Change Of Endothelial Cell Migration VEGFR-2Signal Pathways In Wound Tissue Of Diabetic Rats

ObjectiveTo observe the change in endothelial cell migration VEGFR-2signal pathways inwound tissue of diabetic rats, and to confirm its action links and effect targets.Method1Eight-four SD rats were randomly divided into diabetes group (DM group, n=42)and non-diabetes group (C group, n=42) according to the random number table; the ratsof the two group were produced the deep partial thickness scald on the dorsal skin ateight weeks post diabetes model stabilizing, of which6diabetes rats were acted as shamescald diabetes group(0d) and6non-diabetes rats were acted as shame scald non-diabetesgroup(0d).2The body weight and the times of the wound healing up50%were observed. Theblood glucoses of caudal vein were detected with blood glucose meter. The woundhealing rates were detected with transparent tape graphical method and image software.Six rats in DM group and C group were sacrificed on post scald day0,1,3,7,10,14,21to collect dorsal wound tissues.3Local sugar contents were determined with proteinase K digestion assay.Histopa-thological changes in wound tissue were observed with HE staining and Masson ’sstaining.4The expressions of VEGF, VEGFR-2, F-Actin and AGEs in wound tissue weredetected by enzyme-linked immunosorbent assay.5The expression level of phospho-P38MAPK in wound tissue was determined withWestern Blotting. The contents of VEGFR-2（phospho-Tyr1214）,VEGFR-2（phospho-Tyr1175）,VEGFR-2（phospho-Tyr951）,FAK,PI3K and MVD in wound tissue weredetermined with immunohistochemical method. Result1Compared with non-diabetes group, the local sugar contents of wound tissue indiabetes group, which were closely related to blood glucose level(r=0.848，P<0.01),haveincreased significantly（P <0.01）. High concentration AGEs, which was aggravationwith development of disease, accumulated in wound tissue（P <0.05）.Wound healingwas delayed obviously（P <0.01）.2The expressions of VEGF and VEGFR-2in diabetic wound tissue were significanthigher（P <0.05）than that in non-diabetes group.There was no significant statisticaldifference in the density of MVD between diabetes group and non-diabetes group（P>0.05）.3Compared with those in non-diabetes group, the protein expressions ofphospho-Tyr1214and it’s downstream protein phospho-P38MAPK were down-regulatedin diabetes group（P <0.05）.4Compared with those in non-diabetes group, the protein expressions of phospho-Tyr951were down-regulated in diabetes group（P <0.05）.5There was no significant statistical difference between diabetes group andnon-diabetes group in the expressions of phospho-Tyr1175（P>0.05）. Compared withthose in non-diabetes group, the protein expressions of downstream protein FAK andPI3K were down-regulated in diabetes group（P <0.05）.6Compared with those in non-diabetes group, the protein expressions of F-Actinwere down-regulated in diabetes group（P <0.05）.ConclusionDiabetic wound with refractory was relative to increasing of the level of local sugarand AGEs in wound tissue. Diabetic wound with refractory was relative todown-regulation of phospho-Tyr1214and phospho-Tyr951sites in endothelial cellmigration VEGFR-2signal pathways and low expressions of phospho-P38MAPK、FAKand PI3K which are downstream signaling pathways proteins of VEGFR-2.