The homing and engraftment of hematopoietic stem cells (HSC) into bone marrow is the first critical step for successful clinical hematopoietic stem cell transplantation (HSCT). SDF-1 / CXCR4 is considered to be a very promising target to promote HSC homing. In recent years, with the in-depth research on the HSC homing, a variety of new strategies for promoting HSC homing and engraftment have been explored, such as nuclear hormone receptor, histone deacetylase inhibitor, prostaglandin and metabolic regulation, so as to increase the success rate of HSCT and improve the survival of patients. In this review, the recent research advances in the mechanism of HSC homing and strategies to promote HSC homing and engraftment were summarized and discussed.
Humans ; Hematopoietic Stem Cells/physiology* ; Bone Marrow ; Hematopoietic Stem Cell Transplantation ; Gene Expression Regulation ; Prostaglandins/metabolism*

Bone marrow macrophage is an important component of bone marrow microenvironment, which is closely related to hematopoietic regulation and hematopoietic stem cell transplantation(HSCT). Recent studies have shown that bone marrow macrophage is an important part of hematopoietic stem cell niche, which can help regulate the mobilization and function of hematopoietic stem/progenitor cells. After HSCT, the microenvironment of bone marrow is damaged and a large number of macrophages infiltrate into the bone marrow. Regulating the macrophage-related signal pathways can promote the recovery of hematopoiesis and the reconstruction of hematopoietic function. Co-culture of macrophages and hematopoietic stem cells (HSC) in vitro significantly increased the number of HSCs and their ability of clone formation, which suggests that macrophages play an important role in the regulation of hematopoiesis in the hematopoietic microenvironment of bone marrow. This paper reviews the recent research progress on the role of macrophages in bone marrow hematopoietic microenvironment.
Humans ; Bone Marrow/metabolism* ; Hematopoietic Stem Cells/physiology* ; Hematopoiesis/physiology* ; Stem Cell Niche ; Macrophages/metabolism*

OBJECTIVE: To compare the efficacy of plerixafor (PXF) combined with granulocyte colony-stimulating factor (G-CSF) (PXF+G-CSF) and cyclophosphamide (Cy) combined with G-CSF (Cy+G-CSF) in the mobilization of peripheral blood stem cells (PBSCs) in patients with multiple myeloma (MM). METHODS: The clinical data of 41 MM patients who underwent PBSC mobilization using PXF+G-CSF (18 cases) or Cy+G-CSF (23 cases) in Shanxi Bethune Hospital from January 2019 to December 2021 were retrospectively analyzed, including the count of collected CD34⁺ cells, acquisition success rate, failure rate, and optimal rate. The correlation of sex, age, disease type, DS staging, ISS staging, number of chemotherapy cycle, disease status before mobilization, and mobilization regimen with the collection results was analyzed, and the adverse reactions, length of hospital stay, and hospitalization costs were compared between the two mobilization regimens. RESULTS: The 41 patients underwent 97 mobilization collections, and the median number of CD34⁺ cells collected was 6.09 (0-34.07)×10⁶/kg. The acquisition success rate, optimal rate, and failure rate was 90.2%, 56.1%, and 9.8%, respectively. Univariate analysis showed that sex, age, disease type, and disease stage had no significant correlation with the number of CD34⁺ cells collected and acquisition success rate (P >0.05), but the patients with better disease remission than partial remission before mobilization were more likely to obtain higher CD34⁺ cell count (P <0.05). The PXF+G-CSF group had a larger number of CD34⁺ cells and higher acquisition success rate in the first collection than Cy+G-CSF group (both P <0.05), and had lower infection risk and shorter length of hospital stay during mobilization (both P <0.05), but the economic burden increased (P <0.05). CONCLUSION PXF+G-CSF used for PBSC mobilization in MM patients has high first acquisition success rate, large number of CD34⁺ cells, less number of collection times, and short length of hospital stay, but the economic cost is heavy.
Humans ; Antigens, CD34/metabolism* ; Cyclophosphamide/therapeutic use* ; Granulocyte Colony-Stimulating Factor/therapeutic use* ; Hematopoietic Stem Cell Mobilization/methods* ; Hematopoietic Stem Cell Transplantation ; Heterocyclic Compounds/therapeutic use* ; Multiple Myeloma/drug therapy* ; Peripheral Blood Stem Cells/metabolism* ; Retrospective Studies

OBJECTIVE: To study the effects of the neuro-microenvironment on the mass of mitochondria in hematopoietic stem and progenitor cells (HSPC), and to understand the potential mechanisms how nerve regulates HSPC. METHODS: 6-hydroxydopamine (6-OHDA) and capsaicin were used to interfere with the function of sympathetic nerve and nociceptive nerve in mitochondria-GFP reporter mice, respectively. The fluorescence intensity of GFP in bone marrow and spleen was measured by flow cytometry. The GFP median fluorescence intensity (MFI) of HSPC in normal bone marrow and spleen was analyzed and compared. The changes of the mitochondrial mass in HSPCs in each group after denervation were compared. RESULTS: Hematopoietic stem cells (HSC) had the highest mito-GFP MFI in steady-state (49 793±1 877), and the mito-GFP MFI gradually decreased during the differentiation of HSCs. Compared with control group, pharmaceutical nociceptive denervation significantly increased the mito-GFP MFI of bone marrow multipotent progenitor-1 (MPP1, 50 751±420 vs 44 020±510) and LKS^- cells (15 673±65 vs 13 979±103); pharmaceutical sympathetic denervation significantly reduced the mito-GFP MFI of bone marrow LKS⁺ cells (21 667±351 vs 29 249±973). CONCLUSION Sympathetic and nociceptive nerves can regulate the mass of mitochondria in HSPC and affect the function of HSPCs.
Animals ; Mice ; Hematopoietic Stem Cells ; Bone Marrow/metabolism* ; Cell Differentiation ; Mitochondria ; Pharmaceutical Preparations/metabolism*

OBJECTIVE: To analyze the factors influencing collection of autologous peripheral blood hematopoietic stem cells in lymphoma patients. METHODS: Clinical data of 74 patients who received autologous peripheral blood hematopoietic stem cells mobilization and collection in the 940th Hospital of Joint Logistic Support Force of PLA from April 2009 to April 2021 were collected. The effects of gender, age, disease type, stage, course of disease, chemotherapy cycle number, relapse, radiotherapy, disease status and blood routine indexes on the day of collection on peripheral blood hematopoietic stem cell collection were analyzed. RESULTS: The success rate of collection was 95.9%(71/74), and the excellent rate of collection was 71.6%(53/74). There was a significantly statistical differentce in the number of CD34⁺ cells in grafts collected from patients with chemotherapy cycle ≤6 and >6 ［(9.1±5.2)×10⁶/kg vs (6.4±3.7)×10⁶/kg, P=0.031］. The number of CD34⁺ cells in the first collection was positively correlated with WBC count, hemoglobin, platelet count, neutrophil count, lymphocyte count, monocyte count and hematocrit value on the day of collection ( r value was 0.424,0.486,0.306,0.289,0.353,0.428,0.528, respectively). WBC count, hemoglobin, monocyte count and hematocrit value have higher predictive value for the first collection of CD34⁺ cells. The area under the receiver operating characteristic was 0.7061,0.7845,0.7319,0.7848, respectively. CONCLUSION Low dose CTX and VP16 chemotherapy combined with G-CSF can effectively mobilize autologous peripheral blood stem cells. The cycle number of chemotherapy relates to the collection of autologous peripheral blood stem cells. After mobilization, the success of the first collection can be better predicted by the blood routine indexes.
Humans ; Antigens, CD34/metabolism* ; Neoplasm Recurrence, Local/drug therapy* ; Hematopoietic Stem Cell Mobilization ; Lymphoma/drug therapy* ; Granulocyte Colony-Stimulating Factor/pharmacology* ; Hematopoietic Stem Cells ; Hemoglobins ; Transplantation, Autologous ; Hematopoietic Stem Cell Transplantation

OBJECTIVE: To investigate the effect and relative mechanism of Recombinant Human Thrombopoietin (rhTPO) on long-term hematopoietic recovery in mice with acute radiation sickness. METHODS: Mice were intramuscularly injected with rhTPO (100 μg/kg) 2 hours after total body irradiation with ⁶⁰Co γ-rays (6.5 Gy). Moreover, six months after irradiation, peripheral blood, hematopoietic stem cells (HSC) ratio, competitive transplantation survival rate and chimerization rate, senescence rate of c-kit⁺ HSC, and p16 and p38 mRNA expression of c-kit⁺ HSC were detected. RESULTS: Six months after 6.5 Gy γ-ray irradiation, there were no differences in peripheral blood white blood cells, red blood cells, platelets, neutrophils and bone marrow nucleated cells in normal group, irradiated group and rhTPO group (P>0.05). The proportion of hematopoietic stem cells and multipotent progenitor cells in mice of irradiated group was significantly decreased after irradiation (P<0.05), but there was no significant changes in rhTPO group (P>0.05). The counts of CFU-MK and BFU-E in irradiated group were significantly lower than that in normal group, and rhTPO group was higher than that of the irradiated group(P<0.05). The 70 day survival rate of recipient mice in normal group and rhTPO group was 100%, and all mice died in irradiation group. The senescence positive rates of c-kit⁺ HSC in normal group, irradiation group and rhTPO group were 6.11%, 9.54% and 6.01%, respectively (P<0.01). Compared with the normal group, the p16 and p38 mRNA expression of c-kit⁺ HSC in the irradiated mice were significantly increased (P<0.01), and it was markedly decreased after rhTPO administration (P<0.01). CONCLUSION The hematopoietic function of mice is still decreased 6 months after 6.5 Gy γ-ray irradiation, suggesting that there may be long-term damage. High-dose administration of rhTPO in the treatment of acute radiation sickness can reduce the senescence of HSC through p38-p16 pathway and improve the long-term damage of hematopoietic function in mice with acute radiation sickness.
Humans ; Mice ; Animals ; Thrombopoietin/metabolism* ; Hematopoietic Stem Cells ; Blood Platelets ; Recombinant Proteins/therapeutic use* ; Radiation Injuries ; RNA, Messenger/metabolism*

Somatostatin (SST) is an inhibitory polypeptide hormone that plays an important role in a variety of biological processes. Somatostatin receptor 2 (SSTR2) is the most widely expressed somatostatin receptor. However, the specific cell types expressing Sstr2 in the tissues have not been investigated. In this study, we detected the expression pattern of SSTR2 protein in mouse at different development stages, including the embryonic 15.5 days and the postnatal 1, 7, 15 days as well as 3 and 6 months, by multicolour immunofluorescence analyses. We found that Sstr2 was expressed in some specific cells types of several tissues, including the neuronal cells and astrocytes in the brain, the mesenchymal cells, the hematopoietic cells, the early hematopoietic stem cells, and the B cells in the bone marrow, the macrophages, the type Ⅱ alveolar epithelial cells, and the airway ciliated cells in the lung, the epithelial cells and the neuronal cells in the intestine, the hair follicle cells, the gastric epithelial cells, the hematopoietic stem cells and the nerve fibre in the spleen, and the tubular epithelial cells in the kidney. This study identified the specific cell types expressing Sstr2 in mouse at different developmental stages, providing new insights into the physiological function of SST and SSTR2 in several cell types.
Mice ; Animals ; Receptors, Somatostatin/metabolism* ; Hematopoietic Stem Cells/metabolism* ; Epithelial Cells

OBJECTIVE: To investigate the expression and its relative mechanism of hypoxia-inducible factor-1α(HIF-1α) in bone marrow(BM) of mice during G-CSF mobilization of hematopoietic stem cells (HSC) . METHODS: Flow cytometry was used to detect the proportion of Lin^-Sca-1⁺ c-kit⁺ (LSK) cells in peripheral blood of C57BL/6J mice before and after G-CSF mobilization. And the expression of HIF-1α and osteocalcin (OCN) mRNA and protein were detected by RQ-PCR and immunohistochemistry. The number of osteoblasts in bone marrow specimens of mice was counted under the microscope. RESULTS: The proportion of LSK cells in peripheral blood began to increase at day 4 of G-CSF mobilization, and reached the peak at day 5, which was significantly higher than that of control group (P<0.05). There was no distinct difference in the expression of HIF-1α mRNA between bone marrow nucleated cells and osteoblasts of steady-state mice (P=0.073), while OCN mRNA was mainly expressed in osteoblasts, which was higher than that in bone marrow nucleated cells (P=0.034). After mobilization, the expression level of HIF-1α increased, but OCN decreased, and the number of endosteum osteoblasts decreased. The change of HIF-1α expression was later than that of OCN and was consistent with the proportion of LSK cells in peripheral blood. CONCLUSION The expression of HIF-1α in bone marrow was increased during the mobilization of HSC mediated by G-CSF, and one of the mechanisms may be related to the peripheral migration of HSC induced by osteoblasts inhibition.
Mice ; Animals ; Hematopoietic Stem Cell Mobilization ; Granulocyte Colony-Stimulating Factor/pharmacology* ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Mice, Inbred C57BL ; Bone Marrow Cells/metabolism* ; Osteocalcin/metabolism* ; RNA, Messenger/metabolism*

Objective: To explore the differences in the biological effects of different expansion systems on natural killer (NK) cells, as well as the safety and preliminary clinical efficacy in the treatment of patients with recurrence after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Peripheral blood cells from healthy donors were stimulated with either CD3 combined with CD52 or K562 feeder cells loaded with IL-21/4-1BB to induce NK cell expansion. Changes in the NK cell phenotype, cytokine secretion, and cytotoxicity before and after expansion were detected. We also evaluated the safety and clinical efficacy of two different expansion strategies for patients received NK infusion. Results: Compared with the CD3/CD52 monoclonal antibody amplification system, the feeder cell expansion group had a higher purity of NK cells and higher expression ratios of NK cell surface activation receptors such as DNAM-1 and NKp30, while inhibitory receptor CTLA-4 expression was low and NKG2D/CD25/CD69/ Trail/PD-1/TIM-3/TIGIT had no statistically significant differences between the groups. Further functional results showed that the expression level of KI67 in NK cells after expansion in the two groups increased significantly, especially in the feeder cell expansion group. Simultaneously, the perforin and granzyme B levels of NK cells in the feeder cell expansion group were significantly higher than in the CD3/CD52 expansion group. A retrospective analysis of eight patients who received monoclonal antibody-expanded NK cell reinfusion and nine patients with trophoblast cell-expanded NK cell reinfusion was done. The disease characteristics of the two groups were comparable, NK cell reinfusion was safe, and there were no obvious adverse reactions. Clinical prognostic results showed that in the CD3/CD52 monoclonal antibody amplification group, the MRD conversion rate was 50% (2/4) , and the feeder cell expansion group was 50% (3/6) . After 5 years of follow-up from allo-HSCT, three patients in the monoclonal antibody expansion group had long-term survival without leukemia, and the remaining five patients had died; two patients died in the feeder cell expansion group, and the other six patients had long-term survival. Six cases had GVHD before NK cell reinfusion, and GVHD did not aggravate or even relieved after NK cell reinfusion. Conclusions: Preliminary results show that the biological characteristics of NK cells with diverse expansion strategies are significantly different, which may affect the clinical prognosis of patients with recurrence or persistent minimal residual disease after HSCT. The two groups of patients treated with NK cells from different expansion strategies had no obvious adverse reactions after NK cell infusion, but efficacy still needs to be further confirmed.
Antibodies, Monoclonal/pharmacology* ; Graft vs Host Disease/metabolism* ; Hematopoietic Stem Cell Transplantation ; Humans ; Killer Cells, Natural ; Retrospective Studies ; Treatment Outcome

OBJECTIVE: To investigate the regulatory effect and mechanism of DNA methyltransferase 3A (DNMT3a) in hydroquinone-induced hematopoietic stem cell toxicity. METHODS: Cells (HSPC-1) were divided into 4 groups, that is A: normal HSPC-1; B: HQ-intervented HSPC-1; C: group B + pcDNA3 empty vector; D: group B + pcDNA3- DNMT3a. RT-qPCR and Western blot were used to detect the expression levels of DNMT3a and PARP-1 mRNA and protein, respectively. Cell morphology was observe; Cell viability and apoptosis rate of HSPC-1 were detected by MTT and flow cytometry, respectively. RESULTS: Compared with group A, the expression levels of DNMT3a mRNA and protein in HSPC-1 of group B were decreased, while PARP-1 mRNA and protein were increased (P<0.05); there was no significant difference in the above indexes between group C and group B; compared with group B, the expression levels of DNMT3a mRNA and protein showed increased, while PARP-1 mRNA and protein were decreased significantly in cells of group D transfected with DNMT3a (P<0.05). Cells in each group were transfected with DNMT3a and cultured for 24 h, HSPC-1 in group A showed high density growth and mononuclear fusion growth, while the number of HSPC-1 in group B and C decreased and grew slowly. Compared with group B and C, the cell growth rate of group D was accelerated. The MTT analysis showed that cell viability of HSPC-1 in group B were lower than that of group A at 24 h, 48 h and 72 h (P<0.05); after transfected with DNMT3a, the cell viability of HSPC-1 in group D were higher than that of group B at 24 h, 48 h and 72 h (P<0.05). The apoptosis rate of cells in group B was significantly higher than that of group A (P<0.001), while the apoptosis rate in group D was lower than that of group B (P<0.001). CONCLUSION DNMT3a may be involved in the damage of hematopoietic stem cells induced by hydroquinone, which may be related to the regulation of PARP-1 activity by hydroquinone-inhibited DNMT3a.
Apoptosis ; Cell Proliferation ; DNA Methyltransferase 3A ; Hematopoietic Stem Cells/drug effects* ; Humans ; Hydroquinones/toxicity* ; Poly (ADP-Ribose) Polymerase-1 ; RNA, Messenger/metabolism*