Effect of bone marrow mesenchymal stem cells on the proliferation of bone marrow CD34~+ cells in vitro

Objective To investigate the effect on the marrow CD34+ cells by bone marrow mesenchymal stem cells(BMMSC),VarioMACS was used to sort bone marrow CD34+ cells,and then the purity of CD34+ cell was tested by FCM. Marrow mononuclear cells from abortion fetal bone marrow were isolated,and BMMSC were     

Effect of BMI1 gene overexpression on hematopoietic differentiation colony-forming assay of human embryonic stem cells

正Objective To study the effect of Bmil gene overexpression on hematopoietic differentiation colony-forming assay of human embryonic stem cells.Methods Human embryonic stem cell H1 was co-cultured with mouse bone marrow mesenchymal stem cells OP9 to simulate hematopoietic differentiation in vitro.On the 8th day of co-culture,CD34+hematopoietic progenitor cells were selected     

Liver-specific gene expression in mesenchymal stem cells is induced by liver cells

AIM: The origin of putative liver cells from distinct bone marrow stem cells, e.g. hematopoietic stem cells or multipotent adult progenitor cells was found in recent in vitro studies. Cell culture experiments revealed a key role of growth factors for the induction of liver-specific genes in stem cell cultures. We investigated the potential of rat mesenchymal stem cells (MSC) from bone marrow to differentiate into hepatocytic cells in vitro. Furthermore, we assessed the influence of cocultured liver cells on induction of liver-specific gene expression. METHODS: Mesenchymal stem cells were marked with green fluorescent protein (GFP) by retroviral gene transduction. Clonal marked MSC were either cultured under liver stimulating conditions using fibronectin-coated culture dishes and medium supplemented with SCF, HGF, EGF, and FGF-4 alone, or in presence of freshly isolated rat liver cells. Cells in cocultures were harvested and GFP+ or GFP-cells were separated using fluorescence activated cell sorting. RT-PCR analysis for the stem cell marker Thy1 and the hepatocytic markers CK-18, albumin, CK-19, and AFP was performed in the different cell populations. RESULTS: Under the specified culture conditions, rat MSC cocultured with liver cells expressed albumin-, CK-18, CK-19, and AFP-RNA over 3 weeks, whereas MSC cultured alone did not show liver specific gene expression. CONCLUSION: The results indicate that (1) rat MSC from bone marrow can differentiate towards hepatocytic lineage in vitro, and (2) that the microenvironment plays a decisive role for the induction of hepatic differentiation of rMSC.     

Differentiation of rat bone marrow stem cells in liver after partial hepatectomy

AIM: To investigate the differentiation of rat bone marrow stem cells in liver after partial hepatectomy. METHODS: Bone marrow cells were collected from the tibia of rat with partial hepatectomy, the medial and left hepatic lobes were excised. The bone marrow stem cells (Thy CD3-CD45RA- cells) were enriched from the bone marrow cells by depleting red cells and fluorescence-activated cell sorting. The sorted bone marrow stem cells were labeled by PKH26-GL in vitro and autotransplanted by portal vein injection. After 2 wk, the transplanted bone marrow stem cells in liver were examined by the immunohistochemistry of albumin (hepatocyte-specific marker). RESULTS: The bone marrow stem cells (Thy CD3-CD45RA- cells) accounted for 2.8% of bone marrow cells without red cells. The labeling rate of 10μM PKH26-GL on sorted bone marrow stem cells was about 95%. There were sporadic PKH26-GL-labeled cells among he-patocytes in liver tissue section, and some of the cells expressed albumin. CONCLUSION: Rat bone marrow stem cells can differentiate into hepatocytes in regenerative environment and may participate in liver regeneration after partial hepatectomy.     

Cell sheet therapy for myocardial infarction

Introduction Recently,bone marrow mesenchymal stem cells(MSCs) have been reported to repair chronically infracted myocardium with direct injection.However,it is very difficult to localize the injected cells onto the ischemic area to regenerate sufficient cardiac mass in the thinned scar area.To overcome the problem,we have utilized our cell sheet technology based on temperature-responsive culture dishes.When the culture temperature is reduced from 37℃to 20℃,all cells connected via cell-cell junction proteins are harvested as a single sheet without using proteolytic enzymes.This technology allows us to transplant stem cells in vivo for treatment heart disease without the problems mention in the previous.Methods Male Clawn mini pigs were used in this study.Bone marrow(5-7 mL)was collected under general anesthesia. Histopaqe-1077(15 mL),were added to bone marrow and centrifuged.The cells were collected and cultured for 7 days.We seeded the bone marrow-derived MSCs at the concentration of(6×10~5/ml) on 60 mm diameter temperature -responsive dishes for 7 days.As the culture temperature decreased from 37℃to 20℃,MSC sheet detached itself spon-taneously and floated up into the culture medium. Triple layers were stacked together repeatedly forming special multiplayer.Myocardial infarction was created by the ligation of the left anterior descending branch of the left coronary artery.A cell sheets was transplanted onto the ischemia area.The echocardiography was performed two and four weeks after transplantation.The heart tissue with cell sheets were removed and fixed with 10%formalin for histological analysis one month after the transplantation of cell sheets.Results Most MSCs are positive for CD29,CD90,CD146 and CD73.These mean the culture cell sheets were composed of undifferentiated MSCs and remained multipotent.Monolayers(20- 30μm) and multilayer(120μm) cell sheets were produced,which retained all cell-to-cell contaction. Histological analyses show the cell sheets become closely contacted with the heart tiss     

Magnetically labeled mesenchymal stem cells after autologous transplantation into acutely injured liver

AIM:To evaluate tracking of magnetically labeled mesenchymal stem cells(MSCs) after intraportal transplantation.METHODS:Mononuclear cells were isolated from bone marrow aspirates of pigs by density gradient centrifugation,cultured and expanded,after which,they were incubated with super paramagnetic iron oxide(SPIO).Prussian blue staining was performed to highlight intracellular iron.To establish swine models of acute liver injury,0.5 g/kg D-galactosamine was administrated to 10 pigs,six of which were inject...     

HNF-4α determines hepatic differentiation of human mesenchymal stem cells from bone marrow

AIM: To investigate the differentiation status and key factors to facilitate hepatic differentiation of human bone-marrow-derived mesenchymal stem cells (MSCs). METHODS: Human MSCs derived from bone marrow were induced into hepatocyte-like cells following a previously published protocol. The differentiation status of the hepatocyte-like cells was compared with various human hepatoma cell lines. Overexpression of hepatocyte nuclear factor (HNF)-4α was mediated by adenovirus infection of these hepatocyte-like...     

Bone marrow-derived dendritic cells pulsed with tumor lysates induce anti-tumor immunity against gastric cancer ex vivo

AIM： To investigate whether bone marrow-derived denritic cells pulsed with tumor lysates induce immunity against gastric cancer ex vivo. METHODS： c-kit＋ hematopoietic progenitor cells were magnetically isolated with a MiniMACS separator from BALB/c mice bone marrow cells. These cells were cultured with cytokines GM-CSF, IL-4, and TNFα to induce their maturation. They were analysed by morphological observation, phenotype analysis, and mixed lymphocyte reaction （MLR）. Bone marrowderived DCs （BM-DCs） were pulsed with tumor cell lysate obtained by rapid freezing and thawing at a 1：3 DC：tumor cell ratio. Finally, cytotoxic T lymphocyte （CTL） activity and interferon gamma （IFNγ） secretion was evaluated ex vivo. RESULTS： c-kit^＋ hematopoietic progenitor cells from mice bone marrow cells cultured with cytokines for 8 d showed the character of typical mature DCs.Morphologically, observed by light microscope, these cells were large with oval or irregularly shaped nuclei and with many small dendrites. Phenotypically, FACS analysis showed that they expressed.high levels of la, DEC-205, CD11b, CD80 and CD86 antigen, moderate levels of CD40, and negative for F4/80. Functionally, these cells gained the capacity to stimulate allogeneic T cells in MLR assay. However, immature DCs cultured with cytokines for 5 d did not have typical DCs phenotypic markers and could not stimulate allogeneic T cells. Ex vivo primed T cells with SGC-7901 tumor cell lysate-pulsed （TP） DCs were able to induce effective CTL activity against SGC-7901 tumor cells （E：T = 100：1, 69.55% ± 6.05% specific lysis）, but not B16 tumor cells, and produced higher levels of IFNγ, when stimulated with SGC-7901 tumor cells but not when stimulated with B16 tumor cells （1575.31 ± 60.25 pg/mL in SGC-7901 group vs 164.11± 18.52 pg/mL in B16 group, P 〈 0.01）. CONCLUSION： BM-derived DCs pulsed with tumor lysates Can induce anti-tumor immunity specific to gastric cancer ex vivo.     

Differentiation of rat marrow mesenchymal stem cells into pancreatic islet beta-cells

AIM: To explore the possibility of marrow mesenchymal stem cells (MSC) in vitro differentiating into functional isletlike cells and to test the diabetes therapeutic potency of Islet-like cells. METHODS: Rat MSCs were isolated from Wistar rats and cultured. Passaged MSCs were induced to differentiate into islet-like cells under following conditions: pre-induction with L-DMEM including 10 mmol/L nicotinamide+l mmol/L β-mercaptoethanol+200 mL/L fetal calf serum (FSC) for 24 h, followed by induction with serum free H-DMEM solution including 10 mmol/L nicotinamide+1 mmol/L,β-mercaptoethanol for 10 h. Differentiated cells were observed under inverse microscopy, insulin and nestin expressed in differentiated cells were detected with immunocytochemistry. Insulin excreted from differentiated cells was tested with radioimmunoassay. Rat diabetic models were made to test in vivo function of differentiated MSCs. RESULTS: Typical islet-like clustered cells were observed. Insulin mRNA and protein expressions were positive in differentiated cells, and nestin could be detected in predifferentiated cells. Insulin excreted from differentiated MSCs (446.93±102.28 IU/L) was much higher than that from pre-differentiated MSCs (2.45+0.81 IU/L (P<0.01). Injected differentiated MSCs cells could down-regulate glucose level in diabetic rats. CONCLUSION: Islet-like functional cells can be differentiated from marrow mesenchymal stem cells, which may be a new procedure for clinical diabetes stem -cell therapy, these cells can control blood glucose level in diabetic rats. MSCs may play an important role in diabetes therapy by islet differentiation and transplantation.