小鼠食管肌层形成与分化

Development and differentiation of tunica muscularis of mouse esophagus

目的 :研究α SMA、α SCA、结蛋白和MHC在小鼠食管肌层表达的时空特点及和食管肌层发育关系。方法 :应用免疫组化PAP法和TUNEL凋亡染色法 ,对胎龄 1 2d至生后 5d小鼠食管连续切片进行染色。结果 :α SMA在胎龄 1 2d开始表达。第 1 4～ 1 5d ,可见左侧第 3、4、6弓动脉壁的α SMA阳性细胞延伸至食管后壁。α SCA和结蛋白较强表达见于第 1 4～ 1 5d ,食管下段和内肌层表达强度高于食管上段和外肌层 ,但 1 6d后 ,外肌层显较强α SCA和结蛋白表达。MHC表达开始于 1 6d食管上段外肌层 ,1 8d扩展至甲状腺水平 ,外肌层和食管上段表达较内肌层和食管下段强。结论 :α SMA、α SCA、结蛋白和MHC在食管肌层发育过程中有不同的时空表达模式。

Objective: To investigate spatiotemporal expression patterns of α SMA, α SCA, Desmin and MHC in the tunica muscularis of mouse esophagus and the relationship between these protein expression and the development of muscularis externa. Methods: Serial sections of mouse embryos from ED12 to ED18, and esophagus of mice from postnatal first to 5th day were stained immunohistochemically, and used for TUNEL assays. Results: The expression of α SMA was started at ED12. During the development of ED14 to ED15, α SMA positive cells were seen extending from the walls of left 3,4 and 6 arch arteries towards the dorsal wall of esophagus. Stronger expression of α SCA and Desmin could be detected at ED14 and ED15, expression intensity in caudal region and inner layer was stained stronger than that of cranial region and outer layer, but after ED16, strong expression of α SCA and Desmin was found in the outer layer of tunica muscularis. Expression of MHC was first detected in the outer layer of cranial region of tunica muscularis at ED16, and at ED18. MHC had extended to the level of thyroid gland, staining intensity in the outer layer and cranial region was stronger than that of inner layer and caudal region. Conclusion: α SMA, α SCA, desmin and MHC show different expression patterns during development of tunica muscularis of mouse esophagus. The cells from arch arteries might participate in the development of esophageal muscularis externa.