OBJECTIVETo investigate the mRNA expression profiles of megakaryocytes (MKs) from human cord blood CD34+ cells ex vivo expanded using Solexa technique.

METHODSCD34+ Cells were isolated using density gradient centrifugation and magnetic activated cell sorting. Cultures were stimulated with recombinant human thrombopoietin (100 ng/ml). After 12 days, the MKs fraction was separated from the non-MKs fraction using an anti-CD41 monoclonal antibody by immunomagnetic sorting. The mRNA expression of MKs and non-MKs was detected by Solexa sequencing.

RESULTSWe obtained 3 773 147 and 3 533 805 Tags from MKs and non-MKs, respectively. The amounts of unambiguous tags were 3 291 132 and 2 967 947 and those of distinct tags were 197 769 and 245 318. The expression of 1161 genes was up-regulated and that of 902 genes down-regulated. The expression of 2717 tags was up-regulated and that of 1519 tags down-regulated.

CONCLUSIONSMKs and non-MKs have remarkably different mRNA expression profiles. The differential gene-encoded products may be involved in cellular development, adhesion, apoptosis metabolism, intra- and intercellular signal transduction, and immune response. Further studies on this topic may clarify the expression mechanism, signal transduction, and regulation mechanisms.

Antigens, CD34 ; Cells, Cultured ; Fetal Blood ; cytology ; Humans ; Megakaryocytes ; cytology ; metabolism ; RNA, Messenger ; genetics ; Transcriptome

OBJECTIVE: To induce hematopoietic progenitor/stem cells of umbilical cord blood to differentiate into mature megakaryocytes and platelets in vitro and to investigate the mechanism of production of platelets. METHODS: The CD34+ cells were sorted from umbilical cord blood by magnetic activated cell sorting (MACS) and then cultured in vitro with optimized medium to be differentiated into mature megakaryocytes and platelets. The cultured cells and the platelet-like particles were isolated from the culture and were checked by the fluorescence-activated cell sorter (FACS), immunohistochemistry assays, light microscope,electron microscope and platelet aggregation tests. RESULTS: The cultured megakaryocytes were detected with proplatelets and both the cultured cells and the platelet-sized particles were found to have the same structure with the normal megakaryocytes and platelets by light and electron microscope. The immunohistochemistry assays revealed the cultured cells expressed GP II b III a with a positivity of 95% which was a special antigen for platelets and megakaryocytes. Culture-derived platelet-sized particles aggregated in response to thrombin as the plasma derived-platelets did. The cultured platelets had the same positivity of CD41 as the platelets from platelet rich plasma. CONCLUSION The hematopoietic progenitor/stem cells can be induced to differentiate into purified and mature megakaryocytes and platelets. It provides a practical way to study the mechanism of platelets production.
Antigens, CD34 ; metabolism ; Blood Platelets ; cytology ; Cell Differentiation ; physiology ; Cells, Cultured ; Fetal Blood ; cytology ; metabolism ; Hematopoietic Stem Cells ; cytology ; metabolism ; Humans ; Megakaryocytes ; cytology

The study was aimed to explore the influence of co-culture ex vivo of CD34+ cells from two units of cord blood (CB) on the homing-related adherent molecule expression of each other. Mesenchymal stem cells (MSCs) were obtained from human bone marrow. Two units of CB CD34+ cells were co-cultured on 12 Gy gamma-ray irradiated MSC layer. Their adherent molecule expressions were assessed by flow cytometry. The results showed that the purity of the isolated CD34+ cells was (98.25+/-0.93)%. After co-culture on MSC layer for 6 days, the proportion of CD34+ cells of each unit was dropped to (60.4+/-6.32)% and (60.2+/-5.12)% respectively, but there was no significant difference from the control groups. The expressions of CD44, CD62L, CD184 and CD26 on CD34+ cells of each unit remained unaffected. The expression of CD162 was downregulated and CD54 was first increased but then dropped to the level before co-culture. But there was no significant difference between the experimental and control groups. In conclusion, co-culture of CD34+ cells from two units of CB may have no effects on the adherent molecule expressions of each other.
Antigens, CD34 ; metabolism ; Bone Marrow Cells ; cytology ; Cell Adhesion Molecules ; metabolism ; Coculture Techniques ; Fetal Blood ; cytology ; metabolism ; Hematopoietic Stem Cells ; cytology ; metabolism ; Humans ; Mesenchymal Stromal Cells ; cytology

The aim of this study was to explore the effects of the stromal cell-derived factor (SDF-1) and chemokine receptors (CXCR4) on chemotaxis of cord blood AC133(+) cells. The optimal SDF-1 concentration was determined in Transwell System. The cell migration was calculated from the number of cells passing through polycarbonate membrane with 8 microm pore. The expressions of CXCR4 in fresh and cultured cord blood AC133(+) cells were analyzed by flow cytometry with two-color direct immunofluorescence. The results showed that the chemotactic rate of fresh cord blood AC133(+) cells increased along with increasing concentrations of SDF-1, however, it tended to be stable when the concentration of SDF-1 reached 150 ng/ml. There was no difference in the chemotactic rate of cord blood AC133(+) cells between the group with SDF-1 adding CXCR4-blocking antibody and the group without SDF-1. When AC133(+) cells were cultured in vitro with hemopoietic growth factors, the expression of CXCR4 increased at the early stage, but decreased gradually along with time extending. In conclusion, there was correlation between the chemotactic rate of AC133(+) cells and the expression of chemokine receptor CXCR4.
Cell Line ; Chemokine CXCL12 ; pharmacology ; Chemotaxis ; Fetal Blood ; cytology ; Humans ; Receptors, CXCR4 ; metabolism ; Stromal Cells ; metabolism

Mesenchymal stem cells (MSCs) are capable of self-renewal and differentiation into lineages of mesenchymal tissues that are currently under investigation for a variety of therapeutic applications. The purpose of this study was to compare cytokine gene expression in MSCs from human placenta, cord blood (CB) and bone marrow (BM). The cytokine expression profiles of MSCs from BM, CB and placenta (amnion, decidua) were compared by proteome profiler array analysis. The cytokines that were expressed differently, in each type of MSC, were analyzed by real-time PCR. We evaluated 36 cytokines. Most types of MSCs had a common expression pattern including MIF (GIF, DER6), IL-8 (CXCL8), Serpin E1 (PAI-1), GROalpha(CXCL1), and IL-6. MCP-1, however, was expressed in both the MSCs from the BM and the amnion. sICAM-1 was expressed in both the amnion and decidua MSCs. SDF-1 was expressed only in the BM MSCs. Real-time PCR demonstrated the expression of the cytokines in each of the MSCs. The MSCs from bone marrow, placenta (amnion and decidua) and cord blood expressed the cytokines differently. These results suggest that cytokine induction and signal transduction are different in MSCs from different tissues.
Bone Marrow Cells/*cytology ; Cytokines/genetics/*metabolism ; Female ; Fetal Blood/*cytology ; Gene Expression Profiling ; Humans ; Mesenchymal Stem Cells/cytology/*metabolism ; Placenta/*cytology ; Pregnancy ; Protein Array Analysis

The aim of study was to explore the potential of human erythroid membrane associated protein (ERMAP) gene in erythroid cell differentiation and development, mononuclear cells (MNCs) were isolated from umbilical cord blood and induced to erythroid cell differentiation by SCF, IL-3 and EPO. The cell morphology was observed by using optical microscopy, the positive rate of cells was counted by biphenylamine staining and the ratios of CD36+/CD235a-, CD36+/CD235a+, CD36-/CD235a+ cells were detected by flow cytometry, the change of human ermap gene expression level was analyzed by using fluorescent quantitative PCR (FQ-PCR). The results showed that the ermap gene expression level increased while MNCs were induced to erythroid lineage after treatment with SCF, IL-3 and EPO. It is concluded that the human ermap gene plays an important role in differentiation and development of erythroid cells.
Blood Group Antigens ; genetics ; metabolism ; Butyrophilins ; Cell Differentiation ; genetics ; Cells, Cultured ; Erythroid Cells ; cytology ; Fetal Blood ; cytology ; Humans ; Leukocytes, Mononuclear ; cytology ; metabolism ; Polymerase Chain Reaction ; methods

OBJECTIVETo study both the release of HMGB1 from irradiation-treated mesenchymal stem cells (MSCs) and the effects of HMGB1 on human cord blood CD34(+) hematopoietic progenitor cell proliferation and differentiation.

METHODSMSCs were obtained from human bone marrow. HMGB1 released by the MSCs after treatment with 12 Gy gamma-ray irradiation was determined by enzyme linked immunosorbent assay (ELISA). CD34(+) cells were positively selected with a MACS CD34 isolation kit. The freshly isolated CD34(+) cells were cultured in the presence of HMGB1 for 6 days. Phenotype of cultured cells surface molecules (CD13, CD14, CD11c, CD41 and CD71) were analyzed by flow cytometry. The proliferation and differentiation capacities of cord blood HSCs were assayed by colony forming cell assay. The receptors of HMGB1 (RAGE, TLR2 and TLR4) on cord blood CD34(+) cells were detected by flow cytometry.

RESULTSHMGB1 level in the supernatant \[(4.3 +/- 0.9) ng/ml\] of the irradiated MSC was significantly higher than that in control \[(0.4 +/- 0.2) ng/ml\] (P < 0.01). Human cord blood CD34(+) cells expressed the HMGB1 receptors RAGE, TLR2 and TLR4. The HMGB1-treated CD34(+) cells contained higher proportions of CD13(+) \[(32.6 +/- 5.9)% vs (18.4 +/- 3.8)%\], CD14(+)\[(25.4 +/- 4.4)% vs (12.6 +/- 2.7)%\], CD11c(+) \[(20.3 +/- 3.9)% vs (9.8 +/- 2.1)%\], CD71(+) \[(47.1 +/- 7.4)% vs (26.6 +/- 4.6)%\] cells compared with control group did. But HMGB1 did not induce the generation of CD41(+) cells \[(1.3 +/- 0.5)% vs (1.1 +/- 0.4)%\]. Furthermore, HMGB1 profoundly induced the growth of BFU-E, CFU-GM and total CFU in a dose-dependent manner, and this effect was partially inhibited by TLR2 and TLR4 antibodies.

CONCLUSIONHuman MSC treated with gamma-ray irradiation can release HMGB1, which can induce the proliferation and differentiation of human cord CD34(+) cells.

Antigens, CD34 ; metabolism ; Cell Differentiation ; Cells, Cultured ; Fetal Blood ; cytology ; HMGB1 Protein ; Hematopoietic Stem Cells ; cytology ; Humans

The purpose of this study was to synthesize the complex of magnetic nanoparticles and antibody, and to apply them to isolate the CD34(+) cells from umbilical cord blood, then to evaluate its separation efficiency. The complex of magnetic nanoparticles and antibody was used to separate CD34(+) cells from umbilical cord blood in the outer magnetic field because of its superparamagnetism, specific identification and function of combination with CD34(+) cells. Scanning electron microscopy was used to observe the morphology of the separated CD34(+) cells. Flow Cytometer was applied to evaluate the sorting efficiency of magnetic nanoparticles, liquid culture and colony culture were taken to assay proliferation and differentiation capacity of the separated CD34(+) cells. The results showed that the CD34(+) cells from umbilical cord blood were isolated fast and effectively by the complex of magnetic nanoparticles and monoclonal antibody. Moreover, the isolated CD34(+) cells still maintained its normal morphology, highly proliferative and differentiative capacity. It is concluded that the complex of magnetic nanoparticles and monoclonal antibody has been successfully synthesized and developed as a technique which efficiently and quickly isolates CD34(+) cells from umbilical cord blood.
Antigens, CD34 ; metabolism ; Fetal Blood ; cytology ; Flow Cytometry ; Hematopoietic Stem Cells ; cytology ; immunology ; Humans ; Immunomagnetic Separation ; methods ; Magnetics ; Nanoparticles

OBJECTIVETo investigate the enhanced cytotoxicity against leukemia cells of natural Killer (NK) cells from cord blood (CB) after expansion in vitro.

METHODSNK cells was expanded on a layer of trophoblast cells with irradiated K562-mb15-41BBL cell line for 21 days. The levels of receptors on NK cells were detected by flow cytometry. Cytotoxicity of expanded NK cells against leukemia cells and specific ligand of immunoglobulin like(Ig- liKe)receptors were assessed using 51Cr released assay.

RESULTSThere were no differences of inhibitory receptors expression between fresh NK cells and expanded NK cells [CD158a:(16.77±11.65)% vs(14.37±11.12)%, P>0.05; CD158b: (42.48±18.11)% vs (40.92±19.02)%, P>0.05; NKG2A: (70.20±18.43)% vs (78.90±13.69)%, P>0.05], but higher activated receptors expression on expanded NK cells [NKp30: (54.10±13.27)% vs (4.14±2.05)%, P<0.05; NKp44: (72.10±17.30)% vs (0.52±1.16)%, P<0.05; NKp46: (80.63±14.01)% vs (44.19±6.19)%, P<0.05; NKG2D: (97.50±2.55)% vs (72.25±14.35)%, P<0.05]. Expanded NK cells showed higher cytotoxicity against leuKemia cell lines than fresh NK cells [K562: (74.3±3.6)% vs (55.3±4.2)%, P<0.05; Raji: (60.6±5.0)% vs (12.0±3.6)%, P<0.05]. CD158a⁻ CD158b⁻ NK cells had higher cytotoxicity on four types of target cells, but CD158a⁺CD158b⁻ CB-NK cell had lower cytotoxicity on 221-Cw4 and 221-Cw3Cw4 cells. CD158a⁻ CD158b⁺ CB- NK cells had lower cytotoxicity on 221-Cw3 and 221-Cw3Cw4, but CD158a⁺CD158b⁺ CB-NK cells had higher cytotoxicity on 721- 221 cells.

CONCLUSIONExpression of activated receptors of expanded NK cells were up-regulated, but no changes of inhibitory receptors. Expanded NK cells showed high cytotoxicity against leukemia cells and kept the specificity of ligand of Ig-like receptors, which could be beneficial to cell-therapy for tumor.

Cells, Cultured ; Coculture Techniques ; Fetal Blood ; cytology ; Flow Cytometry ; Humans ; K562 Cells ; Killer Cells, Natural ; cytology ; metabolism

AIMIn order to investigate the effect of mesenchymal stem/progenitor cells on proliferation and differentiation towards megakaryocytes of CD34+ cells from human umbilical cord blood in vitro.

METHODSAfter mesenchymal stem/progenitor cells were advancely planted in DMEM medium and grown up to 80%, then the CD34+ cells were added to culture with mesenchymal stem/ progenitor cells or without mesenchymal stem/progenitor cells in DMEM for 14 days with TPO + IL-3 + SCF, TPO + IL-3 + SCF + IL-11 respectively. After cultured for 14 days, mononuclear cells (MNCs) were counted by automatic cell analyzer. The number of CD41+ cells and platelets were detected by flow cytometry. Platelets function were assessed through platelet aggregation test which was induced by thrombin.

RESULTSAs compared with the control group, the number of MNCs of co-culture system was not increased significantly (P > 0.05), but the number of CD4+ cells and platelets were increased significantly (P < 0.05). The platelets were aggregated by thrombin induced which could be seen in microscope or flow cytometry.

CONCLUSIONIt is concluded that mesenchymal stem/progenitor cells may be promoted to induce the cord blood CD34+ cells to differentiate towards megakaryocyte in the culture medium.

Antigens, CD34 ; metabolism ; Bone Marrow Cells ; cytology ; Cell Differentiation ; physiology ; Cells, Cultured ; Fetal Blood ; cytology ; Humans ; Megakaryocytes ; cytology ; Mesenchymal Stromal Cells ; cytology ; physiology