增生性瘢痕动物模型的建立及其形成过程的动态实验研究

发布时间：2018-05-10 09:21

本文选题：增生性瘢痕 + 动物模型　；参考：《第三军医大学》2006年博士论文

【摘要】： 尽管国内外学者长期以来对增生性瘢痕(hypertrophic scar,HS)进行了大量、不懈的研究,但有关HS的形成机制目前还不清楚,临床上也缺少特别有效的防治手段,造成这种局面的原因之一就是缺少一种理想的HS动物模型。只有人才会自然发生HS,这是HS的特征之一,依据“内因是事物发展的根据,它决定着事物发展的基本趋向”这一自然辩证法则,我们推测HS的形成是人类皮肤的某种或某些内在的因素所决定的,因此通过将人皮肤移植于裸鼠的方法可以建立HS动物模型。本课题研究旨在通过移植人皮肤于裸鼠体表建立HS动物模型,较系统地观察瘢痕形成病理过程,并就瘢痕增生的形成机制进行相关实验研究,主要结果与结论如下: 1.人全厚皮片移植于裸鼠体表后会发生一定程度的排斥反应,移植皮片的表皮及部分真皮逐渐脱落。但由于裸鼠是T细胞免疫缺陷动物,这种排斥反应发生迟,程度较轻,移植人皮片的真皮层部分得以存活,并成为移植皮片干痂脱落后瘢痕增生的基础。我们的结果一方面说明裸鼠体内存在非T细胞依赖的免疫机制,另一方面说明长期的慢性免疫反应可能是瘢痕增生的促进因素。 2.移植人全厚皮片的表皮及部分真皮脱落后,局部可以发生明显的瘢痕增生,该瘢痕无论在大体外观、增生特性还是病理组织学特性上都与人的HS相似。 3.用免疫组织化学的方法研究模型瘢痕中的TGFβ-1的变化规律,发现增生期模型瘢痕中TGF-β1持续高水平表达,而消退期则显著降低。 4.体外细胞培养实验结果表明,模型瘢痕成纤维细胞与人HS成纤维细胞形态上非常相似,细胞增殖及胶原合成活性亦无显著差别。 5.对比模型瘢痕组织以及正常皮肤中胶原酶活性,发现增生期的模型瘢痕胶原酶活性低,表明模型瘢痕中胶原等细胞外基质降解减少。 6.以模型瘢痕组织和正常人皮肤组织及人HS组织的DNA为模板进行PCR,结果发现都可以扩增出人源性特异性基因,说明模型瘢痕组织中肯定存在有人源性DNA。 7.只有移植人的全厚皮片才会发生明显的瘢痕增生,而移植人的刃厚皮片以及大鼠的全厚皮片则根本不发生瘢痕增生,移植人中厚皮片虽然部分可以发生一定程度的瘢痕增生,但增生程度及发生率均明显不如移植人的全厚皮片。这说明人皮肤真皮层是HS发生的决定因素。本发现在人体外证实了只有人皮肤才会发生HS这一现象,并证明了人皮肤真皮层是HS发生的决定因素,而不是表皮层或其他外界环境因素,进一步揭示了HS的发生机制。上述结果表明,人皮肤移植于裸鼠后会发生一定程度的排斥反应,排斥反应的发生使移植的人皮肤的表皮及部分真皮坏死脱落,但仍有部分真皮存活,存活的这部分人真皮是HS发生的基础。真皮中的人成纤维细胞在局部炎性反应的持续刺激下功能状态发生改变,细胞增殖旺盛,并合成大量的胶原等细胞外基质,从而导致瘢痕的持续增生。该模型瘢痕增生明显,增生持续时间长,瘢痕的大体形态、生长特性、组织学特点等都和人HS相似,具有很好的代表性,可用于瘢痕形成机制及临床防治的相关研究。结论: 1.通过在裸鼠背部体表移植人全厚皮片的方法可以建立HS动物模型; 2.人皮肤移植于裸鼠体表后可以发生不完全的排斥反应,其表皮及部分真皮受排斥而逐渐脱落,但有部分真皮长期存活; 3.该模型无论在大体外观、生长特性、组织学特点以及遗传学特性等方面都和人的HS相似,且具有很好的可控性,能观察瘢痕发生发展的全过程,是一种较为理想的人HS动物模型; 4.人皮肤真皮是发生HS的内在决定因素,而局部的持续炎性反应则是重要的促进因素。
[Abstract]:Although scholars at home and abroad have been doing a lot of research on hypertrophic scar (HS) for a long time, the formation mechanism of HS is still unclear, and there is a lack of special effective control methods in clinic. One of the reasons for this situation is the lack of an ideal animal model of HS. Only the talent will naturally occur H. S, which is one of the characteristics of HS, is based on "the internal cause is the basis of the development of things, it determines the basic trend of the development of things", the natural dialectics. We speculate that the formation of HS is determined by some or some intrinsic factors of the human skin. Therefore, the animal model can be established by migrating the human skin to nude mice. This class can be established in this course. The purpose of this study is to establish the HS animal model by transplantation of human skin to nude mice and to systematically observe the pathological process of scar formation and to study the mechanism of scar formation. The main results and conclusions are as follows:
The skin and part of the dermis of the transplanted skin were gradually shedding off the skin and part of the skin of the transplanted skin. However, the repulsive reaction occurred late and light, and the dermis of the transplanted skins survived and became a skin graft after the scab of the transplanted skin after the skin graft of the nude mice. The skin and part of the dermis of the transplanted skin were gradually falling off. Our results, on the one hand, illustrate the existence of non T cell dependent immune mechanisms in nude mice, and on the other hand, long-term chronic immune responses may be a contributing factor to scar proliferation.
2. the epidermis and part of the epidermis of all thick skin graft and partial dermis fall off, local scar hyperplasia can occur locally. The scar is similar to human HS in appearance, proliferation and histopathological characteristics.
3. the change of TGF beta -1 in the model scar was studied by immunohistochemical method. The expression of TGF- beta 1 in the hyperplastic scar was found to be high level, but the decline period was significantly reduced.
4. the results of cell culture in vitro showed that the model scar fibroblasts were very similar to the human HS fibroblasts, and there was no significant difference in cell proliferation and collagen synthesis.
5. the activity of collagenase in the model scar tissue and normal skin was compared. It was found that the hypertrophic scar collagenase activity was low, indicating that the degradation of collagen and other extracellular matrix in the model scar was reduced.
6. the model scar tissue and normal human skin tissue and the DNA of human HS tissue were used as the template for PCR. The results showed that all human specific genes could be amplified, indicating that there must be human DNA. in the model scar tissue.
7. only the full thickness skin graft of the transplant person will have obvious scar hyperplasia, and the transplant people's thick skin slice and the whole thick skin slice of the rat do not have scar proliferation at all. The thickness of the transplanted medium and thick skin can occur to a certain degree of scar hyperplasia, but the degree and incidence of hyperplasia are obviously inferior to that of the whole thick skin graft. The dermis of the human skin is a determinant of the occurrence of HS. This discovery has confirmed that HS is the only phenomenon that only human skin occurs, and that the dermis of the human skin is a determinant of the occurrence of HS, not the epidermis or other external environmental factors, and further reveals the mechanism of the birth of HS.
The results showed that a certain degree of rejection occurred after the human skin transplantation in nude mice. The rejection occurred in the skin and partial dermal necrosis of the transplanted human skin, but some of the dermis still survived. The survival of this part of the human dermis was the basis of HS. The human fibroblasts in the dermis continued to be localized in the local inflammatory response. The function state changes, the cell proliferation is exuberant, and a large number of collagen and other extracellular matrix can be synthesized, which leads to the continuous hyperplastic scar. The model has obvious hyperplastic scar, long duration of proliferation, the gross morphology, growth characteristics and histological characteristics of the scar are similar to those of human HS, which are very representative and can be used for scar formation. The study of mechanism and clinical prevention and treatment.
Conclusion:
1. HS animal model can be established by transplantation of human full-thickness skin on the back of nude mice.
After the skin transplantation of 2. people to the surface of the nude mice, an incomplete rejection could occur, and the epidermis and part of the dermis were gradually removed, but some of the dermis survived for a long time.
3. the model is similar to human HS in terms of gross appearance, growth characteristics, histology and genetic characteristics. It has good controllability and can observe the whole process of scar development. It is an ideal human HS animal model.
The dermal dermis of 4. person is the intrinsic factor determining the occurrence of HS, while local persistent inflammatory reaction is an important promoting factor.

【学位授予单位】：第三军医大学
【学位级别】：博士
【学位授予年份】：2006
【分类号】：R622;R-332

【参考文献】