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Objective: To explore the similarities and variations of biological phenotype and cytotoxicity of human umbilical cord blood natural killer cells (hUC- NK) after human umbilical cord blood-derived mononuclear cells (hUC-MNC) activated and expanded by two in vitro high-efficient strategies., Methods: Umbilical cord blood mononuclear cells (MNC) from healthy donor were enriched by Ficoll-based density gradient centrifugation. Then, the phenotype, subpopulations, cell viability and cytotoxicity of NK cells derived from Miltenyi medium (denoted as M-NK) and X-VIVO 15 (denoted as X-NK) were compared using a "3IL" strategy., Results: After a 14-day's culture, the contents of CD3 - CD56 + NK cells were elevated from 4.25%±0.04% (d 0) to 71%±0.18% (M-NK) and 75.2%±1.1% (X-NK) respectively. Compared with X-NK group, the proportion of CD3 + CD4 + T cells and CD3 + CD56 + NKT cells in M-NK group decreased significantly. The percentages of CD16 + , NKG2D + , NKp44 + , CD25 + NK cells in X-NK group was higher than those in the M-NK group, while the total number of expanded NK cells in X-NK group was half of that in M-NK group. There were no significant differences between X-NK and M-NK groups in cell proliferation and cell cycle, except for the lower percentage of Annexin V+ apoptotic cells in M-NK group. Compared with X-NK group, the proportion of CD107a + NK cells in M-NK group were higher under the same effector-target ratio (E∶T) ( P <0.05)., Conclusion: The two strategies were adequate for high-efficient generation of NK cells with high level of activation in vitro , however, there are differences in biological phenotypes and tumor cytotoxicity.

This study was aimed to investigate the effects of rapamycin on biological function and autophagy of bone marrow mesenchymal stem cells (BM-MSC) from patients with aplastic anemia so as to provide experimental basis for the clinical treatment of aplastic anemia (AA) with rapamycin. BM-MSC were treated with different concentrations of rapamycin (0, 10, 50, 100 nmol/L) for 48 h, the expression of LC3B protein was detected by Western blot to observe the effect of rapamycin on cell autophagy; cell apoptosis and cell cycles were detected by flow cytometry; the proliferation of BM-MSC of AA patients was measured by cell counting kit-8; the adipogenic differentiation of BM-MSC were tested by oil red O staining after adipogenic induction for 2 weeks; the adipogenic related genes (LPL, CFD, PPARγ) were detected by real-time PCR. The results showed that the proliferation and adipogenesis of BM-MSC of AA patients were inhibited by rapamycin. Moreover, the autophagy and apoptosis of BM-MSC were increased by rapamycin in a dose-dependent way.Rapamycin arrested the BM-MSC in G0/G1 phase and prevented them into S phase (P < 0.05). It is concluded that rapamycin plays an critical role in inhibiting cell proliferation, cell cycles, and adipogenesis, these effects may be related with the autophagy activation and mTOR inhibition resulting from rapamycin.

This study was aimed to explore the immunoregulatory function and capability supporting the angiogenesis of exosomes secreted by bone marrow mesenchymal stem cells (BMMSC) from healthy persons. Supernatant of BMMSC (P4-P6) was collected for exosome purification. Transmission electron microscopy (TEM) and Western blot were used to identify the quality of isolated exosomes. The amount of exosomes was quantified through bicinchoninic acid (BCA) protein assay. Human peripheral blood mononuclear cells (PBMNC) were isolated from healthy donor and added with isolating exosomes. After co-cultured for 72 h, IFN-γ from the co-culture system was detected by ELISA. The expression of miRNA-associated with immunity were detected by real-time reverse transcription polymerase chain reaction (Real-time RT-PCR). The interactions between exosomes and human umbilical vein endothelial cells (HUVEC) were observed with confocal microscopy. Subconfluent HUVEC were harvested and treated with the indicated concentration of exosomes. Nude mice were injected subcutaneously with exosomes or PBS as control to verify the ability of angiogenesis. The results showed that diameter range of exosomes was range from 40 to 160 nm. The isolated exosomes expressed the CD9. There was approximately linear relation between the secretion of exosomes and cell density. The exosomes suppressed the production of IFN-γ from PBMNC, and contained miRNA associated with immune regulation such as miR301, miR22 and miR-let-7a. Exosomes induced vascular tube formation in vitro and vascularization of Matrigel plugs in vivo. It is concluded that the BMMSC-derived exosomes can regulate immunity and support vascularization.

Mesenchymal stem cells (MSCs) could be obtained from many sources, and there are differences between them. This study was purposed to compare and analyze the basic biological characteristics of umbilical cord, adipose tissue-and bone marrow-derived MSC (UC-MSCs, AD-MSCs and BM-MSCs). The MSCs were isolated from umbilical cord, adipose tissue and bone marrow were cultured; the morphology of UC-MSCs, AD-MSCs and BM-MSCs was observed by using microscopy; the immunophenotype, differentiation potential and expression of peroxisome proliferation-activated receptor-γ (PPAR-γ) mRNA were detected by using flow cytometry, differentiation test (von kossais and 0:1 red O staining) and quantitative fluorescent PCR, respectively. The results showed that the UC-MSCs, AD-MSCs and BM-MSCs displayed similar morphology under confocal microscope after being stained with rhodamine phalloidin and DAPL. The immunophenotypes of these three originated cells conform to coincide with identification criterion for MSCs, and showed similar expression level. During adipogenic induction the adipogenic potential of these MSCs was different, AD-MSCs exhibited the highest adipogenic potential, UC-MSCs displayed the lowest, while potential of BM-MSCs get between; however, the osteogenic differentiation potential of UC-MSCs, AD-MSCs and BM-MSCs was similar. The PCR detection showed that the expression level of PPAR-γ mRNA was the highest in AD-MSCs and the lowest in UC-MSCs, while expression level in BM-MSCs get between, these results were identical with the adipogenic potential, suggest that the difference of adipogenic potential in 3 kinds of MSCs was associated with basic expression level of PPAR-γ mRNA. It is concluded that UC-MSCs, AD-MSCs and BM-MSCs exhibit similar morphology, the immunophenotypes of these MSCs coincide with identification criterion for MSCs, the osteogenic potential of these MSCs is similar, while the adipogenic potential and the expression level of PPAR-γ mRNA are different. The difference-associated mechanisms need to further study.

15-Deoxy-Δ(12), 14-prostaglandin J2 (15d-PGJ2), a well known peroxisome proliferator activated receptor (PPAR) γ ligand, has been shown to inhibit cellular proliferation and induce apoptosis and differentiation. However, whether 15d-PGJ2 influences the cytokines in the culture supernatant of bone marrow mesenchymal stem cells (BM-MSC) is unknown. This study was purposed to investigate the influence of 15d-PGJ2 on cytokines in the culture supernatant of BM-MSC. The fibroblast-like cells attached to the culture dish from bone marrow of healthy donors were isolated. The immunophenotype and differentiation potential of the obtained cells were detected by flow cytometry and oil red O and von kassa staining respectively to confirm that these cells were BM-MSC. Thereafter, the BM-MSC were cultured with complete medium supplemented with 10, 20, 40 and 60 µmol/L 15d-PGJ2 for 24 hours respectively. The real-time PCR was used to assay the PPARγ mRNA level, the confocal immuno fluorescence technique was used to detect the expression level of PPARγ. The results showed that the BM-MSC underwent apoptosis and got detached from the culture dish when the concentration of 15d-PGJ2 was no less than 20 µmol/L. The PPARγ mRNA level of BM-MSCs cultured with medium containing 10 µmol/L 15d-PGJ2 was higher than that cultured without 15d-PGJ2, and the difference was statistically significant (P < 0.05). The enhancement of PPARγ expression was observed after stimulated by 15d-PGJ2. The protein chip detecting the culture supernatants of BM-MSC cultured with 10 µmol/L 15d-PGJ2 or without 15d-PGJ2 for 24 hours demonstrated that expression levels of some of the cytokines varied. It is concluded that the down-regulation of TIMP-2 exists after treatment of 15d-PGJ2, which is statistical significant.

The main aim of this study was to investigate the biological activities and immune modulation changes of chorionic villi mesenchymal stem cells (CV-MSC) after long term culture. The morphology of the CV-MSC of passage 3 and passage 9 were observed by microscopy, and their phenotypes were detected by flow cytometry. CV-MSC of passage 3 and 9 were co-cultured with PHA-stimulated PBMNC, and IFN-γ concentration in culture medium was detected by ELISA. The mRNA expression of COX-2, HGF and HLA-G in CV-MSC were detected by real-time PCR. The results showed that after long term culture, the CV-MSC kept the MSC morphology and most of the phenotypes including CD31, CD34, CD44, CD45, CD62L, CD73, CD90, CD105, CD117, CD151, CD235a, CD271 and HLA-DR, while the CD49d was significantly up-regulated. Immune modulation ability of CV-MSC was reduced and the mRNA expression of COX-2 and HGF was down regulated after long term culture, but the expression of HLA-G did not found to be obvious change. It is concluded that the long term in vitro expansion changes the expression of CD49d and reduces immune modulation of CV-MSC.

This study was aimed to investigate the effect of IL-1β on hematopoietic support of human umbilical cord mesenchymal stem cells (hUC-MSC). 2×10(6) hUC-MSC were seeded in 75 cm(2) flasks, after adherence to wall for 2 h, 10 ng/ml IL-1β was added in hUC-MSC supernatant and cultured for 36 h, then the culture supernatants and cells were harvested. The effect of conditioned medium with/without IL-1β on CD34(+) cell hematopoietic support was observed, mRNA expression changes of hUC-MSC cultured in medium with/without IL-1β were monitored by real time PCR, the differences in hematopoiesis-related factors were detected by ELISA. The results showed that the conditioned culture medium of hUC-MSC with IL-1β enhanced the ability to form colony of CD34(+) cells, especially CFU-G and CFU-GM in vitro; IL-1β promoted the mRNA expression of GM-CSF, G-CSF, IL-6 on MSC; IL-1β also promoted the secretion of GM-CSF, G-CSF, and IL-6 protein from hUC-MSC. It is concluded that IL-1β enhances hematopoietic support capacity especially, capability of MSC to myeloid differentiation.

Comparing to bone marrow mesenchymal stem cells (MSCs), placenta-derived MSCs have the advantages of adequate sources, low immunogenicity, little risk of viral contamination, and no ethical controversy, and thus possess a better prospect for clinical application. Placental tissue not only includes chorionic and amniotic, but also contains decidua basalis which locate in the maternal placenta surface. The biological characteristics of MSCs isolated from decidua basalis have not been well studied. This study was aimed to investigate the biologic characteristics of placenta decidua basalis-derived MSC from placenta decidua basalis (DB) by enzymatic digestion. Short tandem repeats (STR) test was used to identify the cells derived from the maternal placenta surface. Growth rate of decidua basalis mesenchymal stem cells (DB-MSC) was measured by MTT. Cell cycle and cell phenotype were detected by flow cytometry. Inducing differentiation was used to evaluate multipotency of DB-MSC. For testing the immunosuppression of DB-MSC, they were co-cultured with peripheral blood mononuclear cells (PBMNC) stimulated by phytohemagglutinin (PHA) and then IFN-γ in the co-cultured media was quantified by ELISA. The results showed that the cells were derived from the maternal placenta by STR analysis. DB-MSC showed typical fibroblast morphology in the culture and were positive for the MSC surface markers: CD90, CD73, CD105, CD44 and negative for CD45, CD11b, and CD34. DB-MSC underwent osteogenic, adipogenic and chondrogenic differentiation in inducing medium. DB-MSC could inhibit the secretion of IFN-γ by PBMNC. It is concluded that the cells are isolated from placenta decidua basalis and possess the basic characteristics of MSC. DB-MSC can be an important maternal autologous MSC and may be a safe and effective treatment for immune system diseases, which makes the DB-MSC as an important source of autologous MSC from mother. DB-MSC can be safely for the treatment of the mother's immune system diseases.

This study was purposed to investigate the impact of human umbilical cord-derived mesenchymal stem cells (hUC-MSC) on the sensitivity of HL-60 cells to therapeutic drugs so as to provide more information for exploring the regulatory effect of hUC-MSC on leukemia cells. Transwell and direct co-culture systems of HL-60 and hUC-MSC were established. The apoptosis and cell cycle of HL-60 cells were detected by flow cytometry. RT-PCR and Western blot were used to detect the mRNA and protein levels of Caspase 3, respectively. The results showed that the apoptosis of HL-60 induced by cytarabine (Ara-C) decreased significantly after direct co-cultured with hUC-MSC cycle mRNA (P < 0.05). The similar phenomenon was observed in transwell co-culture system. Cell cycle of HL-60 cells were arrested at G0/G1 phase and did not enter into S phase (P < 0.05) and the expression of Caspase-3 mRNA and protein in HL-60 cells were reduced (P < 0.05). It is concluded that hUC-MSC protected HL-60 from Arc-C induced apoptosis through regulating the cell cycle and down-regulating expression of Caspase 3 in HL-60 cells. In addition, this effect is caused by the soluble factors from hUC-MSC.

This study was aimed to explore whether the conditioned culture medium of human umbilical cord-derived mesenchymal stem cells (hUC-MSC) has supportive effects on hematopoiesis in vitro. hUC-MSC were cultured in 75 cm(2) culture flasks at a concentration of 2×10(6) cells per flask. After 48 h, the conditioned culture medium was harvested. CD34(+) cells were isolated with the human cord blood CD34 positive selection kit. The CD34(+) cells were plated in three different culture systems: the culture supernatant from hUC-MSC added into incomplete methylcellulose without recombinant human cytokines as conditioned culture medium; the complete methylcellulose medium with recombinant human cytokines as positive control medium; incomplete methylcellulose adding DMEM/F12 with 10% FBS instead of conditioned culture medium as the negative control medium. After 14 days of culture, colonies containing ≥ 50 cells were scored and types of colonies were classified under inverted microscope. The immunophenotypes of cells which were collected from the colonies were detected by flow cytometry. The results showed that conditioned culture medium of hUC-MSC supported the differentiation of CD34(+) cells into CFU-G (47.67 ± 0.58), CFU-GM (48.67 ± 4.73) and CFU-M (3.00 ± 2.00) in vitro, while the CFU-E, BFU-E or CFU-GEMM were absent. Comparatively, in the positive control medium all kinds of CFU were observed. Interestingly, the percentage of CD45(+)cells of CFU in conditioned culture medium (97.43 ± 2.15)% was more than CD45(+)cells in positive control medium (39.69 ± 0.96)% (P < 0.05). It is concluded that the conditioned culture medium of hUC-MSC has been confirmed to have ability to support hematopoiesis separately in vitro. Besides, it enhances the differentiation of CD34(+) cells into myeloid cells except cells of erythroid lineage.

Because advantage of tissue origin and proliferation potential, the umbilical cord-derived mesenchymal stem cells (UC-MSC) and placental chorionic villous-derived mesenchymal stem cells (CV-MSC) have clinical application potential, as compared with bone marrow MSC. But whether the differences of biological characteristics exist between UC-MSC and CV-MSC, which deserve to be further explored. This study was purposed to compare the biological characteristics of UC-MSC and CV-MSC. The placental and umbilical cord were cleaned by using the sterile physiological salt, the UC-MSC and CV-MSC were separated by enzyme digestion. Short tandem repeat (STR) analysis was used to detect whether the MSC obtained from fetal tissue. MTT method was used to detect proliferation of MSC. Flow cytometry was applied to analyze cell phenotype. The different differential medium was used to detect their multi-directional differentiation capacity. After the MSC and PHA-stimulated peripheral blood mononuclear cells were co-cultured, the γ-interferon (IFN-γ) levels of the co-culture supernatant were detected using the ELISA. The results showed that these MSC were derived from fetal tissue by STR analysis. They were adherent cells with typical fibroblast morphology. Cells expressed the MSC surface markers CD90, CD73 and CD105 and CD44, not expressed CD45 and of CD11b and CD34.These cells could differentiate into osteoblasts and adipoblasts under culture with different conditioned medium, but in the adipogenic differentiation of CV-MSC, the larger lipid droplets appeared. It is concluded that these cells are obtained MSC. These MSC can inhibit peripheral blood mononuclear cells stimulated by PHA to secrete IFN-γ, and the the CV-MSC have a stronger suppression capacity, which makes the CV-MSC to have a greater advantage in the treatment of autoimmune diseases.

The aim of this study was to investigate the effects of interferon (IFN)-γ on biological characteristics and immunomodulatory property of human umbilical cord-derived mesenchymal stem cells (hUC-MSC). hUC-MSC were treated with IFN-γ 10 ng/ml (IFN-γ group) or without IFN-γ (control group). The phenotype of hUC-MSC was detected by flow cytometry. The proliferation status was detected by CCK-8 method, and its differentiation ability was assessed by oil red O and von Kossa staining. The production of PGE-2 was measured by ELISA, and the mRNA expression levels of COX-2, IDO-1 and IDO-2 in hUC-MSC were detected by real-time quantitative PCR. Furthermore, the proliferation of human peripheral blood mononuclear cells (hPBMNC) was evaluated after co-culture with hUC-MSC, IFN-γ pretreatment or not. The results showed that after IFN-γ stimulation, the expression of SSEA-4 on hUC-MSC decreased significantly [(8.15 ± 2.94) vs (16.42 ± 8.5), P < 0.05], and the expression of CD54 increased [(96.64 ± 3.29) vs (84.12 ± 10.73), P = 0.051]. The immunomodulatory property of hUC-MSC on the proliferation of hPBMNC was enhanced (P < 0.05). All the above mentioned effects were IFN-γ concentration-dependent. When hUC-MSC were stimulated by IFN-γ for 24 h, the production of PGE-2 secreted by hUC-MSC decreased significantly (P < 0.01). The mRNA expression level of COX-2 also decreased though the difference did not reach to statistically significant level. Compared with control group, IDO-1 expression level in IFN-γ group increased significantly (P < 0.01), and the mRNA expression level of IDO-2 remained unchanged. It is concluded that IFN-γ can influence the phenotype of hUC-MSC and enhance the immunomodulatory property of hUC-MSC.

Hematopoietic stem cells (HSC) shift from fetal liver and spleen to bone marrow at neonatal stages and this movement may be due to inductive signals from different microenvironments. Mesenchymal stem cells (MSC) are the precursors of stromal cells in bone marrow microenvironments such as osteoblasts and endothelial cells. Some researchers speculated that fetal bone marrow before birth might be not perfectly suit HSC growth. However, it is still lack of direct evidence to prove this hypothesis. This study was aimed to compare the hematopoietic supportive capacity between human fetal and adult bone marrow MSC in vitro. Adult bone marrow MSC (ABM-MSC) were isolated from three healthy donors and fetal bone marrow MSC (FBM-MSC) were isolated from three fetuses between gestations of 19 to 20 weeks. After irradiation, MSC were co-cultured with CD34(+) cells isolated from umbilical cord blood in long-term culture-initiating cell (LTC-IC) assay. The colony number of colony forming cells (CFC) was counted and the phenotypic changes of co-cultured CD34(+) cells were analyzed by flow cytometry. Cytokine expressions in both kinds of MSC were detected by reverse transcription polymerase chain reaction (RT-PCR). The results showed that ABM-MSC had a stronger hematopoietic supportive capacity than FBM-MSC. Both of them enhanced the differentiation of CD34(+) cells into myeloid lineages. Cytokines were expressed differently in ABM-MSC and FBM-MSC. It is concluded that ABM-MSC possess more potential application in some treatments than FBM-MSC, especially in hematopoietic reconstitution.

Umbilical cord mesenchymal stem cell (UCMSC) transplantation has been widely used in the treatment of a variety of diseases due to their advantages such as abundant resources, low immunogenicity and large ex vivo expansion capacity. This study was aimed to investigate the effects of UCMSC on experimental autoimmune myasthenia gravis (EAMG) rats. The distribution of human-derived cells was observed by immunofluorescence method, the effect of MSC on B-cell in situ-secreted antibodies was assayed by ELISPOT, the secreted IFN-γ level was detected by using Transwell test. The results showed that UCMSC were able to migrate to inflammation region and lymph nudes, moreover human-derived cells could be detected in medulla zone of lymph nudes. In vitro in situ detection of AchR specific antibody secretion revealed that the full contact of MSC with lymphnode-derived lymphocytes could effectively inhibit production of AchR antibody. Transwell test indicated that the direct contact of UCMSC with CD4 T cells could effectively decrease production of IFN-γ, which modulated the unbalance between Th1/Th2 to a certain extent. It is concluded that UCMSC can regulate the immune system by direct cell-cell contact or/and release of cytokines, which bring a new insight into knowledge about MSC-based therapy for EAMG.

This study was aimed to investigate whether mesenchymal stem cells (MSC) can be isolated from bone marrow filters which have always been discarded. The bone marrow (BM) particles from BM filters of 2 healthy donors were cultivated by primary explant culture. After expansion, the number of MSC was counted and their immunophenotype and differentiation potential were detected. The results indicated that many MSC were found in bone marrow particles from filters, and nearly 10(7) MSC were obtained at 3 passages of expansion. They not only possessed the characteristics of morphology and immunophenotype of MSC, but also could differentiate into osteoblasts, chondrocytes and adipocytes. In conclusion, a large amount of MSC can be obtained from BM filters if the BM particles were cultivated by primary explant culture.

Bone marrow (BM) is the major source of mesenchymal stem cells (MSC). In most experiments, MSC were classically cultured from mononuclear cells (MNC) isolated by density gradient centrifugation method. However, several studies have demonstrated that this method was less efficient for MSC recovery. This study was aimed to investigate whether BM particles were the cause resulting in less efficiency of this method and how to isolate them. A total of 20 patients were enrolled in this study. MNC were cultured by standard adherence and BM particles were cultivated by primary explant culture. For BM from patients 1-10, MNC were first isolated and BM particles were then filtered out. The morphology and the fibroblastic colony number were compared between cultures of MNC and BM particles. For BM from patients 11-20, MNC isolation and BM particle filtration were processed in opposite order, then the immunophenotype and function between adherent cells expanded from MNC and BM particles were compared. In addition, for patients 11-20, the left BM aspirates were cultured too after BM particles and MNC were isolated separately. The results showed that adherent cells from BM particles were MSC. After BM particles were filtered out and cultured separately, MSC could be recovered completely from MNC isolated by density gradient centrifugation and no MSC were left in the residual BM aspirates. BM particles, which have been mostly discarded by the method of density gradient centrifugation, are another important source of MSC and they can be cultivated reliably by primary explant culture. It is concluded that more MSC are recovered from a single BM sample by culturing BM particles and MNC separately.

This study was aimed to investigate the enhancement of all-trans retinoic acid-induced HL-60 leukemia cell differentiation by human umbilical cord mesenchymal stem cells (hucMSC). The HL-60 cells were divided into 4 groups: control group (HL-60 cells treated without ATRA), hucMSC group (HL-60 cells co-cultured with hucMSCs), ATRA group (HL-60 cells treated with ATRA) and ATRA + hucMSC group (HL-60 cells treated with ATRA and co-cultured with hucMSCs). The proliferations of control group and hucMSC group were compared by Cell Counting Kit-8 (CCK8). The morphology of HL-60 cells and NBT positive rate in 4 groups were observed and compared by means of microscopy, the c-myc expression of HL-60 cells in different groups was evaluated by real-time PCR, and the CD11b expression on HL-60 cells in different groups were detected by flow cytometry. The results showed that in the co-culturing system, hucMSCs could inhibit the proliferation of HL-60 (hucMSC:HL-60 is 1:1, 48 hours p < 0.05, 72 hours p < 0.01; hucMSC:HL-60 is 1:5, 72 hours p < 0.05). In condition of stimulation with 2 micromol/L ATRA, the neutrophil like HL-60 cells and NBT positive rate in ATRA + hucMSC group were higher than those in ATRA group (p < 0.05). The c-myc expression of HL-60 cells in ATRA + hucMSC group was lower than that in ATRA group (p < 0.05). Furthermore, HL-60 cells in ATRA + hucMSC group had stronger CD11b expression than ATRA group (48 hours p < 0.05, 72 hours p < 0.01). It is concluded that hucMSC not only can inhibit the proliferation of HL-60 cells, but also can enhance the differentiation effect of HL-60 cells induced by ATRA.

The present study was aimed to investigate the pathways, by which IL-27 regulates the expression of adherent molecule Mac-1, chemotactic factor receptor fMLP-R and pro-inflammatory cytokine IL-1beta in human neutrophils. Highly purified human neutrophils were isolated from peripheral blood using Ficoll-Hypaque gradients centrifugation and erythrocyte lysis. The mRNA expression of IL-27 receptor components (WSX-1/TCCR and gp130) in human neutrophils was detected by reverse transcription polymerase chain reaction (RT-PCR). After incubation with IL-27 and specific inhibitors (p38 MAPK inhibitor SB203580, PI3K inhibitor LY294002 and ERK inhibitor U0126), the mRNA levels of fMLP-R and IL-1beta were determined by real time RT-PCR, and the adherent molecule Mac-1 expression in human neutrophils was determined by flow cytometry. The IL-1beta level in culture supernatant of human neutrophils was assayed by radioimmunoassay. The results showed that IL-27 receptor components (WSX-1/TCCR and gp130) were constitutively expressed in human neutrophils. IL-27 down-regulated Mac-1 expression in human neutrophils (p<0.05). After incubation with specific inhibitors, SB203580, not LY294002 and U0126, inhibited the down-regulation of Mac-1 expression by IL-27. However, IL-27 up-regulated the mRNA expression of fMLP-R and IL-1beta, and increased the release of IL-1beta (p<0.05). Interestingly, LY294002, not SB203580 and U0126, inhibited the up-regulation of fMLP-R and IL-1beta by IL-27. It is concluded that the IL-27 may regulate the expression of Mac-1, fMLP-R and IL-1beta in human neutrophils through p38 MAPK and PI3K signal pathways.

In order to analysis the effect of fetal lung mesenchymal stem cell (FL-MSC) on differentiation of umbilical cord blood mononuclear cells (MNC) into megakaryocytes, the fresh umbilical cord blood MNC were isolated and divided into 2 groups in the culture added with TPO, IL-11 and heparin. In the first group MNC were cultured alone and in the second group MNC were cocultured with FL-MSC. The cells were collected at day 7, 10, 14 for cell counting and detection of CD41a and CD61 by flow cytometry. The morphology and ultrastructure of megakaryocytes were observed by immunohistochemistry method and transmission electron microscopy at day 14. The content of DNA was analyzed by flow cytometry at day 14 too. The results indicated that the of CD41a+ and CD61+ cells were obtained mostly in the second group at day 10 and were in 4.5 and 4.7 fold as much as the MNC cultured alone. The morphology and ultrastructure of megakaryocytes showed immature of nuclei in both of two groups. It is concluded that the FL-MSC could effectively enhance the production of CD41a+ and CD61+ cells, where the effect on nucleus development of the young megakaryocyte was not obviously shown.

The present study was aimed to isolate and identify human mesenchymal stem cells from adult bone marrow (BM-MSC) and umbilical cord (UC-MSC), and to compare their ability to support in vitro long-term hematopoiesis. MSC from bone marrow and umbilical cord were isolated by using density gradient centrifugation or enzyme digestion. MSC were further purified by adherent culture. Immunophenotype, adipogenic and osteogenic differentiation potential of BM-MSC and UC-MSC were detected. The hematopoietic supporting capacity of BM-MSC and UC-MSC was assessed by LTC-IC assay. Nonadherent cells in each group were collected for phenotypic analysis at 3, 5 and 7th week of culture. The results showed that BM-MSC and UC-MSC in culture shared a similar spindle-shaped morphology and adhered to the tissue culture substrate. They were both positive for CD90, CD105, CD73, CD29, CD54, CD166, HLA-ABC, and negative for HLA-DR, CD34 and CD45. BM-MSC and UC-MSC could differentiate into adipocytes or osteoblasts confirmed by oil red O staining and von Kossa staining, separately. LTC-IC assay showed that at 5th week of culture, the difference of the CFC yields between UC-MSC group and BM-MSC group was not statistically significant (p>0.05). At 6, 7, 9th week of culture, the CFC yields in the UC-MSC group were lower than those of BM-MSC (p<0.05). The phenotypic analysis of nonadherent cells at 3, 5, 7th week of culture indicated that along with prolongation of time, the percentages of CD34+ cells and CD117+ cells in each group decreased markedly, and the percentages of CD33+ cells, CD13+ cells and CD11b+ cells increased gradually. It is concluded that MSC from human adult bone marrow and umbilical cord can be successfully isolated and identified. UC-MSC are able to support long-term hematopoiesis in vitro, but its hematopoietic supportive capacity is weaker than those of BM-MSC.

The present study was purposed to evaluate the safety of mesenchymal stem cell (MSC)-based therapy impacting on atherosclerosis. Allogeneic MSCs were obtained from rabbit bone marrow aspirates and expanded in vitro. New Zealand white rabbits were divided into three groups: 24 rabbits with hypercholesterolemia receiving intravenous injection of either 5 x 10(7) MSCs (n = 12) or saline (n = 12) after 5 weeks on a high lipid diet and additional rabbits (n = 6) fed with standard rabbit diet were served as controls. Body weight and blood lipids were measured at weeks 0, 5, 9 and 13 during the study. All rabbits were sacrificed at week 13. Atherosclerotic lesion size and vasa vasorum were evaluated by using pathological analysis and immunocytochemical technique. The results showed that the aortic sinus lesion size significantly increased in rabbits infused with MSCs as compared with controls receiving saline (23.35 +/- 3.51% and 11.39 +/- 3.08% respectively). The lesion size in whole aortas of MSC-treated rabbits was 76.64 +/- 12.70% versus 57.61 +/- 9.00% in saline-treated animals (p < 0.05). Moreover, vasa vasorum networks in MSC-treated aortas were more numerous and had increased capillary density. It is concluded that the allogeneic MSC transfusion may result in an increase in atherosclerotic lesion size. In cell therapy with MSCs or cell populations containing MSCs a strategy to attenuate the high potential of MSCs involved in atherogenesis of atherosclerosis should be taken in account.

This study was aimed to examine the expression and promoter CpG island methylation of homeobox B4 (HOXB4) gene in CD34(+) cells from cord blood and peripheral blood mononuclear cells (PBMNCs) from health adult, and to investigate the expression level of HOXB4 in these two cells and its relationship with the promoter methylation. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to examine the expression of HOXB4 in CD34(+) cells and PBMNCs, and bisulfite sequencing technique was used to detect the methylation status of the promoter CpG sites of HOXB4 gene in CD34(+) cells and PBMNCs. The results indicated that highly expressed HOXB4 and unmethylation of HOXB4 promoter CpG island occurred in CD34(+) cells. However, loss of HOXB4 expression and the methylated CpG island of HOXB4 were observed in PBMNCs, and the methylated C residue was positioned at -129 bp in the upstream of ATG. It is concluded that the methylation status of HOXB4 gene promoter may be one negative regulatory mechanism for HOXB4 gene expression. The unmethylation of CpG island in the promoter region of HOXB4 gene may be correlated with the high expression of HOXB4 gene in CD34(+) cells, while the promoter methylation of HOXB4 gene may be associated with HOXB4 gene silencing in PBMNCs. The preliminary identification of HOXB4 promoter methylation site would provide a basis for further study and a novel approach to expand hematopoietic progenitor cells.

Bmi-1 is a transcriptional repressor, which belongs to the polycomb group family. It has been demon- started that over-expression of Bmi-1 occurs in a variety of cancers, including several types of leukemia. Bmi-1 gene plays a key role in regulation of self-renewal in normal and leukemic stem cells. Acute myeloid leukemic cells lacking Bmi-1 undergo proliferation arrest and show signs of differentiation and apoptosis, which leads to the proposal of Bmi-1 as a potential target for therapeutic intervention in leukemia. The purpose of this study was to investigate the effect of short hairpin RNA (shRNA) targeting Bmi-1 on functions of K562 cell line. The shRNA eukaryotic expression vector targeting Bmi-1 was constructed and transfected into K562 cells through lipofectamine 2000. The mRNA and protein levels of Bmi-1 were detected by PCR and Western blot respectively. The proliferation of K562 after Bmi-1 silencing was measured by using MTT assay and clone formation assay. The cell cycle was detected by flow cytometry. The results indicated that among the four shRNA designed, there was a shRNA which efficiently interfered with the expression of Bmi-1. The results of PCR and Western blot validated that the Bmi-1 gene of K562 cells transfected with such a Bmi-1 shRNA was suppressed successfully. Although levels of Bmi-1 mRNA and protein were significantly reduced, delivery of this siRNAs had no effect on cell viability or growth. Flow cytometry analysis suggested that Bmi-1 inhibition did not affect the cell cycle. It is concluded that the suppression of Bmi-1 expression is not able to reduce proliferation of K562 cells, suggesting existence of some other parallel signaling pathways, which are fundamental for leukemic transformation and are independent of Bmi-1 over-expression. Bmi-1 over-expression may play a secondary role in chronic myeloid leukemia transformation.

The purpose of this study was to investigate the expression of human Factor IX (hFIX) in retrovirus-transfected human umbilical cord tissue derived mesenchymal stem cells (hUCT-MSCs). The pLEGFP-N1-hFIX vector was generated by cloning a 3.0 kb Bgl II-BamH I fragment from the pIRES2-EGFP-hFIX plasmid containing the hFIX cDNA and part of intron 1 of hFIX in pLEGFP-N1 vector. The retroviral supernatants were produced from the Phoenix packaging cell line and then infected the hUCT-MSCs. After selection with G418 for 10 day, the expression of FIX was detected by ELISA and Western blot. The biological activity of FIX was determined by the clotting assay employing human Factor IX-deficient plasma. The results showed that compared with the activity of pooled human normal plasma (100%), transduced cells produced biologically active hFIX with 100-130% activity in two-day culture supernatant and expressed hFIX at levels of 2.68 +/- 0.36 microg/10(6) cells/24 hours after G418 selection for 10 days. The secretion of hFIX into culture supernatant was also confirmed by Western blot analysis. It is concluded that genetically modified hUCT-MSCs can express biologically active hFIX and thus serve as an efficient drug delivery vehicle carrying hFIX used as a way of somatic gene therapy for hemophilia B.

The study was aimed to investigate the potential immunotherapeutical values of umbilical cord tissue-derived mesenchymal stem cells (UC-MSC) on patients with chronic idiopathic thrombocytopenic purpura (ITP). UC-MSC was cocultured in vitro with splenocytes isolated from ITP patients who experienced splenectomy. The level of IgG antiplatelet antibody (PAIgG) was determined by a competitive micro-enzyme-linked immunosorbent assay (ELISA) method. The proliferation of platelet-reactive CD4+ T lymphocytes was also measured in the presence of UC-MSCs. The results showed that UC-MSCs could stimulate the spontaneous secretion of PAIgG in supernatants; In the platelet-inducing condition, UC-MSC inhibited the production of PAIgG at a low ratio of 1 UC-MSC to 100 splenocytes, but promoted at a high proportion of 1 UC-MSC to 10 splenocytes. Moreover, UC-MSC exerted a suppressive effect on proliferation of platelet-reactive T helper cells in a dose-dependent manner. It is concluded that the UC-MSCs can regulate secretion of antiplatelet antibodies in vitro. Its concrete regulation mechanism and potential immunotherapeutical value are need to further study.

The purpose of this study was to explore the differences in megakaryocyte progenitor ex vivo expansion between CD34+ cells derived from human umbilical cord blood (CB) and bone marrow (BM). Mononuclear cells (MNCs) were obtained from CB or BM by Ficoll-Hypaque density gradient separation. CD34+ cells were purified by magnetic cell sorting (MACS). The selected CD34+ cells were seeded in serum-free conditions stimulated with thrombopoietin (TPO), TPO+interleukin 11 (IL-11), or TPO+IL11+heparin for 14 days. Amplification product (CD34+, CD41a+, and CD34+ CD41a+ cells) immunophenotypes, megakaryocyte apoptosis rates and the DNA content were measured by fluorescence-activated cell sorting (FACS). The colony-forming units of granulocytes and monocytes (CFU-GM), burst-forming units of erythrocytes (BFU-E), and colony-forming units of megakaryocytes (CFU-Mk) were also evaluated by the colony-forming units (CFU) assay. The results indicated that CD34+ cells derived from CB showed higher expansion ability of total cell counts, CD41a+ and CD34+ CD41a+ cells than those derived from BM for all days 14 of culture (p<0.05, respectively). There were no significant differences in CFU-GM, BFU-E, and total CFU-Mk counts between CB and BM-derived CD34+ cells on day 0 (p>0.05, respectively), but CB-derived CFU-Mk seemed mainly large colonies, and the number of large colonies was higher than that from BM (p<0.05) on day 0. There were no significant differences in expansion ability of CFU-GM between CB and BM-derived cells on days 7, 10, and 14 of culture (p > 0.05, respectively), but the expansion ability of BFU-E and CFU-Mk derived from CB cells was higher than that from BM (p<0.05, respectively). There were no significant differences in apoptosis rates of megakaryocyte from two source cells for days 14 of culture. Megakaryocytes derived from CB mostly showed the 2N DNA content (>90%) for days 14 of culture, while those cells derived from BM showed the increased DNA content, and 4N, 8N or more ploidy cells gradually increased with prolonging of culture time. It is concluded that CB-derived CD34+ cells have a greater proliferation potential than that derived from BM, which is therefore proven to be a better cell source for megakaryocyte progenitor expansion in vitro.

This study was purposed to investigate the biological characteristics and immunogenicity changes of ex vivo expanded megakaryocyte progenitors from human umbilical cord blood CD34(+) cells in order to provide experimental basis for clinical application of ex vivo expanded umbilical cord blood megakaryocyte progenitor cells. Mononuclear cells (MNCs) were obtained from umbilical cord blood by Ficoll-Hyapaque density gradient separation. CD34(+) cells were enriched by magnetic cell sorting (MACS). The selected CD34(+) cells were seeded in serum-free medium stimulated with thrombopoietin (TPO, 50 ng/ml), interleukin 11 (IL-11, 50 ng/ml), and heparin (25 U/ml) for 14 days. The immunophenotyping (CD34(+), CD41a(+), CD61(+), CD34(+) CD41a(+) and CD34(+) CD61(+) cells) of amplificated products, matured megakaryocyte apoptosis, and expression of human leukocyte antigen (HLA) class I and class II molecules were measured by fluorescence-activated cell sorter (FACS). The number of colony-forming units-megakaryocyte (CFU-Mk) was also evaluated by CFU-Mk assay. The results showed that the umbilical cord blood CD34(+) mononuclear cells could be effectively differentiated into megakaryocytes. The peak expression ratios of CD41a(+) and CD61(+) cells were all at 14th days, while that of CD34(+) CD41(+) and CD34(+) CD61(+) cells were at 7th day [(3.41 +/- 2.80)% and (1.89 +/- 1.43)%, respectively]. The expansion times of large and small CFU-Mk reached peak at 7th day (20.66 +/- 32.79) and 10th day (435.62 +/- 482.65), respectively. The apoptotic rates of megakaryocytes at 7th, 10th, 14th day were (19.48 +/- 9.64)%, (26.87 +/- 9.03)%, and (52.46 +/- 11.74)%, respectively. The apoptotic rate of megakaryocytes had no significant difference in 7 and 10 days culture (p > 0.05), while that significantly increased in culture for 14 day culture, compared with culture for 7 and 10 days (p < 0.05, respectively). The expression of HLA class I and class II molecules on megakaryocytes decreased along with the prolongation of expansion time and sharply decreased in 0 to 10 days. It is concluded that the cytokines of TPO, IL-11, and heparin can promote the expansion of megakaryocyte progenitors from umbilical cord blood CD34(+) mononuclear cells effectively in vitro. The peaked expansion times of large CFU-Mk, the peaked expression ratios of CD34(+) CD41(+) and CD34(+) CD61(+) cells were all at 7th day. So the culture for 7 days appeared to be the optimal duration of expanding megakaryocyte progenitors.

This study was aimed to investigate the expression of neuropilin-1 (NRP-1) and NRP-2 mRNA in myeloid leukemia cells and the effect of NRP-1 on cell proliferation and migration. The expressions of NRP-1 and NRP-2 mRNA in bone marrow mononuclear cells of 24 patients with acute myeloid leukemia and in 7 myeloid leukemic cell lines (HL-60, KGIa, NB4, U937, HEL MEG01 and K562) were detected by RT-PCR. The effects of NRP-1 interfered with siRNA on proliferation and migration in leukemic cell line HEL were examined by MTT and migration test. The results showed that the expression of NRP-1 mRNA was found in bone marrow mononuclear cells (BMMNCS) of 24 AML patients, the positive rate was 100% and significantly higher than that in control group (positive rate 67%). The expressions of NRP-2 mRNA were seen in 79% AML patients and in 67% health control, there was no significant difference between them. The increased NRP-1 expression was directly correlated with the blast percentage in both peripheral blood and bone marrow of AML patients (r=05, r=0.4, p<0.05). The expressions of NRP-1 and NRP-2 mRNA were observed in 6/7 and 3/7 myeloid leukemic cell lines respectively. After HEL cells were transfected with siRNA for 24 hours, the expression levels of NRP-1 mRNA and protein decreased obviously. Under VEGF action, the cell number in control group significantly increased, while the cell proliferation in interfered group had been not changed. After being transfected for 24 hours, the migration in interfered group decreased significantly. It is concluded that the higher level of NRP-1 mRNA is expressed in bone marrow mononuclear cells of leukemia patients and plays a pivotal role in proliferation and migration of myeloid leukemic cells. Inhibition of NRP-1 functions may provide a new therapeutic strategy for AML.

In order to investigate expressions of transcription factor GATA-1 and GATA-2 genes in the bone marrow stromal cells (BMSCs) from patients with leukemia or normal controls, bone marrow stromal cells from 34 normal cases and 42 cases with leukemia were cultured long-term in vitro. Nonadherent cells (bone marrow hematopoietic cells) and amplified adherent cells (BMSC) were collected separately. Expressions of GATA-1 and GATA-2 genes were analyzed by using RT-PCR-ELISA; the semi-quantitative expression levels of GATA genes in the BMSCs from patients with leukemia were compared with normal controls. The results showed that expressions of GATA-1 and GATA-2 genes could be detected in the BMSCs and the bone marrow hematopoietic cells from both normal controls and the cases of leukemia. The expression ratio of GATA-1 in the BMSCs from acute lymphocytic leukemia (ALL) (85.7%) was similar to the normal controls (88.2%), whereas the expression ratios in BMSCs from acute myelocytic leukemia (AML) (55.6%) and chronic myelocytic leukemia (CML) (41.2%) were significant lower than the normal controls (P < 0.05). The rank of expression level of GATA-1 gene in the BMSCs was "ALL>AML>normal>CML". There was no difference in the expression level of GATA-2 gene within the BMSCs from normal controls and patients with leukemia. The ranks of expression levels of GATA-1 and GATA-2 genes in bone marrow hematopoietic cells were "AML>normal>ALL>CML" and "AML>CML>ALL>normal". The dominant expression of GATA-2 gene was found in the BMSCs from AML, CML or normal controls. It is inferred that the expressions of GATA-1 and GATA-2 genes in the BMSCs of normal controls and patients with leukemia may influence the regulation of hematopoiesis in the bone marrow stroma and it is worthy of further study to explore their roles in pathogenesis and development of leukemia.

In order to investigate expression of SCL (stem cell leukemia) gene in bone marrow stromal cells (BMSC) and bone marrow cells from patients with leukemia and normal individuals, bone marrow mononuclear cells from AML (18 cases), CML (17 cases), ALL (7 cases) and normal individuals (33 cases) were cultured long-term in vitro. Nonadherent cells (hematopoietic cells) and amplified adherent cells (BMSC) were collected respectively. RT-PCR-ELISA assay was then performed to detect expression of SCL gene. The expression ratio of SCL gene were analyzed and its expression level was normalized by beta(2)M gene acting as an internal reference for the purpose of semi-quantitative analysis. The results indicated that the expression ratio of SCL gene was lower in BMSC from AML (27.8%) and CML (11.8%) than that in normal controls (69.7%, P < 0.05), while was higher in the nonadherent cells from CML (64.3%) than that in its corresponding BMSC (P < 0.05). Semi-quantitative analysis showed that SCL gene expression level in nonadherent cells from AML was higher than that in its corresponding BMSC (P < 0.05). In conclusion, the low-level expression state of SCL gene in BMSC from patients with AML and CML may be involved in the abnormal regulation of hematopoiesis in myelocytic leukemia.