Differentiation of mouse embryonic stem cells into insulin-secreting cells induced by a 5-step model system / 中华内分泌代谢杂志

ABSTRACT

Objective To induce mouse embryonic stem(ES)cells to differentiate into insulin-secreting cells by means of a 5-step model system.Methods E14.1 mouse ES cells were cultured in the presence of leukemia inhibitory factor(LIF)for 2 days(step 1),then the cells were cultured in hanging drops to form embryonic bodies(EBs)and the resulting EBs were cultured in suspension for 6 days in the presence of basic fibroblast growth factor bFGF(step 2).Subsequently the EBs were cultured in the medium containing glucagon- like peptide 1(GLP-1),hepatocyte growth factor(HGF),nerve growth factor(NGF)and nicotinamide for 10 days(step 3).After that,the EBs were dissociated into single cells,and the cells were cultured in monolayer in the presence of GLP-1,betacellulin,activin A,bFGF and nicotinamide for 10 days(step 4).Finally,the cells were cultured in low-glucose medium containing nicotinamide for 4 days(step 5).Insulin and some other islet- related genes expressions were investigated using RT-PCR and insulin expression was also investigated by DTZ- staining and immunohistochemistry.The percentage of insulin-secreting cells was evaluated by flowcytometry and insulin concentrations were measured by RIA.Results mRNA expression of insulin became visible at step 3 and more evident at step 5.Additionally,at step 5,mRNAs of glucagon,somatostatin,pancreatic polypeptide(PP), pancreatic duodenal homeobox 1(PDX-1),beta-cell E box transactivator 2(Beta2)and neurogenin 3(Ngn3) were detected.DTZ-staining positive cells and insulin immunohistochemical staining positive cells were observed. The percentage of insulin-positive cells was(24.0?2.5)%(n=6).In the presence of 5.6 mmol/L and 25 mmol/L glucose,insulin concentrations were(0.05?0.01)?g/L and(0.13?0.02)?g/L respectively(n= 6).Conclusion E14.1 mouse ES cells can be induced to differentiate into insulin-secreting cells by the 5-step model system.Insulin-secreting cells can release insulin into culture medium when treated with glucose,and insulin concentrations increase with rising concentration of glucose.