Wnt/β-Catenin Signaling Regulates Proliferation of Human Cornea Epithelial Stem/Progenitor Cells
Wnt/β-Catenin Signaling Regulates Proliferation of Human Cornea Epithelial Stem/Progenitor Cells
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DOI：
10.1167/iovs.10-6486
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发表时间：
2011-06-01
影响因子：
4.4
通讯作者：
Deng, Sophie X.
中科院分区：
文献类型：
--
作者：
Nakatsu, Martin N.;Ding, Zhenhua;Deng, Sophie X.
目的.目的探讨Wnt信号通路在人角膜缘干细胞（LSCs）中的表达及作用。从人利姆布斯和中央角膜分离总RNA。通过实时定量PCR鉴定角膜缘或角膜特异性转录物。Wnt分子的蛋白表达通过人眼组织的免疫组织化学证实。使用氯化锂在体外实现Wnt信号的激活，并评估其对LSC分化和增殖的影响。Wnt 2、Wnt 6、Wnt 11、Wnt 16 b和四种Wnt抑制剂的表达特异于角膜缘区域，而Wnt 3、Wnt 7a、Wnt 7 b和Wnt 10a在中央角膜中上调。仅在利姆布斯的基底上皮细胞的一个非常小的亚群中观察到β-连环蛋白的核定位。Wnt/β-连环蛋白信号的激活增加了原代人LSC的增殖和集落形成效率。干细胞表型得以维持，表现为假定的角膜上皮干细胞标志物ATP结合盒家族G2和Delta Np 63 α表达水平较高，而成熟角膜上皮细胞标志物细胞角蛋白12表达水平较低。这些发现首次证明Wnt信号传导存在于眼表上皮中，并且在LSC增殖的调节中起重要作用。Wnt信号的调节可能具有临床应用，以提高角膜上皮干/祖细胞移植的体外扩增效率。（Invest Ophthalmol维斯科学。2011;52：4734-4741）DOI：10.1167/iovs.10-6486
PURPOSE. To investigate the expression and role of the Wnt signaling pathway in human limbal stem cells (LSCs).METHODS. Total RNA was isolated from the human limbus and central cornea. Limbal or cornea-specific transcripts were identified through quantitative real-time PCR. Protein expression of Wnt molecules was confirmed by immunohistochemistry on human ocular tissue. Activation of Wnt signaling using lithium chloride was achieved in vitro and its effects on LSC differentiation and proliferation were evaluated.RESULTS. Expression of Wnt2, Wnt6, Wnt11, Wnt16b, and four Wnt inhibitors were specific to the limbal region, whereas Wnt3, Wnt7a, Wnt7b, and Wnt10a were upregulated in the central cornea. Nuclear localization of beta-catenin was observed in a very small subset of basal epithelial cells only at the limbus. Activation of Wnt/beta-catenin signaling increased the proliferation and colony-forming efficiency of primary human LSCs. The stem cell phenotype was maintained, as shown by higher expression levels of putative corneal epithelial stem cell markers, ATP-binding cassette family G2 and Delta Np63 alpha, and low expression levels of mature cornea epithelial cell marker, cytokeratin 12.CONCLUSIONS. These findings demonstrate for the first time that Wnt signaling is present in the ocular surface epithelium and plays an important role in the regulation of LSC proliferation. Modulation of Wnt signaling could be of clinical application to increase the efficiency of ex vivo expansion of corneal epithelial stem/progenitor cells for transplantation. (Invest Ophthalmol Vis Sci. 2011;52:4734-4741) DOI:10.1167/iovs.10-6486