The aim of this study was to detect DNA damage during expansion ex vivo of umbilical cord blood (UCB) hematopoietic cells and explore the optimal harvest time for culture of CB hematopoietic cells. Mononuclear cells (MNCs) separated from UCB were cultured in a serum-free system supplemented with cytokines and colony forming units were assessed by semisolid culture at the same time. On day 0, 7, 14 and 21 cells were collected for single cell gel electrophoresis (SCGE) analysis and CFUs were also assayed by SCGE, CD34+ cells and CD133+ cells were quantitated by fluorescence-activated cell sorting (FACS). The results showed that the percentage of CD34+ and CD133+ cells was found to be highest after short-term culture (<14 days) and the cord blood DNA damage rate was observed to be less than 5.0% at earlier time points, but at day 21 the DNA damage rate was 28.2%, which was higher than that at day 0 (p=0.000), the tail length of the DNA comet was longer than that at day 0 (p=0.000). The tail lengths of DNA damage on other time points were not significantly different from that at day 0. It is concluded that the DNA damage rate is less than 5.0% after short-term (<14 days) culture of UCB cells ex vivo by using this method. After 14 days DNA damage rate increases significantly. The optimal harvest time of cord blood cells after culture ex vivo would be within 14 days.
Cell Division ; Cells, Cultured ; Colony-Forming Units Assay ; DNA Damage ; Fetal Blood ; cytology ; Hematopoietic Stem Cells ; cytology ; Humans

Cell Proliferation ; Colony-Forming Units Assay ; Glioma ; pathology ; Hematopoietic Stem Cells ; pathology ; Humans ; Stem Cells ; cytology ; metabolism

OBJECTIVEThough the rabbit is one of most widely used experimental animals for medical regenerative research, it remains difficult to culture mesenchymal stem cells (MSC) on a in large scale due to the extremely lower number and hematopoietic cell contamination. This study was aimed to establish a novel protocol to generate rabbit MSC by culturing bone marrow plugs instead of bone marrow cells so as to obtain a large amount of MSC with higher proliferation and self-renewal properties.

METHODSThe primary MSC were generated from collagenase digested bone marrow plugs and bone marrow cells, respectively. The surface antigen profile of MSC was analyzed with flow cytometry and the cells were induced to differentiate into osteoblasts and adipocytes. The proliferation capacity of MSC were assessed by CCK-8 method. To test their self-renewal property, the colony forming unit-fibroblast assay was performed. Moreover, the cell yields of passage 1, 2, 3 and 4 were calculated.

RESULTSThe bone marrow plug-derived MSC shared the typical fibroblast-like morphology same as bone marrow cells derived MSC. Moreover, the ratio of CD45 positive hematopoietic cells in bone marrow plug-derived MSCs was significantly lower than that of bone marrow cell-derived MSC. The results of multi-differentiation experiments showed that bone marrow-plug-derived MSC exhibited similar multi-potent property to their bone marrow counterparts. In addition, the results of CCK-8 and CFU-F assay demonstrated that bone marrow plug-derived MSC grew more robustly and more CFU-F were formed in the culture plates, which indicated that the cells possessed higher proliferation and self-renewal capacities. Promisingly, a larger amount of cells were harvested via using the new protocol.

CONCLUSIONThe purity and yields of the bone marrow plug-derived MSC are satisfactory compared with previous rabbit MSC isolation methods. The findings may be helpful for the research of regenerative medicine.

Adipocytes ; Animals ; Bone Marrow ; Bone Marrow Cells ; Cell Differentiation ; Cell Separation ; Colony-Forming Units Assay ; Mesenchymal Stromal Cells ; Osteoblasts ; Rabbits

The aim of this study was to investigate the best method to preserve human bone marrow cells and the effectiveness of long term cryopreservation at -80 degrees C. The human bone marrow cells in 20 samples were firstly frozen by a programmed freezer or -80 degrees C refrigerator, and then were preserved in liquid nitrogen with DMSO-AuP (10% dimethylsulfonamide, 10% autologous plasma) or DMSO-HES-HuA (5% dimethylsulfonamide, 6% hydroxyethyl starch, 4% human serum albumin) as cryoprotectant for 21 to 25 years. They were thawed in 38 degrees C. The cell sample frozen in -80 degrees C refrigerator was frozen at a low frozen speed of 1 degrees C/min which was the same as the programmed freezer before -30 degrees C. Before detection the bone marrow cells were taken from liquid nitrogen and were thawed in 38 degrees C, then the suspension of bone marrow cells was prepared for detection. The cell morphology and recovery rate of erythrocytes, nucleocytes and platelets; the recovery rate of hematopoietic stem progenitors cells, as well as mesenchymal stem cells were determined. The results showed that the protective effectiveness of DMSO-HES-HuA was better than DMSO-AuP. The mature erythrocytes were destroyed lightly [(3.5 +/- 1.5)% versus (12.6 +/- 4.8)%], the hemolysis rate was lower [(3.3 +/- 1.6)% versus (23.1 +/- 5.1)%]. Osmotic fragility of erythrocytes in the former was not changed, but was dropped in the latter. The recovery rates of red cell, platelet, granulocyte-macrophage colony forming units and long term culture-initiating cells were higher in the former than that in the latter [(96.1 +/- 1.8)%, (70.0 +/- 9.5)%, (49.2 +/- 10.9)%, (54.2 +/- 13.8)% versus (76.3 +/- 5.6)%, (52.7 +/- 8.1)%, (43.5 +/- 12.3)%, (47.2 +/- 13.6)% respectively]. With each kind of cryoprotectant or frozen method, the frozen MSC could keep the original growth properties. With the same cryoprotectant and different frozen method, the cryopreservative effectiveness was not different. The influence of the cryoprotectant prescriptions and the frozen methods on the cryopreservative effectiveness was little. It is concluded that the human bone marrow cells with DMSO-AuP or DMSO-HES-HuA as cryoprotectant, frozen by a programmed freezer or -80 degrees C refrigerator, could be then preserved in liquid nitrogen for long time. When the preserving time was as long as 21 to 25 years, the morphology, the recovery rate and the activity of various kinds of cells were still good. The method of freezing by -80 degrees C refrigerator with 5% DMSO-6% HES-4% HuA and preserving in liquid nitrogen would be convenient, cheap and easily-manipulated for preservation of the human bone marrow cells.
Bone Marrow Cells ; cytology ; Cell Survival ; Colony-Forming Units Assay ; Cryopreservation ; methods ; Cryoprotective Agents ; Humans ; Nitrogen ; Time Factors

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+IL3 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.
Angiotensin II/*pharmacology ; Antigens, CD34/*metabolism ; Cells, Cultured ; Colony-Forming Units Assay ; Fetal Blood/*cytology ; Granulocyte-Macrophage Colony-Stimulating Factor ; Hematopoietic Stem Cells/*cytology

OBJECTIVE: To investigate the effect of hematopoietic stimulating factors on the expansion of mature megakaryocytes. METHODS: (2, 4, 6, 8, 10) x 10(5)/mL bone marrow single nucleus cells (BMNC) were added in the culture system of colony forming unit-megkaryocyte (CFU-Meg) to find out the relationship of the cultured BMNC with the output of CFU-Meg. rmSCF + rmTPO + rmIL-3 (3HSFs) and rmSCF + rmTPO + rmIL-3 + rmIL-6 (4HSFs) or F-CM were added in the liquid culture system of megkaryocytes respectively. The number of mature megakaryocytes were counted every other day. RESULTS: The number of CFU-Meg increased with the increase of the cultured BMNC. The CFU-Meg productivity of 1 x 10(6) BMNC/mL culture system was more than that of 2 x 10(5) BMNC/mL culture system. 3HSFs and 4HSFs or F-CM significantly promoted the expansion of mature megakaryocytes in the liquid culture system, but the effect was different. The peak time of the number of mature megakaryocytes in 3HSFs and 4HSFs or F-CM were 7 d, 7 d and 5 d respectively. CONCLUSION 3HSFs and 4 HSFs or F-CM had positive effect on the expansion of mature megakaryocytes. 4HSFs was better than 3HSFs and F-CM. 3HSFs was better than F-CM. The peak time of the number of mature megakaryocytes in different culture systems was different.
Animals ; Cells, Cultured ; Colony-Forming Units Assay ; Female ; Hematopoietic Cell Growth Factors ; pharmacology ; Interleukin-3 ; pharmacology ; Interleukin-6 ; pharmacology ; Macrophage Colony-Stimulating Factor ; pharmacology ; Male ; Megakaryocytes ; cytology ; Mice

To study the regulation of TGF-beta(1) on the development of hemangioblast, embryonic stem cell-derived blast forming cells (BL-CFC) were used as the model of hemangioblast in vitro. TGF-beta(1) or anti-TGF-beta(1) neutralization antibody was added in the medium of embryoid body (EB) generation for observating influence of TGF-B(1) addition in different culture stages on number of BL-CFC and differentiation of BL-CFC to endothelial and hematopoietic cells. The results showed that antagonizing TGF-beta(1) in the course of EB growth could significantly reduce the number of BL-CFC (P<0.01), and the frequency of Flk-1(+) cells was also decreased consistently. Furthermore, the BL-CFC derived from EB pretreated with TGF-beta(1) demonstrated remarkably elevated hematopoietic and endothelial potential, whereas such bi-potential was impaired in the group with neutralizing antibody. It is concluded that TGF-beta(1), a conventional negative regulator in hematopoiesis and angiogenesis exert positive effects on the development and differentiation capacities of BL-CFC in vitro.
Animals ; Cell Differentiation ; drug effects ; Cells, Cultured ; Colony-Forming Units Assay ; Embryonic Stem Cells ; cytology ; Hematopoiesis ; physiology ; Mice ; Neovascularization, Physiologic ; physiology ; Transforming Growth Factor beta1 ; antagonists & inhibitors

OBJECTIVETo isolate and identify the phenotype and biological characteristics of pancreas derived mesenchymal stem cell.

METHODSFresh pancreas of 4-5 months old aborted fetus was dissected free from connective tissue, and was cut into small pieces. The adherent cells were harvested and subcultured, after the third subculture, the cells were used for examination. Cell cycle was analyzed by measuring DNA content by FACScan flow cytometer. Phenotype of MSCs was analyzed by immunohistochemical SA technique and differentiated cells were identified by relevant specific staining.

RESULTSFetal pancreas derived cells gave rise to a population of adherent cells characterized by the presence of a predominant cell type with a typical fibroblast like morphology. By transmission electron microcopy, MSC had few endoplasmic reticulums and mitochondrias. During the log phase of growth, MSC proliferated with a two fold population at 30 h. MSC can be ex vivo expanded by successive cycles of trypsinization, seeding, and culture. Under these conditions, MSC had capability of passaging up to 30 times without displaying significant changes in morphology, with 2-fold increase in cell number after each passage. This indicates the high ex vivo expansion potential of MSC. The results showed that the yield of CFU-Fs was above 200 clones even after the 6th passage. Cell cycle analysis by flow cytometry revealed that more than 83% of cells were in the G0/G1 phases, while a small population of cells were actively engaged in proliferation (S + G2 + M = 17%). We also showed that more than 86% of cells were positive stained by FITC labeled CD44, CD29, CD13, and only about 1% of cells were positive for CD34, HLA-DR. Expression of collagen I, III was positive while vWF was negative. In the differentiation study, we found culture-expanded pancreas MSCs could be directed into the osteogenic lineage as detected by osteoblastic morphology, expression of alkaline phosphatase, modulation of osteocalcin mRNA production and the formation of a mineralized extracellular matrix. We also found that MSCs could give rise to the adipogenic and chondrogenic lineage as evidenced by accumulation of lipid-rich vacuoles within cells and the expression of lipoprotein lipase mRNA or the expression of collagen II and the deposition of proteoglycans.

CONCLUSIONMesenchymal stem cells existing in human pancreas can be isolated by their adherent ability and should be essential to sustain a steady supply of primitive cells in tissue remodeling.

Cell Differentiation ; Cell Division ; Cell Separation ; Cells, Cultured ; Colony-Forming Units Assay ; Fetus ; Fibroblasts ; cytology ; Humans ; Mesoderm ; cytology ; Osteogenesis ; Pancreas ; cytology ; Phenotype ; Stem Cells ; cytology

OBJECTIVETo explore a stable technology for inducing ES cell to committed hematopoietic differentiation.

METHODSThe effects of various inductive factors on BLast Colony-Forming Cell (BL-CFC) were investigated. In vitro differentiative system for ES cells was employed in this study.

RESULTSA high linear correlation between the number of D3.5 EB-derived cells plated and the number of blast cell colonies was developed, r = 0.9931. With high frequency of blast colonies observed (1.08-1.2 colonies per 100 cells). 20%-30% D4T conditioned medium (D4T CM) showed the most significant growth potentials of blast colonies. D4T CM, EPO or KL alone had no blast colony growth promoting effect (P > 0.05). But VEGF alone had high significant blast colony growth promoting effect (P < 0.001). However, any two factors combination from above four factors exerted better growth promoting effect than VEGF alone (EPO + D4T CM, P < 0.05; KL + D4T CM, P < 0.01; VEGF + D4T CM, P < 0.001). There were no significant difference among VEGF + KL and EPO + D4T CM or KL + D4T CM, and KL + D4T CM (P > 0.05). While the combination of VEGF + D4T CM was better than KL + D4T CM, VEGF + KL or EPO + D4T CM (P < 0.001). Moreover, the combination of VEGF + KL + D4T CM + EPO, had the highest significant blast colony growth promoting effect (P < 0.001). And the highest frequency of blast colonies was observed (1.5-1.2 colonies per 100 cells).

CONCLUSIONVEGF may be the main factor which stimulates the growth of significant numbers of blast cell colonies. D4T CM maybe contains strong cofactors. EPO and KL are the main factors for the induction of BL-CFC to committed hematopoietic differentiation. D3.5 EB-derived cells are more sensitive to various stimulators and have strong blast colony growth promoting effect than that of D3.25 EB-derived cells.

Animals ; Cell Differentiation ; Colony-Forming Units Assay ; Embryo, Mammalian ; Hematopoietic Stem Cells ; cytology ; metabolism ; Mice ; Stem Cells ; cytology ; Vascular Endothelial Growth Factor A ; metabolism

BACKGROUNDPolycythemia vera (PV) is a malignant disorder of hemaopoietic stem cells which is characterized by clonal hyperproliferation and a low rate of apoptosis. This study was to assess endogenous erythroid colony (EEC) formation in the bone marrow of PV patients and determine its clinical significance.

METHODSThe bone marrow mononuclear cells of 26 patients with PV, 2 patients with secondary erythrocytosis (SE), and 19 normal controls were cultured by Marsh's method for EEC evaluation, and the clinical significance was evaluated.

RESULTSEECs appeared in 25 patients with PV but not in 2 patients with SE and 19 normal controls. The number of EECs and the EEC ratio [EEC/erythropoietin (EPO)-dependent colony forming unit-erythroid (CFU-E)] in PV patients positively correlated with hemoglobin (Hb) levels. Their EEC number did not correlate with white blood cell (WBC) counts, platelet (PLT) counts, or leukocyte alkaline phosphatase (LAP) scores. Their EEC did not correlate with serum EPO levels. Fifteen patients with PV were treated with hydroxyurea (Hu) and/or interferon-alpha (IFN-alpha). Their EEC ratio before treatment positively correlated with the treatment time required for complete remission (CR) and negatively correlated with the time before relapse. The EEC numbers of 7 PV patients treated with Hu/IFN-alpha decreased after the blood cell counts dropped to normal levels. There was a positive correlation between the EEC ratio and the incidence of attacks of vascular thrombosis in PV patients. The numbers of apoptosised bone marrow mononuclear cells in PV patients were lower than those in normal controls. The EEC numbers of PV patients negatively correlated with the rate of apoptosis of bone marrow mononuclear cells.

CONCLUSIONSEEC formation is characteristic in PV patients. EEC number in PV patients positively correlates with Hb levels, the time required for CR, and the incidence of attacks of vascular thrombosis. EEC number negatively correlates with the time before relapse. Bone marrow suppressive treatment might decrease EEC number. Thus, EEC number is a sensitive and specific parameter reflecting the abnormal hematopoietic clone burden induced by polycythemia vera. EEC number is an important diagnostic parameter for PV patients.

Adult ; Aged ; Apoptosis ; Colony-Forming Units Assay ; Erythroid Precursor Cells ; physiology ; Erythropoiesis ; Erythropoietin ; blood ; Female ; Humans ; Male ; Middle Aged ; Polycythemia Vera ; blood ; therapy ; Thrombosis ; epidemiology