The Expression Differences Of The CollagenⅠ,Ⅲand Pkc-γ,-λ Between Skin Regeneration And Scar Healing

Objective There are often two different healing situations after skin trauma, completely healing(regeneration) and incompletely healing(scar healing). The mechanisms and differences between regeneration repair and scar healing remain unclear. The difference expressions of collagen type I, type III, PKC-γ and PKC-λ in different healing are also unknown. This study is to establish integrated model of regeneration and scar healing of rabbit ear, to detect expression differences of collagen type I, type III, PKC-γ and PKC-λ between regeneration healing and scar healing by immunohistochemistry and in situ hybridization techniques.Materials and Methods A total of18adult, healthy New Zealand white rabbits (purchase from Lan Zhou Institute Of Biological Agents, conventional animals, all had the quality certificate) 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 parallel2.0cm-long of the stereotyped wound apart from1.0cm have been made by a homemade jig(Photol),the jig is to produce a standardized wound that was deep at one end and superficial at the other,12(2.0cm×0.5cm) speciments (Figure3)were havested from each wound site at Oh,3d,6d,9d,12d and27d. The expression levels of collagen typel, type III, PKC-γ and PKC-λ were detected by H&E staining, immunohistochemical staing and in situ hybridization techniques. The mean light density of random10fields at×400were analyzed by software of Image Pro-Plus6.0at each time. The data was expressed with(x±s), which were assessed by analysis of variance when Homogeneity of variance between groups and their further multiple comparison by LSD(least significant different) method, using 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 expression levels of collagen type I in the depth wound were always higher than in shallow’sIn shallow wound, the levels of collagen type I were detected at3d post-trauma, and reached peak at9d, and then decreased. In depth wound, the expressions of collagen type I kept increasing from3d to9d, and achieved maximum at27d(p<0.05). The expressions of collagen type I in depth wound were always higher than the levels in shallow’s(p<0.05).The expressions level of collagen type I mRNA in shallow wound kept increasing until9d post-injury, then declined gradually. In depth wound, the expressions of collagen type I mRNA kept increasing from3d to27d. The levels of the expressions of collagen type I mRNA in depth wound were always more than the levels in shallow wound(p<0.05).2. The expressions levels of collagen type III in depth wound were always lower than in shallow’sIn shallow wound, the expression levels of collagen type III increased in time-dependent manner, with a peak at27d. In depth wound, the expressions of collagen type III were detected at3d post-trauma, and reached peak at9d, and then reduced. The expressions of collagen type III in depth wound were always lower than the levels in shallow’s(p<0.05) but at9d(p>0.05).In shallow wound, the expressions of collagen type III mRNA increased in time-dependent manner. In depth wound, the expressions of collagen type III mRNA increased at3d, with a peak at9d post-injury and then decreased. The levels of the expression of collagen type III mRNA in depth wound were always lower than the levels in shallow’s(p<0.05) but6d post-injury (p>0.05).3. The less expressions PKC-γ in shallow woundIn shallow wound, PKC-γ was detected at3d, with a peak at9d post-injury, and then declined. In depth wound, the expressions of PKC-y kept increasing from3d to27d. The expression levels of PKC-γ in depth wound were always higher than in shallow’s(p<0.05).4. The more expressions of PKC-λ in depth woundIn shallow and depth wounds, PKC-λ was detected at3d,with a peak at9d post-injury, and then reduced. However, the expressions of PKC-λ in depth wound were higher than in shallow’s after6d post-trauma(p<0.05).5. Regeneration healing in shallow wound and scar healing in depth woundConclusions1. The expressions of protein and mRNA of collagen type I in depth wound were always higher than in shallow’s. However, the expression levels of protein and mRNA of collagen type III is opposite.2. The expressions of PKC-γ, PKC-λ in depth wound were always higher than the levels in shallow’s.3. The depth wound resulted in scar healing whereas shallow wound was regeneration. All results suggested that the integration model of regeneration and scar healing in rabbit ear is successful and reliable. The scar formation may be relevant to the rised ratio of collagen I/III and activation of PKC-γ,PKC-λ.