【摘要】 背景:Wnt5a是唯一在真皮高表达,与毛囊真皮成分发生密切相关的信号分子。目的:通过观察E12.5-E15.5胎龄的大鼠胚胎皮肤和大鼠触须毛囊上段裸鼠移植诱导毛乳头再生过程Wnt5a的表达,初步研究毛乳头胚胎发生和体外再生的启动机制。方法:将孕SD大鼠在E12.5、E13.5、E14.5、E15.5麻醉后处死,取出完整胚胎制作石蜡切片;另取单个SD大鼠触须毛囊切除毛乳头,毛囊上段拔除毛干后移植至Nu/Nu裸鼠背部皮肤;分别取以上胎龄的大鼠胚胎皮肤及裸鼠背部移植部位的毛囊标本,用酶标免疫组化法观察Wnt5a在大鼠胚胎皮肤及大鼠触须毛囊上段裸鼠移植诱导毛乳头再生过程的表达,苏木精-伊红染色观察大鼠触须毛囊上段移植后毛囊下段的再生情况。动物实验均已获得汕头大学医学院动物伦理委员会批准。结果与结论:①E12.5 Wnt5a在表皮细胞表达;E13.5 Wnt5a在表皮细胞表达增强;E14.5 Wnt5a表达由表皮转移至真皮,在真皮细胞浆明显表达;E15.5Wnt5a表达在真皮结缔组织明显增强,在表皮的表达消失;②大鼠触须毛囊上段移植后第3天开始至第9天,毛囊上段向下形成新的毛球部,恢复完整毛囊结构,再生过程相关组织Wnt5a均呈强阳性表达;③Wnt5a在胚胎毛囊发生前后和毛囊下段再生模型毛乳头形成的部位呈现高表达,说明Wnt信号通路与毛乳头再生有密切的关系,其中Wnt5a可能扮演了非常主要的角色。更多还原

【Abstract】 BACKGROUND: Wnt5a is the only signaling molecule that is highly expressed in the dermis and closely related to the occurrence of hair follicle dermal components. OBJECTIVE: To preliminarily discuss initiation mechanism of dermal papilla embryogenesis and regeneration in vitro by observing Wnt5a expression of E12.5-E15.5 fetal rat skin and the upper part of tentacle hair follicle during dermal papilla regeneration induced by transplantation. METHODS: The pregnant Sprague-Dawley rats at E12.5, E13.5, E14.5 and E15.5 days were killed under anesthesia. The embryos were taken out to make paraffin sections. The hairy papilla was removed from the tentacle hair follicles of Sprague-Dawley rats, and the hair follicles were removed from the upper segment of the hair follicles and then injected into the skin of the back of Nu/Nu nude mice. The skins of rat embryos at above gestational age and hair follicles at transplanted back positions of the nude mice were taken. Enzymatic immunohistochemical method was used to observe the Wnt5a expression in rat embryonic skin and the upper segment of hair follicle during dermal papilla regeneration induced by transplantation. Hematoxylin-eosin staining was used to observe the regeneration of the inferior segment of hair follicle after transplantation in the upper segment. The animal experiment was approved by the Animal Ethics Committee of Shantou University Medical College. RESULTS AND CONCLUSION:(1) E12.5 Wnt5a was expressed in epidermal cells; E13.5 Wnt5a was expressed in epidermal cells and enhanced; E14.5 Wnt5a was transferred from epidermis to dermis and expressed in dermal cytoplasm; E15.5 Wnt5a was expressed in dermal connective tissue, obviously enhanced, and disappeared in epidermis.(2) From the third day to the ninth day after transplantation of the upper part of the rat hair follicle, the upper fragment of the hair follicle was observed to be growing downward. The complete follicles were re-formed. Wnt 5A was strongly expressed in the regeneration related tissues.(3) The high expression of Wnt5a in the site of dermal papilla formation in this model and dermal papilla embryogenesis suggests that Wnt signaling pathway is closely related to the regeneration of dermal papilla, and Wnt5a may play a very important role.更多还原