There are plenty of haematopoietic stem cells in umbilical cord blood, which are regarded as important resources for transplantation therapy. There are some arguments on whether or not mesenchymal stem cells(MSCs) exist in umbilical cord blood. Some researchers have such opinions that there exist a number of MSCs in umbilical cord blood as similar with one from bone marrow in many aspects. Others believe that the content of MSCs in umbilical cord blood is too low to expand in vitro. We summarized the data from last five years researches. On umbilical cord blood MSCs during last to help further research and application of this resource of MSCs.

BACKGROUND: Reproductive activity of hepatocytes is limited. There are numerous studies concerning stem cells differentiation into hepatocytes, including embryonic stem cells, bone marrow cells, pancreas stem cells, neural stem cells, various sources of mesenchymal stem cells.OBJECTIVE: To explore the possibility of induction of mesenchymal stem cells (MSCs) from umbilical cord blood (UCB) into hepatocyte-like cells in vitro culture.DESIGN, TIME AND SETTING: A cytological in vitro study was performed at the Institute of Hematology, Medical College of Jinan University from October 2005 to April 2006.MATERIALS: Fetus cord blood was obtained from spontaneous delivery and caesarean delivered healthy pregnant women at the Department of Obstetrics and Gynecology, First Affiliated Hospital of Jinan University. The parturients signed the informed consents.METHODS: UCB-MSCs were incubated in vitro, and digested in trypsin-EDTA. The third passage of cells at 5 × 10~4 cells/cm~2 wereinoculated. Original medium was removed 48 hours later. Cells were washed in phosphate-buffered saline. In the first phase, cells were incubated in F12 medium supplemented with dexamethasone, hepatocyte growth factor, epidermal growth factor and 1 ×its for 2 weeks. In the second phase, cells were incubated in F12 medium containing dexamethasone, hepatocyte growth factor,oncostatin M and 1 × ITS for two weeks.MAIN OUTCOME MEASURES: The following parameters were measured: expression of surface marker of UCB-MSCs using flow cytometry, expression of related gene and protein of hepatocytes following induction respectively using RT-PCR and immunofluorescence staining.RESULTS: No CD34/CD45/CD14 of hematopoietic markers were detected, either no the CD54, CD49f, HLA-DR were found. The low expression of CD106 and high expression of CD29, CD44, CD13 were found. The gene expression of a-fetoprotein, albumin,CK-18 and TAT were discovered, and three kind of protein a-fetoprotein, albumin, CK-18 were positively observed in cytoplasm after 4 weeks of induction using immunofluorescence staining.CONCLUSION: UCB-MSCs are able to differentiate into hepatocyte-like cells in vitro culture following combination with many growth differentiation factors, such as dexamethasone, hepatocyte growth factor, epidermal growth factor, tumorigenesis M and ITS.

Objective To discuss the possibility of differentiation of mesenchymal stem cells(MSCs)from umbilical cord blood(UCB)into hepatocyte-like cells in the in vitro culture.Methods MSCs were isolated from UCB,cultured and passaged.The surface markers were examined by flow cytometry.When cells were cultured to the third passage,they were inoculated into a 6-well plate.A two-stage induction method was used:MSCs in the first phase were cultured in DMEM/F12 medium supplemented with dexamethasone(final concentration of 0.5 μmol/L,the same below),hepatocyte growth factor(HGF,10 ng/ml),epidermal growth factor(10 ng/m1)and 1×insulin-transferrin-Se(ITS)for two weeks,then in DMEM/F12 supplemented with 0.5 μmol/L dexamethasone,10 ng/ml HGF,1×ITS,10 ng/ml Oncostatin M for another two weeks.Morphological changes were observed under a microscope.The gene expression correlated with hepatocytes was detected by using RT-PCR.Immunofluorescence staining was used to identify the expression of specific protein related to hepatocytes(AFP,Albumin,CK-18).Ultrastructure was detected under an electron microscope.Results In the cultured MSCs from UCB,CD34/CD45/CD14,CD54,CD49f and HLA-DR were not detected,there was low expression of CD106 and strong expression of CD29,CD44 and CD13.The gene expression of AFP,albumin,CK-18 and TAT was discovered and three kinds of protein AFP,albumin and CK-18 were positively showed in cytoplasm after 4 weeks'induction.The hepatin granules and fatty drops in cytoplasm of cells induced for 4 weeks were found under an electron microscope.Conclusion The MSCs fromUCB can differentiate into hepatocyte-like ceils in the in vitro culture under some conditions.

BACKGROUND: At present,there are many reports regarding the differentiation of bone marrow-derived mesenchymal stem cells or pancreatic gland stem cells into pancreatic islet β-like cells.But little is about umbilical cord blood-derived mesenchymal stem cells(UCBMSCs)differentiation into pancreatic islet β-like cells in vitro.OBJECTIVE: To investigate whether UCBMSCs can differentiate into pancreatic islet β-like cells in vitro and the optimal inducing condition.METHODS: UCB samples were obtained sterilely from healthy parturients.Nucleated cells were isolated by sedimentation with hydroxyethyl starch and MSCs were obtained by adherent method.Then purified UCBMSCs were induced with epidermal growth factor,β-mercaptoethanol,high glucose,Activin A and hepatocyte growth factor(HGF).Following cell morphology observation,induced cells were identified by insulin immunofluorescence.In addition,insulin secretion and glucose-stimulated insulin release were examined by chemiluminescence immunoassay.RESULTS AND CONCLUSION: After induction,many cells exhibited a round appearance and produced islet-like cell clusters.Immunofluorescence assay showed insulin positive in the treated cells.In addition,chemiluminescence immunoassay demonstrated low expression of insulin and secretion of insulin upon glucose challenge.UCBMSCs can differentiate into pancreatic islet β-like cells in vitro.

AIM: To explore the possibility of differentiating functional insulin-producing cells from human BM-derived stem cells. METHODS: Mesenchymal stem cells were isolated from human bone marrow. Then these cells were induced with epidermal growth factor, β-mercaptoethanol and high concentration of glucose. The gene expression related to islet β cells was detected by RT-PCR. Insulin in the treated cells was examined by immunocytochemistry. In addition, the levels of insulin secretion and glucose-stimulated insulin release were examined by microparticle enzyme immunoassay. Finally, the induced cells were implanted into the right renal subcapsular space of diabetic mice. Blood glucose levels were monitored 16 d after implantation. The right kidneys of the treated mice were harvested for immunohistochemistry. RESULTS: The key genes related to pancreatic β cells had been confirmed to express by PCR and insulin was detected by immunocytochemistry in differentiated human BM-derived stem cells induced by high glucose, which responded to glucose challenge. Furthermore, implantation of the cells in renal subcapsular space was able to lower the glucose levels in hyperglycemic mice. After 16 days, the implanted cells were determined still to be insulin positive cells by immunohistochemistry. CONCLUSION: These results indicate human BM-derived stem cells are capable of differentiating into functional insulin-producing cells and may represent a pool of cells for the treatment of diabetes.

Objects To observe whether mesenchymal stem cells exist in umbilical cord blood and if they can differentiate into osteoblasts and adipocytes.Methods Nucleated cells were separated with Hespan,Mesenchymal-like stem cells were identified by surface marker with flow cytometry.Osteoblast was identified by von Kossa staining and alkaline phosphatase staining,adipocyte was identified by Oil Red O staining.Results From the Nucleated fraction of UCB,we demonstrated the presence of a subset of cells that express adhesion molecules CD13+,CD29+,and CD44+,but not antigens of hematopoietic CD34,CD45,CD14 and neither antigens of endothelia CD106.Exposure of these cells to osteogenic inductive agents resulted in an increase in the expression of alkaline phosphatase and the appearance of hydroxyapatite nodules by Von Kossa staining.Incubation with adipogenic inductive agents resulted in morphological change and positive staining with oil Red O.Conclusions Mesenchymal-like stem cells exist in cord blood and have a lower precursor frequency.The cells can differentiate into osteoblast and adipocyte.Cord blood may function as a new source of cells for cellular therapeutics.

[Objective] To investigate the construction and inhibitory effects of artificial microRNA targeted on hepatitis B virus.[Methods] Four artificial microRNA sequences for HBV gene were designed with Invitrogen online design software (BLOCK-iTTM RNAi Designer),amiRNA eukaryotic expression plasmid were constructed and transfected into human hepatocellular carcinoma cell line HepG2.2.15.Hepatitis B virus DNA in supernatant was detected by quantitative fluorescence PCR.HBsAg and HBeAg detected by ELISA.[Results] All of the four artificial microRNA sequences could down regulate the level of HBV-DNA,HBsAg and HBeAg.miR3 had the most significant effect on inhibiting HBV-DNA replication.[Conclusion] Artificial microRNA sequences can effectively inhibit the replication of HBV in vitro.

Objective To optimized the culture conditions of the human umbilical cord blood mesenchymal stem cells.Methods The umbilical cord blood was taken in Guangzhou Hua Qiao Hospital between Oct.2004 to Feb.2005.The isolation method,planting density,the time of the first medium changing,the influence of culture medium on the growth of MSC were analyzed. Mesenchymal stem cells were identified using the surface marker by flow cytometry.Osteoblast was identified by Von Kossa staining and alkaline phosphatase staining,adipocyte was identified by Oil Red O staining. Results When the other conditions were the same,the hespan isolation was better than Ficoll isolation;5?10~6/cm~2 was the best planting density;the best first medium changing was on the seventh day at primary culture. Under optimized conditions,the MSC expressed adhesion molecules CD_ 13 ,CD_ 29 and CD_ 44 ,but not antigens of hematopoietic CD_ 34 ,CD_ 45 ,CD_ 14 and not antigens of endothelia CD_ 106 . Exposure of these cells to osteogenic inductive agents resulted in an increase in expression of alkaline phosphatase and the appearance of hydroxyapatite nodules. Incubation with adipogenic inductive agents resulted in morphological change and staining with Oil Red O. Conclusion Mesenchymal stem cells exist in Cord blood,but slower to establish in culture.Cord blood may prove to be a new source of cells for cellular therapeutics.

AIM:To investigate the effect of Sonic Hedgehog ( Shh) signaling blockade on the growth of hema-tocarcinoma cells and underlying mechanisms.METHODS: The expression of Shh signaling molecules in hematocarci-noma cell lines BEL-7402, Huh7 and HepG2 was detected by RT-PCR.The cell viability was detected by MTT assay.The cell cycle and apoptosis were analyzed by flow cytometry.The expression of apoptosis-related proteins was determined by Western blot.RESULTS:Shh signaling molecules were all expressed in BEL-7402, Huh7 and HepG2 cells.The mRNA expression of Patched ( Ptch) , Gli1 and Gli2 was down-regulated by anti-Shh antibody.Blockade of Shh signaling pathway inhibited the proliferation of hepatocarcinoma cells with increasing cells in G0/G1 phase and induced the apoptosis of hepa-tocarcinoma cells.Treatment with anti-Shh antibody down-regulated the protein expression of pro-caspase-3, pro-caspase-8 and pro-caspase-9, while up-regulated the protein levels of cleaved caspase-3, cleaved caspase-8 and cleaved caspase-9 in BEL-7402 cells.CONCLUSION:Blockade of Shh signaling pathway inhibits the growth of hepatocarcinoma at different levels by cell cycle arrest and inducing apoptosis of hematocarcinoma cells.