Study On The Difference Of Expression And Deposition Between MMP-2 And TIMP-1 In Hypertrophic Scar

Objective: To investigate tho role of MMP -2 and TIMP-1 in theformation of hypertrophic scar, by comparing the expression anddeposition of MMP-2 and TIMP-1 in different period of hypertrophicscar.Methods: The samples were incised from 42 patients ,in which thereare 9 with hypertrophic scar in middle period, 17 with hypertrophic scar inlate period, there are 9 with normal skin and 7 with surgical scar ascontrol. Immunohistological SABC staining was used to detect theexpression of MMP-2 and TIMP-1.Three sections were incised by serialsection from each sample.The third section was used for negative controlwith PBS as the first antibody. To capture immunohistochemical imageof keratinocytes, fibroblasts and vascular endothelial cells in everysection., To analyse the positive results with mean optical density(mOD)as the relative index for measuring protein expression by usingprofessional image analyse software.Results:1. The differences of MMP-2 expression by keratinocyte in the 4 kinds tissues are both significant(P＜0.05). The differences of TIMP-1expression by keratinocyte in surgical scar and normal skin is notsignificant(P＞0.05),but which in the 2 periods hypertrophic scar issignificant(P＜0.05). The levels of MMP-2 expression and TIMP-1expression by keratinocyte of hypertrophic scar in the 2 period are bothhigher than that of normal skin and surgical scar. And the levels of.MMP-2 expression and TIMP-1 expression by keratinocyte of hypertr--ophic scar in the late period are higher than that in the middle period.The differences of MMP-2 expression and TIMP-1 expression byfibroblast in hypertrophic scar in the 2 periods are both signify--cant(P＜0.05), and so does vascular endothelial cell. The fibroblast andvascular endothelial cell of hypertrophic scar in the middle period expressmore MMP-2 than which in late period, contrasted to MMP-2,the level ofTIMP-1 expression by the fibroblast and vascular endothelial cell ofhypertrophic scar in middle period is lower than which in late period.2. In the tissue of hypertrophic scar in middle period: MMP-2 andTIMP-1 are mainly expressed by vascular endothelial cell.The level ofMMP-2 expression by keratinocyte is lower than which by fibroblast and(P＜0.05). The differences of TIMP-1 expression by keratinocyte andfibroblast is is not significant(P＞0.05). In the tissue of hypertrophic scarin late period: MMP-2 is still mainly expressed by vascular endothelialcell,and keratinocyte still express the lest in the 3 kinds of cell (P＜0.05). But for TIMP-1, The level of expression by keratinocyte andvascular endothelial cell are both significantly higher than which byfibroblast (p＜0.05).But the difference of TIMP-1 expression betweenvascular endothelial cell and keratinocyte is not significant(P＞0.05).Conclusion:1.MMP-2 which is mainly expressed by fibroblast and vascularendothelial cell may contribute to the hyperplasia of hypertrophic scar inmiddle period.2.The failure remodeling of hypertrophic scar in late period maycorrelate with TIMP-1 which is mainly expressed by keratinocyte andvascular endothelial cell.