The Expression Differences Of The Tenascin-C,Hyaluronic Acid And PKC-α,-β₁Between Skin Regeneration And Scarring

Objective There are often two different healing situations after skin trauma, completely healing(regeneration) and incompletely healing(scarring). The difference expressions of tenascin-C, Hyaluronic Acid(HA), Protein Kinase C(-a, PKC-a) and PKC-β1in regeneration and scar healing remain unclear. This study is to establish integrated model of regeneration and scar healing of rabbit ear, to detect expression differences of tenascin-C, HA, PKC-a and PKC-β1between regeneration and scarring by immunohistochemistry and in situ hybridization techniques.Materials and Methods A total of18adult, healthy New Zealand white rabbits, was purchased from Lan Zhou Institute Of Biological Agents of either sex, each weighing2.0-2.5Kg. Each rabbit was then housed in a separate cage and was feeded for one week.The ear ventral fur was removed by5%sodium sulfide72hours before operation. After anesthetization with a single auricular vein sodium pentobarbital (1.0ml/Kg body weight), two parallel10.0mm-long of the stereotyped wound apart from10.0mm have been made by a blade, and the jig is to produce a standardized wound that was deep at one end and superficial at the other. The wound specimens(10.0mm×10.0mm) were havested from each wound site at Oh,3d,6d,9d,12d and27d post-wound. The expression levels of tenascin-C, HA, PKC-a and PKC-β1were detected by immunohistochemical staing or in situ hybridization techniques. The wounds were divided into10sections(1.0mm×10.0mm) from the superficial side to the deep side.The optical density of five fields at x40in100μm area of the each section were analyzed by software of Image Pro-Plus6.0at each time. The data was expressed with x±s and assessed by analysis of variance when Homogeneity of variance among groups, their further multiple comparison by LSD(least significant different) method, by the Kruskal-Wallis Test when heterogeneity of variance. Data were analyzed using SPSS17.0for Windows. A p<0.05was considered statistically significant.All study protocols were permitted by animal care committees of Lanzhou University and all animals received humane care. Results1. The superficial wounds (i.e. the wounds of=3mm to superficial side) regenerated at9d after injury, whereas the wounds of=8mm apart from superficial side (i.e. the deep wounds) healing at12-14d after injury and scarring at27d after injury.2. Tenascin-C expression of the deep wounds was higher than the superficial woundThe tenascin-C expression in superficial and deep wounds expressed at3d after injury and reached the peak gradually at9d and decreased after12d, but the deep wounds27d after injury (scar reconstruction period) again increased (p<0.05). The Tenascin-C expression in the deep wounds was significantly higher that than the superficial side at12d and27d after injury (p<0.05).3. HA expression of the deep wounds was lower than the superficial wounds.The HA expression started to increase from3d post-trauma and the highest at27d in the superficial wounds, whereas HA expression levels reached a peak at9d after injury, in the deep wounds. The HA expression in the deep wounds was significantly lower that than the superficial side at12d and27d after injury (p<0.05).4. The less expressions PKC-a in the superficial wounds.The PKC-a expression in the superficial wounds increased gradually at post-trauma and reached the peak gradually at9d and decreased after12d, whereas the PKC-a expression levels in the deep wounds continued to rise. The PKC-a expression in the deep wounds was significantly higher that than the superficial side at each time point (p<0.05).5. The less expressions PKC-β1in the superficial wounds.The PKC-β1expression in the superficial wounds increased gradually at post-trauma and reached the peak gradually at9d and decreased after12d, whereas the PKC-β1expression levels in the deep wounds continued to rise. The PKC-β1expression in the deep wounds was significantly higher that than the superficial side at each time point (p<0.05).6. Regeneration healing in superficial wounds and scarring in deep wounds.Conclusions1. The expressions of tenascin-C, PKC-a, PKC-β1in the deep wounds were always higher than the superficial’s. However, the expression levels of HA is opposite.2. The integration model of regeneration and scarring in rabbit ear is successful and reliable.