Search

Background: Postoperative cognitive dysfunction (POCD) is one of the common postoperative complications, which is more common in aged patients. POCD mainly manifests as cognitive function changes after surgery, such as memory decline and inattention. In some severe cases, patients may suffer from personality changes and (or) social behavior decline. The aim of the current study is to confirm the effect and elucidate the mechanism of bone marrow mesenchymal stem cells (BMSCs) in postoperative central inflammatory mice., Methods: Mice were randomly assigned to four groups: sham, sham+BMSCs, model, and BMSCs group. In the model group, mice were intraperitoneally injected 8 mg/kg per day lipopolysaccharide for 5 days. In sham+BMSCs and BMSCs group, BMSCs (1 × 10 7 ) in 100 µL saline were injected into sham mice and model mice, respectively., Results: In the model group, transforming growth factor β (TGF-β) protein expression was significantly increased, compared with that in the sham group. BMSCs were treated into postoperative central inflammatory mice, which resulted in a decreased of TGF-β protein expression. TGF-β and smad2 protein expression were suppressed, and apoptosis rate and inflammation were inhibited in coculture with BMSCs. The suppression of TGF-β inhibited the effects of BMSCs on apoptosis rate and inflammation in postoperative central inflammatory through a smad2 signaling pathway. The promotion of TGF-β reduced the effects of BMSCs on apoptosis rate and inflammation in postoperative central inflammatory through a smad2 signaling pathway., Conclusion: The present study demonstrates that BMSCs regulates TGF-β to adjust neuroinflammation in postoperative central inflammatory mice., (© 2019 Wiley Periodicals, Inc.)

Background/aims: Plastrum testudinis extracts (PTE) show osteoprotective effects on glucocorticoid-induced osteoporosis in vivo and in vitro. However, the underlying molecular mechanism of PTE in promoting osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is unclear., Methods: BMSC proliferation was investigated using the Cell Counting Kit-8 assay. BMSC differentiation and osteogenic mineralization were assayed using alkaline phosphatase and Alizarin red staining, respectively. The mRNA expression levels of Let-7f-5p, Tnfr2, Traf2, Pi3k, Akt, β-catenin, Gsk3β, Runx2, and Ocn were measured using real time quantitative polymerase chain reaction. Protein levels of TNFR2, TRAF2, p-PI3K, p-AKT, p-β-CATENIN, and p-GSK3β were analyzed by western blotting. The functional relationship of Let-7f-5p and Tnfr2 was determined by luciferase reporter assays., Results: The optimum concentration for PTE was 30 μg/ml. PTE significantly promoted BMSC osteogenic differentiation and mineralization after 7 and 14 days in culture, respectively. The combination of PTE and osteogenic induction exhibited significant synergy. PTE upregulated Let-7f-5p, β-catenin, Runx2, and Ocn mRNA expression, and downregulated Tnfr2, Traf2, Pi3k, Akt, and Gsk3β mRNA expression. PTE inhibited TNFR2, TRAF2, and p-β-CATENIN protein expression, and promoted p-PI3K, p-AKT, and p-GSK3β protein expression. In addition, Tnfr2 was a functional target of Let-7f-5p in 293T cells., Conclusions: Our results suggested that PTE may promote BMSC proliferation and osteogenic differentiation via a mechanism associated with the regulation of Let-7f-5p and the TNFR2/PI3K/AKT signaling pathway., (© 2018 The Author(s). Published by S. Karger AG, Basel.)

Objective: To explore the mechanism of ibrutinib on drug resistance diffuse large B-cell lymphoma (DLBCL) cells. Methods: DLBCL cell line was cultured with mesenchymal stem cells (MSC) , and DLBCL cells which migrated and adhered to MSC under microscope was counted. The secretion of CXCL12 by MSC were measured by ELISA. The expression of CXCR4 on DLBCL cells were measured by flow cytometry, HBL-1 cells were transfected with a CXCR4-lentivector. An Annexin Ⅴ-binding assay was used to detect the induction of apoptosis. Clonogenic growth of DLBCL cells was evaluated on MethoCult media. Ibrutinib was injected into NOD/SCID mice, tumor growth was assessed via caliper measurements every 3 days. Results: MSC promoted migration and adhesion of DLBCL cells to MSC. Ibrutinib inhibited migration and adhesion of DLBCL cells to MSC in a dose-dependent manner ( P <0.05) . CXCL12 secreted by MSC and CXCR4 expressed on DLBCL cells could induce each other, which upgraded the levels of secretion and expression. Ibrutinib could inhibit the secretion of CXCL12 (SUDHL10: 660 pg/ml vs 1 400 pg/ml, P =0.004; HBL-1: 720 pg/ml vs 1 490 pg/ml, P =0.018; DLBCL:850 pg/ml vs 1 450 pg/ml, P =0.004) and expression of CXCR4 ( P <0.05) . When co-cultured with MSC, the ratio of HBL-1 cells apoptosis in the group of control, mitoxantrone, ibrutinib, mitoxantrone+ibrutinib were respectively 15.1%, 17.5%, 23.5%, 58.7%. After transfected with a CXCR4-lentivector and overexpressed CXCR4, the ratios of HBL-1 cells apoptosis were 14.2%, 16.1%, 22.5%, 38.3% respectively. The ratio of DLBCL cells apoptosis induced by mitoxantrone was lower when co-cultured with MSC ( P <0.05) . But with the addition of ibrutinib, the ratio of apoptosis was increaed and it was similar to cultivation without MSC, which suggested ibrutinib could inhibit drug-resistance induced by MSC. But after transfected with a CXCR4-lentivector, the overexpression of CXCR4 was detected and the ratio of apoptosis was significantly lower when co-cultured with MSC which demonstrated that ibrutinib inhibited drug-resistance by inhibiting the expression of CXCR4. MSC enhanced lymphoma clonogenicity in vitro and lymphoma cell growth in vivo. The number of colonies of control, MSC, Ibrutinib, MSC+Ibrutinib were 113±5, 205±4, 62±9, 123±3 (2.5×10(3)/well, x ± s ) , respectively. The tumor volume of NOD/SCID mice were respectively 6 500, 17 000, 4 000, 10 000 mm(3). Ibrutinib inhibited lymphoma clonogenicity in vitro and lymphoma cell growth in vitro . Conclusion: Ibrutinib targeted the CXCL12/CXCR4 axis, inhibited the expression of CXCR4 and inhibited MSC-mediated drug resistance. Ibrutinib also inhibited lymphoma clonogenicity in vitro and lymphoma cell growth in vivo . These results provided a scientific rationality for relapsed/refractory DLBCL treatment with ibrutinib.

Objective: This study aims to explore the protection effect of bone marrow mesenchymal stem cells (BMSCs) on PC12 cells apoptosis mediated by transient axonal glycoprotein 1 (TAG1)., Methods: PC12 cells were divided into control group, Aβ25-35 group and BMSCs + Aβ25-35 group. The effects of BMSCs on PC12 cells treated by Aβ25-35 were detected using MTT, Hoechst 33258 and Annexin V-FITC/PI staining methods. The expression levels of TAG1, β-amyloid precursor protein (APP), AICD and p53 were determined by RT-PCR and Western blotting methods. The expression levels of Bax and Bcl-2 were determined by Western blotting method. The activity of Caspase 3 was detected by spectrophotometric method., Results: MTT results showed that cell activity decreased after the treatment of 20 μM Aβ25-35 for 48 h (P<0.01) while it increased in BMSCs + Aβ25-35 group (P<0.01). Hoechst 33258 and Annexin V-FITC/PI staining results showed that Aβ25-35 could induce the apoptosis of PC12 cells while the apoptosis of PC12 cells was inhibited in BMSCs + Aβ25-35 group. RT-PCR and Western blotting methods showed that 20 μM Aβ25-35 could increase the expression levels of TAG1, APP, AICD and p53 (P<0.01) while they decreased in BMSCs + Aβ25-35 group (P<0.01). 20 μM Aβ25-35 could increase the expression levels of Bax and decrease the expression levels of Bcl-2 (P<0.01), while the expression levels of Bax decreased and the expression levels of Bcl-2 increase in BMSCs + Aβ25-35 group (P<0.01). 20 μM Aβ25-35 could enhance Caspase 3 activity while it decreased in BMSCs + Aβ25-35 group (P<0.01). Conclusions BMSCs with Aβ25-35 could inhibit the apoptosis of PC12 cells, which maybe related with TAG1/APP/AICD signal pathway.

Parkinson's disease (PD) is a neurodegenerative movement disorder that is characterized by the progressive degeneration of the dopaminergic (DA) pathway. Mesenchymal stem cells derived from human umbilical cord (hUC-MSCs) have great potential for developing a therapeutic agent as such. HGF is a multifunctional mediator originally identified in hepatocytes and has recently been reported to possess various neuroprotective properties. This study was designed to investigate the protective effect of hUC-MSCs infected by an adenovirus carrying the HGF gene on the PD cell model induced by MPP+ on human bone marrow neuroblastoma cells. Our results provide evidence that the cultural supernatant from hUC-MSCs expressing HGF could promote regeneration of damaged PD cells at higher efficacy than the supernatant from hUC-MSCs alone. And intracellular free Ca(2+) obviously decreased after treatment with cultural supernatant from hUC-MSCs expressing HGF, while the expression of CaBP-D28k, an intracellular calcium binding protein, increased. Therefore our study clearly demonstrated that cultural supernatant of MSC overexpressing HGF was capable of eliciting regeneration of damaged PD model cells. This effect was probably achieved through the regulation of intracellular Ca(2+) levels by modulating of CaBP-D28k expression.

Multiple sclerosis (MS) is a complex disease of neurological disability, affecting more than 300 out of every 1 million people in the world. The purpose of the study was to evaluate the therapeutic effects of human umbilical cord-derived mesenchymal stem cell (hUC-MSC) transplantation in MS patients. Twenty-three patients were enrolled in this study, and 13 of them were given hUC-MSC therapy at the same time as anti-inflammatory treatment, whereas the control patients received the anti-inflammatory treatment only. Treatment schedule included 1,000 mg/kg of methylprednisolone intravenously (IV) daily for 3 days and then 500 mg/kg for 2 days, followed by oral prednisone 1 mg/kg/day for 10 days. The dosage of prednisone was then reduced by 5 mg every 2 weeks until reaching a 5-mg/day maintenance dosage. Intravenous infusion of hUC-MSCs was applied three times in a 6-week period for each patient. The overall symptoms of the hUC-MSC-treated patients improved compared to patients in the control group. Both the EDSS scores and relapse occurrence were significantly lower than those of the control patients. Inflammatory cytokines were assessed, and the data demonstrated a shift from Th1 to Th2 immunity in hUC-MSC-treated patients. Our data demonstrated a high potential for hUC-MSC treatment of MS. This manuscript is published as part of the International Association of Neurorestoratology (IANR) special issue of Cell Transplantation.

Objective: To explore the relationship between multi-differentiation potential of monoclonal immortalized human mesenchymal stem cells (hMSC-TERT) in vivo and their cluster of differentiation antigens (CD)., Methods: Monoclonal hMSC-TERT were isolated using limiting dilution. Direct immunofluorescence staining flow cytometry was used to detect the cluster of differentiation antigens (CD44, CD45, CD105) of these cell lines. Their adipocytic, osteogenic, neuronal differentiation potential in vitro were determined by Oil Red O staining, Von Kossa staining and immunocytochemistry for tubulin-β III antibody. Then hMSC-TERTs were transplanted subcutaneously into severe combined immunodeficiency (SCID) mice. The cell grafts were removed and analyzed by immunohistochemistry for pathologic tissue markers for multi-differentiation potential of hMSC-TERT cells in vivo., Results: CD105+ cell was 84.68% positive in hMSC-TERT-C19 while <5% in other monoclonal cell lines. The positive rate of cytokeratin in grafts formed by hMSC-TERT-C19 cell line in SCID mice was much higher than the others (P < 0.01)., Conclusion: The positive CD105 of monoclonal hMSC-TERTs may be directly correlated with its epithelial differentiation potential.

Objective: To explore the role of c-Myc in mesenchymal stromal cell-mediated drug resistance and elucidate the molecular mechanism of acute myeloid leukemia (AML) from the version of tumor microenvironment., Methods: AML cell lines U937 and KG1a were co-cultured with mesenchymal stromal cells (MSC) from bone marrow of healthy donors between January to March 2012. The AML cell lines plated alone was cultured as controls. Apoptosis induced by mitoxantrone was measured by flow cytometry and Annexin V/PI double and 4'-6-diamidino-2-phenylindole (DAPI) staining. And c-Myc protein was detected by Western blot under both culturing conditions. After a pre-treatment of c-Myc inhibitor 10058-F4, the apoptosis of AML cell was also evaluated., Results: Apoptosis of AML cells (U937 and KG1a) significantly decreased during co-culturing with MSC (9.88% ± 1.53% vs 42.83% ± 2.03%, P = 0.004;20.60% ± 2.87% vs 42.53% ± 5.29%, P = 0.030). Drug resistance was implicated. The co-culturing of AML cells with MSC significantly induced an up-regulation of c-Myc. The inhibition of c-Myc with 10058-F4 could induce apoptosis of AML cells. After an addition of 10058-F4 into the co-culture system, the apoptotic rate of KG1a cells significantly increased from 23.87% ± 1.55% to 57.23% ± 3.88% (P = 0.009). Similarly the apoptotic rates spiked from 16.07% ± 2.11% to 53.47% ± 4.08% in U937 cells (P = 0.004) to overcome the stromal cell-mediated drug resistance., Conclusions: The co-culturing of AML cells and MSC induces an up-regulation of c-Myc protein so as to cause the emergence of chemoresistance. Therefore targeting c-Myc protein may provide a novel therapeutic strategy of AML.

Aim of this study was to explore the effects of cryopreservation on biological characteristics of wharton's jelly derived mesenchymal stem cells (WJ-MSC), and to provide experimental evidence for clinical applications and the establishment of WJ-MSC bank. Primary WJ-MSC were produced by umbilical cord tissue culture in vitro. Fifth passage of WJ-MSC acquired by continuous cell culture were mixed with cryoprotectants, frozen in -80°C refrigerator and stored in liquid nitrogen. After the cryopreserved WJ-MSC were thawed, the first passage of WJ-MSC was obtained through cell culture and was taken as the 1st preserved passage (PP1). Thus, PP2-PP15 WJ-MSC were obtained by continuous cell subculture. The 1st control passage (CP1) to 15th passage (CP15) represented the 6th passage to 21st passage WJ-MSC acquired by subculturing in non-cryopreserved group. The biological characteristics of WJ-MSC from cryopreserved and control group, including the recovery rate of nucleated cells, trypan blue exclusion, CCK-8 activity, cell apoptosis, cell adherence, proliferation index, cell surface antigen, cell cycle and the capacities of induced differentiation into adipocyte, osteoblast and neuron, were detected and compared. The results indicated that the recovery rate of nucleated cells of cryopreserved WJ-MSC was 98.2%, trypan blue exclusion rate was 94.3%, CCK-8 activity was 91.4%, apoptotic rate was 3.9%, and the adherence rate was 92.6%. There was a statistically significant difference in proliferation index between PP1 and CP1 (P < 0.05), but there were no statistically significant differences between PP2-PP15 and their corresponding controls. The subculture cells highly expressed CD29, CD44, CD71, CD73, CD90, CD105, CD166 and HLA-ABC, and lowly expressed CD34, CD45 and HLA-DR. The expressions of above-mentioned surface antigens were not different statistically between two groups. The proliferation latency and logarithm proliferation of the subculture cells between two groups were also not different. After induced differentiation into adipocyte, osteoblast and neuron, the staining with oil red O, alkaline phosphatase and neuron-specific enolase was performed respectively, and the positive degrees were not clearly different macroscopically between two groups. Relatively high levels of triglyceride, alkaline phosphatase, and neuron-specific enolase in relevant cells could be detected, but had no significant differences between two groups. It is concluded that some WJ-MSC (< 10%) are damaged after cryopreservation, and the biological characteristics of WJ-MSC in cryopreservation group keep constant, as compared with that in non-cryopreservation group.

Objective: To evaluate long-term cryopreserved human bone marrow cells (BMCs) as a source of functional mesenchymal stem cells (MSCs)., Methods: Samples of human BMCs that were cryopreserved for 23-25 years (n=20) were thawed to obtain an initial culture and a primary culture (P(0)) that was propagated through five passages (P(1)-P(5)) to obtain MSCs. Freshly collected human bone marrow samples (n=20) were used as controls for comparison of efficiency of recovery and growth characteristics of MSCs. P(3) cultures were tested for their capacity to differentiate into osteoblasts, adipocytes, and neuronal cells. Appropriate staining, immunohistochemical and biochemical methods were employed to ascertain cell type identities at different stages of culturing., Results: In the initial culture, the cell adherence rate of the cryopreserved cells was significantly lower than that of controls (19.7% vs. 38.2%, p<0.05) while the relative rate of recovery of MSCs was only 48.5±8.6% in P(0). At the end of P(3), fibroblast-like cells accounted for about 95% of cells in both cryopreserved and control groups (p>0.05). These cells were positive for essential MSC surface molecules (CD90, CD105, CD166, CD44, CD29, CD71, CD73) and negative for haematopoietic and endothelial cell markers (CD45, CD34, HLA-DR). The cell growth and cell cycle patterns were similar for both groups. MSCs at P(3) from both groups had similar capacities to differentiate in vitro into osteoblasts, adipocytes, and neuronal cells., Conclusion: Using the methods described here, long-term (23-25 years) cryopreserved human BMCs can be successfully cultivated to obtain MSCs that have good differentiation capabilities., (Copyright © 2012 Elsevier Inc. All rights reserved.)

This study was aimed to evaluate whether human mesenchymal stem cell (MSC) and the Stro-1 positive subgroup have inducing immune tolerance effect in mouse skin graft model. Human MSC were isolated and cultured from bone marrow-derived mononuclear cells of healthy adults, and Stro-1 positive cells were sorted out. Female C57BL/6 mice and female BALB/c mice were respectively used as donors and recipients in skin allogenic graft model. The recipients were divided randomly into 4 groups: (1) Stro-1(+) MSC group: 2×10(6) Stro-1(+) MSC were injected into the irradiated recipient mice before skin graft. (2) MSC group: 2×10(6) MSC were injected into the irradiated recipient mice before skin graft. (3) Irradiation control group: the recipient mice were just irradiated before skin allogenic graft. (4) Congenic control group: the irradiated BALB/c mice received the skin from the congenic mice. The survival time and pathologic changes of skin grafts were observed by macro- and microscopy with HE staining. The transforming growth factor β1 (TGF-β1) concentration in plasma of recipient mice was measured by ELISA before and after grafting. The results indicated that the survival time of skin grafts in the MSC group was (12.13 ± 3.34) d, which was not notably longer than the irradiation control group (11.38 ± 1.01) d. The survival time of skin grafts was significantly prolonged in the Stro-1(+) MSC group (30.68 ± 5.89) d, as compared with the irradiation control group and the MSC group, respectively; the pathologic examination of skin grafts showed a clear structure. After grafting, the TGF-β1 concentration in plasma of recipient mice was almost the same as before grafting in the irradiation control group and the congenic control group, but it significantly increased in the MSC group and the Stro-1(+) MSC group. It is concluded that the Stro-1(+) MSC induce greater immune tolerance than the unsorted MSC, and significantly prolong the survival time of skin grafts in vivo, while TGF-β1 does not contribute to the immune tolerance.

The objective of this study was to explore the effect of mesenchymal stem cells (MSC) on HL-60 proliferation and its molecular mechanism. HL-60 cells co-cultivated with MSC were used as experiment group, and the cells cultivated solely were taken as control group. HL-60 cells in the two groups were counted at different time. The time-quantity curve was drawn. The cell cycle and apoptosis ratio of HL-60 cells were compared between the two groups and expressions of Survivin and Bcl-2 protein were detected by flow cytometry. The results showed that HL-60 cells cultivated with MSC were obviously inhibited, especially on day 5 and 7 (P < 0.01). HL-60 cells were distributed on the phase of G(0)/G(1) [control group (47.0 ± 9.0)% vs experiment group (70.0 ± 16.0)%, P = 0.003], and apoptotic peak appeared. Both of Survivin and Bcl-2 protein expressions in HL-60 cells decreased [Bcl-2 protein in control group (63.0 ± 9.1)% vs experiment group (50.0 ± 14.1)%, P = 0.045; Survivin in control group (94.0 ± 9.3)% vs experiment group (77.0 ± 11.8)%, P = 0.006]. It is concluded that the MSC can inhibit HL-60 cell proliferation, and promote HL-60 cell apoptosis.

The aim of this study was to explore the effect of mesenchymal stem cell (MSC) conditioned medium (MSC-CM) on proliferation, migration and adhesion of human umbilical vein endothelial cell (CRL1730) and its mechanism. Isolation and purification of MSC were performed with the classic adhering method, the surface markers (CD29, CD90, CD45 and CD34) in MSC were detected by flow cytometry. MSC were treated and cultured for 3 d, the MSC-CM or MSC overexpressing stem cell-derived factor-1 (SDF-1) conditioned medium (Ad-SDF-1-MSC-CM) were collected. Subsequently, CRL1730 cells were treated respectively with 2% FBS-DMEM, 15% FBS-DMEM (control group), MSC-CM or Ad-SDF-1-MSC-CM for 24 h, the proliferation of CRL1730 cells was detected by MTT method. CRL1730 cell migration in vitro was performed by using wound healing system. The adhesion ability of CRL1730 cells was analyzed by microscope. The results indicated that the CRL1730 cells treated with Ad-SDF-1-MSC-CM showed greater proliferative capacity than CRL1730 cells treated with MSC-CM. While adding with AMD3100 5 µmol/L, the blocker of CXCR4, the CRL1730 proliferation mediated by Ad-SDF-1-MSC-CM was significantly reduced. Meanwhile, compared with MSC-CM, Ad-SDF-1-MSC-CM had greater effects for promoting CRL1730 migration and enhancing adhesion ability of CRL1730 cells, these effects were significantly inhibited by AMD3100. It is concluded that MSC-CM promotes the migration and adhesion ability of CRL1730 cells through SDF-1 expressed by MSC.

Objective: Poor survival of mesenchymal stem cells (MSC) compromised the efficacy of stem cell therapy for ischemic diseases. The aim of this study is to investigate the role of PEP-1-CAT transduction in MSC survival and its effect on ischemia-induced angiogenesis., Methods: MSC apoptosis was evaluated by DAPI staining and quantified by Annexin V and PI double staining and Flow Cytometry. Malondialdehyde (MDA) content, lactate dehydrogenase (LDH) release, and Superoxide Dismutase (SOD) activities were simultaneously measured. MSC mitochondrial membrane potential was analyzed with JC-1 staining. MSC survival in rat muscles with gender-mismatched transplantation of the MSC after lower limb ischemia was assessed by detecting SRY expression. MSC apoptosis in ischemic area was determined by TUNEL assay. The effect of PEP-1-CAT-transduced MSC on angiogenesis in vivo was determined in the lower limb ischemia model., Results: PEP-1-CAT transduction decreased MSC apoptosis rate while down-regulating MDA content and blocking LDH release as compared to the treatment with H(2)O(2) or CAT. However, SOD activity was up-regulated in PEP-1-CAT-transduced cells. Consistent with its effect on MSC apoptosis, PEP-1-CAT restored H(2)O(2)-attenuated mitochondrial membrane potential. Mechanistically, PEP-1-CAT blocked H(2)O(2)-induced down-regulation of PI3K/Akt activity, an essential signaling pathway regulating MSC apoptosis. In vivo, the viability of MSC implanted into ischemic area in lower limb ischemia rat model was increased by four-fold when transduced with PEP-1-CAT. Importantly, PEP-1-CAT-transduced MSC significantly enhanced ischemia-induced angiogenesis by up-regulating VEGF expression., Conclusions: PEP-1-CAT-transduction was able to increase MSC viability by regulating PI3K/Akt activity, which stimulated ischemia-induced angiogenesis.

Objective: To observe the effect of vascular endothelial growth factor (VEGF) on bone marrow-derived mesenchymal stem cell (MSC) proliferation and explore the signaling mechanism involved., Methods: MSC culture was performed following the classical whole bone marrow adhering method. The characteristics of MSC were identified by induction of multi-lineage differentiation and flow cytometry for surface marker analysis (CD34, CD45, CD29, and CD90). Following the addition of 50 nmol/L wortmannin, 50 µmol/L PD98059, 30 µmol/L SB203580, 10 µmol/L H89, 20 µmol/L Y27632, 1 µmol/L rapamycin, 10 µmol/L straurosporine, 6 nmol/L Go6976, or 50 µmol/L Pseudo Z inhibitors in the cell culture, the MSC were treated with 20 ng/ml VEGF and the changes of the cell proliferation rate was measured with MTT assay., Results: Cultured MSC were capable of multi-linage differentiation and did not express VEGF-R, CD29 or CD90. Treatment with 20 ng/ml VEGF obviously promoted MSC proliferation, and this effect was inhibited partially by p38 mitogen-activated protein kinase (MAPK) inhibitor rapamycin, PD98059, SB203580, Go6976, and straurosporine., Conclusions: VEGF promotes MSC proliferation in close relation to the AKT-PKC pathway, in which PKC signal pathway may play the central role.

Aims: The objective of this study was to investigate whether vascular endothelial growth factor (VEGF) secreted by mesenchymal stem cells (MSC) improves myocardial survival and the engraftment of implanted MSC in infarcted hearts and promotes recruitment of stem cells through paracrine release of myocardial stromal cell-derived factor-1α (SDF-1α)., Methods and Results: VEGF-expressing MSC ((VEGF)MSC)-conditioned medium enhanced SDF-1α expression in heart slices and H9C2 cardiomyoblast cells via VEGF and the vascular endothelial growth factor receptor (VEGFR). The (VEGF)MSC-conditioned medium markedly promoted cardiac stem cell (CSC) migration at least in part via the SDF-1α/CXCR4 pathway and involved binding to VEGFR-1 and VEGFR-3. In vivo, (VEGF)MSC-stimulated SDF-1α expression in infarcted hearts resulted in massive mobilization and homing of bone marrow stem cells and CSC. Moreover, VEGF-induced SDF-1α guided the exogenously introduced CSC in the atrioventricular groove to migrate to the infarcted area, leading to a reduction in infarct size. Functional studies showed that (VEGF)MSC transplantation stimulated extensive angiomyogenesis in infarcted hearts as indicated by the expression of cardiac troponin T, CD31, and von Willebrand factor and improved the left ventricular performance, whereas blockade of SDF-1α or its receptor by RNAi or antagonist significantly diminished the beneficial effects of (VEGF)MSC., Conclusion: Exogenously expressed VEGF promotes myocardial repair at least in part through SDF-1α/CXCR4-mediated recruitment of CSC.

Objective: To investigate the multi-differentiation potential and VEGF secretory volume of monoclonal immortalized human mesenchymal stem cells (hMSC-TERT) and to determine the relationship between them., Methods: Monoclonal hMSC-TERT were isolated using limiting dilution. The growth curves of them were detected by method of MTT. ELISA was used to detect the concentration of VEGF in the supernatant of those monoclonal hMSC-TERT. Their adipocytic, osteogenic, neuronal differentiation potential in vitro were determined by Oil Red O staining, Von Kossa staining and immunocytochemistry for Tubulin-βIII antibody. Those Monoclonal hMSC-TERT were transplanted into the subcutaneously of severe combined immunodeficiency (SCID) mice. The grafts of those cells were removed and analyzed by immunohistochemistry for pathologic tissue markers to discover the multi-differentiation potential of those monoclonal hMSC-TERT in vivo., Results: There was statistically significant difference between different monoclonal hMSC-TERT in mult differentiation potential and the decreased concentration of VEGF in the supernatant of those monoclonal hMSC-TERT from the 3(rd) day to the 5(th) day. The positive rates of CK in grafts formed by those monoclonal hMSC-TERT in SCID mice were direct correlation with the decreased concentration of VEGF in the supernatant of those cells., Conclusion: The secretory capability of VEGF of those monoclonal hMSC-TERT may direct correlation with the epithelial differentiation potential of those cells.

Objective: To investigate the effect of ecdysterone on the proliferation of human umbilical cord mesenchymal stem cells (hUCMSCs) in vitro., Methods: hUCMSCs isolated by enzyme digestion from human umbilical cord tissues were cultured and identified for the surface antigens using fluorescence-activated cell sorting (FACS). The cells were treated with ecdysterone at the concentrations of 0, 25, 50, 100, 150, and 200 µg/ml, and the changes in the cell proliferation were detected using MTT assay., Results: The third-passage hUCMSCs were positive for CD29 and CD105 and negative for CD34 and CD45 as shown by flow cytometry. Treatment with ecdysterone resulted in significantly increased cell proliferation as compared to the control cells (P<0.05), but no significant differences were found in cells treated with 100, 150, and 200 µg/ml ecdysterone (P>0.05). The growth curves of the cells also demonstrated the definite effect of ecdysterone in promoting the proliferation of hUCMSCs., Conclusion: Ecdysterone can promote the proliferation of hUCMSCs in vitro with the optimal concentration of 100 µg/ml, suggesting its potential value in the enrichment of mesenchymal stem cells.

Objective: In order to investigate whether or not thrombopoietin (TPO) could promote the fibrogenesis of bone marrow stromal cells in absence of megakaryocytes (MKs)., Methods: Improved dexter culture system with various TPO concentrations was used for ex vivo culture of bone marrow stromal cells. Relative proliferation index, the expressions of fibronectin, laminin and type IV collagen, and the systhesis of type III procollagen were detected at different time points during culture process., Results: TPO stimulated the proliferation of bone marrow stromal cells. Relative proliferation index of the stromal cells increased with the TPO concentration increasing, and was not related to the exposure time. The expressions of fibronectin, laminin, and type IV collagen appeared stronger in the TPO groups than those in the control group. But the expressions of these molecules were not dependent upon the culture time. TPO could accelerate the synthesis of type III procollagen in bone marrow stromal cells, and this acceleration was unrelated to the TPO concentration., Conclusion: These findings suggested that TPO could stimulate the stromal cells with a consequence of increased syntheses and secretions of the extracellular matrix and collagen in absence of MKs. In other words, TPO could promote the fibrogenesis of bone marrow stromal cells without the existence of MKs.

Objective: To study the immunomodulatory effects and mechanisms of mesenchymal stem cells (MSC) derived from the bone marrow in acute leukemia patients in vitro., Methods: Bone marrow mononuclear cells from acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) were obtained and cultured in low serum medium. The immunophenotypes were assessed by FACS and immunol histochemistry. The levels of cytokines were evaluated by enzyme linked immunosorbant assay (ELISA). T-cell suppression ability was evaluated by Transwell chamber assay. Moreover, the immunoregulatory ability of AML- and ALL-derived MSC was detected by mixed lymphocyte culture assay., Results: ALL-derived MSC showed a typical fibroblast-like morphology. They were positive for CD29, CD44 and CD105, the positive rate were 98.81%, 99.25% and 90.52%, respectively, while negative for CD31, CD45 and CD34. Moreover, ALL- and AML-derived MSC didn't express HLA-DR and co-stirnulatory molecules (CD40, CD80 and CD86). ALL and AML derived MSC could secret several cytokines, such as TGF-β1 (567.58 ± 52.64 and 357.15 ± 33.52), HGF (647.27 ± 102.54 and 219.67 ± 62.37), IL-6 (59.67 ± 15.69 and 54.35 ± 12.31) and IL-11 (102.58 ± 23.54 and 78.21 ± 9.67), the level of secretion of TGF-β1 and HGF were higher in ALL bone marrow derived MSC than that of in AML bone marrow derived MSC. ALL and AML derived MSC significantly suppressed T lymphocyte proliferation in a dose-dependent manner, the counts per minute (CPM) were (3.58 ± 0.54) × 10(4), (2.87 ± 0.33) × 10(4), (1.78 ± 0.51) × 10(4) and (1.15 ± 0.15) × 10(4) for AML derived MSC, and CPM were (1.96 ± 0.31) × 10(4), (1.57 ± 0.28) × 10(4), (0.91 ± 0.41) × 10(4) and (0.22 ± 0.11) × 10(4) for ALL derived MSC when MSC were 0.5 × 10(4), 1 × 10(4), 2 × 10(4) and 5 × 10(4). In addition, the CPM was (4.01 ± 0.72) × 10(4) in control group. The immunosuppressive ability was different between MSCs derived from AML and ALL. The immunosuppressive effect of ALL derived MSC could be reversed by anti-TGF-β1 and anti-HGF antibody., Conclusion: ALL-derived MSC show immunoregulatory effect in vitro and this effect is achieved through cytokines. But MSCs derived from AML display abnormal changes in T-cell suppression ability.

In order to explore the effect of VEGF on mesenchymal stem cell (MSC) proliferation and its possible signal transduction mechanism, MSC culture was performed with the classical bone marrow adhering method; characteristics of passage 3 rat MSC (P3MSC) was identified through multi-differentiation and surface marker assay (CD34, CD45, CD90, CD29); P3MSC were treated with 20 ng/ml VEGF, and the effect of VEGF on the MSC proliferation was measured during 12, 36 and 72 hours by MTT assay. Subsequently, P3MSC were treated with extracellular-signal regulated kinase (ERK1/2) inhibitor PD98059 (50 µmol/L) or p38 mitogen-activated protein kinase (p38MAPK) inhibitor SB203580 (30 µmol/L) for 30 minutes, the culture medium was replaced with new medium including 20 ng/ml VEGF. After 72 hours, the effect of PD98059 or SB203580 on MSC proliferation mediated by VEGF was measured by MTT assay. The result showed that the cultured MSC expressed PDGFR-α, PDGFR-β and NRP1, but did not express VEGF-R (Flk1 and Flt1). The MSC had the multi-differentiation ability and displayed the characteristics of CD90+ (96.7%), CD29+ (94.6%), CD34- (0.79%) and CD45- (0.84%). The MSC proliferation rate increased gradually with prolonging of the functioning time of 20 ng/ml VEGF, and MSC proliferation rate may reach to maximum value after treating with 20 ng/ml VEGF for 72 hours. The effect of VEGF on MSC proliferation was found to be abolished, even was under level of control group after treating with PD98059 or SB203580 for 30 minutes. Furthermore, the inhibitory effect of PD98059 on MSC proliferation was obviously higher than that of SB203580. It is concluded that the VEGF can promote MSC proliferation, and its possible mechanism may relate to ERK1/2 pathway.

Objective: To investigate the effect of ecdysterone (EDS) on the proliferation of human bone marrow mesenchymal stem cells (hMSCs) in vitro., Methods: hMSCs were isolated from human bone marrow cell suspension by density gradient centrifugation. The expression of integrins CD44, CD105, CD34 and CD29 were examined by immunocytochemical method. EDS at 10, 25, 50 or 100 microg/ml were added in hMSC culture system, using the routine culture medium for hMSCs as control. The cell viability were analyzed by MTT assay and the cell cycle changes were examined by flow cytometry., Results: The optical density (OD) differed significant between the EDS treatment groups and the control group (P<0.01), and 25 microg/ml EDS group showed the highest OD value (P<0.01) without significant differences among 10, 50 and 100 microg/ml EDS groups (P>0.05). Flow cytometry showed that treatment of the cells with 25 microg/ml EDS significantly increased the cell percentages in S and G(2)M phases and the proliferation index (PI) of the cells as compared with the control group., Conclusion: Within a given concentration range, EDS can promote the proliferation of hMSCs in vitro, and this effect can be the most obvious at the concentration of 25 microg/ml. The effect of EDS in promoting the proliferation of hMSCs does not positively correlate to EDS concentration administered.

This study was aimed to compare the influences of bone marrow mesenchymal stem cells (BMMSCs) from patients with acute myeloid leukemia (AML), AML patients with complete remission (CR) and non-leukemia patients on HL-60 cells. The HL-60 cells were divided into three groups: group of co-cultivation with BMMSCs of AML patients, group of co-cultivation with BMMSCs of AML patients with CR and group of co-cultivation with BMMSCs of non-leukemia patients. The count of HL-60 cells, the CD11b and survivin expression of HL-60 cells, the cell cycle distribution of the HL-60 cells in 3 groups were compared by flow cytometry, the morphology and differentiation rate of HL-60 cells in 3 groups were observed and compared by microscopy. The results showed that there were no differences in HL-60 cell count at five and seven days, in HL-60 distribution at the G(0)/G(1) phase, in survivin and CD 11b expressions in 3 groups. All cells of 3 groups began to mature, and the differentiation rates in 3 groups were 18.0 +/- 3, 17.0 +/- 1.3 and 19.0 +/- 2.0 respectively, therefore there were no significant differences between the 3 groups (p = 0.23). It is concluded that there is no influence of BMMSCs in 3 groups on the proliferation and differentiation of HL-60 cells.

This study was aimed to compare partial biological characteristics of bone marrow mesenchymal stem cells (BMMSCs) in AML patients, AML patients with complete remission (CR) and non-leukemia patients. The bone marrow (BM) MSCs were divided into 3 groups: group of MSCs from AML patients, group of MSCs from AML patients with CR, group of MSCs from non-leukemia patients. The morphologic features of MSCs were observed by light microscopy; CFU-F numbers of MSCs were counted after Wright-Giemsa staining in situ; the fusion times of MSCs were determined; the growth curves of MSCs were drawn by counting cell numbers; the immunophenotypes and cell cycle of MSCs were detected by flow cytometry; the DI values of MSCs were calculated. The results showed that the morphologic features of MSCs in 3 groups did not display difference; there was significant difference (p < 0.01) of CFU-F numbers in 3 groups, while CFU-F number of MSCs in AML group was minimal; there was significant difference of MSC fusion time in 3 groups, while fusion time of MSCs in AML group was most long; the growth curves of MSCs in 3 groups were similar; MSCs in 3 groups highly expressed CD105 and CD106, but not expressed CD45; the cell distribution ratios at phase of G(0)/G(1) for MSCs in 3 groups were 89.9 +/- 4.0%, 90.2 +/- 3.0% and 91.0 +/- 3.0% respectively; the DI values of MSCs in 3 groups were between 0.9 and 1.1. It is concluded that no significant difference of biological characteristics of the second generations of MSCs is found between those in leukemia and non-leukemia patients.

The aim of this study was to explore the difference of MSC migration mediated by SDF-1/CXCR4 axis through Boyden chamber in vitro migration assay. The SDF-1 density-dependence of MSC migration was observed. Subsequently, the effects of different blocking agents on hSDF-MSC migration were observed after MSC were treated with 50 nmol/L wortmannin, 10 micromol/L LY294002, 50 micromol/L PD98059, 10 micromol/L U73122, 126 micromol/L AMD3100 and 50 nmol/L verapamil respectively. The results showed the efficiency of MSC migration increased gradually with the increasing of hSDF-1 density. And after MSCs treatment with 50 nmol/L wortmannin, 10 micromol/L LY294002, 50 micromol/L PD98059, 10 micromol/L U73122 and 126 micromol/L AMD3100 respectively, the ability of MSC migration decreased. The ability of MSCs migration obviously decreased when MSCs were treated with U73122, AMD3100. It is concluded that the SDF-1/CXCR4-mediated MSC migration may be related to mitogen-activated protein kinase (MAPK), phosphatidylinositol phospholipase C (PI-PLC) and protein kinase (PKC) signal pathways.

The myelodysplastic syndromes (MDS) include a diverse groups of clonal and potentially malignant bone marrow disorders. Evidences exist that microenvironment cells from MDS marrow show functional abnormalities, which may be relevant to the incidence of such a disease. Mesenchymal stem cells (MSCs) are a very important component of hematopoietic microenvironment. This study was supposed to investigate the biological characteristics and functions of MSC derived from patients with MDS in low-risk. MSCs from bone marrow samples of 11 low-risk MDS patients were isolated, cultured and expanded. Morphology, immunophenotype and osteoblasts differentiation were analyzed. Their capacity of proliferation and hematopoietic supporting in vitro were measured. A real-time quantitative reverse transcriptase polymerase chain reaction method (RQ RT-PCR) was used for detecting the expression levels of relative cytokines and chemokines in MSC. MSCs from healthy donors were used as controls. The results showed that the culture-expanded cells from MDS patients displayed a typical fibroblast-like morphology. Cells were positive for SH2 (CD105), SH3 (CD73), Thy-1 (CD90), while negative for CD34 and CD45. After induction, these cells could differentiate into osteoblasts. The proliferative ability of MSCs in MDS patients were not different from those of MSC isolated from normal bone marrow (p > 0.05), however, their capacity of hematopoietic supporting in vitro were significantly weaker (p < 0.05). RQ RT-PCR detection indicated that the SDF-1 gene expression level in MSCs of low-risk MDS patients was significantly higher than that in MSC derived from healthy donors (p < 0.01). It is concluded that the abnormal function of MSC influences the regulation of hemotopoiesis in the bone marrow microenvironment of MDS patients. It is worthy to further investigate the new clue in etiological mechanism and therapeutic strategies for MDS.

Objective: 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., Methods: Rat bone marrow-derived MSCs were infected with 100 ml recombinant adenovirus containing human SDF-1alpha gene (Ad-hSDF-1alpha), and the cell migration changes were observed at 1, 2, and 3 days after the infection. Twelve hours after Ad-hSDF-1alpha transfection, the MSCs in separate cultures were treated with wortmannin (50 nmol/L), LY294002 (10 mmol/L), PD98059 (50 mmol/L), U73122 (10 mmol/L), AMD3100 (0.1 g/L), or verapamil (50 nmol/L), respectively, and the signal transduction pathways involved in MSC migration were analyzed., Results: The MSCs grew in colonies after transfection with Ad-hSDF-1alpha, but this growth pattern was substantially attenuated after treatment with wortmannin, LY294002, PD98059, U73122, AMD3100 and verapamil, among which U73122 and AMD3100 treatments resulted in the most conspicuous inhibitory effects., Conclusion: The effect of SDF-1 in promoting MSC migration is related to mitogen-activated protein kinase, phosphatidylinositol phospholipase C, and protein kinase signal pathways.

This study was aimed to evaluate whether mesenchymal stem cells (MSCs) obtained from patients with myelodysplastic syndrome possess immunosuppressive effect. MSCs from bone marrow samples of MDS patients were isolated, cultured and expanded. MSCs were morphologically analyzed and their immunophenotype were determined by flow cytometry. Various amounts of MSCs were added into one-way mixed lymphocyte reaction. MSCs from MDS patients were tested for their ability to suppress in vitro proliferation of autologous and allogeneic peripheral blood lymphocytes (PBLs). The results showed that 3 x 10(3 - 1) x 10(5) MSCs from MDS patients could inhibit autologuous PBLs proliferation to (66.9 +/- 20.1)% - (30.2 +/- 5.9)% of maximal response, as well as inhibit allogeneic PBLs proliferation to (56.6 +/- 14.7)% - (20.5% +/- 9.7)% of maximal response, as compared with inhibitory ability of MSCs from healthy donors, there was no significant difference (P>0.05). It is concluded MSCs from patients with myelodysplastic syndrome also possess immunosuppressive activity.

Objective: To investigate the expression of human leukocyte antigens (HLA) in human fetal bone marrow mesenchymal stem cells (MSCs) after long time culture as well as the changes in response to interferon-gamma (IFN-gamma) treatment., Methods: Human fetal MSCs were collected from 23 to 24-weeks-old fetues with the approval of Ethic Committee of Peking University Health Science Center. The cells of passage 5 and passage 12 were analyzed for HLA expression before and after IFN-gamma (50 microg/L) treatment by flow cytometry at different time points. The passage 5 cells were also treated with an additional dose of IFN-gamma (5 microg/L) and the HLA expression was analyzed 24, 48, 72, 96 and 120 h after treatment. RT-PCR was used to evaluate HLA-G and HLA-E expression at mRNA level in human fetal MSCs., Results: Flow cytometry results showed that fetal MSCs expressed high level of HLA class I (HLA-I) antigen, but extremely low level of HLA class II (HLA-II) antigen. The percentage of HLA-I positive MSCs in total MSCs was approximately over 50%, while that of HLA-II positive MSCs in total MSCs was less than 10%. IFN-gamma (50 microg/L) enhanced the HLA-I and HLA-II expression in a time dependent manner and increased the percentage of HLA-I positive cells in both passage 5 and passage 12 cells but preferably in passage 5 cells. The enhanced HLA-II expression was seen 48 h after IFN-gamma treatment in passage 5 cells (59.9%) but 72 h in passage 12 cells (48.1%). The treatment of 5 microg/L IFN-gamma also increased percentage of HLA-I and HLA-II positive MSCs, but with a relatively less extent compared to the 50microg/L IFN-gamma treatment group. RT-PCR result indicated HLA-G and HLA-E were expressed at mRNA level in human fetal MSCs., Conclusion: Human fetal MSCs can be induced to express both HLA class I and class II antigens by IFN-gamma. The long time culture might reduce the IFN-gamma effects. Human fetal MSCs express HLA-G and HLA-E at mRNA level.

Objective: To explore a new method for in vitro expansion of human mesenchymal stem cells (MSC) by using platelet-rich plasma (PRP) in place of fetal calf serum (FCS)., Methods: Bone marrow(BM) samples were obtained from the proximal femurs of patients with normal haematopoietic function undergoing total hip arthroplasty. 2 x 10(5)/cm2 BM nucleated cells were seeded in 25 cm2 flasks for MSC cultivation containing one of the 3 mediums: complete Dexter medium with 12.5% FBS and 12.5% horse serum (medium1), alpha-MEM with 10% FCS (medium2) and alpha-MEM with 5% PRP(medium3). At the same time, 1 x 10(6) nucleated BM cells and same amount of nucleated cells from iliac aspirate were seeded in 25 cm2 tissue flasks, colony forming unit-fibroblast (CFU-F) assay., Results: Culture-expanded cells from proximal femurs presented a typical fibroblast-like morphology. Cells were positive for SH2 (CD 105), SH3 (CD73), Thy-1 (CD90), while negative for CD34 and CD45. On induction, these cells could differentiate into osteoblasts. A significantly higher proliferative capacity of MSCs expanded in medium3 was observed in comparison to those in mediuml or 2 without alteration of the phenotype and the differentiation property. CFU-F assays indicated that bone marrow from the proximal femoral contained significantly more CFU-F than that from iliac aspirate., Conclusion: Platelet-rich plasma can be used in place of FCS to provide a safer and more effective culture condition to expand MSCs for clinical purpose. The proximal femur BM cells can be obtained in hip surgeries.

This study was aimed to investigate the expression level of stromal cell derived factor-1 gene (SDF-1) in bone marrow mesenchymal stem cells (MSC) of patients with myelodysplastic syndrome (MDS). The MSC from bone marrow samples of MDS patients were isolated, cultured and expanded, the morphology and immunophenotype of MSC were analyzed. The expression levels of SDF-1 and internal reference GAPDH in MSC of MDS patients were detected by real-time quantitative reverse transcriptase polymerase chain reaction (RQ-RT-PCR) method and were compared with expression levels of healthy donors. The results showed that the expression levels of SDF-1 in MDS patients were significantly different from those in healthy donors (1.53 +/- 0.92 vs 5.51 +/- 0.99) (P < 0.01). SDF-1 gene expression levels in bone marrow MSC of MDS patients were significantly higher than that in MSC derived from healthy donors. It is concluded that the abnormal expression of SDF-1 gene in MSC may influence the regulation of hematopoiesis of the bone marrow microenvironment in MDS patients and it is worthy of further investigation for new clue on etiological mechanism and treatment of MDS.

Objective: To evaluate whether mesenchymal stem cells (MSCs) obtained from human proximal femurs possess immunosuppressive effect so as to look for ideal bank of MSCs for clinical prophylaxis and treatment of graft versus host disease (GVHD)., Methods: Human marrows were collected from the proximal femurs of patients undergoing hip replacement to isolate MSCs. The puncture materials obtained from the iliac bone marrow of 12 healthy donors were used as controls. Peripheral blood lymphocytes (PBLs) were obtained from the peripheral blood of healthy persons. 1 x 10(5) PBLs were mixed with allogeneic PBLs radiated by 60 cobalt and put into the wells of a 96-well plate. MSCs of the concentrations of 1 x 10(5), 3 x 10(4), 1 x 10(4), and 3 x 10(3), were added into the culture fluid of the mixed PBLs to be co-cultivated for 5 days. 1 microCi/well [(3)H] TdR was added in the last 18 hours. The cells were collected and the counts per minute (cpm) was detected. 3 x 10(4) and 1 x 10(4) MSCs were put into the wells. When the MSCs adhered to the wall, a membrane with micropores was inserted value of 1 x 10(5) PBLs and radiated allo-PBLs were put onto the top of which. Five days after cultivation 1 microCi/well [(3)H] TdR was added and the cpm was tested. MSCs were cultured in RPMI-1640 culture fluid and then contacted MLR constructed by 1 x 10(5) PBLs and 1 x 10(5) allo-PBL directly or via Transwell membrane with micropores. Five days after the supernatant was collected. ELISA was used to detect the content of TGF-beta(1). 0.1 microg/ml, 1 microg/ml, or 10 microg/ml anti-human TGF-beta1 antibody was added to the co-cultivation system. Five days after [(3)H] TdR was added so as to test the value cpm., Results: 3 x 10(3) - 1 x 10(5) MSCs from proximal femurs inhibited the PBLs proliferation to 62 +/- 18% - 28 +/- 12% of maximal response, however, not significantly different from that observed in MSCs collected from bone marrow of healthy donors via iliac crest aspiration (58 +/- 12% - 27 +/- 6%, P > 0.05). When these cells were separated physically from MLR system via a membrane with micropores 0.2 microm in diameter, 3 x 10(4) and 1 x 10(4) cells still markedly suppressed the PBLs proliferation to 36 +/- 8% and 53 +/- 13% of maximal response. ELISA showed that TGF-beta1 was measured in the supernatants of MSCs, MSCs + MLR and MSCs + MLR in Transwell system, without significant differences among these experimental conditions. Furthermore, the presence of increasing amounts of neutralizing anti- TGF-beta1 antibody did not reverse the inhibitory effect., Conclusion: MSCs obtained from the proximal femurs possess immunosuppressive activity. A soluble factor/factors was/were involved in such effect, however, TGF-beta1 was not a candidate.

To study the biological characteristics of mesenchymal stem cells (MSC) from patients with myelodysplastic syndrome (MDS) and their supportive capacity for hematopoiesis in vitro, MSCs from bone marrow samples of MDS patients were isolated, cultured and expanded. Morphology, immunophenotype, osteoblasts differentiative and proliferative property of MSC and colony forming unit-fibroblast (CFU-F) were measured and analyzed. Mononuclear cells (MNC) of cord blood were plated onto a feeder layer formed by MSC of MDS patient, cells count and CFU-GM production were observed. The results showed that the culture-expanded cells from MDS patients presented a typical fibroblast-like morphology. Cells were positive for SH2 (CD105), SH3 (CD73), Thy-1 (CD90), but negative for CD34 and CD45. After induction, these cells could differentiate into osteoblasts. Their proliferative capacity and CFU-F number were similar to those of MSC from healthy donors. The total cell count and CFU-GM yield in supernatants after culture for 2 weeks were significantly lower than those of control in hematopoiesis supportive experiments in vitro (P < 0.05). It is concluded that the biological characteristics of MSC from bone marrow of MDS patients are not different from those of MSC isolated from bone marrow of normal donors, however, their capacity of hematopoiesis support in vitro are significantly weaker.