The effects of intergrin-linked kinase on angiogenesis in hypertrophic scar / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effects and regulatory mechanism of ILK on angiogenesis in hypertrophic scar.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>(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).</p><p><b>CONCLUSIONS</b>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.</p>

Expression of integrin-linked kinase in fibroblasts of scar induced by cobalt chloride and its effect on cell proliferation / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the expression of integrin-linked kinase (ILK) in fibroblasts (Fbs) of scar induced by cobalt chloride (CoCl2) and its effect on cell proliferation.</p><p><b>METHODS</b>The human hypertrophic scar Fbs of seven patients were isolated and cultured in vitro. Cells from the 5th to the 6th passages were used in the experiment. Six bottles of Fbs were obtained from each of the seven patients, and they were respectively cultured with DMEM nutrient solution containing CoCl2 in the concentration of 0, 50, 100, 150, 200, and 250 µmol/L for 24 h. The expression of ILK mRNA was determined with real-time fluorescence quantitative PCR. Fbs were stimulated by CoCl2 in the most suitable concentration (100 µmol/L) and the protein expression of ILK was determined 0, 1, 2, 4, 12, and 24 h after the stimulation. Then the Fbs were divided into control group (cultured with nutrient solution), negative control group (transfected with con-siRNA), and ILK siRNA group (transfected with ILK siRNA). They were cultured with nutrient solution containing CoCl2 in different concentrations 24 h after transfection, with 4 wells for each concentration in each group. The cell proliferation was detected by XTT assay. Data were processed with one-way analysis of variance (ANOVA) and ANOVA for repeated measurement, and LSD method was used in multiple comparisons.</p><p><b>RESULTS</b>The expression level of ILK mRNA was highest in Fbs cultured with 100 µmol/L CoCl2 for 24 h, with significant difference compared with those of Fbs cultured with other concentrations of CoCl2 (F = 50.958, P < 0.001). The expression of ILK protein in Fbs cultured with 100 µmol/L CoCl2 for 1 h (0.243 ± 0.009) was lower than that cultured for 0 h (0.387 ± 0.017), and it started to increase from 2 h (0.361 ± 0.010), and exaggerated at 4 h (0.584 ± 0.028), 12 h (0.730 ± 0.029), and 24 h (0.785 ± 0.031). The expression levels of ILK protein at 1, 4, 12, 24 h were statistically different from that at 0 h (P values all below 0.05). XTT showed that cell proliferation level was highest in control group when cultured with 100 µmol/L CoCl2 (F = 488.026, P < 0.001), which decreased from 150 µmol/L. The cell proliferation level in control group cultured with 250 µmol/L CoCl2 was significantly lower than that with 0 µmol/L (P values all below 0.05). There was no significant change in cell proliferation in ILK siRNA group among different concentrations of CoCl2 (F = 2.542, P = 0.056). The cell proliferation level in ILK siRNA group was significantly lower than that in control group and negative control group (F = 2519.542, P < 0.001).</p><p><b>CONCLUSIONS</b>ILK may be a key protein in response of hypoxia in Fbs. The mild hypoxia can stimulate the expression of ILK and promote the proliferation of Fbs, while severe hypoxia can reduce the expression of ILK and inhibit cell proliferation.</p>

Expression of integrin-linked kinase in human hypertrophic scar and its relationship with angiogenesis / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the expression of integrin-linked kinase (ILK) in scar in different growth stages, as well as its relationship with angiogenesis.</p><p><b>METHODS</b>(1) Fifteen burn patients with scar formation time shorter than 6 months, ranging from 6 to 12 months, and longer than 12 months were hospitalized from December 2009 to December 2010. They were divided into A, B, and C groups according to the scar formation time, with 5 patients in each group. Scar specimens were harvested for observation of ILK expression with immunohistochemistry method, and ILK mRNA expression with real time fluorescence quantitative RT-PCR. (2) Microvascular endothelial cells (MEC) were isolated from scar tissue in A group and cultured in vitro, and then they were purified by immunomagnetic beads and identified with coagulation factor VIII marked by immunofluorescence (fibroblasts from human normal skin were used as control). The cultured cells in logarithmic growth phase were divided into control group (cultured with M131 medium containing microvascular growth supplement), transfection 1 group (transfected with empty plasmid), and transfection 2 group (transfected with ILK cDNA plasmid) according to the random number table. After 24 hours, the expressions of ILK mRNA, Flt-1 mRNA, and KDR mRNA were determined with real time fluorescence quantitative RT-PCR. Data were processed with one-way analysis of variance.</p><p><b>RESULTS</b>Immunohistochemical observation showed that ILK in A group mainly expressed in the basal layer cells of epidermis, cytoplasm of fibroblasts, and MEC in scar, while ILK in B group only distributed in the basal layer cells of epidermis, but ILK expression in C group was not obvious. The expression of ILK mRNA in A group (0.34 ± 0.16) was significantly higher than those in B and C groups (0.17 ± 0.06, 0.07 ± 0.13, F = 37.007, P = 0.000). MEC grew up showing cobble stone formation after purification. The expression of coagulation factor VIII was positive in cytoplasm of purified MEC, while that was negative in fibroblast of human normal skin. The expressions of ILK mRNA (57.807 ± 5.556), KDR mRNA (0.836 ± 0.014), and Flt-1 mRNA (0.162 ± 0.005) in transfection 2 group were higher than those in control and transfection 1 groups (0.018 ± 0.003, 0.028 ± 0.020, 0.023 ± 0.004 and 0.042 ± 0.005, 0.039 ± 0.007, 0.046 ± 0.003; F(ILK) = 87.110, F(KDR) = 11.241, F(Flt) = 18.199, with P values all below 0.01).</p><p><b>CONCLUSIONS</b>ILK mainly expressed in scar tissue with formation time shorter than 6 months, and it may affect vascularization of scar by regulating gene expressions of KDR and Flt-1 in MEC, which plays an important role in early scar formation.</p>