Effects of thyroxine hormone on proliferation and migration of human umbilical vein endothelial cells at ultra-structure level

Abstract：Objective To observe the effects of thyroxine hormone ( TH) on the proliferation and migration of human umbilical vein endothelial cells (HUVECs).Methods HUVECs were co-cultured with TH.The proliferation rate of HUVECs was examined by MTT assay , while the cell migration ability was assessed by using the modified of wound healing assay and transwell chamber assay .The morphology and ultrastructure observation of HUVECs membrane surface was carried out by atomic force microscope ( AFM) .Results TH significantly induced proliferation of HUVECs in a dose -dependent manner ( P<0.01 ) .The proliferation rates of HUVECs in each group ( 10 -10 , 10 -9 , 10 -8 10-7 and 10 -6 mmol/L) were (11.572 ±0.68)%, (18.549 ±7.53)%, (24.183 ±4.02)%, (38.724 ±1.98)% and (32.492 ± 0.76)%, respectively.The migration distance of HUVECs and the number of cells passing the transwell chamber were both significantly increased in the groups treated with TH than in control group (0 mmol/L) (P<0.01).The migration distances in control, 10-9 mmol/L and 10-7 mmol/L groups were (18.649 ±2.370), (58.176 ±4.163) and (140.354 ± 25.239)μm, respectively;while the numbers of HUVECs passing the transwell chamber were 37.673 ±2.302, 73.860 ± 2.608 and 117.405 ±5.128, respectively.According to AFM image, HUVECs were more active after the treatment with TH than the control group (0 mmol/L) cells, presenting with more pseudopodium , granules extended the edges of cell and rough surface in cell membrane .Conclusion TH can change the ultrastructure of the HUVECs surface thus to promote cell proliferation and migration .