小鼠角膜的发生与细胞凋亡

目的 通过观察小鼠角膜的发生过程，探讨角膜细胞的增殖与凋亡对角膜结构修复与塑形的作用。方法 各日龄共计120只小鼠，用HE染色或4’，6-二脒基-2-苯基吲哚（DAPI）染色对小鼠角膜的一般结构进行观察；用5′-溴脱氧尿嘧啶核苷（BrdU）技术标记角膜增殖细胞和免疫荧光法标记干细胞和凋亡细胞。结果 胚胎发育及出生后早期，角膜以实质层的发育为主。出生14d（P14）左右，角膜上皮细胞层开始增殖分化为两层细胞，同时内皮细胞也开始分化。至P30时，我们可以辨别出角膜的6层结构。BrdU阳性细胞主要存在实质层中的成纤维细胞，出生以后也可见于角膜上皮细胞层和内皮细胞层。随着角膜发育，P10左右，其他层的BrdU阳性细胞都消失，仅存在于角膜上皮细胞层。增殖细胞核抗原（PCNA）阳性细胞在发育早期散在分布于角膜的各层，P14以后PCNA阳性细胞均匀的分布于角膜上皮细胞的基底层，并维持在稳定状态。在角膜发育早期，在各层可见许多细胞凋亡。结论 角膜的发育与其感光功能形成的过程相一致，角膜干细胞的增殖与其修复有关；有大量的凋亡细胞参与角膜结构的塑形。

Histogenesis and cellular apoptosis of the mouse cornea

Objective Our aim was to observe the histogenesis, cellular proliferation and apoptosis of the mouse cornea. Methods A total of 120 mice were used in the study. HE staining and DAPI staining were used to observe the general structure of the mouse cornea. Brdu detetion and immunofluorescent labeling were carried out to study corned proliferating cell, stem cells apoptic cells. Caspase-8 immunofluorescent staining was uesd to detect corneal apoptotic cells. Results During embryonic development and early postnatal stage, the stroma layer was observed in the developing cornea. About P14, the corneal epithelial cell layer began to proliferate and differentiate into two layers, with differentiation of endothelial cells. At P30 the six-layer structure of the cornea was identified. BrdU positive cells were mainly located in fibroblasts of the stroma layer and observed in the corneal epithelial and endothelial cell layers after birth. With the development of the cornea, at about P10, the BrdU-positive cells existed only in the corneal epithelial cell layer and disappeared in other layers.PCNA-positive cells were scattered in all layers of the cornea during the early development and distributed evenly in the basal corneal epithelial cell layer after P14. Apoptosis of cells was observed at every layer during early corneal development. Conclusion Corneal development is consistent with the formation of its photoreceptor function, and corneal stem cell proliferation is related to its structural repair. A large number of apoptotic cells are involved in the structural remodeling of the cornea.