Inflammation and Infection Research Centre, Department of Pathology, School of Medical Sciences, University of New South Wales, Sydney, 2052, Australia.
Stem Cell Rev Rep. 2011 Jun;7(2):256-68. doi: 10.1007/s12015-010-9199-1.
The cornea, the most anterior segment of the eye, provides us with exquisite vision. Unlike other vital tissues, it is poorly protected from the environment and is thus reliant on a self-renewal program to preserve integrity. This function is reserved for corneal epithelial stem cells located in the basal layer of the limbus, a narrow transition zone that segregates the peripheral cornea from the adjacent conjunctiva. Under physiological conditions, these cells replenish the corneal epithelium when mature or traumatized cells are lost. However, when the limbus is extensively damaged, stem cell activity is compromised, resulting in a condition known as limbal stem cell deficiency (LSCD). This disease is characterized by corneal neovascularization and persistent epithelial defects which impair vision. Over the past 20 years a myriad of treatment options have been developed for LSCD, most of which incorporate stem cell transplantation. Due to the disadvantages associated with the use of allogeneic and xenogeneic material, researchers are currently focusing on refining techniques involving autologous limbal tissue transplantation and are delving into the possibility that stem cells found in other organs can provide an alternative source of corneal epithelium. Determining where donor stem cells reside on the recipient's ocular surface and how long they remain viable will provide further insights into improving current therapeutic options for patients with LSCD.
角膜是眼睛最前面的部分，为我们提供了敏锐的视力。与其他重要组织不同，它不能很好地受到环境的保护，因此依赖于自我更新程序来保持完整性。这个功能保留给位于角膜缘基底层的角膜上皮干细胞，角膜缘是一个狭窄的过渡区域，将周边角膜与相邻的结膜分开。在生理条件下，当成熟或受伤的细胞丢失时，这些细胞会补充角膜上皮。然而，当角膜缘广泛受损时，干细胞活性受损，导致称为角膜缘干细胞缺乏症（LSCD）的情况。这种疾病的特征是角膜新生血管和持续的上皮缺损，损害视力。在过去的 20 年中，已经开发出了许多针对 LSCD 的治疗选择，其中大多数都包含干细胞移植。由于使用同种异体和异种材料的缺点，研究人员目前正专注于改进涉及自体角膜缘组织移植的技术，并深入研究在其他器官中发现的干细胞是否可以为角膜上皮提供替代来源。确定供体干细胞在受者眼表面的位置以及它们保持存活的时间，将为改善 LSCD 患者的现有治疗选择提供进一步的见解。
