ABSTRACT
Objective To isolate and culture human adipose-derived stem cells (hADSCs),investigate the influence of hADSCs on the cellular morphology,survival rate,and function of human islet cells under the in vitro non-contact co-culture conditions,and explore its mechanism.Method hADSCs were isolated by collagenase digestion method,then cultured,and identified by morphology,immunofluorescence and multi-directional differentiation.Adult islet cells were separated and purified by Liberase enzyme and Ficoll 400,then divided into co-culture group and individual group.The cellular growth morphology of islet cells was observed by inverted phase contrast microscope.The survival rate of islet cells,insulin secretory volume,insulin stimulation index and concentration of growth factor in the supernatant were compared between the two groups.Result hADSCs of the third generation showed uniform long spindle fibrocyte-like morphology,and had multi-directional differentiational potentials of osteogenesis and adipogenesis.Immunofluorescence test of surface antigens on hADSCs revealed CD44 + and CD49d +,CD31-,CD34-and CD106-.After 14-day culture,the islet cellular morphology in co-culture group was more intact than that in individual group.The survival rate of islet cells in co-culture group was (82.83 + 2.32) ％,and that in individual group was (53.00 + 2.82) ％ (P＜0.01).Insulin secretory volumes were (23.66 + 2.11) and (7.82 +1.09) mU/L respectively in co-culture group and individual group under high glucose concentration,and 13.22 + 0.77 and 6.40 + 0.44 mU/L respectively under low glucose concentration (P＜0.01 for all).Insulin stimulation index was decreased from 1.67 + 0.10 (at 3rd day) to 1.77 + 0.13 (at 14th day) in co-culture group,and from (1.67 + 0.10) (at 3rd day) to (1.77 + 0.13) (at 14th day) in individual group (P＜0.01).After 14-day culture,the concentrations of HGF,TGF-β,VEGF and bFGF in the supernatant were higher in co-culture group than in individual group (P＜0.01).Conclusion hADSCs were isolated and cultured successfully from adult adipose tissue.They could increase the survival rate and improve the function of islet cells when co-culture with the adult islet cells in vitro through secreting HGF,TGF-β,VEGF and b-FGF.