[Comparison of the Biological Functions between Human Bone Marrow Derived CD106 +Mesenchymal Stem Cells and CD106 - Subgroup].

Objective To analyze the differences in biological functions between bone marrow(BM)-derived CD106 +mesenchymal stem cells(MSCs)and the CD106 - subgroup. Methods The MSCs from normal BM were isolated and expanded.The subgroups of CD106 + and CD106 -MSCs were sorted.The cell proliferation and adhesion functions,chemotactic activities,adipogenic and osteogenic potentials,senescence,and senescence protein 21(p21)were detected.The capacity of translocation into nucleus of nuclear factor-kappa B(NF-κB)when stimulated by tumor necrosis factor(TNF-α)was measured. Results The proliferative ability was higher in CD106 +MSCs than that in CD106 -MSCs.In 48 hours,the value of optical density(OD)was significantly higher in CD106 +MSCs than that in CD106 - subgroup(1.004±0.028 vs. 0.659±0.023,t=3.946,P=0.0225).In 72 hours,this phenomenon was even more pronounced(2.574±0.089 vs. 1.590±0.074,t=11.240,P=0.0000).The adhesive capacity of CD106 +MSCs was significantly stronger than that of CD106 - subgroup(0.648±0.018 vs. 0.418±0.023,t=7.869,P=0.0002).Besides,the metastasis ability of CD106 +MSCs were significantly stronger than that of CD106 - subgroup(114.500±4.481 vs.71.000±4.435,t=6.900,P=0.0005).The CD106 +MSCs had signifcnatly lower proportions of senescent cells.The expression of aging protein p21 in CD106 +MSCs was significantly lower than that in CD106 -MSCs [(17.560±1.421)% vs.(45.800±2.569)%,t=9.618,P=0.0000].Furthermore,there were no visible pigmenting cells after ß-galactosidase staining in CD106 +MSCs subgroup.However,in CD106 -MSCs,some colored green cells were detected.The rate of NF-κB translocation into nucleus after stimulated by TNF-α was significantly higher in CD106 +MSCs than CD106 - MSCs [(37.780±3.268)% vs.(7.30±1.25)%,t=8.713,P=0.0001]. Conclusion Bone marrow-derived CD106 +MSCs possess more powerful biological functions than CD106 -MSCs.

[Effect of CD106+ Mesenchymal Stem Cell on Bone Marrow Vascular Failure in Patients with Aplastic Anemia].

Objective To investigate the vascularization ability of mesenchymal stem cells(MSCs)and explore its influencing factors in aplastic anemia(AA) patients. Methods MSCs were isolated from the bone marrow of AA patients(AA MSCs) and normal controls(N MSCs) were cultured and then evaluated by flow cytometry and immunofluorescene staining technique.The expression level of vascular cell adhesion molecule-1(CD106) was detected by gene sequencing,and the content and fluorescene intensity of CD106+MSCs was determined by fluorescence-activated cell sorting.The content of CD105+CD106+MSCs in fresh AA bone marrow was measured,followed by the determination of the capability of endothelial differentiation from AA MSCs and N MSCs with immunofluorescene analysis;finally,the capability of CD31+cell differentiation from CD106-blocking N MSCs and its tubular structures formation in matrigel were tested.Results The expression of CD106 in AA patients was defective(decreased by 12.13 times when compared with N MSCs) and the concentration and fluorescene degree of CD106+MSCs was also decreased in AA patients [(28.03±17.71)% vs.(59.61±12.26)%,P=0.000].The content of CD105+CD106+MSCs decreased significantly in the fresh bone marrow [(0.33±0.10)% vs.(2.98±0.46)%,P=0.0005].Besides, the capability of CD31+cell differentiation from AA MSCs was significantly delayed [(13.67±1.50)% vs.(43.24±0.96)%,P=0.0004].Also,the capability of CD31+cell differentiation and tubular structures formation of CD106-blocking N MSCs was also obviously decreased [(26.00±2.65)% vs.(91.78±2.44)%,P=0.000;(13.81±1.98)mm vs.(68.12±6.78)mm,P=0.0015].Conclusion The deficient or decreased expression of CD106+MSCs accelerate the bone marrow vascularization failure in AA patients.

Comparisons of Different Models on Dynamic Recrystallization of Plate during Asymmetrical Shear Rolling.

Asymmetrical shear rolling with velocity asymmetry and geometry asymmetry is beneficial to enlarge deformation and refine grain size at the center of the thick plate compared to conventional symmetrical rolling. Dynamic recrystallization (DRX) plays a vital role in grain refinement during hot deformation. Finite element models (FEM) coupled with microstructure evolution models and cellular automata models (CA) are established to study the microstructure evolution of plate during asymmetrical shear rolling. The results show that a larger DRX fraction and a smaller average grain size can be obtained at the lower layer of the plate. The DRX fraction at the lower part increases with the ascending speed ratio, while that at upper part decreases. With the increase of the offset distance, the DRX fraction slightly decreases for the whole thickness of the plate. The differences in the DRX fraction and average grain size between the upper and lower surfaces increase with the ascending speed ratio; however, it varies little with the change of the speed ratio. Experiments are conducted and the CA models have a higher accuracy than FEM models as the grain morphology, DRX nuclei, and grain growth are taken into consideration in CA models, which are more similar to the actual DRX process during hot deformation.

Knockdown of IL-8 Provoked Premature Senescence of Placenta-Derived Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) have shown promise for use in cell therapy, and due to their tumor tropism can serve as vehicles for delivering therapeutic agents to tumor sites. Because interleukin-8 (IL-8) is known to mediate the protumor effect of MSCs, elimination of IL-8 secretion by MSCs may enhance their safety for use in cancer gene therapy. However, little is known concerning the effect of endogenously secreted IL-8 on MSCs. We performed studies using placenta-derived MSCs (PMSCs) to determine whether knockdown of IL-8 would influence their biological activity. We first verified that IL-8 and its membrane receptor CXCR2, but not CXCR1, were highly expressed in PMSCs. We then employed lentivirus-mediated small hairpin RNA interference to generate stable IL-8-silenced PMSCs, which displayed a variety of characteristic senescent phenotypes. We observed that at day 9 post-transfection, IL-8-silenced PMSCs had become larger and displayed a more flattened appearance when compared with their controls. Moreover, their proliferation, colony forming unit-fibroblast formation, adipogenic and osteogenic differentiation, and immunosuppressive potentials were significantly impaired. Enhanced senescence-associated ß-galactosidase (SA-ß-gal) activity and specific global gene expression profiles confirmed that IL-8 silencing evoked the senescence process in PMSCs. Increased levels of p-Akt and decreased levels of FOXO3a protein expression suggested that reactive oxygen species played a role in the initiation and maintenance of senescence in IL-8-silenced PMSCs. Notably, the majority of CXCR2 ligands were downregulated in presenescent IL-8-silenced PMSCs but upregulated in senescent cells, indicating an antagonistic pleiotropy of the IL-8/CXCR2 signaling pathway in PMSCs. This effect may promote the proliferation of young cells and accelerate senescence of old cells.

[Influence of MicroRNA-382 on Biological Properties of Human Umbilical Cord-Derived Mesenchymal Stem Cells].

OBJECTIVE: To investigate the effect of microRNA-382 (miR-382) on the biological properties of human umbilical cord-derived mesenchymal stem cells (hUC-MSC). METHODS: The mimics and inhibitor of miR-382 were transfected into hUC-MSC with lipo2000. Inverted microscopy was used to observe the morphology change of hUC-MSC. The proliferation of hUC-MSC was detected by CCK-8. Oil red O and alizarin red staining were applied to assess the adipogenic and osteogenic differentiation of hUC-MSC. Cetylpyridinium chloride was used to the quantitative analysis of osteogenic differentiation. The expression of Runx2 and some cytokines were detected by RT-PCR. RESULTS: miR-382 did not influence the morphology, proliferation and adipogenic differentiation of hUC-MSC miR-382 inhibited the expression of Runx2, thus could inhibit the osteogenesis of hUC-MSC, being confirmed by alizarin red stain; miR-382 could influence the expression of key cytokines secreted from hUC-MSC, such as IL-6, IDO1, G-CSF, M-CSF, GM-CSF. CONCLUSION: miR-382 decreases the expression of Runx2 and inhibites the osteogenesis of hUC-MSC. In addition, it also affects the expression of some key cytokines secreted from hUC-MSC.

[Human Umbilical Cord-derived Mesenchymal Stem Cells Secrete Interleukin-6 to Influence Differentiation of Leukemic Cells].

OBJECTIVE: To investigate the effect of human umbilical cord-derived mesenchymal stem cells (UC-MSC) on the differentiation of leukemic cells. METHODS: The co-culture system of UC-MSC with acute promyelocytic leukemic cell line NB4 cells was constructed in vitro,and the differentiation status of the leukemic cells was assessed by cell morphology,nitroblue tetrazolium reduction test,and cell surface differentiation marker CD11b. RESULTS: UC-MSC induced the granulocytic differentiation of NB4 cells. When UC-MSC and a small dose of all-trans retinoic acid were applied together,the differentiation-inducing effect was enhanced in an additive manner. Interleukin (IL)-6Ra neutralization attenuated differentiation and exogenous IL-6-induced differentiation of leukemic cells. CONCLUSION: UC-MSC can promotd granulocytic differentiation of acute promyelocytic leukemia cells by way of IL-6 and presented additive effect when combined with a small dose of all-trans retinoic acid.

Inhibition of Notch Signaling Promotes the Adipogenic Differentiation of Mesenchymal Stem Cells Through Autophagy Activation and PTEN-PI3K/AKT/mTOR Pathway.

BACKGROUND: The Notch signaling pathway is implicated in a broad range of developmental processes, including cell fate decisions. This study was designed to determine the role of Notch signaling in adipogenic differentiation of human bone marrow derived MSCs (BM-MSCs). METHODS: The Notch signaling was inhibited by the γ-secretase inhibitor N-[N-(3,5-difluor- ophenacetyl-L-alanyl)]-S-phenylglycine t-butylester (DAPT). The markers involving adipogenic differentiation of MSCs, the relative pathway PTEN-PI3K/Akt/mTOR and autophagy activation were then analyzed. Furthermore, the autophagy inhibitor chloroquine (CQ) and 3-methyladenine (3-MA) were used to study the role of autophagy in the DAPT-induced the adipogenic differentiation of MSCs. RESULTS: We first confirmed the down -regulation of Notch gene expression during MSCs adipocyte differentiation, and showed that the inhibition of Notch signaling significantly enhanced adipogenic differentiation of MSCs. Furthermore, Notch inhibitor DAPT induced early autophagy by acting on PTEN-PI3K/Akt/mTOR pathway. The autophagy inhibitor CQ and 3-MA dramatically abolished the effects of DAPT-induced autophagy and adipogenic differentiation of MSCs. CONCLUSION: Our results indicate that inhibition of Notch signaling could promote MSCs adipogenesis mediated by autophagy involving PTEN-PI3K/Akt/mTOR pathway. Notch signaling could be a novel target for regulating the adipogenic differentiation of MSCs.

[Biological characteristics of exosomes secreted by human bone marrow mesenchymal stem cells].

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.

[Effects of rapamycin on biological characteristics of bone marrow mesenchymal stem cells from patients with aplastic anemia].

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.

[Effect of 15-deoxy-Δ(12), 14-prostaglandin J2 on the cytokines in the culture supernatant of bone marrow mesenchymal stem cells].

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.

[Culture of pancreatic progenitor cells in hanging drop and on floating filter].

OBJECTIVE: To construct a method to culture pancreatic progenitor cells in hanging drop and on floating filter,and to examine if pancreatic progenitor cells can differentiate into mature endocrine cells with this method. METHODS: Murine embryos at day 12.5 were isolated and digested into single cells,which were then cultured in hanging drop for 24h and formed spheres.Spheres were cultured on the filter for 6 days,which floated in the dish containing medium.During culture,the expressions of pancreas duodenum homeobox-1(PDX-1)and neurogenin3(Ngn3)were determined.The expressions of endocrine and exocrine markers,insulin,glucagon,and carboxypeptidase(CPA)were determined on day 7 by immunohistochemistry.Insulin secretion of spheres stimulated by glucose was detected by ELISA.The changes of pancreatic marker expressions during culture were monitored by real-time polymerase chain reaction(PCR). RESULTS: One day after the culture,there were still a large amount of PDX-1 positive cells in pancreatic spheres,and these cells proliferated.On day 3,high expression of Ngn3 was detected,and the Ngn3-positive cells did not proliferate.On day 7,The expressions of endocrine and exocrine markers in the differentiated pancreatic progenitor cells were detected,which were consistent with that in vivo.Insulin was secreted by spheres upon the stimulation of glucose. CONCLUSION: In hanging drop and on floating filter,pancreatic progenitor cells can differentiate into mature endocrine cells.

[Human umbilical cord mesenchymal stem cells reduce the sensitivity of HL-60 cells to cytarabine].

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.

Establishment of a new method to induce the differentiation of embryonic pancreatic cells into mature endocrine cells.

OBJECTIVE: To establish a new culture method to induce the differentiation of embryonic pancreatic cells into mature endocrine cells. METHODS: Mouse embryos at day 12.5 were used and embryonic pancreata were isolated. The isolated embryonic pancreata were cultured on the filter for 7 days, which floated in the dish containing medium. During culture, the expression of pancreas duodenum homeobox-1 (PDX-1), a pancreatic stem cell marker, was examined at day 1. The expression of neurogenin 3 (Ngn3), a pancreatic progenitor cell marker, was examined at day 3. The expressions of endocrine and exocrine markers, insulin, glucagon, and carboxypeptidase (CPA) were examined at day 7 by immunohistochemistry. The kinetics of pancreatic marker expression during culture was assayed by real-time PCR. RESULTS: Many pancreatic stem cells still existed in embryonic pancreata cultured for 1 day; meanwhile, these pancreatic stem cells proliferated in high rate. A large amount of pancreatic progenitor cells were found in embryonic pancreata cultured for 3 days.Pancreatic stem/progenitor cells differentiated into mature endocrine and exocrine cells in embryonic pancreata after having been cultured for 7 days. Furthermore, the expression pattern of pancreatic marker is consistent with that in vivo. CONCLUSION: We successfully established a new culture method, with which embryonic pancreatic cells can efficiently differentiate into mature endocrine cell.

[Effects of interferon-γ on biological characteristics and immunomodulatory property of human umbilical cord-derived mesenchymal stem cells].

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.

CD72 gene expression in immune thrombocytopenia.

To explore the role of CD72 in the pathogenesis of immune thrombocytopenia (ITP), we detected CD72, Sema4D, IL-2, IL-4, and IFN-γ mRNA expressions and the levels of plasma Sema4D, IL-2, IL-4, IL-6, and IFN-γ in ITP patients (n = 39) and controls (n = 23). The levels of plasma IL-2, IL-4, and IL-6 were assayed by radioimmunoassay, and the levels of plasma IFN-γ and Sema4D were analyzed by enzyme-linked immunosorbent assay. Sema4D, CD72, IL-2, IFN-γ, and IL-4mRNA expressions were analyzed by real-time quantitative reverse-transcription polymerase chain reaction. The expression of CD72 mRNA in ITP patients (n = 23) with active disease was significantly lower than that in patients in remission (p = 0.029) (n = 16) and controls (p = 0.0296) (n = 23). The IFN-γ/IL-4 mRNA (Th1/Th2) expression in ITP patients with active disease and in remission was significantly higher than that in controls (p = 0.0023, p = 0.0125, respectively). The expression of IL-2 mRNA in ITP patients with active disease was significantly lower than that in patients in remission (p = 0.0418) and controls (p = 0.004). The level of plasma IL-2 in ITP patients with active disease was significantly lower than that in patients in remission (p = 0.0029) and controls (p = 0.0101). The levels of plasma IL-4 in ITP patients with active disease and in remission were significantly higher than that of controls (p = 0.0093, p = 0.0053, respectively). CD72 mRNA expression level might correlate with Sema4D mRNA expression in peripheral blood mononuclear cells and level of plasma IL-2 in active ITP patients (p = 0.024 and p = 0.036). Our findings suggest that CD72 might be involved in the pathophysiological process of the ITP disease by increasing B-cell receptor signals.

[Control effects of mowing in combining with planting tree species on Chromolaena odorata in karst region of Guangxi, China].

A field experiment was conducted in 2006-2008 to evaluate the control effects of three mowing frequencies in combining with planting three tree species with three densities on the Chromolaena odorata in southwestern Karst region of Guangxi. In all treatments, the relative coverage, height, density, and aboveground biomass of C. odorata were decreased by 89.7%-99.3%, 41.6% - 81.2%, 61.4% - 83.2% and 91.7% - 97.8%, respectively, and the capitulum number was significantly lesser than that in the control (P<0.05). The control effects on the growth of C. odorata were in the order of mowing frequency > tree species > planting density, and the optimal control mode was mowing twice one year and planting four plants of Delavaya yunnanensis per plot (4 m x 4 m).

Comparison of hematopoietic supportive capacity between human fetal and adult bone marrow mesenchymal stem cells in vitro.

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.

[The effects of stem cell factor on proliferation, transmigration, capillary tube formation of endothelial cells and on the chemotaxis of CD133(+) cells].

OBJECTIVE: To explore the effects of stem cell factor (SCF) on proliferation, transmigration, capillary tube formation of human umbilical vein endothelial cells (HUVEC) and on the chemotaxis of CD133(+) cells. METHODS: In the presence of blank control, SCF, vascular endothelial growth factor (VEGF), anti-human SCF (anti-SCF) or human IgG, the difference in proliferation capacity of HUVEC was analyzed by MTT and CCK-8 methods, and wound scratch assay and three-dimensional in vitro Matrigel assay were used for transmigration and capillary tube formation of HUVEC, respectively. In addition, the chemotaxis of CD133(+) cells sorted from human umbilical cord blood by flow cytometry was investigated by Transwell migration assay. RESULTS: SCF didn't improve the proliferative capacity of HUVEC, but significantly enhanced the transmigration capacity, and increased capillary tube formation in a dose-dependent manner. The number of intact tubules [(30.0 ± 3.4)/10(5) HUVEC] formed by HUVECs in the presence of the optimal concentration of SCF (100 ng/ml) was remarkably higher than that in blank control group [(5.0 ± 2.6)/10(5) HUVEC, P < 0.01]. SCF also significantly induced a chemotactic response of CD133(+) cells, the transmembrane migration cell number into Transwell lower chamber was significantly higher in SCF group [(118.0 ± 6.5)/10(4) CD133(+) cells] than in blank control group [(47.0 ± 4.7)/10(4) CD133(+) cells, P < 0.01 ]. CONCLUSIONS: SCF significantly promotes the transmigration and capillary tube formation of HUVEC, and induces a chemotactic response of CD133(+) cells. SCF/c-kit signaling possibly plays a critical role in regulating angiogenesis of vascular endothelial cells and vasculogenesis of endothelial progenitor cells.

[Isolation of mesenchymal stem cells from bone marrow filters by primary explant culture].

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.

More mesenchymal stem cells enriched from bone marrow aspirates by culturing bone marrow particles and mononuclear cells separately.

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.