Apoptosis to cleft palate development in mice.

本研究推测细胞凋亡参与了继发性腭突融合过程中上皮细胞的消失。5-本实验于ICR小鼠妊娠11-13天（plug day=0）腹腔注射溴脱氧尿苷（BrdU），故意使细胞程序性死亡失控，造成腭裂小鼠模型。应用形态学和免疫组化方法观察正常组和BrdU组腭架端细胞的活动。体视显微镜下观察正常组大鼠活体外Nile蓝硫酸盐染色。结果显示尼罗蓝阳性细胞，融合区有巨噬细胞聚集。BrdU组大鼠出现腭裂，腭架端内侧缘上皮未见尼罗蓝阳性细胞。H-E染色显示正常组在次级腭突融合后间充质组织中可见上皮休止和凋亡小体。BrdU组腭架分离，中线鳞状上皮接缝薄于鼻腔侧和口腔侧表皮。应用TUNEL法进行免疫组化染色，观察细胞DNA断裂情况，并以肿瘤坏死因子（TNF）家族的Fas/Fas配体系统作为细胞凋亡的执行过程。结果在正常组中识别出一个阳性细胞，而BrdU检测未识别出阳性细胞，细胞凋亡提示继发性腭突融合后腭内侧缘上皮消失，BrdU诱导腭裂的机制可能与细胞凋亡的不实现有关。

This study hypothesized that apoptosis participates in disappearance of epithelial cell in fusion of secondary palatal shelves. 5-bromodeoxyuridine (BrdU) was administered to pregnant ICR mice by intraperitoneal injection at 11-13 day of gestation (plug day=0), and we made cleft palate model mouse by letting programed cell death be out of order intentionally. In normal group and BrdU group, cell action of the palatal shelf tips were observed by morphology and immunohistochemistry. In mormal group, supravital Nile blue sulphate staining was observed by using stereoscopic microscope. The result recognized Nile blue positive cells which showed accumulation of macrophage in fusion region. Cleft palate was observed in BrdU group, and Nile blue positive cells were not recognized in the medial edge epithelium of the palatal shelf tips. Epithlial rest and apoptotic body was confirmed during mesenchymal tissue after fusion of secondary palatal shelves in H-E staining of norma group. The palatal shelves were apart in BrdU group, and midline squamous epithelium seam to be thinner than epidermis of nasal cavity side and oral side. Furthermore, DNA fragmentation which used TUNEL method for immunohistochemistry was observed, Fas/Fas ligand sysyem which was TNF (tumor necrosis factor) family as execution course of apoptosis was referred. The result recognized a positive cell in normal group and didn't recognize positive cells with BrdU.The disappearance of palatal medial edge epithelium after fusion of secondary palatal shelves was suggested by the apoptosis, and the mechanisms of BroU-induced cleft palate was regarded as a thing by nonfulfillment of apoptosis.