To explore the effect of different doses of thrombopoietin on proliferation of bone marrow mesenchymal stem cells (MSCs) in mice, 20 Kunming mice (35 +/- 5 g) were divided randomly into 4 groups: low-dose TPO group, moderate-dose TPO group, high-dose TPO group and normal control group (n = 5). The experimental groups were subjected to intraperitoneal injections of TPO at a dose of 25, 50, 100 microg/kg, respectively, and normal control group were treated with saline at a dose of 0.1 ml/g per day for 5 days. The bone marrow was harvested on 12 hours after the final administration. The bone marrow nucleated cells (BMNCs) were counted and seeded at a density of 10(6) cells/cm(2). The colony-forming unit-fibroblast (CFU-F) of MSCs was cultured and evaluated. The CFU-F of MSCs underwent osteo-genic induction and adipogenic induction, and cytochemical and immunocytochemical staining were performed to verify their multipotential. CFU-F and the cell percentage of CD90(+), CD105(+), CD34(+) in BMNCs were analyzed by flow cytometry. The results showed that the number of BMNCs and the cell percentage of CD90(+), CD105(+), CD34(+) and CFU-F increased obviously in TPO groups as compared with the normal control group (p < 0.05). The number of BMNCs increased most obviously in the 50 microg/kg TPO group. However, there was no significant difference in number of CFU-F between 50 microg/kg and 100 microg/kg TPO group (p > 0.05). The CFU-F of MSCs in bone marrow had their osteogenic and adipogenic differentiation potentials in vitro. It is concluded that the number of BMNCs and the cell percentage of CD90(+), CD105(+) and CFU-F increased after administration with TPO. It means that TPO can enhance MSCs to proliferate in bone marrow. However, the number of BMNCs and CFU-F can not increase with the increase of TPO dose.

The objective of this study was to explore the effects of BMP-4 and VEGF on the development of primary hematopoietic stem cells during the differentiation of embryonic stem cells (ESCs) into embryoid body (EB). Murine E14 ESCs were seeded into semisolid methylcellulose-based medium for EB formation. According to added or not cytokines, experiments were divided into: (1) group of spontaneous differentiation without cytokine as control; (2) group of BMP-4 in different concentrations (0, 5, 15, 25 and 50 ng/ml); (3) group of BMP-4 combined with VEGF; (4) group of VEGF alone. EBs were collected on days 3, 6, 9, 12, 15, and the proportion of Flk-1(+) cells were assayed by flow cytometry. The results showed that in the different BMP-4 concentration groups, the proportions of Flk-1(+) cells were significantly different, and it reached the peak values in 25 ng/ml BMP-4 group as 6.51 +/- 1.02% at day 3 and 7.70 +/- 1.12% at day 6 respectively, which were statistically higher than those in control group without-BMP-4 and in 5 ng/ml BMP-4 group (p < 0.05). When BMP-4 was used in combination with VEGF, Flk-1(+) cells went to peak proportion value at day 9 as 27.53 +/- 8.14%, which was statistically higher than that in spontaneous differentiation group as 8.77 +/- 2.35% (p < 0.05) and VEGF treatment group as 11.21 +/- 2.23% (p < 0.05). It is concluded that BMP-4 in combination with VEGF can promote Flk-1(+) cells genesis during EB formation in vitro, which provides experimental evidence for researches on directed differentiation of ESCs into hematopoietic stem cells simulating the microenvironment in vivo.

The objective of this study was to investigate the effect of ligustrazine on the expression of stem cell factor mRNA (SCF) in bone marrow tissue and explore the mechanism of hematopoietic reconstitution after bone marrow transplantation (BMT). The colony forming unit of spleen (CFU-S) were counted, the survival rate at days 7, 14 and 21 after BMT were measured, as well as the expression level of SCF mRNA was detected by RT-PCR. The results showed that in ligustrazine group CFU-S counts on day 10 and survival rate, expression level of SCF mRNA on day 7, 14 and 21 after BMT were higher than that in the control group (p < 0.01 or p < 0.05). In conclusion, ligustrazine promotes the recovery of hematopoietic cells in bone marrow, enhances the repair of bone marrow microvessels, and then improves bone marrow microenvironment and promotes hematopoietic reconstitution.

This study was aimed to explore the factors impacting on effect of the recombinant human granulocyte colony-stimulating factor (rhG-CSF) in mobilizing and collecting peripheral blood stem/progenitor cells (PBSPC) from healthy donors, and to determine the optimal time for PBSPC harvest. A mobilization course in 431 healthy donors was retrospectively studied and the factors influencing the efficacy of mobilization were analyzed. The normal donors underwent leukapheresis for PBSPC collection in multicentres after mobilization with G-CSF administered. A variety of items analyzed included donor age, sex, weight, body mass index (BMI), daily G-CSF dose and schedule of G-CSF administration. The results showed that G-CSF was administered subcutaneously at median 5.7 microg/kg for mobilization for 3 - 5 days, The median number of peripheral blood mononuclear cells (PBMNC) count of per kg recipient weight was 9.57 x 10(8) and CD34(+) cells per kg recipient weight was 4.91 x 10(6) after a median of 1.7 leukapheresis. The side effects were mild and well tolerated. By univariate analysis, BMI, daily G-CSF dose and schedule of administration were significantly correlated with the yield of PBMNCs, CD34(+) cells. The best apheresis yields of PBMNCs and CD34(+) cells were achieved on day 5 after treatment with rhG-CSF. Because the narrow range and low dose of rhG-CSF administration, there were minor effects of rhG-CSF dose compared with schedule of administration. It is concluded that mobilization and leukapheresis are safe in healthy donors and that the low dose of rhG-CSF in 5-day administration are probably optimal for donor management.

The purpose of this study was to investigate the growth characteristics and the expression level of integrin mRNA of the cultured bone marrow mesenchymal stem cells (BMMSCs) from patients with chronic myeloid leukemia (CML) in myeloid crisis (MC), and explore the role of BMMSCs in pathogenesis of CML. Five CML patients were enrolled in experimental group, five healthy persons were used as control. BMMSCs were cultured in vitro. The morphology of BMMSCs was observed every day and the growth curve were portrayed, and the ability of cell proliferation were detected according to the daily results of cell counting. Total RNA was extracted from third and fourth passages of BMMSCs, The expression of integrins mRNA of BMMSCs were measured by real-time PCR. The results showed that the BMMSCs of experimental and control groups had no difference in growth characterisctics, but the expression of integrins mRNA of the BMMSCs was higher in CML patients than in normal control group (p < 0.05). It is concluded that the abnormally high expression of integrins of BMMSC from the CML patients take part in pathogenesis of CML.

In order to investigate the effect of shRNA targeted to beta-catenin on the growth of K562 cells, plasmid containing beta-catenin specific shRNA sequence was transfected into K562 cells by lipofectamine 2000, and G418 was added to screen the positive cells. Real-time PCR and Western blot were used to detect the expression of beta-catenin. Cell growth curve, MTT and colony forming cell assays were used to evaluate the proliferation potential of cells. The results showed that the mRNA level of beta-catenin was reduced significantly in K562 cells transfected into interfering plasmid as compared with control plasmid, while the protein level failed to demonstrate difference by the time of 72 hours after transfection. After long-term culture with G418, the count of positive cells enhanced in control group while no positive cells survived in the interfering group. Colony-forming cell assays revealed that the K562 cells in interfering group formed colonies with very small size and low forming rate, compared with the control group, though the growth curve and MTT failed to illustrate differences. It is concluded that the beta-catenin-specific shRNA mediated by plasmid can effectively knockdown the expression of beta-catenin gene and inhibit the colony-forming ability in K562 cells, it is a potential target for the therapy of CML, even in blast crisis.

At present there is no effective therapeutic approach for stage IV neuroblastoma. We report our experience with allogenic hematopoietic stem cell transplantation as a means of treating this disorder in one child.

The abnormality of hemopoietic inductive microenvironment (HIM) is involved in the pathophysiology of aplastic anemia (AA). Mesenchymal stem cells (MSC) are main source of bone marrow stromal cells which constitute the bone marrow HIM. Thus, the bone marrow failure in AA may be related to the function of MSC. The aim of the study was to investigate the hematopoiesis support function of MSC in children with AA in vitro.

By genetic recombinant technique, the rat GDNF cDNA was recombinated to the retroviral vector pLXSN. The recombinant plasmid pLXSN-GDNF was verified by digestion with restriction endonucleases and PCR. Then neural stem cells (NSCs) were infected with pLXSN-GDNF. Immunocytochemistry, RT-PCR and western-blot were used to detect the transfection effect. Results showed that GDNF cDNA was cloned into retroviral vector pLXSN correctly, and the pLXSN-GDNF can infect NSCs efficiently. These results provide the possibility for transplantation and gene therapy with GDNF of nervous system diseases and injury.

This study examined the effects of flow shear stress on the bio-capacity of the endothelial cells' induced from mesenchymal stem cells (MSCs). After cultivating the SD rat mesenchymal stem cells in vitro, we exposed them under different intensity of flow shear stress and induced these cells to endothelial cells. The variations of total anti-oxidation competence (T-AOC) and quantity of nitrogen monoxide (NO) were tested. The results showed that shear stress has an enhanced effect on the T-AOC and NO of endothelial cells induced from MSCs in an intensity-dependent manner. Flow shear stress could provide a protective action on the in vitro induction of endothelial cells, thus formulating a theoretical foundation for the therapeutics of ischemic heart diseases and vascular tissue engineering.

To investigate the effect of regulating intracellular ROS with antioxidants on the ex vivo expansion of cord blood CD34(+) cells.

Spermatogonial stem cells are male germ line stem cells, whose potency of proliferation is indispensable for the permanent production of male germ cells. With the advances in the technology of cryopreservation, in vitro culture and intracytoplasmic sperm injection (ICSI), the transplantation of spermatogonial stem cells is showing a splendid vista of application in basic medical research and clinical practice. This review briefly introduces the genesis and differentiation of spermatogonial stem cells, the current situation of their transplantation and the prospects of its application in medical science.

To explore the potential of human bone marrow stromal cells (MSCs) as the feeding-layer to promote ex vivo expansion of cord blood CD34+ cells and engraftment of the expanded cells in NOD/SCID mice.

To establish an xenogeneic acute graft-versus-host disease model by engraftment of G-CSF mobilized human mononuclear cells into NOD/SCID mice.

To observe the engraftment, survival and graft-versus-host disease (GVHD) after 2 units unrelated cord blood (UCB) transplantation for treatment of adult hematological malignancies.

To review the latest development of amniotic fluid-derived stem cell(AFS) and to predict its future application.

To explore an effective method for treating Gentamicin-induced deafness and the mechanism.

To explore the role of stromal-derived factor-1 (SDF-1) in the migration of mesenchymal stem cells (MSCs) and the underlying signal transduction mechanism.

To evaluate the effect of human hair keratin (HHK) in peripheral nerve repair and explore the mechanism of sciatic nerve regeneration.