Effects of liraglutide on the biological behavior of human endothelial colony forming cell induced by high glucose via regulating sirtuin expression / 解放军医学杂志

ABSTRACT

Objective To explore whether liraglutide could affect high glucose induced-biological behavior of human endothelial colony forming cell (ECFC) by regulating sirtuin. Methods Mononuclear cells in human peripheral blood were isolated by density gradient centrifugation. ECFCs were induced and cultured with EBM-2 complete medium. The cells were randomly divided into three groups normal glucose group (NG, 5.5 mmol/L D-glucose for 6 days), high glucose group (HG, 30 mmol/L D-glucose for 6 days), and osmotic pressure group (OSM, 5.5 mmol/L D-glucose+24.5 mmol/L mannitol for 6 days). The proliferation, migration, tube formation and senescence of ECFCs in the three groups were tested by EdU, Transwell, tube formation and SA-β-gal experiments respectively. The protein expression levels of Sirtuins (Sirtuin1-7), vascular endothelial growth factor (VEGF) and angiogenin were measured by Western blotting. Except NG and HG groups mentioned above, NG + liraglutide intervention group (5.5 mmol/L D-glucose+100 nmol/L liraglutide) and HG+liraglutide intervention group (30 mmol/L D-glucose+100 nmol/L liraglutide) were added in order to observe the effects of liraglutide on ECFC biological behavior and the expression of VEGF and angiogenin. The intervention time in all groups is 6 days. Results EdU, Transwell and tube formation experiments showed that the proliferation rate, migration ability and tube formation ability of ECFCs were lower in HG group [(30.16±12.36)%, 25.11±6.05, 27.50±3.90, respectively] than in NG group [(88.00±13.77)%, 64.89±10.73, 69.61±5.48, respectively], while the SA-β-gal experiment showed the senescence rate of ECFCs was higher in HG group than in NG group [(87.63±9.63)% vs. (71.35±7.58)%], all with statistical significance (P<0.05). Under high glucose conditions, the expression of Sirtuins family was generally reduced, and the expressions of VEGF and angiogenin significantly decreased (P<0.05). The expression of Sirtuin1 showed an upward trend with the increase of liraglutide concentration. After intervention with appropriate concentration of liraglutide, the expressions of VEGF and angiogenin significantly increased (P<0.05). EdU experiment showed the proliferation rate of ECFCs was higher in HG+liraglutide intervention group than in NG group [(54.09±27.29)% vs. (29.01±7.56)%], the Transwell and tube formation experiments showed that the migration ability and tube formation ability of ECFCs were higher in HG+liraglutide intervention group (32.25±4.99, 69.61±8.11) than in HG group (21.75±3.10, 39.85±5.78), and the SA-β-gal experiment showed the senescence rate of ECFCs was lower in HG+liraglutide intervention group than in HG group [(52.06±7.94)% vs. (69.03±1.57)%], all with statistical significance (P<0.05). Conclusions High glucose may accelerate ECFCs senescence while decrease the ability of proliferation, migration and tube formation of ECFCs, accompanied by down-regulation of Sirtuins, VEGF and angiogenin. Liraglutide may reverse the changes of ECFCs biological behavior induced by high glucose and up-regulate the expression of Sirtuin1, VEGF and angiogenin.