Department of Cell Biology and Histology, School of Medicine and Nursing, University of the Basque Country, Sarriena, S/N, 48940, Leioa, Spain.
Department of Cell Biology and Histology, School of Medicine and Nursing, University of the Basque Country, Sarriena, S/N, 48940, Leioa, Spain; Department of Ophthalmology, University Hospital of Cruces, Cruces Plaza S/N, 48903, Barakaldo, Spain; BioCruces Bizkaia Health Research Institute, Begiker, Cruces Plaza S/N, 48903, Barakaldo, Spain.
Exp Eye Res. 2021 Oct;211:108720. doi: 10.1016/j.exer.2021.108720. Epub 2021 Aug 11.
The transplantation of expansions of limbal epithelial stem cells (LESC) remains one of the most efficient therapies for the treatment of limbal stem cell deficiency (LSCD) to date. However, the available donor corneas are scarce, and the corneas conserved for long time, under hypothermic conditions (after 7 days) or in culture (more than 28 days), are usually discarded due to poor viability of the endothelial cells. To establish an objective criterion for the utilisation or discarding of corneas as a source of LESC, we characterized, by immunohistochemistry analysis, donor corneas conserved in different conditions and for different periods of time. We also studied the potency of LESCs isolated from these corneas and maintained in culture up to 3 cell passages. We hoped that the study of markers of LESCs present in both the corneoscleral histological sections and the cell cultures would show the adequacy of the methods used for cell isolation and how fit the LESC enrichment of the obtained cell populations to be expanded was. Thus, the expressions of markers of the cells residing in the human limbal and corneal epithelium (cytokeratin CK15 and CK12, vimentin, Collagen VII, p63α, ABCG2, Ki67, Integrin β4, ZO1, and melan A) were analysed in sections of corneoscleral tissues conserved in hypothermic conditions for 2-9 days with post-mortem time (pmt) < 8 h or for 1 day with pmt > 16 h, and in sclerocorneal rims maintained in an organ culture medium for 29 days. Cell populations isolated from donor corneoscleral tissues were also assessed based on these markers to verify the adequacy of isolation methods and the potential of expanding LESCs from these tissues. Positivity for several putative stem cell markers such as CK15 and p63α was detected in all corneoscleral tissues, although a decrease was recorded in the ones conserved for longer times. The barrier function and the ability to adhere to the extracellular matrix were maintained in all the analysed tissues. In limbal epithelial cell cultures, a simultaneous decrease in the melan A melanocyte marker and the putative stem cell markers was detected, suggesting a close relationship between the melanocytes and the limbal stem cells of the niche. Holoclones stained with putative stem cell markers were obtained from long-term, hypothermic, stored sclerocorneal rims. The results showed that the remaining sclerocorneal rims after corneal transplantation, which were conserved under hypothermic conditions for up to 7 days and would have been discarded at a first glance, still maintained their potential as a source of LESC cultures.
移植扩增的角膜缘上皮干细胞(LESC)仍然是治疗角膜缘干细胞缺乏症(LSCD)最有效的方法之一。然而,现有的供体角膜稀少,而在低温条件下(7 天后)或在培养中(超过 28 天)保存的角膜,由于内皮细胞的活力差,通常会被丢弃。为了建立一个利用或丢弃角膜作为 LESC 来源的客观标准,我们通过免疫组织化学分析,对不同条件和不同时间保存的供体角膜进行了特征描述。我们还研究了从这些角膜中分离并在培养中培养至 3 个细胞传代的 LESC 的潜能。我们希望对存在于角膜组织学切片和细胞培养物中的 LESC 标志物的研究能够表明用于细胞分离的方法的适当性,以及获得的细胞群体的 LESC 富集程度是否适合扩增。因此,分析了在低温条件下保存 2-9 天(死后时间(pmt)<8 小时)或在 1 天(pmt>16 小时)的角膜缘和角膜上皮细胞(细胞角蛋白 CK15 和 CK12、波形蛋白、胶原 VII、p63α、ABCG2、Ki67、整合素β4、ZO1 和黑素 A)的角膜缘组织中的细胞的标记物。还根据这些标记物评估了从供体角膜缘组织中分离的细胞群体,以验证分离方法的适当性和从这些组织中扩增 LESC 的潜力。在所有的角膜缘组织中都检测到了几种假定的干细胞标记物(如 CK15 和 p63α)的阳性,但在保存时间较长的组织中,其活性有所下降。所有分析的组织都保持了屏障功能和与细胞外基质的粘附能力。在角膜缘上皮细胞培养物中,同时检测到黑素 A 黑素细胞标记物和假定的干细胞标记物的减少,这表明黑素细胞与龛状的角膜缘干细胞密切相关。从长期低温保存的角膜缘组织中获得了用假定的干细胞标记物染色的全克隆。结果表明,角膜移植后剩余的角膜缘组织,在低温条件下保存长达 7 天,乍一看就会被丢弃,但仍保持作为 LESC 培养物来源的潜力。
Exp Eye Res. 2016-5
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