The Expression Differences Of The TGF-β1,2, And3between Skin Regeneration And Scarring

Objective There are two ways of wound healing, one is regeneration, the other one is scar healing. Thus far, The most closely related growth factor to wound healing and scaring is transforming growth factor-β(TGF-β). According to the exsting literatures, there are three subtypes(TGF-β1,β2,β3) in mammals and the effect of each subtype is different to others. However, the dynamic expression and the difference of each subtype in skin regeneration and scaring, has not been reported. The aims of the thesis is to detect the expression of TGF-β1,β2,β3in regeneration and scaring, and compare the dynamic expression, in order to analyze the different effects of TGF-β1, β2, β3in regeneration and scaringMaterials and methods1.Twenty one Japanese white rabbits (all of them were purchased from veterinary research institute of GanSu province with the certification, conventional animals, weighting2-2.5kilogram, female and male do not limited) were reared in a single cage, kept a week to let them adapt to the environment, then removed the hair of ventral of rabbits’ears with5%sodium sulphide, and established the animal models after three days restoration. After intravenous anesthesia with2%pentobarbital sodium by rabbit Ear Vein, flattened the ventral of rabbits’ear on the fixed platform which made by ourselves, then made two parallel wound(avoiding the great vessels) with the skin by using the tool which made by ourselves, each size is10mm×10mm, distance is15mm, the wounds directions from the superficial to the deep are from tip to root of the ear and from root to tip of the ear respectively. The wounds reach down as far as cartilage layer.2. Observe record and take photos of the situation of wound healing and scaring, at Oth,3rd,6th,9th,12th,27th and50th day after wounded, then harvested the specimens of three rabbits which were taken randomly.There are12specimens from each group, for a total of84specimens. Fixed the specimens in10%formaldehyde and made the marks, then made two pathological sections from one specimen after24hours, for a total of168.After dewaxing, do the hematoxylin-eosin staining and immunohistochemistry, to observe the histologic change in the process of wound healing and scaring, and detect the dynamic expression of TGF-β1, β2,β3-3. Divide the wound into10sections, from the deep side to the superficial side, the width of each section is1mm, make the normal skin that is1mm wide and adjacent to the superficial side of wound as the blank group.Choose five fields from each section, and use Image-Pro-Plus6.0to detect the average optical density.4. Analyze the data with SPSS19.0, let means±standard denotes each group data, then analysis the difference among the groups, if there is heterogeneity of variance, use Kruskal-Wallis test, if variance is homogenous, use variance analysis or Least Significant Difference method, to achieve the comparison among the groups or between two groups, P<0.05was considered statistical significance.Results1.The superficial wounds(the distance to the superficial side<4mm) had achieved regeneration at9th day after injury, while the deep wounds(the distance to the deep side<4mm) had almost finished re-epithelization and formed scar on the12nd day, On the27th day, the scar thickness had reached the peak, on the50th day, the scar had mutated and become softer and flatter than before.2.TGF-β1, β2expressed in the early stage of wound healing, the expression levels reached the peak at3d and decreased gradually with the wound healing, the expression in the superficial wounds returned to normal baseline at12d(P>0.05), whereas at50d in the deep wounds (P>0.05), the peaks of the expressions in the deep wounds are obviously higher than the superficial wounds(P<0.05);3.TGF-β3expressed in the early stage of superficial wounds,3d>normal control(P<0.05),the expression reached the peak gradually at9d and decreased after12d(P<0.05), while the TGF-β3expressed in the middle and late stages of deep wounds,6d>normal control(P<0.05),the expression reached the peak gradually at27d and decreased after50d(P<0.05). The peak of the expressions in superficial wounds is earlier and lower than the deep wounds.Conclusions1.The superficial wounds had achieved regeneration, while the deep wounds had formed scars, the rabbit ear regeneration-scaring wound model had been successful. 2. It suggest that TGF-β1,β2are significant in the early stage of wound healing, the TGF-β3plays a key role in the scaring and tissue reconstruction.