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Objective To investigate the effects of peroxisome proliferator activated receptor-gamma(PPARγ)gene silen-cing in human bone marrow stromal cells(HS-5)on hematopoietic function in bone marrow-suppressed mice,and to explore the potential mechanisms involved.Methods A bone marrow-suppressed mouse model was established by whole-body X-ray irradi-ation.Two hours after modeling,the mice were randomly divided into three groups:experimental group(intravenous injection of PPARγ RNAi-interfered HS-5 cells through the tail vein),control group(intravenous injection of PPARγ RNAi-uninterfered HS-5 cells through the tail vein),and blank group(intravenous injection of an equal amount of saline through the tail vein),with 5 mice in each group.Peripheral blood routine tests were performed before,24 hours after,1 week after,and 2 weeks after radio-therapy.In vitro osteogenic and adipogenic induction was performed in cells,and the cells were divided into experimental group(PPARγ RNAi-interfered HS-5 cells),control group(PPARγ-uninterfered HS-5 cells),and blank group(HS-5 cells without os-teogenic/adipogenic induction).Osteogenic/adipogenic staining was observed.The effects of PPARγ gene-silenced HS-5 cells on mouse bone marrow hematopoietic stem cells(HSCs)were detected by CCK-8 proliferation assay.The groups included experi-mental group(PPARγ RNAi-interfered HS-5 cells were co-cultured with mouse HSCs after 3 days of osteogenic induction dif-ferentiation),positive control group(HS-5 cells treated with 50 μmol/L PPARγ inhibitor were co-cultured with mouse HSCs af-ter 3 days of osteogenic induction differentiation),negative control group(PPARγ RNAi-uninterfered HS-5 cells were co-cul-tured with mouse HSCs after 3 days of osteogenic induction differentiation),and blank group(Mouse HSCs were cultured alone without co-culturing with HS-5 cells).Results After radiotherapy,the hematological parameters of mice in each group showed a decreasing trend initially,and then increased.One week after radiotherapy,there were significant differences in platelet and white blood cell levels among the three groups(experimental group＞control group＞blank group,all P＜0.05).Two weeks after radiotherapy,there were significant differences in the percentage of adipocyte vacuole area among the three groups(experi-mental group＜control group＜blank group,all P＜0.05).Pearson correlation analysis showed a negative correlation between hematological parameters and PPARγ expression levels(all P＜0.05),as well as a negative correlation between hematological parameters and the percentage of adipocyte vacuole area(all P＜0.05).After in vitro osteogenic/adipogenic induction differenti-ation,compared to the control group,the experimental group showed a significantly lower proportion of orange-red cells and a significantly higher proportion of red calcium nodules.After 3 days of osteogenic induction differentiation,the experimental group,positive control group,and negative control group of human bone marrow stromal cells were co-cultured with mouse HSCs,while HSCs were solely cultured in the blank group.The results showed that after 24 h,48 h and 72 h of co-culture,the A values of mouse HSC cells in the experimental group and positive control group were higher than those in the negative control group and blank group(all P＜0.05).Conclusion Silencing of the PPARγ gene in HS-5 cells implanted into bone marrow-sup-pressed mice contributes to enhanced hematopoietic function in mice.After interference and silencing of the PPARγ gene,the os-teogenic differentiation ability of HS-5 cells is enhanced,while the adipogenic differentiation ability is weakened.Furthermore,osteogenic-induced HS-5 cells can further enhance the proliferation capacity of mouse HSCs.
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BACKGROUND:Piezo1,a mechanosensitive protein,is tightly connected to osteogenic differentiation,and it has been demonstrated that TAZ has a role in regulating osteogenic differentiation.It is unclear whether TAZ participates in the regulation of osteogenic differentiation of human bone marrow mesenchymal stem cells by Piezo1,so it is crucial to investigate its unique mechanism to prevent osteonecrosis of the femoral head. OBJECTIVE:To elucidate what function Piezo1 plays in osteogenic differentiation and TAZ expression in human bone marrow mesenchymal stem cells. METHODS:The siRNA targeting Piezo1 was constructed and transfected into 293T cells.The silencing efficiency was detected by RT-qPCR.The selected Piezo1-Home-2337 was packaged according to the silencing efficiency,and its optimal multiplicity of infection value was assayed by immunofluorescence staining.The packaged Piezo1 silencing recombinant lentivirus was transfected into human bone marrow mesenchymal stem cells,and its silencing effect was detected by RT-qPCR and western blot assay.Alizarin red staining,alkaline phosphatase activity analysis,immunofluorescence staining,RT-qPCR and western blot assay were utilized to analyze the effect of silencing Piezo1 on the osteogenic differentiation of human bone marrow mesenchymal stem cells. RESULTS AND CONCLUSION:(1)The mRNA and protein levels of Piezo1 in human bone marrow mesenchymal stem cells transfected by si-Piezo1 were decreased significantly,with a statistically significant difference compared with normal and negative control groups.(2)The alkaline phosphatase activity in the si-Piezo1 group was much lower and the calcium deposition in the si-Piezo1 group was significantly reduced compared with the negative control group.(3)The mRNA levels of osteogenesis-related genes including Runt-related transcription factor 2(Runx2),osteopontin(OPN),distal-less homeobox 5(DLX5),osteocalcin,β-catenin and Tafazzin(TAZ)in the si-Piezo1 group were significantly decreased compared with the negative control group.Afterward,the expression levels of TAZ and β-catenin protein in the si-Piezo1 group were down-regulated significantly compared with the negative control group,whereas the expression levels of p-TAZ and p-β-catenin protein in the si-Piezo1 group had the opposite condition.(4)The results of immunofluorescence staining showed that the expression of TAZ and β-catenin in human bone marrow mesenchymal stem cells in the si-Piezo1 group was less compared with the negative control group.(5)These findings indicate that Piezo1 can promote the osteogenic differentiation of human bone marrow mesenchymal stem cells.The osteogenic ability of human bone marrow mesenchymal stem cells is significantly reduced after silencing Piezo1,and the expression of TAZ is also reduced.
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BACKGROUND:Studies have found that activation of nuclear factor-erythroid 2-related factor 2/heme oxidase-1(Nrf2/HO-1)pathway can alleviate oxidative stress caused by cerebral ischemia-reperfusion injury,but whether human bone marrow mesenchymal stem cells(hBMSC)can activate Nrf2/HO-1 pathway to alleviate cerebral ischemia-reperfusion injury is still lacking relevant studies. OBJECTIVE:To investigate whether intracranial transplantation of hBMSC alleviates oxidative stress injury in cerebral ischemia-reperfusion animal models by activating Nrf2/HO-1 pathway. METHODS:Totally 40 male SPF SD rats were randomly divided into sham operation group,model group,hBMSC transplantation group,hBMSC+solvent group and hBMSC+Nrf2 inhibitor group.Each group consisted of eight animals.In the model group and the hBMSC transplantation group,middle cerebral artery occlusion model was prepared by thread embolization method.The thread embolization was removed 1 hour later,and 30 μL PBS or hBMSC cultured to at least passage 5 was injected into the right cortex and striatum of rats.In the hBMSC+Nrf2 inhibitor group and hBMSC+solvent group,the left ventricle was injected with Nrf2 inhibitor Brusatol and its solvent dimethyl sulfoxide respectively 24 hours before model establishment,then the middle cerebral artery occlusion model was prepared,and hBMSC was injected.Relevant indexes were detected 3 days after transplantation. RESULTS AND CONCLUSION:(1)CT and TTC staining showed the same area and volume of cerebral infarction:model group>hBMSC+Nrf2 inhibitor group>hBMSC+solvent group>hBMSC transplantation group>sham operation group.(2)Hematoxylin-eosin staining and Nissl's staining showed that the ischemic brain tissue was intact and the neurons were normal in the sham operation group.Compared with the model group,the pathological morphology and neuronal injury of the hBMSC transplantation group and the hBMSC+solvent group were significantly improved.Compared with the hBMSC+solvent group,the hBMSC+Nrf2 inhibitor group had more serious pathological morphology and neuronal damage.(3)Western blot assay and oxidative stress index detection results showed that compared with the sham operation group,Nrf2 and HO-1 proteins were decreased(all P<0.05),malondialdehyde was increased and superoxide dismutase was decreased(all P<0.05)in the model group.Compared with the model group,the expression levels of Nrf2 and HO-1 proteins were increased(all P<0.05),malondialdehyde was decreased and superoxide dismutase was increased(all P<0.05)in the hBMSC transplantation group and the hBMSC+solvent group.Compared with the hBMSC+solvent group,the expression levels of Nrf2 and HO-1 proteins were simultaneously decreased(all P<0.05),and malondialdehyde was increased and superoxide dismutase was decreased(all P<0.05)in the hBMSC+Nrf2 inhibitor group.(4)These results indicate that hBMSC can alleviate cerebral ischemia-reperfusion injury possibly by activating Nrf2/HO-1 pathway.
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Objective To screen the active components of total flavonoid extracts of Sarcandra glabra to promote megakaryocyte differentiation.Methods(1)A model of megakaryocyte differentiation disorder was established by co-culturing human megakaryocytic leukaemia cells(Dami)with human bone marrow stromal cells(HS-5)as an evaluation system,and the experimental groupings were as follows:the Dami group(Dami),the control group(Dami+HS-5),and the PMA group[Dami+HS-5+5 ng·mL-1 foprolol 12-tetradecanoate 13-acetate(PMA)],and model group[Dami+HS-5+1%rabbit anti-rat platelet serum(APS)+5 ng·mL-1 PMA]were cultured for 48 hours.The expressions of megakaryocyte differentiation and maturation surface marker molecules,CD41a and CD61 were detected by flow cytometry.(2)Forty-nine SD male rats were randomly divided into blank plasma group,15-minute group,30-minute group,60-minute group,90-minute group,120-minute group,and 240-minute group,with 7 rats in each group.The rats in each administration group were gavaged with 1.26 g·kg-1 of total flavonoids extracts of Sarcandra glabra,and blood was collected at six set time points(15,30,60,90,120,240 minutes)for the preparation of time-dependent serum-containing plasma of total flavonoids extracts of Sarcandra glabra.(3)Ultra-high performance liquid chromatography-quadrupole tandem time-of-flight mass spectrometry(UHPLC-Q-TOF/MS)was used to analyze the plasma of the time-dependent serum-containing plasma of the total flavonoids extracts of Sarcandra glabra,and the peak area was used to construct a matrix(X-matrix)of the amount of chemical composition change over time in the time-dependent serum-containing plasma of the total flavonoids extracts of Sarcandra glabra.The collected time-dependent serum-containing plasma of the total flavonoids extracts of Sarcandra glabra at six different time points was used to intervene in the model of megakaryocyte differentiation and maturation disorder,and the expression of cell surface molecules CD41a and CD61 was detected by flow cytometry to construct the matrix of effect of time-dependent serum-containing plasma of the total flavonoids extracts of Sarcandra glabra(Y-matrix).(4)After the data of X and Y matrices were standardized,partial least squares(PLS)was used to calculate and analyze the quantitative and qualitative effect relationship,and variable importance for projection(VIP)>1 was used as the threshold to screen the effect components related to the changes of cell surface molecules CD41a and CD61,and chemical composition identification,as the potential effector components in the total flavonoid extracts of Sarcandra glabra were used to promote the differentiation of megakaryocytes,and finally the regression evaluation system was used to verify the efficacy of its medicinal effect.Results(1)Compared with the Dami group,the expression level of CD41a on the surface of Dami cells in the control group was significantly increased(P＜0.05).Compared with the control group,the expression levels of CD41a and CD61 on the surface of Dami cells in the PMA group were significantly increased(P＜0.01).Compared with the PMA group,the expression levels of CD41a and CD61 on the surface of Dami cells in the model group were significantly reduced(P＜0.01).(2)Compared with the blank plasma group,the expression levels of the molecules CD41a and CD61 on the surface of Dami cells at each time point of 15,30,60,90,120,and 240 minutes were significantly increased(P＜0.01),and the expression levels of CD41a and CD61 were both highest in the 30-minute group.The potential effective components with VIP value greater than 1 were screened out in the positive and negative ion mode,and 540.3638@12.25 and 559.2991@11.53 were selected for pharmacodynamic verification.559.2991@11.53 was identified as daucosterol(Dau),540.3638@12.25 was identified as rosmarinic acid 4-O-β-D-glucoside(Ros).After Ros and Dau intervened in the megakaryocyte differentiation and maturation disorder model respectively,the expression levels of CD41a and CD61 on the surface of Dami cells in the low-,medium-and high-dose groups(40,60 and 80 μg·mL-1)of Ros and Dau were significantly increased compared with the model group(P＜0.05,P＜0.01).Conclusion Ros and Dau may be the active components of the total flavonoids extracts of Sarcandra glabra to promote the differentiation of megakaryocytes.
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OBJECTIVE@#To explore the effect of basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and the combination of bFGF and EGF in the neural differentiation of human bone marrow mesenchymal stem cells (hBMSCs), and the role of Wnt/β-catenin signaling pathway in this process.@*METHODS@#The identified 4th-generation hBMSCs were divided into five groups according to different induction conditions, namely control group (group A), EGF induction group (group B), bFGF induction group (group C), EGF and bFGF combined induction group (group D), and EGF, bFGF, and Dickkopf-related protein 1 (DKK-1) combined induction group (group E). After 7 days of continuous induction, the cell morphology was observed by inverted fluorescence phase contrast microscopy, levels of genes that were related to neural cells [Nestin, neuron-specific enolase (NSE), microtubule-associated protein 2 (MAP-2), and glial fibrillary acidic protein (GFAP)] and key components of the Wnt/β-catenin signaling pathway (β-catenin and Cyclin D1) were detected by RT-PCR, and the levels of proteins that were related to neural cells (Nestin and GFAP) as well as genes that were involved in Wnt/β-catenin signaling pathway [β-catenin, phosphorylation β-catenin (P-β-catenin), Cytoplasmic β-catenin, and Nuclear β-catenin] were explored by cellular immunofluorescence staining and Western blot.@*RESULTS@#When compared to groups A and B, the typical neuro-like cell changes were observed in groups C-E, and most obviously in group D. RT-PCR showed that the relative expressions of Nestin, NSE, and MAP-2 genes in groups C-E, the relative expressions of GFAP gene in groups D and E, the relative expression of NSE gene in group B, the relative expressions of β-catenin gene in groups C and D, and the relative expressions of Cyclin D1 gene in groups B-D significantly increased when compared with group A ( P<0.05). Compared with group E, the relative expressions of Nestin, NSE, MAP-2, GFAP, β-catenin, and CyclinD1 genes significantly increased in group D ( P<0.05); compared with group C, the relative expression of Nestin gene in group D significantly decreased ( P<0.05), while NSE, MAP-2, and GFAP genes significantly increased ( P<0.05). The cellular immunofluorescence staining showed that the ratio of NSE- and GFAP-positive cells significantly increased in groups C-E than in group A, in group D than in groups C and E ( P<0.05). Western blot assay showed that the relative expression of NSE protein was significantly higher in groups C and D than in group A and in group D than in groups C and E ( P<0.05). In addition, the relative expression of GFAP protein was significantly higher in groups C-E than in group A and in group D than in group E ( P<0.05). Besides, the relative expressions of β-catenin, Cytoplasmic β-catenin, Nuclear β-catenin, and the ratio of Nuclear β-catenin to Cytoplasmic β-catenin were significantly higher in groups C and D than in group A and in group D than in group E ( P<0.05), whereas the relative expression of P-β-catenin protein was significantly lower in groups C and D than in group A and in group D than in group E ( P<0.05).@*CONCLUSION@#Different from EGF, bFGF can induce neural differentiation of hBMSCs. In addition, EGF can enhance the hBMSCs neural differentiation of bFGF, while the Wnt/β-catenin signaling pathway may play a positive regulatory role in these processes.
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Humains , bêta-Caténine/métabolisme , Cellules de la moelle osseuse , Différenciation cellulaire , Cellules cultivées , Facteur de croissance épidermique/métabolisme , Cellules souches mésenchymateuses , Voie de signalisation Wnt , Neurones , Facteur de croissance fibroblastique de type 2/métabolismeRésumé
OBJECTIVE@#To explore the effect of human bone marrow mesenchymal stem cells (MSCs) with ectopic high OCT4 expression on T-cell proliferation, activation and secretion in vitro.@*METHODS@#Peripheral blood mononuclear cells were isolated from healthy children. Anti-CD3 and anti-CD28 monoclonal antibodies were used to activate T lymphocytes, which were stimulated by interleukin (IL)-2 for one week in vitro. Then MSCs with ectopic high OCT4 expression (MSC-OCT4) were co-cultured with activated T lymphocytes. After one week of co-culture, the supernatant was collected and the levels of Th1/Th2 cytokines [IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α and interferon (IFN)-γ] were determined by flow cytometry. The lymphocytes after one week of co-culture were collected and counted by Countstar software. After the proportions of activated/inactivated T cell subsets were determined by flow cytometry, the absolute lymphocyte counts were calculated and expressed as mean ± standard deviation.@*RESULTS@#Compared with control T cell alone culture group, the proliferation of CD3+ T cells, CD3+CD4+ T cells, and CD3+CD8+ T cells were significantly inhibited in MSC group and MSC-OCT4 group. Compared with MSC, MSC-OCT4 could inhibit CD3+CD8+ T cell proliferation better (P =0.049), and mainly inhibited early T cell activation. Compared with control T cell alone culture group, the levels of IL-2 and INF-γ were significantly down-regulated both in MSC group and MSC-OCT4 group.After co-culture with T cells for one week, the level of IL-6 significantly increased in MSC group and MSC-OCT4 group compared with that before co-culture. Compared with control MSC group, MSC-OCT4 group had higher viable cell numbers after 1 week of co-culture (P =0.019), and could resist the inhibition of proliferation by higher concentration of mitomycin C.@*CONCLUSION@#Both MSC and MSC-OCT4 can inhibit the proliferation and activation of IL-2-stimulated T cells in vitro. After overexpression of OCT4, MSC has better proliferation ability in vitro and can inhibit the proliferation of CD3+CD8+ T cells more effectively, which may have a better and more lasting immunosuppressive ability to regulate the balance of Th1/Th2.
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Enfant , Humains , Cellules de la moelle osseuse , Lymphocytes T CD8+/métabolisme , Prolifération cellulaire , Cellules cultivées , Interleukine-2 , Interleukine-6/métabolisme , Agranulocytes/métabolisme , Activation des lymphocytes , Cellules souches mésenchymateuses , Facteur de nécrose tumorale alpha/métabolismeRésumé
Objective:To investigate the effect and potential mechanism of serum exosome-derived cirC_0009362 on the osteogenic differentiation of human bone marrow mesenchymalstem cells (hBMSCs) .Methods:Serum samples from patients with osteoporosis (OP) were collected and exosomes were isolated. The expression level of circ_0009362 in exosomes was detected by qRT-PCR. hBMSCs osteogenesis was induced and the expression of circ_0009362 and miR-29b-3p was detected. The interaction between circ_0009362 and miR-29b-3p was detected by dual luciferase reporter assay. Alkaline phosphatase (ALP) kit was used to detect ALP activity and alizarin red (ARS) staining was used to detect calcium deposition.Results:Compared with healthy control group, the expression of circ_0009362 in serum exosomes of OP patients was increased, and the expression of circ_0009362 was decreased after inducing hBMSCs osteogenesis (all P<0.05) . The ALP activity and the percentage of calcium deposition in hBMSCs were decreased by exosomes, and this effect was achieved by secreting circ_0009362. The effect of exosomes was partially offset by circ_0009362 expression in knockdown exosomes (all P<0.05) . The expression of miR-29b-3p was increased after inducing hBMSCs osteogenesis ( P<0.05) . Circ_0009362 had a targeting relationship with miR-29b-3p, and exosomes inhibited the expression of miR-29b-3p by secreting circ_0009362. The ALP activity and the percentage of calcium deposition in hBMSCs were promoted by overexpression of miR-29b-3p, which was partially offset by exosomes (all P<0.05) . Conclusion:Serum exosomes of OP patients inhibit the osteogenic differentiation of hBMSCs by secreting circ_0009362 to down-regulate the expression of miR-29b-3p.
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OBJECTIVE@#To examine the morphology and biocompatibility of a native acellular porcine pericardium (APP) in vitro and to evaluate its barrier function and effects on osteogenesis when used in guided bone regeneration (GBR) in vivo.@*METHODS@#First, the morphology of APP (BonanGenⓇ) was detected using a scanning electron microscope (SEM). Next, for biocompatibility test, proliferation of human bone marrow mesenchymal stem cells (hBMSCs) were determined using cell counting kit-8 (CCK-8) after being seeded 1, 3 and 7 days. Meanwhile, the cells stained with phalloidine and 4, 6-diamidino-2-phenylindole (DAPI) were observed using a confocal laser scanning microscopy (CLSM) to view the morphology of cell adhesion and pattern of cell proliferation on day 5. A 3-Beagle dog model with 18 teeth extraction sockets was used for the further research in vivo. These sites were randomly treated by 3 patterns below: filled with Bio-OssⓇand coverd by APP membrane (APP group), filled with Bio-OssⓇand covered by Bio-GideⓇmembrane (BG group) and natural healing (blank group). Micro-CT and hematoxylin-eosin (HE) were performed after 4 and 12 weeks.@*RESULTS@#A bilayer and three-dimensional porous ultrastructure was identified for APP through SEM. In vitro, APP facilitated proliferation and adhesion of hBMSCs, especially after 7 days (P < 0.05). In vivo, for the analysis of the whole socket healing, no distinct difference of new bone ratio was found between all the three groups after 4 weeks (P>0.05), however significantly more new bone regeneration was detected in APP group and BG group in comparison to blank group after 12 weeks (P < 0.05). The radio of bone formation below the membrane was significantly higher in APP group and BG group than blank group after 4 and 12 weeks (P < 0.05), however, the difference between APP group and BG group was merely significant in 12 weeks (P < 0.05). Besides, less resorption of buccal crest after 4 weeks and 12 weeks was observed in APP group of a significant difference compared in blank group (P < 0.05). The resorption in BG group was slightly lower than blank group (P>0.05).@*CONCLUSION@#APP showed considerable biocompatibility and three-dimentional structure. Performing well as a barrier membrane in the dog alveolar ridge preservation model, APP significantly promoted bone regeneration below it and reduced buccal crest resorption. On the basis of this study, APP is a potential osteoconductive and osteoinductive biomaterial.
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Animaux , Chiens , Humains , Matériaux biocompatibles , Régénération osseuse , Ostéogenèse , Péricarde , Suidae , Extraction dentaire , Alvéole dentaireRésumé
BACKGROUND: Perivascular cells have been shown to be the precursor cells of mesenchymal stem cells, which regulate the behavior of hematopoietic stem cells and support hematopoiesis through cell-to-cell contact or paracrine effects. Hematopoietic support of human skeletal muscle-derived pericytes/perivascular cells (hMD-PCs) remains to be studied. OBJECTIVE: To identify the biological characteristics of hMD-PCs isolated from human skeletal muscle and to study their supporting effect on umbilical cord blood CD34+ cells in vitro. METHODS: (1) hMD-PCs with phenotype CD146+ CD56-CD34-CD144-CD45- were sorted from human skeletal muscle by enzymatic digestion and multiparameter fluorescence-activated cell sorting, and their biological characteristics were identified. (2) The in vitro culture system of umbilical cord blood CD34+ cells co-cultured with human CD146+ hMD-PCs (experimental group) or with human bone marrow mesenchymal stem cells (positive control group) was established. After 1, 2 and 4 weeks of co-culture, the number of cells, the colony formation ability and immunophenotype were measured and statistically analyzed. RESULTS AND CONCLUSION: (1) CD146+ hMD-PCs were sorted by multiparameter fluorescence-activated cell sorting and the purity was (91.5±1.85)% (n=5). CD146+ hMD-PCs expressed mesenchymal surface markers CD73, CD90, CD105, CD44, and did not express hematopoietic cell and endothelial cell markers CD45, CD34, and CD31. After induced culture, CD146+ hMD-PCs could differentiate into osteoblasts, chondrogenesis, adipocytes and myoblasts. (2) There were no significant differences in the cell number, colony f ormation ability or immunophenotype (CD45+, CD34+ CD33-, CD14+, CD10+/CD19+) between experimental and positive control groups (P > 0.05, n=6). The number of cells in the blank control group without feeder was significantly decreased at 1 week of culture, and there was almost no cell survival at 2 weeks of culture. (3) In summary, CD146+ hMD-PCs, like human bone marrow mesenchymal stem cells, have hematopoietic support capacity in vitro.
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BACKGROUND: The dense microstructure of biological scaffolds and the limitation of cell growth microenvironment are the two major difficulties in the application of biological scaffolds in bone tissue repair. OBJECTIVE: To prepare fluffy hydroxyapatite/polylactic acid composite fiber scaffold, so that cells can easily enter into the scaffold and to realize three-dimensional culture of bone marrow mesenchymal stem cells. METHODS: Fluffy hydroxyapatite/polylactic acid composite scaffold was prepared by using modified electrospinning technology combined with biomineralization. The physical and chemical properties of the fiber scaffold were measured and observed. Human bone marrow mesenchymal stem cells were inoculated on the fluffy hydroxyapatite/polylactic acid composite scaffold and traditional hydroxyapatite/polylactic acid composite scaffold. Cell proliferation, adherence and morphological changes were detected. RESULTS AND CONCLUSION: (1) The thickness of hydroxyapatite coating in the fluffy hydroxyapatite/polylactic acid composite scaffold was about 8.3 µm, most of hydroxyapatite fibers were in discrete state with a diameter of 8-14 µm. The fibers were connected by pores, and the pore diameter was (65±35) µm. The surface area, porosity and water absorption of the scaffold were significantly higher than those of the traditional scaffold (P < 0.01). (2) After 12 hours of culture, the adherence of bone marrow mesenchymal stem cells on the two scaffolds was similar, 83% and 81% cells adhered on the traditional and fluffy scaffolds, respectively. (3) After 7 days of culture, the number of proliferated cells in the fluffy hydroxyapatite/polylactic acid composite scaffold was significantly more than that in the traditional hydroxyapatite/polylactic acid composite scaffold (P < 0.01). (4) After 7 days of culture, FDA staining and scanning electric microscopy showed that cell-cell independent shape appeared in the traditional scaffold. A large number of cells appeared in the fluffy scaffold and grew into cell clusters with high cell activity, which formed a cell-fiber construction. These results indicate that this new type hydroxyapatite/polylactic acid composite scaffold is beneficial for cell entry and proliferation.
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Objective: To investigate the effect of micro RNA (miR)-335-5p regulating bone morphogenetic protein 2 (BMP-2) on the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). Methods: hBMSCs were cultured in vitro and randomly divided into control group (group A), miR-335-5p mimics group (group B), miR-335-5p mimics negative control group (group C), miR-335-5p inhibitor group (group D), and miR-335-5p inhibitor negative control group (group E). After grouping treatment and induction of osteogenic differentiation, the osteogenic differentiation of cells in each group was detected by alkaline phosphatase (ALP) and alizarin red staining; the expressions of miR-335-5p and BMP-2, Runt-related transcription factor 2 (Runx2), osteopontin (OPN), and osteocalcin (OCN) mRNAs were detected by real-time fluorescence quantitative PCR analysis; the expressions of Runx2, OPN, OCN, and BMP-2 proteins were detected by Western blot. Results: Compared with group A, the relative proportion of ALP positive cells and the relative content of mineralized nodules, the relative expressions of BMP-2, miR-335-5p, OPN, OCN, Runx2 mRNAs, the relative expressions of Runx2, OPN, OCN, and BMP-2 proteins in group B were significantly increased ( P0.05). Conclusion: miR-335-5p can up-regulate BMP-2 expression and promote osteogenic differentiation of hBMSCs.
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BACKGROUND: The dense microstructure of biological scaffolds and the limitation of cell growth microenvironment are the two major difficulties in the application of biological scaffolds in bone tissue repair. OBJECTIVE: To prepare fluffy hydroxyapatite/polylactic acid composite fiber scaffold, so that cells can easily enter into the scaffold and to realize three-dimensional culture of bone marrow mesenchymal stem cells. METHODS: Fluffy hydroxyapatite/polylactic acid composite scaffold was prepared by using modified electrospinning technology combined with biomineralization. The physical and chemical properties of the fiber scaffold were measured and observed. Human bone marrow mesenchymal stem cells were inoculated on the fluffy hydroxyapatite/polylactic acid composite scaffold and traditional hydroxyapatite/polylactic acid composite scaffold. Cell proliferation, adherence and morphological changes were detected. RESULTS AND CONCLUSION: (1) The thickness of hydroxyapatite coating in the fluffy hydroxyapatite/polylactic acid composite scaffold was about 8.3μ m, most of hydroxyapatite fibers were in discrete state with a diameter of 8-14μm. The fibers were connected by pores, and the pore diameter was (65±35) μm. The surface area, porosity and water absorption of the scaffold were significantly higher than those of the traditional scaffold (P<0.01).(2) After 12 hours of culture, the adherence of bone marrow mesenchymal stem cells on the two scaffolds was similar, 83% and 81% cells adhered on the traditional and fluffy scaffolds, respectively. (3) After 7 days of culture, the number of proliferated cells in the fluffy hydroxyapatite/polylactic acid composite scaffold was significantly more than that in the traditional hydroxyapatite/polylactic acid composite scaffold (P<0.01).(4) After 7 days of culture, FDA staining and scanning electric microscopy showed that cell-cell independent shape appeared in the traditional scaffold. A large number of cells appeared in the fluffy scaffold and grew into cell clusters with high cell activity, which formed a cell-fiber construction. These results indicate that this new type hydroxyapatite/polylactic acid composite scaffold is beneficial for cell entry and proliferation.
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Objective: To explore the effects of the microenvironment of rabbit bladder acellular matrix graft (BAMG) on proliferation, cell surface markers, and molecular protein level of human bone marrow mesenchymal stem cells (hBMSCs). Methods: We prepared BAMG immersion fluid medium and detected its effect on the proliferation of hBMSCs by MTT method. The expressions of CD44, CD45, CD73 and PDGFRβ were detected by flow cytometry. The expressions of PPAR, OCN and α-SMA were detected by RT-PCR, and the expression of OCT was detected by Western blot. Results: hBMSCs had good compatibility with BAMG. The MTT method showed that BAMG and BAMG immersion medium did not affect the proliferation capacity of hBMSCs. The surface of hBMSCs cells cultured with immersion fluid still expressed CD44, CD73 and PDGFRβ, but not CD45. RT-PCR showed that OCN, PPAR, and α-SMA were all expressed. Western blot test also showed the positive expression of OCT-4. Conclusion: hBMSCs can still keep their original biological characteristics in the microenvironment of rabbit BAMG. It can be the seed cells and combined substrate materials for urinary system tissue engineering.
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Objective To investigate different expression levels between young and old bone marrow mesenchymal stem cells in microRNAs (miRNAs) that are significantly conserved between humans and mice.Additional studies have been conducted to discover changes in miRNA expression in old mice relative to that in young adults and discussed the roles of miRNAs in primary osteoporosis.Methods MiRNAs that are highly conserved between human and mice,and are expressed at significantly different levels in the bone marrow mesenchymal stem cells of young and old people were identified by searching the Gene Expression Omnibus (GEO) database.Human bone mesenchymal stem cells (hBMSCs) were transfected with miRNA mimics,and their relative alkaline phosphatase (ALP) activity levels were then determined.Micro-CT scanning was employed to quantitatively characterize cortical and cancellous bones of young and old mice,and to confirm that these mice accurately modeled natural aging osteoporosis.Simultaneously,we investigated differences in expression levels of miRNAs that influence ALP activity in hBMSCs in the two groups of mice.Correlations between miRNA expression levels,and parameters of bone mass and bone strength were studied.Results 28 miRNAs were found to be more than 2 fold up-regulated (down-regulated) with statistical significance (P＜0.05) in the GEO database.We also found that ALP activity was lower in hBMSCs transfected with 4 miRNAs (mir-124-3p,mir-126-3p,mir-128-3p,mir-424-5p,P＜0.05 or P＜ 0.01).The micro-CT scans indicated that the mice are accurately modeled natural aging osteoporosis.Expression of mir-124-3p increased significantly in older mice.This upregulation correlated positively with trabecular separation,and negatively with trabecular pattern factor in trabecular bone.However,in cortical bone,its expression correlated positively with trabecular separation,and negatively with bone volume fraction,trabecular number,and bone mineral density (P＜ 0.05).Conclusion Hsa-mir-124-3p,which is expressed differently in young and old bone marrow stromal cells,inhibited the osteogenic differentiation of hBMSCs.Upregulation of this miRNA in the bone tissue of aged mice may be related to the development of osteoporosis.
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@#【Abstract】 【Objective】To investigate the differential expression of long non-coding RNA-1708(lncRNA-1708)in osteogenic differentiation of human bone marrow mesenchymal stem cells(hBMSC)and its effect on osteogenic differentiation of hBMSC.【Methods】Purchased 3 groups of hBMSC from different sources and cultured in vitro. qRT-PCR was used to detect the expression of lncRNA-1708 after osteogenic differentiation of three groups of hBMSC,and the relationship between lncRNA-1708 and hBMSC osteogenic differentiation was analyzed. LncRNA-1708 overexpressing lentivirus and lncRNA-1708 interferenced plasmid were transfected respectively,to obtain stable hBMSC cell line. After 14-day osteogenic differentiation on transfected hBMSC,RT-PCR was used to detect the expressions of runt-related transcription factor 2(RUNX2)and alkaline phosphatase(ALP)mRNA,and alkaline phosphatase staining was made.【Results】The expression of lnc-1708 decreased after osteogenic differentiation of hBMSC for 7 d(P < 0. 001).Two cell lines,which respectively express high lncRNA-1708 and low lncRNA-1708,were constructed successfully. In lnc-1708-overexpressed BMSC,the mRNA levels of osteogenic markers RUNX2 and ALP were both significantly down-regulated(0.46±0.03 vs.1.00±0.02,0.15±0.07 vs. 1.02±0.28,P < 0.01). On the contrary,in the lnc-1708-silencing BMSC,the expressions of RUNX2 and ALP mRNA level were significantly up-regulated(1.62±0.18 vs. 1.00±0.04,1.58±0.11 vs. 1.01±0.18,P < 0.01).【Conclusion】LncRNA-1708 may have an inhibitory effect on osteogenic differentiation of hBMSC.
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Objective: To investigate the effect of KR-12 analog, KR-12-a5, on osteogenic differentiation of human bone marrow mesenchymal stem cells (HBMSCs). Methods: Osteogenic differentiation-related experiments were performed using HBMSCs. KR-12-a5 was used as additional stimulation under osteogenesis inducing environment. By alkaline phosphatase (ALP) staining assay, ALP quantitative assay, alizarin red staining and elution quantitative analysis, and real-time quantitative polymerase chain reaction (RT-qPCR), the effect of KR-12-a5 on osteogenic differentiation of HBMSCs was verified. Results: As the concentration of KR-12-a5 increased, the staining intensity of ALP and alizarin red also increased. The strongest staining effect was exhibited at the highest concentration (50 μg/mL) of KR-12-a5. Quantitative tests showed similar results. After 3 days of stimulation with KR-12-a5, the mRNA level of RUNX2 increased in a dose-dependent manner. On the 7th day, the expression levels of ALP, COL1A1, BSP and BMP2 in the KR-12-a5-treated group showed significant changes. On the 14th day, OSX, OCN and OPN levels increased significantly. Conclusion: KR-12-a5 promoted the osteogenic differentiation of HBMSCs in a dose-dependent manner.
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Objective:To compare the ability between bone marrow-derived mesenchymal stem cells (MSCs) (BM-MSCs) and adipose-derived MSCs (AD-MSCs) or umbilical cord-derived MSCs (UC-MSCs) on promotion of vessels formation and vessds stabilization relevant to the functions of EPCs.Methods:In vitro,co-culture blood vessel test was performed to compare the angiogenic ability between BM-MSCs,AD-MSCs or UC-MSCs.In vivo,angiogenic assay dependent on basement membrane matrix Matrigel and immunohistochemistry were performed to compare the ability of vessels formation functions between BM-MSCs and AD-MSCs or UC-MSCs.Results:The lengths and dots of vascular structures formed by EPCs on AD-MSCs layer are greater than those by EPCs on BM-MSCs layer and UC-MSCs layer in angiogenic assay in vitro.The stability of the capillary-like structures formed by EPCs with AD-MSCs on Matrigel was more stable than that by the BM-MSCs,UC-MSCs or EPCs.AD-MSCs and EPCs could form abundant functional vessels with blood perfusion in Matrigelin vivo;UC-MSCs and EPCs could form a few functional vessels with blood perfusion in Matrigelin vivo;BM-MSCs and EPCs could form broken vessels with hemocytes leakage in Matrigel in vivo.Conclusion:AD-MSCs have the stronger ability to promote the angiogenesis and stabilize the vessels compared with BM-MSCs or UC-MSCs ex vivo and in vivo.
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AIM:To explore the regulatory effect of chemokine CCL 3 on exosome secretion from human bone marrow mesenchymal stem cells(hBMSCs).METHODS: hBMSCs were stimulated with chemokine CCL 3 at different concentrations in vitro.The proliferation of hBMSCs was measured by CCK-8 assay and viable cell counting.Exosome se-cretion from hBMSCs was qualitatively analyzed by transmission electron microscope(TEM)and flow cytometry, and the quantitative analysis was carried out by flow cytometry and nanoparticle tracking analysis(NTA).RESULTS:Compared with control group,the viability of the hBMSCs detected by CCK-8 assay was increased when hBMSCs were treated with CCL3(P<0.05).The results of viable cell counting demonstrated that the number of hBMSCs was raised in CCL 3 group in a dose-dependent manner(P<0.05).The results of flow cytometry showed that hBMSCs expressed 3 CCL3-related spe-cific receptors,CCR1,CCR5 and CCR9.Compared with control group,the fluorescence intensity of CCR9 in CCL3 group was obviously enhanced.However,no significant difference of fluorescence intensity for CCR 5 and CCR1 was observed be-tween the 2 groups.The results of NTA demonstrated that the secretion capacity of CCL 3-induced hBMSCs was far less than that in control group(P<0.05).However, the microvesicles larger than 100 nm in CCL3 groups were increased(P<0.05).The above results indicated that the higher concentration of CCL 3 induced the lower secretion of exosomes.In addi-tion,the results of flow cytometry demonstrated that CCL 3-induced hBMSCs showed lower quantity of CD 9 +exosomes than those in control group(P<0.01).CONCLUSION:CCL3 promotes the proliferation of hBMSCs but depresses the secre-tion of exosomes in a dose-dependent manner.CCL3 affects the size distribution of exosomes and increases the number of nonfunctional microvesicles of larger than 100 nm in size.CCL3 induces the expression of CCR9 in hBMSCs.
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Objective To observe the promoting effect of hypoxia on proliferation of human bone marrow mesenchymal stem cells (BMMSCs) and maintaining their potential of multi-directional differentiation in vitro.Methods BMMSCs were isolated from bone marrow blood samples of patients with bone fracture, and cultured under hypoxic (group A) or normoxic (group B) conditions.The morphology, proliferation and osteogenic and adipogenic potential of the BMMSCs were observed.Results BMMSCs in the group A showed a long spindle shape and a fish shoal-like distribution, and were well-grown, while the morphology of cells in the group B appeared polygonal or flat.The quantity and growth rate of BMMSCs in the group A were increased compared with the group B (P< 0.05), with an osteogenic and adipogenic potential.Conclusions Hypoxia can promote the proliferation of BMMSCs in vitro and maintain their multi-directional differentiation potential.
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AIM:To explore the effect of dasatinib on the viability, migration, cell cycle and apoptosis of human bone marrow mesenchymal stem cells (hBMSCs), as well as the underlying signal pathway to evaluate the influence of dasatinib on hematopoietic microenvironment clinically.METHODS:The cell viability was measured by CCK-8 assay.The migration ability was detected by wound healing assay.The cell cycle and apoptosis were analyzed by flow cytometry.Acridine orange/ethidium bromide staining was also used to detected apoptosis.The secretion of transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) were measured by ELISA.The protein levels of cleaved caspase-3, protein kinase B (Akt) and phosphorylated Akt were determined by Western blot.RESULTS:Compared with control group, dasatinib at 1~10 nmol/L suppressed the viability and migration ability of hBMSCs, and dasatinib at concentration of 7 nmol/L was adopted in the following assays.Dasatinib promoted apoptosis, and blocked the cell cycle in G1 phase.In addition, the secretion of TGF-β1 and TNF-α was increased markedly.The protein levels of cleaved caspase-3 was increased, but the protein levels of Akt and phosphorylated Akt were decreased.CONCLUSION:Dasatinib inhibits the viability and migration ability of hBMSCs in a dose-dependent manner, promotes the secretion TGF-β1 and TNF-α, and induces cell cycle arrest and apoptosis.Dasatinib might regulate the biological behaviors of hBMSCs observed above by modulating the expression and phosphorylation of Akt.