Effects of liraglutide on proliferation and apoptosis in human umbilical cord mesenchymal stem cells

Abstract

Objective To observe the effects of liraglutide on proliferation and apoptosis of human umbilical cord mesenchymal stem cells (HUC-MSCs) in vitro, and further to investigate the relationship with phosphatidylinositol 3 kinase/serine-threonine kinase (PI3K/AKT) signaling pathway. Methods HUC-MSCs cultured in DMEM/F12 media were treated with varying concentrations of liraglutide(10-9, 10-8, 10-7 mol/L and control) for 24 and 48 hours separately. In order to explore the best concentrations and application time, cell proliferation was detected by cell counting kit-8 (CCK-8) assay, apoptosis rate was detected by flow cytometry. LY294002, the specific inhibitor of PI3K, was added in the culture at 20 μmol/L concentration. The cyclic adenosine monophosphate (cAMP) concentration was detected by ELISA, the protein expression of serine-threonine kinase (AKT) and phosphorylated AKT (P-AKT) were measured by Western blotting. Difference between two groups was analyzed by t test, and variance analysis was used for multiple variables analysis. Results Compared with 10-9 mol/L group (0.52±0.10) , 10-8 mol/L group (0.68±0.07) and control group (0.44±0.09) separately, cell proliferation was increased significantly in 10-7 mol/L liraglutide group (0.78±0.04) after 24 hours (t=8.383, 4.167, 12.100, all P<0.05). Compared with 10-9 mol/L group (3.295±0.346) and control group (16.315±0.474) , apoptosis rate was decreased significantly in 10-7 mol/L liraglutide group (1.380±0.255) (t=6.299, 39.272, all P<0.05); Compared with control group and LY294002 group separately, the concentration of cAMPwas increased significantly in liraglutide group (t= 14.307, 23.378, all P<0.05) , and the expression of p-AKT/AKT was increased in liraglutide group (t=7.861, 8.486, all P<0.05); Compared with liraglutide group, the concentration of cAMP and the expression of p-AKT/AKT were all decreased in liraglutide + LY294002 group(t=16.473, 3.172, all P<0.05). Conclusions Liraglutide can promote proliferation and inhibit apoptosis of HUC-MSCs and the optimal concentration and culture time are 10-7 mol/L and 24 hours. The mechanism may be related to the activation of the PI3K/AKT signaling pathway. Key words: Liraglutide; Human umbilical cord mesenchymal stem cells; Proliferation; Apoptosis