Notch signaling： a novel regulating differentiation mechanism of human umbilical cord blood-derived mesenchymal stem cells into insulin-producing cells in vitro  

作　　者：HU Yan-hua WU De-quan GAO Feng LI Guo-dong ZHANG Xin-chen 

机构地区：[1]Department of General Surgery, Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, China

出　　处：《Chinese Medical Journal》2010年第5期606-614,共9页中华医学杂志（英文版）

基　　金：This work was supported by the grants from the Natural Science Foundation of Heilongjiang Province （No. ZJY0505） and the Innovation of Foundation of Backbone Teachers of Heilongjiang Provincial University （No. 1054G026）.

摘　　要：Background Human umbilical cord blood-derived mesenchymal stem cells （UCB-MSCs） could be induced to differentiate into insulin producing cells （IPCs） in vitro, which have good application potential in the cell replacement treatment of type-1 diabetes. However, the mechanisms regulating this differentiation have remained largely unknown. Notch signaling is critical in cell differentiation. This study investigated whether Notch signaling could regulate the IPCs differentiation of human UCB-MSCs. Methods Using an interfering Notch signaling protocol in vitro, we studied the role of Notch signaling in differentiation of human UCB-MSCs into IPCs. In a control group the induction took place without interfering Notch signaling. Results Human UCB-MSCs expressed the genes of Notch receptors （Notch 1 and Notch 2） and ligands （Jagged 1 and Deltalike 1）. Human UCB-MSCs with over-expressing Notch signaling in differentiation resulted in the down-regulation of insulin gene level, proinsulin protein expression, and insulin-positive cells percentage compared with the control group. These results showed that over-expressing Notch signaling inhibited IPCs differentiation. Conversely, when Notch signaling was attenuated by receptor inhibitor, the induced cells increased on average by 3.06-fold （n=-4, P 〈0.001） in insulin gene level, 2.60-fold （n=-3, P 〈0.02） in proinsulin protein expression, and 1.62-fold （n=-6, P 〈0.001） in the rate of IPCs compared with the control group. Notch signaling inhibition significantly promoted IPCs differentiation with about 40% of human UCB-MSCs that converted to IPCs, but these IPCs were not responsive to glucose challenge very well both in vitro and in vivo. Hence, further research has to be carried out in the future. Conclusions Notch signaling may be an important mechanism regulating IPCs differentiation of human LICB-MSCs in vitro and Notch signaling inhibition may be an efficient way to increase the number of IPCs, which may resolve the shortage of islet of cellBackground Human umbilical cord blood-derived mesenchymal stem cells （UCB-MSCs） could be induced to differentiate into insulin producing cells （IPCs） in vitro, which have good application potential in the cell replacement treatment of type-1 diabetes. However, the mechanisms regulating this differentiation have remained largely unknown. Notch signaling is critical in cell differentiation. This study investigated whether Notch signaling could regulate the IPCs differentiation of human UCB-MSCs. Methods Using an interfering Notch signaling protocol in vitro, we studied the role of Notch signaling in differentiation of human UCB-MSCs into IPCs. In a control group the induction took place without interfering Notch signaling. Results Human UCB-MSCs expressed the genes of Notch receptors （Notch 1 and Notch 2） and ligands （Jagged 1 and Deltalike 1）. Human UCB-MSCs with over-expressing Notch signaling in differentiation resulted in the down-regulation of insulin gene level, proinsulin protein expression, and insulin-positive cells percentage compared with the control group. These results showed that over-expressing Notch signaling inhibited IPCs differentiation. Conversely, when Notch signaling was attenuated by receptor inhibitor, the induced cells increased on average by 3.06-fold （n=-4, P 〈0.001） in insulin gene level, 2.60-fold （n=-3, P 〈0.02） in proinsulin protein expression, and 1.62-fold （n=-6, P 〈0.001） in the rate of IPCs compared with the control group. Notch signaling inhibition significantly promoted IPCs differentiation with about 40% of human UCB-MSCs that converted to IPCs, but these IPCs were not responsive to glucose challenge very well both in vitro and in vivo. Hence, further research has to be carried out in the future. Conclusions Notch signaling may be an important mechanism regulating IPCs differentiation of human LICB-MSCs in vitro and Notch signaling inhibition may be an efficient way to increase the number of IPCs, which may resolve the shortage of islet of cell

关 键 词：Notch signaling mesenchymal stem cells DIFFERENTIATION insulin producing cells DIABETES 

分 类 号：R[医药卫生]