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Objective To set up the optimized conditions,the amplification of eord blood CDCD+34 cells in vitro were analyzed by comparing the conditions such as different feeder-layers, stimulating-factors or purity/contents of those cells. Methods The cord blood CDCD+34 cells proliferation was analyzed by the methods of MTT, cell counting, and flow eytometer. The amplification and clone-forming ability of cord blood CDCD+34 cells were detected under optimized condition. Resulits The growth rates of cord blood CD+34 cell under optimized conditions(10 times) were significantly higher than that of the control(2.8 times) (P ＜0.01), and the cloneforming ability of cord blood CDCD+34 cells under optimized conditions(CFU-C 36.67±6.11) were also better than that of the control(CFU-C 16.33±1.53) (P ＜0.01). Conclusion The cord blood CD+34 cells proliferation can be promoted in the co-cultured system, and the character of the stem cells were kept well in that system.
ABSTRACT
Objective To explore whether human umbilical venous endothelial cells could be used as feeder layer to support the growth of embryonic stem cells (ESC) and keep ESC undifferentiated.Methods The venous vessels of umbilical cord obtained from healthy puerperal were perfused with collagenase.The isolated endothelial cells went through primary culture and passages for expansion.Factor Ⅷ antigens determination was implemented.Endothelial cells with good growth and 3 or above passages were treated with mitomycin-C(10 mg/L) and prepared as feeder layer,on which E14.1 ESC was transplanted for subculturing to observe the morphological characterization and determine ESC alkaline psphatase (AKP) activity and the expression of stem cell marker Oct-4.Severe combined immune deficiency(SCID) mouse in vivo terotoma formation experiment was performed to identify its pluripotent properties.Results Human umbilical vein-derived endothelial cells grew well in culturing in vitro and regenerate in large numbers.The endothelial cells maintained normal cellular morphological and biological characterization after 10 passages.The cells stopped proliferating after being treated with mitomycin-C,but its activity and morphological properties were well-maintained with 24 hours,which was a fundamental property of serving as feeder layer.E14.1 ESC remained undifferentiated in human umbilical venous endothelial cells after 3-8 passages,the cells grew in colony and showed high expression of AKP and stem cell Oct-4.In vivo pluripotency experiment showed that 6 weeks after being transplanted to SCID mice E14.1 ESC of 6 and 10 passages in endothelial cells both could form teratoma containing 3 layers of tissue cells.Conclusions Human umbilical venous endothelial cell serve as a convenient feeder layer cell with rich sources.It can effectively support ESC growth and heterogenous and prevent the heterogeneous protein pollution and pathogenic microorganisms caused by animal cell feeder layers,thus solve the problem of biological safety of ESC clinical application.
ABSTRACT
Objective To investigate whether human umbilical vein endothelial cells as a feeder layer was capable of supporting the growth of embryonic stem cells in vitro.Methods Human umbilical vein endothelial cells were isolated and cultured and then prepared as feeder cells after 3 passages.Alkaline posphatase activity(AKP) staining,stem cell surface marker test and karyotypes were conducted in different periods of cell culture.The suspension of stem cells cultured after 20 passages on endothelial cells were inoculated to the legs of severe combined immunodeficiency(SCID) mice subcutabeously to test the teratoma formation.Results E14.1 embryonic stem cells retained good colonies when they were cultured on endothelial cells for 3 passages and 8 passages.In addition,they expressed SSEA-1,Oct-4,and a membrane alkaline phosphatase to a high extent at passages 3 and 8.Embryonic stem cells cultured for 15 passages stably retaind a normal karyotype.Embryonic stem cells cultured on endothelial cells for 20 passages were inoculated into the hind leg of SCID mouse,teratomas containing three embryonic layers were recovered six weeks later.Conclusion Human umbilical vein endothelial cells would support effectively embryonic stem cells expansion,and provide a clinically safe method to expand ES cells for futureclinical application.