Nakamura Hiroshi, Ueda Jun, Sugar Joel, Yue Beatrice Y J T
Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago College of Medicine, 60612, USA.
Invest Ophthalmol Vis Sci. 2005 Nov;46(11):4092-6. doi: 10.1167/iovs.05-0324.
To examine the expression of transcription factor Sp1 in the cornea of the mouse eye throughout developmental stages. The environmental effect of light on Sp1 expression was also assessed.
C57BL/6 mice were set up for timed mating. Embryos on embryonic day (E)10.5, E12.5, E15.5, and E18.5 and eyes from mice on postnatal day (P)0, P7, P11, P15, P30, and P60 were collected for immunohistochemical staining and in situ hybridization. One group of mice was bred strictly in the dark between E18.5 and P15, and the eyes were collected at P0, P7, P11, and P15 time points.
Sp1 expression was observed in the ectoderm and lens vesicle as early as E10.5. Both Sp1 protein and mRNA were abundant in the corneal basal epithelium and keratocytes until P11. Their levels were markedly reduced at P15, right after eyelid opening, and declined further between P15 and P60. In those mice bred in the dark, Sp1 was evident in the cornea at P0. The Sp1 level gradually increased until P11 and was decreased at P15. This expression pattern was nearly identical in mice bred either in a light/dark cycle or in the dark. The Sp1 level in the central lens epithelium was much lower than that in the cornea from E15.5 to late stages.
The present study indicates that Sp1 expression is developmentally regulated, providing a basis for further investigations on the regulation of the Sp1 gene during the course of corneal development and in diseases such as keratoconus.
研究转录因子Sp1在小鼠眼睛角膜发育各阶段的表达情况。同时评估光照对Sp1表达的环境影响。
设置C57BL/6小鼠进行定时交配。收集胚胎期第（E）10.5天、E12.5天、E15.5天和E18.5天的胚胎以及出生后第（P）0天、P7天、P11天、P15天、P30天和P60天小鼠的眼睛，用于免疫组织化学染色和原位杂交。一组小鼠在E18.5至P15期间严格饲养在黑暗环境中，并在P0、P7、P11和P15时间点收集眼睛。
早在E10.5时，在外胚层和晶状体泡中就观察到Sp1表达。直到P11，Sp1蛋白和mRNA在角膜基底上皮和角膜细胞中都很丰富。在P15时，即眼睑张开后，它们的水平明显降低，并在P15至P60之间进一步下降。在黑暗中饲养的那些小鼠中，P0时角膜中Sp1明显可见。Sp1水平逐渐升高直至P11，并在P15时降低。这种表达模式在光/暗循环或黑暗环境中饲养的小鼠中几乎相同。从E15.5到后期，中央晶状体上皮中的Sp1水平远低于角膜中的水平。
本研究表明Sp1表达受发育调控，为进一步研究角膜发育过程中以及圆锥角膜等疾病中Sp1基因的调控提供了基础。
