Apoptosis to cleft palate development in mice.

本研究假设细胞凋亡参与了次级腭架融合过程中上皮细胞的消失。5-溴脱氧尿苷(BrdU)于孕11~13天(Plug day=0)经腹腔注射给ICR小鼠，故意扰乱程序性细胞死亡，造成腭裂模型小鼠。用形态学和免疫组织化学方法观察正常组和BrdU组上颌骨顶端的细胞活动。正常组用体视显微镜观察活体尼罗蓝硫酸盐染色。结果识别出尼罗蓝阳性细胞，显示融合区域有巨噬细胞聚集。BrdU组可见腭裂，腭架尖端内侧缘上皮未见尼罗蓝阳性细胞。Norma组次生腭架融合后的间充质组织中可见上皮静息和凋亡小体。BrdU组腭突分离，中线鳞状上皮缝较鼻腔侧和口侧表皮薄。以肿瘤坏死因子家族Fas/Fas配体系统作为细胞凋亡的执行过程。结果发现正常组有阳性细胞，BrdU不识别阳性细胞。细胞凋亡提示次生腭架融合后腭侧缘上皮细胞消失，而Brou诱导腭裂的发生机制可能与细胞凋亡未完成有关。

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.