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Objective To study the ability of human embryonic stem cells to integrate into mouse liver and to repair chronic liver injury of the recipient.Methods On day 1,day-7 and day-15 after human embryonic stem cells were induced to differentiate into hepatocyte-like cells and were transplanted into mice with chronic liver failure,liver histopathology,liver function,liver tissue regeneration and mature hepatocytes of mice were tested respectively.Results Hepatic tissue pathology of mice significantly improved after transplantation and necrotic foci diminished,hemorrhage and congestion of hepatic cells relieved,and liver function improved.It was observed that human embryonic stem cells survived,proliferated,integrated with host liver,and differentiated into mature hepatocytes.Conclusions Human embryonic stem cells xenotransplanted into mice can participated liver tissue regeneration to some extent,and differentiated into functional liver cells.
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Objective To establish a simple ,stable acute liver injury model induced by CCl4 to observe effects of hepatocyte transplantation .Methods CCl4 plant oil with different concentration of 20% and 50% was used in mice by intraperitoneal injection , of which the dose was 2 mL/kg ,and then materials were taken at different time points respectively .Mice survival rate ,alanine amin-otransferase (ALT) ,aspartate aminotransferase (AST) and the pathological changes of the liver were detected .Results Mice sur-vival rate in 20% CCl4 intraperitoneal injection was significantly higher than that of 50% .ALT and AST in experiment group were significantly higher than that of control group ,but there was no significant difference between two experimental groups .Pathologi-cal examination showed that mice liver cells showed typical cytoplasmic ,ballooning ,scattered punctate ,piecemeal necrosis and in-flammatory cell infiltration in 20% CCl4 intraperitoneal injection ;while in 50% CCl4 ,there was obvious fibrosis ,in addition to the mentioned heavier lesions .Conclusion 20% -50% CCl4 intraperitoneal injection in 2 mL/kg dose can induce different degrees of relatively stable liver injury ,and its concentration determines the degree of liver injury .Acute liver injury induced by 20% -50%CCl4 was an ideal model for hepatocyte transplantation experiment .
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AIM: To investigate the possibility that hepatocyte growth factor (HGF) directly induces differentiation of human embryonic stem cells (hESCs) into neural progenitors (NPs). METHODS: hESCs colonies were induced to form the embryoid body (EB). Four-day-old EBs were randomly divided into 4 groups: control group (EBs were cultured in neural induction medium);G5 supplement group (EBs were cultured in neural induction medium supplied with G5 supplement);HGF group (EBs were cultured in neural induction medium supplied with 10 mg/L HGF), and HGF+G5 group (EBs were cultured in neural induction medium supplied with 10 mg/L HGF and G5 supplement). After induced in suspension system for 7 days, EBs with various treatments were cultured in poly-D-lysine/laminin-coated plates for 7-10 days for selection of NPs. NPs were gathered by 0.3 g/L dispase treatment and characterized by immunofluorescence staining. The percentages of the nestin+ cells in NPs in various groups were detected by fluorescent activated cell sorter (FACS). The multipotency of NPs was determined by immunofluorescence staining after the NPs were cultured without G5 and HGF for 7 days. The expression of region markers of neural progenitors treated with sonic hedgehog (Shh) protein (one of the neural inductive signals), was detected by RT-PCR. RESULTS: HGF+G5 supplement induced hESCs differentiation into neural progenitors. Immunofluorescence staining indicated that NPs differentiated from hESCs expressed NP markers including nestin, Pax6 and musashi-1. FACS data showed that the proportion of nestin positive cells in HGF+G5 supplement group (87.3%±3.9%) was the highest in all treatment groups. The time of HGF and G5 supplement treatment was important to differentiate into NPs, the maximal effect was observed at 7th day. After treated with Shh, the expression of ventral forebrain/hindbrain marker genes (Nkk2.1, and Nkk2.2) and hindbrain progenitor marker gene Gbx2 in NPs were upregulated, while the forebrain progenitor marker genes Otx2 and Bf1 were downregulated. CONCLUSION: The neural induction system containing HGF and G5 supplement effectively induces the differentiation of hESCs into NPs, which might be a potent model for investigating the mechanism of neural development and differentiation.
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Objective To investigate the protective effect of hepatocyte growth factor (HGF) on cultured Sprague-Dawley rat cortical neurons injured through hypoxia/reoxygenation.Methods Primary cultured cerebral cortical neurons were isolated from newborn rots.Neurons were pre-incubated with different concentrations (15,30 and 60 μg/L) of HGF.The cell viability was detected by MTT.Apoptosis was measured by Hoechst 33258 staining and flow cytometer.Lactate dehydrogenase (LDH) and caspase-3 activity were determined by colorimetry.Results Compared with normal group,hypoxia/reoxygenation treatment significantly decreased cell viability,increased LDH activity and the percentage of apoptotic cells.Pretreatment of HGF for 12 h could remarkably reverse the decrease of cell viability and the increase of apoptosis rate in neurons induced by hypoxia/reoxygenation treatment.HGF pre-treatment also attenuated the activity of LDH and caspase-3 in a dose-dependent manner.The effects of HGF could be inhibited by a special PI3K/Akt pathway inhibitor,LY294002.Condusion HGF could attenuate rat cortical neuron injury induced by hypoxia/reoxygenation.The neuroprotective effect of HGF may be related to activating PI3K/Akt pathway,and further suppressing the expression of caspase-3.
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BACKGROUND:FGF2,TGFβ/activin/nodal and IGF signal pathways are necessary for keeping functions of human embryonic stem calls,but there was no report concerning whether addition of exogenous basic fibroblast growth factor,transforming growth factor β and insulin can maintain self-renewal of human embryonic stern cells.OBJECTIVE:To establish a feeder layer-and serum-free culture system of human embryonic stem cells.DESIGN,TIME AND SETTING:The cytological in vitro study was performed at the Kunming Animal Institute of Chinese Academy of Sciences from September 2007 to February 2009.MATERIALS:Pregnancy 12.5 or 13.5-day ICR strain mica (clean grade) were provided by the Animal Center of Kunming Medical College.Human embryonic stem cell line BG02 was purchased from Bresagen,USA.METHODS:BG02 cells were digested,centrifuged,resuspended in feeder layer-free medium,and then incubated for 5-7 days.Differentiated human embryonic stem cells were removed.Dispase was added for digestion.Samples were cut into blocks,centrifuged,resuspended,and then incubated at 1:3 in a 4-well plate coated with laminin in feeder layer-free and serum-free medium,supplemented with 80% DMEM/F12,20% KSR,2 mmol/L glutamine,1% non-essential amino acid,0.1 mmol/L β-mercaptoethanol,insulin-transferrin-selenium (ITS) (×1),10~6 U/L penicillin,100 mg/L streptomycin,4 μg/L basic fibroblast growth factor (bFGF) and 0.12 μg/L transforming growth factor-β1 (TGF-β1).ICR fetus mica were sterilely obtained to culture mouse embryonic flbroblasts by tissue pancreatin digestion method.These cells were incubated in a 6-well plate coated with 0.1% gelatin.Human embryonic stem cell line BG02 cultured on mouse embryonic fibroblasts feeder layers was transferred to laminin-coated plates in serum-free medium containing bFGF,TGFβ1 and ITS.MAIN OUTCOME MEASURES:The morphology of BG02 cells in feeder layer-and serum-free condition was observed.The specific molecular markers of human embryonic stem cells were determined by immunohistochemical staining.The karyotype and differentiation ability in vitro of BG02 cells were analyzed.The differences in the proliferation and the differentiated rate of BG02 clumps in feeder layer-and serum-free condition or mouse embryonic fibroblast feeder layer condition were compared.RESULTS:BG02 calls had been continuously cultured for at least 20 passages in feeder layer-and serum-free culture condition.BG02 clones in this culture system had typical human embryonic stem cell morphology.BG02 cells all expressed SSEA-4,SSEA-3,TRA-1-60,TRA-1-81,Oct-4,but did not express SSEA-1.After 20 days of culture,BG02 cells had the capacity to differentiate into derivatives of embryonic endoderm,mesoderm,and ectoderm.Differentiated cells could express alpha-fetoprotein,nestin,α-actin.At passage 20,call karyotype was normal (46XY).The growth of BG02 cells cultured in feeder layer-and serum-free condition was more slowly compared with mouse embryonic fibroblast feeder,and doubling time was significantly prolonged (P ＜ 0.05).Differentiation rate of the colonies was significantly increased (P ＜ 0.05).CONCLUSION:A feeder layer-and serum-free condition for culture of BG02 cells has been established.The addition of bFGF,TGFβ1 and ITS can maintain the self-renewal of BG02 cells.
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Objective To study the effects of cinobufacin(cino) combined with fluorouracil(5-FU) on inhibiting proliferation and inducing apoptosis of human gastric carcinoma cells in vitro. Methods The experiment was divided into control group,cinobufacin group,5-FU group and cino+5-FU group. Cell morphological variation,cell inhibitory rate, cell cycle and ratio of apoptotic cell of human gastric carcinoma cell line BGC-823 were studied by cell culture, inverse microscopy, fluoroscopy, MTT assay and flow cytometry on different concentrations of cino and 5-FU. Results Cino could markably inhibit proliferation of human gastric carcinoma cells in time-and dose-dependent response. The cino+5-FU group inhibited the rate of proliferation of BGC-823 cells was significantly more than either cino or 5-FU alone group(P
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0 05)in all parameters The tumor inhibitory rate and the cells detained in G 0～G 1 phase significantly increased, meanwhile, cells in S phase, the PI and PCNA significantly decreased in rhGH+L OHP group compared with control group or rhGH group ( P
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0.05).Compared with control group, cell inhibition rate significantly increased in rhGH+L-OHP group (63.2% vs. 50.8%,P