Type1 Transglutaminase and the Differentiation of Corneal Epithelium

1型转谷氨酰胺酶与角膜上皮的分化

基本信息

批准号：
08672020
负责人：
OHASHI Yuichi
金额：
$ 1.34万
依托单位：
Ehime University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

The corneal epithelium continueously proliferates and properly differentiates in order to maintain its transparency. To clarify the process of corneal epithelial differentiation, we attempted to analyze the expression of the transglutaminase (TG), one of the enzymes which regulate keratinization, in the human corneal and conjunctival epithelium. The expression of mRNA for the TG was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR). Subsequent immunohistochemical study has revealed the presence of the cornifin, a substrate for the TG,in the corneal and conjunctival epithelium as well.In the next study, we monitored the chronological change of the TG in the corneal epithelium of the rats which were fad with vitamin A-deficient diet. Superficial punctate keratopathy appeared together with decreased lacrimation at 9 weeks after initiating the regimen, progressing to filamentary keratitis by week 12. Finally, the lesion simulating keratomalacia developed at Week 18.The seniquatative RT-PCR has demonstrated that the expression of type 1 TG was increased well in accordance with the duration of the treatment, while that of type 2 TG was gradually decreased.In another study, we obtained hyperimmune sera from the rabbit which had been immunized with the recombinant TG protain. Immunohistochemical studies using this particular antibody has demonstrated the presence of TG in the corneal amd conjunctival epithelium of the rats and humans. The staining was found to be intense especially at the cell membrane.These result strongly indicated that TG is involved in the keratinization process of corneal and conjunctival epithelium, shedding an insight to search for a new substance which is able to control the differentiation of ocular surface eipthelia.

角膜上皮不断增殖并适当分化以保持其透明度。为了阐明角膜上皮分化的过程，我们尝试分析转谷氨酰胺酶（TG）在人角膜和结膜上皮中的表达，TG是调节角化的酶之一。通过逆转录聚合酶链式反应（RT-PCR）证明了 TG mRNA 的表达。随后的免疫组织化学研究表明，角膜和结膜上皮中也存在 TG 的底物 Cornifin。在接下来的研究中，我们监测了大鼠角膜上皮中 TG 的时间变化。饮食缺乏维生素A。开始治疗后第 9 周出现浅表点状角膜病变并伴有流泪减少，第 12 周进展为丝状角膜炎。最后，第 18 周出现模拟角膜软化的病变。提前 RT-PCR 表明 1 型 TG 的表达随着治疗时间的延长，2型TG逐渐下降。在另一项研究中，我们获得了超免疫来自用重组TG蛋白免疫的兔子的血清。使用这种特殊抗体进行的免疫组织化学研究表明，大鼠和人类的角膜和结膜上皮中存在 TG。发现染色特别强烈，尤其是在细胞膜处。这些结果有力地表明TG参与了角膜和结膜上皮的角化过程，为寻找能够控制眼表分化的新物质提供了思路。上皮细胞。