from fetal liver of 14.5 d embryo or bone marrow of 8 week-old mice were isolated to receive a single dose of 5 or 10 Gy irradiation in vitro using a 60Co irradiator. Twelve hours later, the cell apoptosis, mitochondrial reactive oxygen species (ROS) level, colony formation ability and DNA damage in HSPCs were detected. Freshly isolated HSPCs were injected into lethally irradiated CD45.1 + C57BL/6J mice (4.5 Gy+ 5 Gy with an interval of 30 min) Chimerism rate, lineage constitution, and cell cycle were analyzed 12 weeks after transplantation. Results:Compared with bone marrow HSPCs after irradiation, the percentage of apoptosis in fetal liver HSPCs was significantly higher ( t=16.21, 12.27, P<0.05), the level of ROS was dramatically elevated ( t=68.72, 18.89, P<0.05). At 10 Gy, fetal liver HSPCs could not form colonies at all ( t=12.41, 15.67, 9.46, P<0.05). γ-H2AX immunofluorescence staining showed that the DNA damage of fetal liver HSPCs was more severe after irradiation, and the number of Foci formed was significantly higher than that of bone marrow HSPCs ( t=2.27, 2.03, P< 0.05), which indicated that fetal liver HSPCs were more sensitive to radiation. The chimerism rate of transplanted fetal liver HSPCs was lower than that of bone marrow cells ( t=5.84, P<0.05) with a higher proportion of myeloid lineage, suggesting that fetal liver HSPCs had lower in vivo reconstitution capacity than bone marrow HSPCs and were more prone to myeloid differentiation. The cell cycle of bone marrow HSPCs from transplanted chimeric mice was examined, and the proportion of S-phase was significantly higher in the fetal liver group than that in the bone marrow group ( t=2.89, P<0.05). Mitochondrial stress results showed that fetal liver HSPCs had higher basal respiratory capacity ( t=39.19, P<0.05), proton leakage ( t=6.64, P<0.05), ATP production ( t=9.33, P<0.05), and coupling efficiency ( t=7.10, P<0.05) than bone marrow c-Kit + cells, while respiratory reserve capacity ( t=5.53, P< 0.05) was lower than that of bone marrow c-Kit + cells. Conclusions:HSPCs derived from fetal liver display higher radiosensitivty compared with bone marrow HSPCs, laying the foundation for an in-depth illustration of the effects of radiation on hematopoietic stem cells at different developmental stages.
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Objective:To study the effect of different doses of 60Co γ-ray ionizing radiation on mitochondrial function in mouse hematopoietic stem and progenitor cells (HSPCs). Methods:C57BL/6 mice were divided into control group, 1 Gy irradiation group and 4.5 Gy irradiation group. The mitochondrial functions were detected at 12 h and 24 h after irradiation, including ROS level, membrane potential, mitochondrial structure, and mitochondrial stress. Bone marrow c-Kit + cells received a single 15 Gy irradiation in vitro, after 24 h, mitochondrial function was detected. Results:It was found that mice leukocytes ( t=12.41, 18.31, 16.48, 14.16, 19.08, 20.25, P<0.05), red blood cells ( t=4.81, 6.62, P<0.05) and platelets ( t=4.33, 6.68, P<0.05) were significantly reduced. The numbers of bone marrow colony formation unit ( t=16.27, 55.66, 17.06, 43.75, P<0.05), and HSPCs ( t=5.16, 11.55, P<0.05) were decreased dose-dependently post-irradiation. Under 1 Gy irradiation, the mitochondrial function and mitochondrial basal metabolic index of HSPCs ( t= 7.36, 3.68, 4.58, 3.15, 3.15, P<0.05) were enhanced at 24 h post-irradiation. Under 4.5 Gy irradiation, mitochondrial number, mitochondrial membrane potential ( t=12.29, 10.46, P<0.05), maximal respiration and spare respiratory capacity were decreased ( t=7.81, 5.78, 6.70, 5.83, P<0.05), ROS level was increased ( t=4.63, 4.12, P<0.05). The basal respiration and oxidative phosphorylated ATP production were reduced at 12 h after irradiation ( t=8.48, 3.80, P<0.05); and the proton leakage was increased ( t=6.57, P<0.05) and coupling efficiency was reduced ( t=11.43, P<0.05) at 24 h after irradiation. In cultured c-Kit + cells, the level of ROS ( t=11.30, P<0.05) and the maximum respiration and spare respiratory capacity were increased ( t=4.25, 3.44, P<0.05) while the mitochondrial membrane potential was decreased ( t=34.92, P<0.05) significantly. Conclusions:A method for systematically assessing mitochondrial function in HSPCs was established, and the effect of ionizing radiation on mitochondrial function of HSPCs was clarified, laying a foundation for further revealing the mechanism of ionizing radiation-induced mitochondrial damage in HSPCs.
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ABSTRACT While first-line induction therapy for patients with multiple myeloma has changed over the years, autologous hematopoietic stem cell transplantation still plays a significant role, improving both depth of response and progression-free survival of myeloma patients. Our 25-year experience in mobilizing hematopoietic stem and progenitor cells for 472 transplant-eligible myeloma patients was retrospectively reviewed. Patients were stratified according to the remission induction therapy received, and the outcomes were compared among the cohorts that received vincristine, adriamycin and dexamethasone (VAD) (n = 232), bortezomib and dexamethasone (BD) (n = 86), cyclophosphamide, bortezomib and dexamethasone (CyBorD) (n = 82) and other regimens (n = 67). Cyclophosphamide plus granulocyte colony-stimulating factor was the predominant mobilization regimen given. A greater number of CD34+ cells (9.9 × 10E6/kg, p = 0.026) was collected with less hospital admissions in BD patients (13%, p = 0.001), when compared to those receiving VAD (7.5 × 10E6/kg, 29%), CyBorD (7.6 × 10E6/kg, 19%), or other regimens (7.9 × 10E6/kg, 36%). Induction therapy did not influence the overall rate of unscheduled visits or the length of hospitalization because of complications following mobilization. The myeloma response was not significantly deepened following the cyclophosphamide administered for mobilization. This analysis demonstrates the importance of monitoring the impact of initial treatment on downstream procedures such as stem cell mobilization and collection.
Subject(s)
Humans , Male , Female , Stem Cells , Remission Induction , Hematopoietic Stem Cells , Cyclophosphamide , Multiple Myeloma , Hematopoietic Stem Cell Transplantation , Hematopoietic Stem Cell MobilizationABSTRACT
Objective To investigate the protective effect of hydrogen-rich water (HRW) on radiation-induced hematopoietic stem and progenitor cells (HSPCs) injury.Methods Totally 32 C57BL/6 mice were randomly divided into four groups with 8 mice in each group,including control,HRW,radiation and radiation + HRW.Mice in HRW and radiation + HRW groups received 0.5 ml hydrogen-rich water per day by intragastric administration 5 min before irradiation until 7 d post-irradiation.Mice in other groups received 0.5 ml distilled water.Mice in radiation and radiation + HRW group were irradiated with 2 Gy of total body irradiation.Bone marrow cells were isolated at 15 d post-irradiation,and LSK cells were examined for the percentage of hematopoietic stem and progenitor cells,the ability of colony formation and reconstitution,reactive oxygen species (ROS) levels and cell apoptosis.Results Compared with radiation group,the percentages of hematopoietic progenitor cells and LSK cells,colony number of bone marrow cells were significantly increased in radiation + HRW group (t =-4.935,-7.898,5.488,P ＜ 0.05).An elevation of donor chimerism was also found in recipient mice administered HRW after competitive bone marrow transplantation (t =-12.769,P ＜ 0.05).Compared with radiation group,the ROS levels and cell apoptosis in LSK cells were significantly decreased (t =4.380,3.954,P ＜ 0.05).Conclusions Hydrogen-rich water exhibited a protective effect on radiation-induced HSPCs injury.
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Hematopoietic stem and progenitor cells (HSPCs) can produce all kind of blood lineage cells, and gut microbiota that consists of various species of microbe affects development and maturation of the host immune system including gut lymphoid cells and tissues. However, the effect of altered gut microbiota composition on homeostasis of HSPCs remains unclear. Here we show that compositional change of gut microbiota affects homeostasis of HSPCs using Rag1(-/-) mice which represent lymphopenic condition. The number and proportions of HSPCs in Rag1(-/-) mice are lower compared to those of wild types. However, the number and proportions of HSPCs in Rag1(-/-) mice are restored as the level of wild types through alteration of gut microbiota diversity via transferring feces from wild types. Gut microbiota composition of Rag1(-/-) mice treated with feces from wild types shows larger proportions of family Prevotellaceae and Helicobacterceae whereas lower proportions of family Lachnospiraceae compared to unmanipulated Rag1(-/-) mice. In conclusion, gut microbiota composition of lymphopenic Rag1(-/-) mice is different to that of wild type, which may lead to altered homeostasis of HSPCs.
Subject(s)
Animals , Humans , Mice , Feces , Homeostasis , Immune System , Lymphocytes , Microbiota , Stem CellsABSTRACT
Objective: To investigate the changes of gene expression in CD34+ hematopoietic stem and progenitor cells (HSPCs) under different growth environments. Methods: Umbilical cord blood mononuclear cells (UCB MNCs) were cultured in static and stirred systems. After 7 days of culture, CD34+ cells were isolated and total RNA was extracted. Gene expression patterns of CD34+ cells from fresh, static and stirred cultures were compared using differential display (DD). Results: 30 gene fragments displayed differential expression levels based on the conditions of DD. One of differentially expressed genes was identified as RAN, which is a member of oncogene RAS family. This gene may be associated with proliferation of hematopoietic cells. Conclusion: Different growth environments induced differential gene expression patterns of CD34+ HSPCs. These differentially expressed genes would give new insights into optimizing in vitro environments for expanding hematopoietic cells.
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Objective:To explore the effect of angelica polysaccharide(APS)on adhesion molecules expressions in murine hematopoietic cells,in order to provide experimental evidence of APS on hematopoietic regulation and the mechanism of mobilizing.Methods:Techniques of peripheral blood white blood cell(WBC)and bone marrow mononuclear cells(MNC)count were made.Flow cytometry detected the rate of Sca-1~+ cells in peripheral blood and bone marrow and the expression of CD49d (VLA-4 of a chain),CD44 on bone marrow MNC and Sca-1~+ cells.Results:1.In APS group(4mg/kg):the number of peripheral blood WBC and Sca-1~+ cells were markedly higher than that of NS group(P