Lawrence Jean M, Singhal Shweta, Bhatia Bhairavi, Keegan David J, Reh Thomas A, Luthert Philip J, Khaw Peng T, Limb Gloria Astrid
Ocular Repair and Regeneration Biology Unit, Department of Cell Biology, Institute of Ophthalmology, London, UK.
Stem Cells. 2007 Aug;25(8):2033-43. doi: 10.1634/stemcells.2006-0724. Epub 2007 May 24.
Growing evidence suggests that glial cells may have a role as neural precursors in the adult central nervous system. Although it has been shown that Müller cells exhibit progenitor characteristics in the postnatal chick and rat retinae, their progenitor-like role in developed human retina is unknown. We first reported the Müller glial characteristics of the spontaneously immortalized human cell line MIO-M1, but recently we have derived similar cell lines from the neural retina of several adult eye donors. Since immortalization is one of the main properties of stem cells, we investigated whether these cells expressed stem cell markers. Cells were grown as adherent monolayers, responded to epidermal growth factor, and could be expanded indefinitely without growth factors under normal culture conditions. They could be frozen and thawed without losing their characteristics. In the presence of extracellular matrix and fibroblast growth factor-2 or retinoic acid, they acquired neural morphology, formed neurospheres, and expressed neural stem cell markers including betaIII tubulin, Sox2, Pax6, Chx10, and Notch 1. They also expressed markers of postmitotic retinal neurons, including peripherin, recoverin, calretinin, S-opsin, and Brn3. When grafted into the subretinal space of dystrophic Royal College of Surgeons rats or neonatal Lister hooded rats, immortalized cells migrated into the retina, where they expressed various markers of retinal neurons. These observations indicate that adult human neural retina harbors a population of cells that express both Müller glial and stem cell markers and suggest that these cells may have potential use for cell-based therapies to restore retinal function. Disclosure of potential conflicts of interest is found at the end of this article.
越来越多的证据表明，神经胶质细胞在成体中枢神经系统中可能具有神经前体细胞的作用。尽管已表明 Müller 细胞在出生后的鸡和大鼠视网膜中表现出祖细胞特征，但它们在发育成熟的人类视网膜中的祖细胞样作用尚不清楚。我们首次报道了自发永生化的人类细胞系 MIO-M1 的 Müller 神经胶质细胞特征，但最近我们从几位成年眼供体的神经视网膜中获得了类似的细胞系。由于永生化是干细胞的主要特性之一，我们研究了这些细胞是否表达干细胞标志物。细胞以贴壁单层的形式生长，对表皮生长因子有反应，并且在正常培养条件下无需生长因子即可无限扩增。它们可以冷冻和解冻而不丧失其特性。在细胞外基质和成纤维细胞生长因子-2 或视黄酸存在的情况下，它们获得神经形态，形成神经球，并表达包括 βIII 微管蛋白、Sox2、Pax6、Chx10 和 Notch 1 在内的神经干细胞标志物。它们还表达有丝分裂后视网膜神经元的标志物，包括外周蛋白、恢复蛋白、钙视网膜蛋白、S-视蛋白和 Brn3。当移植到营养不良的皇家外科学院大鼠或新生李斯特戴帽大鼠的视网膜下间隙时，永生化细胞迁移到视网膜中，在那里它们表达视网膜神经元的各种标志物。这些观察结果表明，成年人类神经视网膜中存在一群既表达 Müller 神经胶质细胞标志物又表达干细胞标志物的细胞，并提示这些细胞可能在基于细胞的视网膜功能恢复治疗中具有潜在用途。潜在利益冲突的披露见本文末尾。
