Objective: To investigate the effects and regulatory mechanism of ILK on angiogenesis in hypertrophic scar.
Methods: The human scar microvascular endothelial cells (HSMECs) were isolated from 6 patients' hypertrophic scar in vitro. The HSMECs with good condition in 2nd to 4th generation were selected as experimental objectives. (1) HSMECs were divided into the blank control group (treated with routine culture), negative control group (treated with only Lipofectamine 2000), LY294002 group (incubated with 50 nmol/L LY294002), ILK siRNA group (incubated with 20 nmol/L ILK siRNA). RT-PCR and Western Blot were used to detect the expression of ILK mRNA and its protein after transfecion for 48 h. (2) The digested HSMECs of four groups were resuspended with DMEM without serum and then seeded onto the upper compartment of transwell insert which contained complete medium in its lower compartment. The cell migration experiment was stopped in 10 h and then the migrated cells were counted to analyze the effects of different interventions on the migration ability of HSMECs. (3) The thawed ECMatrix was put into each well of pre-colled 48-well tissue culture plate, and then the plate was put into the incubator at 37 degrees C to make it to become gel. The HSMECs of four groups were seeded onto the surface of the ECMatrix gel and were put into incubator. Eight random view-fields per well should be valued by the sheet of pattern recognition about angiogenesis after 8 hours to evaluate the ability of angiogenesis in vitro between four groups.
Results: (1) The expression of ILK mRNA (ILK mRNA = 0.829 +/- 0.109, t = 13.151, P = 0.006) and protein (ILK protein = 0.096 +/- 0.049, t = 36.656, P = 0.000) were both inhibited obviously in ILK siRNA group compared with the blank control group (ILK mRNA = 0.829 +/- 0.109, ILK protein = 1). And, the expression of ILK in LY294002 group was slightly lower than that of black control group, but there was no statistical difference. (2) The number of migrated cells in ILK siRNA group (88.111 +/- 3.079) and LY294002 group (138. 667 +/- 2.404) were respectively lower than that in blank control group (322.333 +/- 3.712, P < 0. 05) in 10th hour. (3) Compared to blank control group (4.333 +/- 0.191), the ability of angiogenesis in vitro decreased significantly ILK siRNA group (2.625 +/- 0.125) and LY294002 group (3.125 +/- 0.250), in which, the vascular network structures were not formed perfectly in 8th hour (P < 0.05).
Conclusions: The ability of HSMECs' migration and angiogenesis in vitro are inhibited significantly when the expression of ILK is down-regulated. It reveals that ILK may play an role in the regulation of scar angiogenesis.