Immunohistochemical Study On The Change Of IL-1, IL-8, VEGF And Its Relationship With The Would Age During The Would Healing In Mice Skin

The value of cytokines in forensic medicine is mainly embodiedin their relationship with wound age estimation. The estimation ofwound age is mostly focused on the basis of pathophysiologytraditionally;vital reaction is an important one of the researchobjects. However in most of the violent cases, the casualties onlysurvive for a really short time, which is too short to result in a typicalvital reaction. At the same time the supravital reaction also interferesthe estimation of wound age. Therefore the traditional way is alreadyout-of-date in the estimation of wound age.The knowledge of modern wound healing manifested thatcytokines have played an important role in wound healing process,especially in the early time of would healing, but it is not so clearabout the expression changes of these cytokines in wound healingprocess as well as their relationship to would age. To explore therelationship between the expression change of cytokines and woundage during the healing process has been recognized as a hotresearch topic of accurate estimating wound age in the field offorensic medicine.Cytokines are released from a variety of immunocytes(lymphocyte,monocyte) and related cells ( fibre cell,endothelialcell). They are involved in the healing process as early as theappearance of bleeding after wounding, so they provide a newpossibility for wound age estimation. There are many types ofcytokines such as IL ,PDGF,PDGFR,TGF, FGF,EGF, VEGF,IGF,TNF,MCP-1,MIP -1α, MIP-2, etc. Their expression in thewound tissue all have the relationship with would age estimation.In this study, Immunohistochemical and image-analysis methodswere performed in 42 cases of rat's skin wounds and postmortemdamage in order to explore the relationship between the expressionchange of cytokines IL-1, IL-8, VEGF and the wound age duringthe healing process of rats skin wound.The results are as follows:1. the expression of IL-1, IL-8 and VEGF was also found inmacrophages and fibroblasts of the granulation tissue, and theexpression changes in the postmortem damage group showed that noany changes was found.2. IL-1α,IL-1β were expressed at early phase after wound, andtwo expression peaks were found at 5h and 3d after wound, theirexpression resume to normal level at 5d after wound.3. The Expression of IL-8 was detectable in polymorph nuclearcells (PMNs) in the wound specimens aged 4h. In the woundspecimens aged from 12h～1d after injury , IL-8 was identified in alarge number of infiltrating PMNs and part of mononuclear cells(MNCs) . Afterwards, the MNCs and fibroblastic cells (FBCs)accounted in the most part of the IL-8-positive cells. Morphmetrically, the ratio of the number of the IL-8-stained PMNs, MNCsand FBCs to total number of the cells in the wounds was evaluatedand calculated. The ratio of the IL-8-positive cells was low in thewound specimens (16.0 ±10.1 %) , and maximized in the woundspecimens aged between 5 days (59.6 % ±8.7 %) . Thereafter, theexpression decreased step by step.4. Persistent positive expression of VEGF was seen in theepidermal cells and sebaceous gland cells and persisted to 12h to 3d.At 5h, some neutrophils showed VEGF-positive reactions.macrophages and fibroblasts were the main VEGF-positive cellsAfter 12h. The amount of positive cells increased with wound age,and the peak occurred at 5d. There were still some VEGF-positivemacrophages and fibroblast s at 7d after incision.According to the study above, the conclusion is as follows:1.The expression characteristics of the above mentioned cytokinesin wound repair should be related to the wound age and it remindstherefore that they may be uses as immunohistochemical criteria foraccurate determining the wound age.2.The result s suggest that IL-8 can be used as a marker for thewound age determination3.The amount and distribution of inflammation and repair cellsthat express VEGF is changed in a time-related manner in thehealing process of mouse skin wounds. This experiment usingimmunohistochemistry to explore the relationship between theexpression change of cytokines IL-1, IL-8, VEGF and the wound ageduring the healing process of rats skin wound. The study manifestthat those cytokines have a time-related expression during woundhealing process. It provide exact theoretical base for the applicationof cytokines IL-1, IL-8, VEGF in forensic pathology.