Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom.
Tissue Eng Part A. 2011 Mar;17(5-6):741-50. doi: 10.1089/ten.TEA.2010.0343. Epub 2011 Jan 16.
Transparency of the human cornea is dependent upon the integrity of its epithelium and hence a population of limbal epithelial stem cells (LESCs). We have previously shown that LESCs reside in limbal epithelial crypts at the periphery of the human cornea. In this study the anatomy and functionality of the porcine limbus was evaluated for the first time as a novel model of the human limbus. Scanning electron microscopy, confocal microscopy, and histology revealed common structures in the porcine and human limbus in terms of the location and topography of palisades of Vogt and limbal epithelial crypts. Epithelial cells harvested from crypt regions achieved higher colony forming efficiency than cultures established from the noncrypt regions and central cornea. Also, expression of the putative SC markers p63α and integrin β1 brightness was higher in the basal layer of the crypt regions, as shown by immunocytochemistry. De-epithelialized porcine corneas were used as an in vitro organ culture model to study the fate of transplanted human epithelium cultured from the limbus. Multilayered epithelium was observed after ∼1 week. Subsequently, wounds were inflicted on the central corneal epithelium. The wounded tissue healed within 5-7 days, and multilayering of the central corneal epithelium was re-established. The transplanted epithelia were repeatedly wounded at least four times and the wounds healed by 1 week. Putative SC marker expression of the transplanted epithelia was confirmed using immunohistochemistry. These results demonstrate that the porcine limbus shares features with the human limbus and as such provides a suitable model for the study of cultured limbal epithelial cell transplantation. These data have significant clinical value as this model can provide information on LESC fate post-transplantation and their ability to respond to injury, which is not possible to study in patients.
人眼角膜的透明度取决于其上皮细胞的完整性，因此需要有一群角膜缘上皮干细胞（LESCs）。我们之前已经证明，LESCs 存在于人眼角膜周边的角膜缘上皮隐窝中。在这项研究中，我们首次评估了猪眼角膜缘的解剖结构和功能，将其作为人眼角膜缘的新型模型。扫描电子显微镜、共聚焦显微镜和组织学显示，猪和人眼角膜缘在 Vogt 栅栏和角膜缘上皮隐窝的位置和形态上具有共同的结构。从隐窝区域收获的上皮细胞比从非隐窝区域和中央角膜建立的培养物具有更高的集落形成效率。此外，通过免疫细胞化学显示，在隐窝区域的基底层，假定的干细胞标志物 p63α 和整合素 β1 亮度表达更高。脱上皮化的猪眼角膜被用作体外器官培养模型，以研究从角膜缘培养的移植人上皮的命运。大约 1 周后观察到多层上皮。随后，在中央角膜上皮上造成创伤。受伤组织在 5-7 天内愈合，中央角膜上皮的多层化重新建立。对移植上皮进行了至少 4 次重复创伤，创伤在 1 周内愈合。通过免疫组织化学证实了移植上皮的假定干细胞标志物表达。这些结果表明，猪眼角膜缘与人类角膜缘具有相似的特征，因此为培养的角膜缘上皮细胞移植研究提供了合适的模型。这些数据具有重要的临床价值，因为该模型可以提供有关 LESC 移植后命运及其对损伤反应的信息，而这些信息在患者中是无法研究的。
