Effect Of Taurine On Proliferation And Differentiation Of Rat Pancreatic Stem Cells In Vitro

The incidence of diabetes is increasing in recent years,which seriously affect the life quality of patients and could induce diabetic complications.Traditional therapy was to increase the insulin secretion by medice or directly insulin injection,which could balance the blood glucose of patients.But these therapy could not repair the islet damage of diabetic patients.Recent research found that islet stem cells were exist inside the islet,and could be induced to functional islet βcells in vitro,which provide a new idea for the treatment of disbetes.Clinical and animal experiments proved that taurine could lower the blood glucose of diabetic patients,ameliorate the clinical symptom and prevent the complications of diabetes.Our previous results also found that taurine could increase the number of panecretic stem cells of diabetic rats treated with STZ,up-regulate the expression of markers in the differentiation form panecretic stem cells to isletβcells,suggesting that taurine could promote the differentiation of panecretic stem cells of rats under disbetes,but the mechamism remains unclear.The present study aims to discuss the effect and mechanism of taurine on the differentiaon of panecretic stem cells in vitro,in order to provide theory evidence for the treatment of diabetes using taurine.Pancreatic stem cells were isolated from 180-220g SD rats by mechanical digestion,and was identified by nestin immunohistochemistry staining.Different concentrations of taurine were added in the cultural medium of the 4th to 6th generation of pancreatic stem cells.MTS method was used to detect the proliferation of pancreatic stem cells after cultured for 24h,48h,72h,96h,120h and 144h to determine a suitable taurime concentration.After being cultured using the suitable concentration of taurine to the 4th generation,total protein was extracted from the pancreatic stem cells,western-blotting was carried out to detect the expressions of factors regulating the development of pancreatic stem cells including PDX1,Ptfla,Ngn3,Nestin,CK19 and SOX9.The results showed that the immunohistochemistry staining of PDX1,Nestin and CK19 were all positive,indicating the cells isolated and cultured were pancreatic stem cells;the proliferation activities in 10 mmol/L and 15 mmol/L taurine groups were much higher than the other groups,so 10 mmol/L and 15 mmol/L taurine were used in the following experiment;the protein expressions of factors regulating pancreatic stem cells showed that expressions of PDX1 and Ptfla had no significant changes in 10mmol/L taurine group compared with control group,but the expression of CK 19 increased significantly(p<0.05),the three proteins all significantly up-regulated by 15 mmol/L taurine(p<0.01);expressions of SOX9 and Ngn3 increased significantly compared with the control group(p<0.01).Nestin expression showed no significant changes among all the groups.In conclusion:1,taurine could obviously promote the proliferation of pancreatic stem cells,and the most suitable concentrations are 10mmol/Land 15mmol/L;2,taurine could significantly up-regulate the expressions of PDX1,Ptfla,Ngn3,CK19 and SOX9,while exerts no effect on the expression of Nestin,indicating that taurine could promote the differentiation of pancreatic stem cells;3,Further analysis revealed that the mechanism of taurine on the differentiation may through the regulation on the Wnt,Notch and FGF 10 pathways.