Tracing the Fate of Limbal Epithelial Progenitor Cells in the Murine Cornea
Tracing the Fate of Limbal Epithelial Progenitor Cells in the Murine Cornea
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DOI：
10.1002/stem.1769
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发表时间：
2015-01-01
期刊：
影响因子：
5.2
通讯作者：
Lyons, J. G.
中科院分区：
文献类型：
--
作者：
Di Girolamo, N.;Bobba, S.;Lyons, J. G.
干细胞（SC）的分裂、部署和分化是促进角膜上皮更新的过程。到目前为止，研究这些细胞在哺乳动物体内的命运是不可能的。然而，诱导多色遗传标记和强大的成像技术的出现，使得这在半透明的和容易接近的小鼠角膜中实现。K14CreER(T2)-Confetti小鼠携带两个Brainbow 2.1盒拷贝，荧光蛋白随机重组产生多达10种颜色，用于监测活体动物角膜上皮内的K-14（+）祖细胞动力学。基底缘上皮细胞以10.8 mm/天的速度向中央角膜扩展和线性迁移，形成彩色的细胞柱。此外，荧光团的永久表达，从祖先传递到后代，有助于将单个克隆区分为光谱上不同的条纹，在照射区域内含有1000多个细胞。向心克隆扩增提示单个祖细胞负责维持狭窄的角膜上皮细胞通道。我们的数据一致认为角膜缘是SC的储存库，而不是SC分布在整个角膜中央。这是第一个用多色遗传示踪技术描述小鼠角膜中干细胞/祖细胞命运的报道。该模型为监测稳态条件下的SC动力学和命运选择提供了强有力的新资源，并可能有助于评估角膜发育、衰老、伤口愈合、疾病和移植后的克隆进化。
Stem cell (SC) division, deployment, and differentiation are processes that contribute to corneal epithelial renewal. Until now studying the destiny of these cells in a living mammal has not been possible. However, the advent of inducible multicolor genetic tagging and powerful imaging technologies has rendered this achievable in the translucent and readily accessible murine cornea. K14CreER(T2)-Confetti mice that harbor two copies of the Brainbow 2.1 cassette, yielding up to 10 colors from the stochastic recombination of fluorescent proteins, were used to monitor K-14(+) progenitor cell dynamics within the corneal epithelium in live animals. Multicolored columns of cells emerged from the basal limbal epithelium as they expanded and migrated linearly at a rate of 10.8 mm/day toward the central cornea. Moreover, the permanent expression of fluorophores, passed on from progenitor to progeny, assisted in discriminating individual clones as spectrally distinct streaks containing more than 1,000 cells within the illuminated area. The centripetal clonal expansion is suggestive that a single progenitor cell is responsible for maintaining a narrow corridor of corneal epithelial cells. Our data are in agreement with the limbus as the repository for SC as opposed to SC being distributed throughout the central cornea. This is the first report describing stem/progenitor cell fate determination in the murine cornea using multicolor genetic tracing. This model represents a powerful new resource to monitor SC kinetics and fate choice under homeostatic conditions, and may assist in assessing clonal evolution during corneal development, aging, wound-healing, disease, and following transplantation.