Stem Cells and Eye Research Laboratory, University of Debrecen, Debrecen, Hungary.
BMC Genomics. 2013 Dec 17;14:900. doi: 10.1186/1471-2164-14-900.
The surface of the human eye is covered by corneal epithelial cells (CECs) which regenerate from a small population of limbal epithelial stem cells (LESCs). Cell therapy with LESCs is a non-penetrating treatment for preventing blindness due to LESC deficiency or dysfunction. Our aim was to identify new putative molecular markers and upstream regulators in the LESCs and associated molecular pathways.
Genome-wide microarray transcriptional profiling was used to compare LESCs to differentiated human CECs. Ingenuity-based pathway analysis was applied to identify upstream regulators and pathways specific to LESCs. ELISA and flow cytometry were used to measure secreted and surface expressed proteins, respectively. More than 2 fold increase and decrease in expression could be found in 1830 genes between the two cell types. A number of molecules functioning in cellular movement (381), proliferation (567), development (552), death and survival (520), and cell-to-cell signaling (290) were detected having top biological functions in LESCs and several of these were confirmed by flow cytometric surface protein analysis. Custom-selected gene groups related to stemness, differentiation, cell adhesion, cytokines and growth factors as well as angiogenesis could be analyzed. The results show that LESCs play a key role not only in epithelial differentiation and tissue repair, but also in controlling angiogenesis and extracellular matrix integrity. Some pro-inflammatory cytokines were found to be important in stemness-, differentiation- and angiogenesis-related biological functions: IL-6 and IL-8 participated in most of these biological pathways as validated by their secretion from LESC cultures.
The gene and molecular pathways may provide a more specific understanding of the signaling molecules associated with LESCs, therefore, help better identify and use these cells in the treatment of ocular surface diseases.
人类眼睛的表面覆盖着角膜上皮细胞（CECs），这些细胞由一小部分缘上皮干细胞（LESCs）再生而来。LESCs 的细胞治疗是一种非穿透性治疗方法，可预防因 LESC 缺乏或功能障碍导致的失明。我们的目的是鉴定 LESCs 及其相关分子途径中的新的潜在分子标记物和上游调节剂。
使用全基因组微阵列转录谱分析比较 LESCs 与分化的人 CECs。应用基于 Ingenuity 的途径分析来鉴定 LESCs 特有的上游调节剂和途径。ELISA 和流式细胞术分别用于测量分泌蛋白和表面表达蛋白。在这两种细胞类型之间，有 1830 个基因的表达水平增加或减少了两倍以上。在 LESCs 中发现了许多在细胞运动（381）、增殖（567）、发育（552）、死亡和存活（520）以及细胞间信号转导（290）中起作用的分子，其中一些通过流式细胞术表面蛋白分析得到了验证。可以分析与干细胞特性、分化、细胞黏附、细胞因子和生长因子以及血管生成相关的定制基因组。结果表明，LESCs 不仅在上皮分化和组织修复中起关键作用，而且在控制血管生成和细胞外基质完整性方面也起着关键作用。一些促炎细胞因子在干细胞特性、分化和血管生成相关的生物学功能中被发现很重要：IL-6 和 IL-8 作为验证，它们从 LESC 培养物中分泌出来，参与了这些生物学途径的大部分。
这些基因和分子途径可以提供对与 LESCs 相关的信号分子的更具体的理解，从而有助于更好地识别和使用这些细胞来治疗眼表疾病。
