The Expression Of TLR2,TLR4 In The Skin Wound Healing And Its Forensic Significance

Objective: To investigate the expression of TLR2 and TLR4 during skin wound healing and explore the new method for accurate wound age determination.Methods: The experimental model of incised wound were used in mice and immunohistochemical method was used to detect the expression of TLR2 and TLR4 in different wound age. 48 Km mice were divided into 15 experimental groups according to different wound age of 0h,1h,3h,6h,12h,1d,2d,3d,4d,5d,6d,7d,8d,9d and 10d.Each group contain 3 mice and they were sacrificed at different wound age. Then the histopathological and immunohistochemical methods were used for detecting TLR2 and TLR4 expression.3 intact mice were used as control.Results: The expression of TLR2 and TLR4 in mononuclear phagocyte (MP) in incised wound area is related to the lasting time of injure presenting bidirectional change. During the inflammation period, the expression of TLR2 and TLR4 increased gradually with proceeding. The peak was respectively observed at 5d and 3-4d, then declined gradually. The regression equation of TLR2 and TLR4 are Y=23.8099+0.9572X-0.0077X²+1.5×10^-5X³ (R²=0.872 ) and Y=25.2256+0.7893 X-0.0059X²+1.0×10^-5X³ (R²=0.879) respectively. The X is the lasting time of injure and the Y is the ratio(the number of positive MP to the total number of neutrophil, mononuclear phagocyte and fibroblast) of the TLR2 and TLR4 positive MP.Conclusion: The ratio of TLR2 and TLR4 positive MP is related to the lasting time of incised wound presenting bidirectional change.Combined with the histopathological feature in different wound age, detecting the expression of TLR2 and TLR4 in MP of injured area may be a new method for accurate wound age determination.