Clusters of corneal epithelial cells reside ectopically in human conjunctival epithelium
Clusters of corneal epithelial cells reside ectopically in human conjunctival epithelium
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DOI：
10.1167/iovs.05-1084
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发表时间：
2006-04-01
影响因子：
4.4
通讯作者：
Kinoshita, S
中科院分区：
文献类型：
--
作者：
Kawasaki, S;Tanioka, H;Kinoshita, S
目的。眼表面覆盖着两种生物学上不同的上皮：角膜上皮和结膜上皮。目前，角化蛋白12 （K12）的表达被认为是角膜类型分化的标志。本研究对人球结膜上皮中k12阳性细胞的生物学特性进行了观察。采用免疫染色、原位杂交、Western blot、逆转录聚合酶链反应（RT-PCR）、荧光活化细胞分选（FACS）等方法对人结膜组织中k12阳性细胞进行研究。利用引入的扩增片段长度多态性（iAFLP）对这些细胞进行基因表达谱分析。为了确定干细胞或祖细胞的存在，进行了免疫染色和集落形成试验。Western blot分析、RT-PCR检测显示K12在结膜上皮中表达。免疫染色分析显示k12阳性细胞主要聚集在结膜上皮内。FACS分析显示，从下球结膜收集的结膜上皮细胞中有0.2% ~ 1.7%为K12阳性。iAFLP分析显示，这些细胞的基因表达模式与角膜上皮细胞高度相似。p63和ABCG2在k12阳性细胞下表达。部分集落形成细胞表达k12。k12阳性细胞似乎是位于结膜上皮内的异位、自我维持的角膜上皮细胞。
PURPOSE. The ocular surface is covered by two biologically distinct epithelia: corneal and conjunctival. The expression of keratin12 (K12) is currently considered a hallmark of cornea-type differentiation. In the current study, the biological features of K12-positive cells in human bulbar conjunctival epithelium were examined.METHODS. Human conjunctival tissues were subjected to investigate the K12-positive cells in Conjunctiva by immunostaining, in situ hybridization, Western blot analysis, reverse transcriptase-polymerase chain reaction (RT-PCR), and fluorescence-activated cell sorting (FACS). Gene expression profiling of these cells was performed with introduced amplified-fragment length polymorphism (iAFLP). To determine the presence of stem- or progenitor cells, immunostaining and colony-forming assays were performed.RESULTS. Western blot analysis, RT-PCR revealed that K12 was expressed in conjunctival epithelium. Immunostaining analysis showed that K12-positive cells reside mainly in clusters in conjunctival epithelium. FACS analysis showed that 0.2% to 1.7% of conjunctival epithelial cells collected from the inferior bulbar conjunctiva were K12 positive. iAFLP analysis revealed that the gene expression patterns of these cells were highly similar to that of corneal epithelial cells. p63 and ABCG2 were expressed beneath the K12-positive cells. Some colony-forming cells expressed K12.CONCLUSIONS. The K12-positive cells appear to be ectopically residing, self-maintaining corneal epithelial cells in the conjunctival epithelium.