Stem cells of the corneal epithelium lack connexins and metabolite transfer capacity
Stem cells of the corneal epithelium lack connexins and metabolite transfer capacity
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DOI：
10.1046/j.1432-0436.1997.6140251.x
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发表时间：
1997-05-01
期刊：
影响因子：
2.9
通讯作者：
Wolosin, JM
中科院分区：
文献类型：
--
作者：
Matic, M;Petrov, IN;Wolosin, JM
角膜上皮谱系的干细胞局限于利姆布斯的基底细胞层，即血管化的角膜外缘。这些具有很大增殖潜力的慢周期细胞维持角膜上皮团。由于细胞间通讯在发育和分化中起着重要作用，我们进行了两个角膜连接蛋白的表达，Cx43和Cx 50，和示踪剂转移能力的角膜缘和角膜上皮细胞使用刮加载技术的比较检查。Cx43在覆盖角膜的上皮的基底细胞层中大量表达，但在小鼠、人、新生兔和鸡的角膜缘上皮中基本上不存在。在成年兔的角膜缘上皮显示整体弱Cx43免疫反应性，但Cx43自由分离的基底细胞可以区分。Cx 50在三种哺乳动物角膜的整个角膜上皮中表达，但在利姆布斯中检测不到。兔刮片负载实验产生的结果与免疫组织学发现一致;角膜缘上皮缺乏示踪剂（荧光黄）转移能力，强烈表明不存在功能性间隙连接。总之，我们的研究结果表明，干细胞的无能间隙连接介导的细胞间通讯。这种特性可能反映了这些独特细胞维持独特细胞内环境的需要。
The stem cells of the corneal epithelial lineage are confined to the basal cell layer of the limbus, a vascularized outer corneal rim. These slow cycling cells of great proliferative potential maintain the corneal epithelial mass. Since cell-cell communication plays an important role in development and differentiation, we conducted a comparative examination of the expression of two corneal connexin's, Cx43 and Cx50, and the tracer transfer capacity of the limbal and corneal epithelia using the scrape loading technique. Cx43 is abundantly expressed in the basal cell layer of the epithelium covering the cornea, but is essentially absent from the mouse, human, neonatal rabbit, and chicken limbal epithelium. In the adult rabbit the limbal epithelium displays an overall weak Cx43 immunoreactivity, but Cx43-free isolated basal cells can be distinguished. Cx50 is expressed throughout the corneal epithelium of the three mammalian corneas, but is not detectable in the limbus. Scrape loading experiments in the rabbit yielded results which were consistent with the immunohistological findings; limbal epithelium lacked tracer (lucifer yellow) transfer capacity, strongly suggesting the absence of functional gap junctions. Altogether, our results demonstrate the incompetence of stem cells for gap junction-mediated cell-to-cell communication. This property may reflect the need of these unique cells to maintain a distinct intracellular environment.