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1.
LI Ping  ZHONG Xue-yun 《园艺学报》2009,25(8):1652-1655
The tumor stem cell theory supposed that tumor stem cells are the origin of tumor abnormal proliferation, invasion, metastasis, drug resistance and recurrence. As the theory is put forward, it redefines the functions of classic stem cells in tumorigenesis. It is a great event for recent studies on glioma initiating cells as brain tumor stem cells were identified and isolated successfully. A lot of evidence from experiments in vivo and in vitro demonstrates that brain tumor stem cells might play an important role in glioma tumorigenesis. In this review, we discuss the relationship between tumor stem cells and tumorigenesis, and the research on the correlation between brain tumor stem cells and glioma genesis.  相似文献   

2.
Induced pluripotent stem cells (iPSCs) have been first induced from mouse fibroblasts since 2006, and the research on iPSCs has made great progress in the following years. iPS cell lines were established from different somatic cells through DNA, RNA, protein, and small molecule compounds and various methods of transduction, making the induction of iPSCs more secure and effective, and more attractive prospect of clinical application. In this review, different somatic cell reprogramming, different levels of reprogramming, different transduction pathways, and prospect of application are discussed.  相似文献   

3.
AIM: To select an efficient way of promoting induced pluripotent stem cells (iPSC) to differentiate into neural stem cells (NSC) by comparing 2 methods. METHODS: The culture system in method A contained SB431542 (5 mmol/L) and drosomophorin (5 mmol/L) with 100% initial cell density, while that in method B contained SB431542 (5 mmol/L) and drosomophorin (1 mmol/L) with 30%~50% initial cell density. For comparison and identification of the 2 methods, the growth state was observed under microscope, and the expression of Pax6, nestin, Sox1 and Sox2 was quantitatively detected by real-time PCR and flow cytometry. The related protein expression and the ability of spontaneous differentiation were determined by immunofluorescence analysis. RESULTS: The cells derived from method A with 5 mmol/L of SB431542 and drosomophorin and 100% initial cell density achieved the higher expression of Pax6, nestin, Sox1 and Sox2. The growth state was better and the cells differentiated into neurons and astrocytes normally. CONCLUSION: The method A was superior to method B, and we recommend the method A with 5 mmol/L of SB431542 and drosomophorin and 100% initial cell density as the method for differentiating NSC.  相似文献   

4.
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5.
AIM: To generate and identify primary ovarian insufficiency (POI) patient-derived induced pluripotent stem cells (iPSCs) and to explore their differentiation potential to primordial germ cells. METHODS: Plasmid pEB-C5 expressing reprogramming factors Oct4, Sox2, c-Myc, Klf4 and Lin28, and plasmid pEB-Tg expressing SV40 T antigen, were transfected into peripheral blood mononuclear cells (PBMCs) derived from POI patients at the same time. PBMCs were reprogrammed into iPSCs, and the pluripotency of the cells was identified. After supplementation of transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein 4 (BMP4), the mRNA and protein expression of primordial germ cell markers was detected by real-time PCR and Western blot, respectively. RESULTS: iPSCs derived from the PBMCs of POI patient differentiated into 3-germ layer cells and maintained pluripotency by the detection of alkaline phosphatase staining, immunofluorescence, embryoid body and teratoma formation. After addition of TGF-β1 and BMP4, the primordial germ cell markers, including stem cell growth factor receptor (c-Kit), developmental pluripotency-associated 3 (STELLA/DPPA3) and DEAD box polypeptide 4 (VASA/DDX4) were increased at mRNA level (P<0.05), and VASA/DDX4 was also up-regulated at protein level in induced group. CONCLUSION: PBMCs of POI patient are reprogrammed into integration-free iPSCs in vitro and maintain pluripotency. They differentiate into primordial germ cells by adding TGF-β1 and BMP4.  相似文献   

6.
AIM: In this study, we aim to obtain the induced pluripotent stem cells (iPSCs) from the patients with sporadic Alzheimer disease (AD). METHODS: Three typical Alzheimer's patients were chosen, and the epithelial cells were isolated from their urine. We reprogrammed these cells into induced pluripotent stem cells by transfection of 4 factors (Oct4, Sox2, Klf4 and SV40LT) with the technique of electro-transfection. After getting these iPSCs, we continue to differentiate them into neural cells by a specific method—dual inhibition of Smad signaling. RESULTS: The primary cells from 3 AD patients were successfully reprogrammed to iPSCs, and these patients-derived iPSCs were differentiated into neural cells. There was no significant difference, during iPSCs reprogramming and neural differentiation, between cells from AD patients and normal people. CONCLUSION: The urine cells from AD patients were able to transfer to iPSCs, functional neurons and neurogliocytes.  相似文献   

7.
AIM: To study the direct reprogramming method of mouse embryonic fibroblasts (MEFs) converted into induced neural stem cells (iNSCs). METHODS: Sox2-infected MEFs were cultured in NSCs culture medium for 10 d. Subsequently, repeated suspension and adherent culture were performed for 3 times for the purification of iNSCs. The iNSCs were cultured in suspension medium. Real-time PCR was used to detect the expression of neural stem cell marker genes and pluripotent marker gene. In vivo, iNSCs were microinjected into the mouse cerebral cortex. Immunofluorescence was performed to detect the expression of neural stem cell, neuron, oligodendrocyte and astrocyte markers in vitro and vivo. RESULTS: A variety of neural stem cell marker gene expression was significantly increased in iNSCs detected by real-time PCR. Immunofluorescence confirmed that iNSCs expressed nestin and differentiated into neurons, oligodendrocytes and astrocytes in vitro and vivo. CONCLUSION: Sox2 is sufficient to trigger the direct reprogramming from MEFs to iNSCs. iNSCs have the ability of self-renew and 3 differentiation potentials in vivo and vitro. iNSCs are the suitable seed cells of SCI.  相似文献   

8.
AIM: To investigate the protective effect of mesenchymal stem cell (MSC)-conditioned medium (MSCCM) on myocardial cell line H9c2 and its mechanism. METHODS: Verification of MSC was performed by flow cytometry analysis, followed by MTT assay to determine the optimal incubation time of MSCCM with myocardial cells. The cells were divided into 4 groups: normal (N) group, model (M) group, M+MSCCM group and MSCCM group. The cells in M+MSCCM group and MSCCM group were pre-incubated with MSCCM for 24 h. The cells in M group and M+MSCCM group were treated with 300 μmol/L H2O2 for 4 h to imitate oxidative injury of myocardial cells. Mitochondrial membrane potential and apoptotic rate of injured myocardial cells were detected by flow cytometry. The ROS production was measured by fluorescence microscopy. The nuclear translocation of Nrf2 and expression of HO-1 was examined by Western blot. RESULTS: No difference of mitochondrial membrane potential, apoptotic rate or ROS production between MSCCM group and N group was observed (P>0.05). The mitochondrial membrane potential depolarization, apoptotic rate and ROS production in M+MSCCM group were significantly lower than those in M group (P<0.01). The nuclear translocation of Nrf2 and expression of HO-1 in the myocardial cells were increased with MSCCM incubation time prolonged. CONCLUSION: MSCCM protects the myocardial cells against oxidative injury induced by H2O2. The anti-oxidative mechanism would be associated with the activation of Nrf2/ARE pathway.  相似文献   

9.
AIM: To investigate the effects of induced pluripotent stem cells-derived mesenchymal stem cells (iPSC-MSCs) on cobalt chloride (CoCl2)-induced injuries of PC12 cells and its possible mechanism. METHODS: PC12 cells were exposed to CoCl2 to set up a chemical-induced cellular injury model and were cocultured with iPSC-MSCs. The cell viability was tested by CCK-8 assay. The apoptosis was measured by flow cytometry using Annexin V/PI staining. The mitochondrial membrane potential (MMP) was analyzed by flow cytometry using JC-1 staining. Immunofluorescence was employed to observe mitochondrial transfer from iPSC-MSCs to PC12 cells. RESULTS: Apoptosis of PC12 cells was increased and MMP of PC12 cells was decreased after exposed to CoCl2 at concentration of 400 μmol/L for 24 h. Coculture of PC12 cells with iPSC-MSCs reduced the apoptosis and recovered the MMP of the PC12 cells. Tunneling nanotubes were formed between iPSC-MSCs and PC12 cells, through which the iPSC-MSCs transferred the mitochondria to the PC12 cells. CONCLUSION: iPSC-MSCs protect PC12 cells from CoCl2-induced injuries, which may be associated with the mitochondrial transfer from iPSC-MSCs to PC12 cells.  相似文献   

10.
Mesenchymal stem cells (MSCs) are a population of multipotent cells that can proliferate and differentiate into marrow and non-marrow cell types, such as adipocytes, chondrocytes, myocytes, and so on. In recent years, many researchers have studied whether MSCs are capable of differentiation into neurons in vivo and ex vivo. The result that MSCs-derived neurons express NSE and NF, but don't express GFAP suggests MSCs can differentiate into neurons, some researchers have achieved success in promoting functional recovery in Pakinsons and transactional spinal cord injury rat models by use of MSCs-derived neurons. Therefore, MSCs-derived neurons will play an important role in the therapy for a variety of diseases of the nervous system.  相似文献   

11.
AIM: Retinoblastoma-like protein 2 (Rbl-2) plays an important role in the cell proliferation and DNA methyltransferase (DNMT) may involve in the regulation of differentiation in embryonic stem cells. This study is to investigate the effect of knocking down Rbl-2 by specific siRNA on apoptosis in human cardiac stem cells.METHODS: The siRNA of Rbl-2 (siRbl-2) was transfected into human cardiac stem cells. The mRNA expression of Rbl-2 and DNMT-3B was detected by real-time RT-PCR 48 h after transfection. The DNMT-3B protein expression and the activation of caspase-3 were determined by Western-blotting. The cell apoptosis was analyzed by flow cytometry with annexin V-FITC/PI staining. RESULTS: Knocking down of Rbl-2 gene increased the expression of DNMT-3B in human cardiac stem cells, and induced cell apoptosis. Compared with negative control group, caspase-3 was activated and cleaved caspase-3 was increased in the stem cells transfected with siRbl-2. The cleaved caspase-3 accounted for more proportions of total caspase-3 in transfected cells than that in non-transfected cells (P<0.01). The apoptotic rate was also increased significantly in transfected group (P<0.01).CONCLUSION: Rbl-2 plays an important role in the regulation of survival and apoptosis in human cardiac stem cells. This regulatory mechanism may involve in epigenetic modification, which is mediated by DNMT.  相似文献   

12.
AIM: To establish a method of isolating,culturing the adipose tissue-derived mesenchymal stem cells in vitro and to investigate the possibility of exogenous transplanting the adipose tissue derived mesenchymal stem cells for treatment of rat acute myocardial infarction.METHODS: 18 male rats were separated randomly into 3 groups: sham surgery group (control,n=6),acute myocardial infarction control group (AMI,n=6) and myocardial infarction plus cell transplantation group (AMI+cell,n=6).The infarcted hearts were made by occlusion of left coronary artery.The mesenchymal stem cells were isolated from the rats’ peritoneum by using digestion methods and reproduced in vitro,then the cells were labeled with BrdU and implanted into the infarcted heart of the rats.Heart functions were measured 4 weeks after implantation.The hearts were also harvested for pathological and histoimmunochemical observations to determine the survival and location of the implanted cells.RESULTS: Plenty of mesenchymal stem cells were obtained from the adipose tissue of rats’ peritoneum.Compared with the AMI group,the left ventricular systolic pressure in the cell therapy group was increased significantly (P<0.01),the left ventricular end-diastolic pressure was decreased (P<0.01),and the ratio of the left ventricular pressure rise and decay (±dp/dt) was decreased (P<0.05).The number of blood vessels was increased at the boundary of infarction site by pathological observation.The labeled cells were founded in the infarcted myocardium and the blood vessel wall.CONCLUSION: The adipose tissue is a new optional stem cell source.The methods of exogenous transplantation of adipose tissue derived mesenchymal stem cells for treatment of AMI is effective and feasible.  相似文献   

13.
AIM: To investigate the implantation of matrigel carrying human adipose-derived mesenchymal stem cells to enhance the cell survival and the improvement of the ventricular functions in infarct heart.METHODS: Human adipose-derived mesenchymal stem cells (ADMSCs) were isolated and cultured from adult adipose tissue. SD rats with one-week-old myocardial infarction were randomly received the following 4 treatments: injection of PBS, matrigel, PBS+ADMSCs or matrigel+ADMSCs, respectively. Labeled ADMSCs either in matrigel or in saline were injected into the border area of ischemia. The controls received the injection of matrigel or saline only. Four weeks after injection, the heart functions were determined by echocardiography. The densities of the micro-vessels within the infarct area were also measured.RESULTS: Four weeks after implantation of ADMSCs, the cell graft size, the heart functions and the micro-vessel densities within the infarct area improved in matrigel+ADMSCs group as compared to other groups.CONCLUSION: The co-injection of ADMSCs with matrigel enhances the graft survival, increases the density of the micro-vessels in the myocardium and improves the cardiac functions.  相似文献   

14.
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15.
AIM: To generate thalassemia-specific integration-free induced pluripotent stem cells(iPSC) and to detect their ability of differentiation into hematopoietic precursors.METHODS: The plasmids pEB-C5 and pEB-Tg were transfected into the fibroblast cells from hemoglobin Bart's hydrops fetalis's skin by the method of nuclear transfection to reprogramm the cells into iPSC. The ability of the iPSC to differentiate into 3-germ layer cells was determined. The iPSC were cocultured with mouse OP9 cells to differentiate into hematopoietic precursors and the hematopoietic precursor specific antigens were detected. RESULTS: The integration-free iPSC from hemoglobin Bart's hydrops fetalis's skin fibroblasts were successfully derived, and had the ability to differentiate into 3 germ layers. When cocultured with OP9 cells for 9 d, the positive rate of hematopoietic progenitor cell marker CD34 was 18.7%, and the CD34 and CD45 double positive rate was 12.2%. CONCLUSION: Hemoglobin Bart's hydrops fetalis's skin fibroblasts can be successfully induced into "integration-free" iPSC. This cell line has the ability to differentiate into 3 germ layers, and can be differentiated into hematopoietic precursors when cocultured with OP9 cells.  相似文献   

16.
AIM To detect the subunits of nicotinic acetylcholine receptors (nAChRs) in stem cells and the changes of the receptors after nicotine treatment. METHODS Human embryonic stem cell line H9 and human induced pluripotent stem cells (IPSC) were cultured without feeder layer cells. Human umbilical cord mesenchymal stem cells (UCMSC) and human bone marrow mesenchymal stem cells (BMMSC) were also selected. Total RNA and protein were extracted from 4 kinds of cells after subculture, and total RNA was extracted after nicotine treatment. The mRNA and protein expression levels of the subunits of nAChRs were determined by RT-PCR, RT-qPCR and Western blot, and the expression location of the receptors was observed by cellular immunofluorescence. RESULTS The results of RT-PCR and Western blot showed that α2, α3, α4, α7, α9 and β1 subunits of nAChRs were detected in H9 cells, IPSC and UCMSC, while only α4, α7, α9 and β1 were expressed in BMMSC. After nicotine treatment, RT-qPCR results showed that α2 was significantly down-regulated in H9 and UCMSC but up-regulated in IPSC, while β2 was significantly up-regulated in BMMSC and IPSC but down-regulated in UCMSC. CONCLUSION The subunits of nAChRs expressed in embryonic stem cells and adult stem cells are different, and with the higher differentiation potential, the cells express the more types of subunits. The regulatory effect of nicotine on nAChR subunit expression in various stem cells is different, and H9 cells show high sensitivity to the effect of nicotine.  相似文献   

17.
AIM: To direct embryonic stem cells (ESCs) into hematopoietic stem cells (HSCs) in vitro by simulating the hematogenic microenvironment in human early embryonic aorta-gonad-mesonephero (AGM) region.METHODS: Murine E14 embronic stem cell line was used for two-step differentiation.In the first step of primary differentiation,E14 ESCs were seeded into semisolid methylcellulose-based medium containing bone morphogenesis protein 4 (BMP4) and vascular endothelial growth factor (VEGF) for embryoid body (EB) formation.On days 3,6,9,12 and 15,single EB cells were analyzed for Flk-1+ cells amount through flow cytometry.In the second step,single cell from EB containing most Flk-1+ cells was further co-cultured with human AGM stromal cells in non-contact system.On co-culture days of 3,6,9 and 12 days,cells were collected for cell count,flow cytometry for Sca-1+c-kit+ cells analysis,and colony forming cell assay.RESULTS: During the EB formation,BMP4+VEGF promoted Flk-1+ cell genesis on day 9 at peak pencentage value of 27.53%±2.84％,which was statistically higher than that in control group as 8.77±1.10 (P<0.05).Collagenase-disassociated single cell from day 9 EB was co-cultured with human AGM stromal cells of hAGMS3 or hAGMS4 for further hematopoietic differentiation.On day 6 Sca-1+c-kit+ cells got to peak value as 7.31%±1.21％ ［(2.57±0.48) folds］ and 7.62%±1.52％ ［(2.35±0.36) folds］ in hAGMS3 and hAGMS4 feeder systems,respectively,both of which were greater than those values of no-stroma groups at the same culture duration (P<0.05).Colonogenic cell assay showed that these Sca-1+c-kit+ cells had ability of forming multiple lineage hematopoietic colonies.CONCLUSION: BMP4 in combination with VEGF promotes Flk-1+ cell genesis during EB formation in vitro.Stromal cells from early human embryonic AGM region further enhance the directed differentiation of these primitive cells into HSCs.This two-step induction differentiation model can be used for molecular mechanism study of ESCs hematopoietic differentiation.  相似文献   

18.
《园艺学报》2000,16(5):474
As a major component of the hematopoietic microenvironment,stromal cells have been proved to support hematopoiesis. This review describes the constitution, origin of stromal cells and its mrechanism of regulate hematopoiesis, and then elaborates that the stromal cells play a important role in the hematopoietic restitution of hematopoietic stem cell transplantation.  相似文献   

19.
AIM: To induce mouse induced pluripotent stem cells (iPSCs) to differentiate into insulin-producing cells (IPCs) by a new 3-step method, and to detect the efficiency and maturity for the treatment of diabetic mice. METHODS: We constructed iPSCs from mouse embryonic fibroblasts of male C57/C mouse by piggyBac transposon, then induced the iPSCs into IPCs by a 3-step method. The cell morphological change was traced by microscopy during the process of differentiation. The expression of mRNA and protein associated with islet β cell development was determined by real-time PCR and immunofluorescence staining. Flow cytometry was used to analysis the efficiency of differentiation. Insulin and C-peptide secretions of IPCs in response to glucose at high (25 mmol/L) or low (5.5 mmol/L) level were measured by ELISA. The IPCs were transplanted into the capsul of left kidney in the male C57/C diabetic mouse model. Blood glucose was continuously monitored for 28 day, serum insulin was tested by ELISA in different stages. The glucose tolerance test was performed on the 28th day, and the left kidney was excised. RESULTS: IPCs were obtained from mouse iPSCs by the 3-step method. The cells expressed the marker genes (Pdx1, Ngn3, Pax6 and Ins2) and proteins (Pdx1, Nkx6.1 and insulin) of β cells. The glucose stimulation induced the secretion of insulin and C-peptide. The efficiency of differentiation was 28% detected by flow cytometry. After transplantation of IPCs to the diabetic mice, the blood glucose was decreased to normal level on the 3rd day,and serum insulin level and the ability of regulating glucose were improved. IPCs were still alive after 28 d of transplantation by pathological observation. CONCLUSION: iPSCs is efficiently induced into IPCs by a 3-step method , and the induction time is shortened significantly. The hyperglycemia of diabetes mice is reversed after transplanting IPCs to same sex inbred strain mice.  相似文献   

20.
AIM：To investigate the promoting role of Transwell contact co-culture system in the growth and differentiation of single-dissociated induced pluripotent stem cells (iPSCs). METHODS：Bovine corneal endothelial cells (CECs) at passage 1~2 (P1~2) were seeded on the underside of Transwell inserts placed into culture plates and were cultured in 37 ℃ and 5% CO2 for 8 h. Accutase digestion and 40 μm filter process disaggregated colony-aggregated iPSCs into single-dissociated iPSCs, and the cells were seeded on the inside of Transwell inserts with CECs in medium of mTeSR1 for 3 d and then in low-glucose DMEM supplemented with 10% FBS for 2 weeks. The characteristics and differentiation markers were evaluated by real-time fluorescence quantitative polymerase chain reaction (qPCR), immunofluorescence staining, live & dead cell staining and alkaline phosphatase (ALP) staining. The group of iPSCs cultured in conventional medium was used as control group 1. The group of single-dissociated iPSCs co-cultured with CECs was set as experimental group, while single-dissociated iPSCs without co-culture were as control group 2. RESULTS：The bovine CECs showed typical hexagonal cobblestone shape. iPSCs showed colony-like growth, while became single-dissociated cells after Transwell contact co-culture with bovine CECs for 3 d. The single-dissociated iPSCs positively expressed the undifferentiated markers, Nanog and Oct4. The mRNA expression levels of Nanog, Oct4 and Sox2 between experimental group and control group 1 were both positive and had no statistical significance difference (P>0.05). The dead cells in experimental group decreased significantly, and there was statistically significant difference compared to control group 2 (P<0.01). After 14 d of induced differentiation co-culture, the single-dissociated iPSCs showed rather uniform polygonal morphology, increased dimension and no obvious colony existence. Negative ALP staining, positive immunofluorescence staining for ZO-1, AQP1 and CD31, and negative for CD34 and CD133 were also observed. The results of qPCR showed that the mRNA expression of Oct4, Nanog and Sox2 significantly decreased, and had statistically significant difference compared with control group 1 (P<0.01). CONCLUSION：When co-cultured with bovine CECs, iPSCs morphologically changed to endothelial-like cells and expressed some markers of CECs. Transwell contact co-culture system not only enhances the growth of single-dissociated iPSCs, but also promotes their differentiation.  相似文献   

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