Institute of Medical Science, University of Toronto, 1 King's College Circle , Toronto, Ontario M5S 1A8 , Canada.
Biol Open. 2012 Mar 15;1(3):237-46. doi: 10.1242/bio.2012027. Epub 2012 Feb 3.
Self-renewing, multipotential retinal stem cells (RSCs) reside in the pigmented ciliary epithelium of the peripheral retina in adult mammals. RSCs can give rise to rhodopsin positive-cells, which can integrate into early postnatal retina, and represent a potentially useful option for cellular therapy. The ability to purify a stem cell population and direct the differentiation toward a particular cell lineage is a challenge facing the application of stem cells in regenerative medicine. Here we use cell sorting to prospectively enrich mouse RSCs based on size, granularity and low expression of P-cadherin and demonstrate that only rare cells with defined properties proliferate to form colonies. We show that clonally-derived mouse and human RSC progeny are multipotent and can differentiate into mature rhodopsin-positive cells with high efficiency using combinations of exogenous culture additives known to influence neural retinal development, including taurine and retinoic acid. This directed RSC differentiation follows the temporal sequence of photoreceptor differentiation in vivo, and the cells exhibit morphology, protein and gene expression consistent with primary cultures of rods in vitro. These results demonstrate that the RSC, an adult stem cell, can be enriched and directed to produce photoreceptors as a first step toward a targeted cell replacement strategy to treat retinal degenerative disease.
自我更新的多潜能视网膜干细胞 (RSCs) 存在于成年哺乳动物周边视网膜的色素性睫状上皮中。RSCs 可以产生视紫红质阳性细胞，这些细胞可以整合到早期出生后的视网膜中，代表了细胞治疗的潜在选择。纯化干细胞群体并将其分化为特定细胞谱系的能力是再生医学中应用干细胞所面临的挑战。在这里，我们使用细胞分选技术，根据大小、颗粒度和 P-钙黏蛋白的低表达，前瞻性地富集小鼠 RSCs，并证明只有少数具有特定特性的细胞能够增殖形成集落。我们表明，通过使用已知影响神经视网膜发育的外源性培养添加剂（包括牛磺酸和视黄酸）的组合，克隆衍生的小鼠和人 RSC 后代具有多潜能性，并能高效分化为成熟的视紫红质阳性细胞。这种定向的 RSC 分化遵循体内光感受器分化的时间顺序，并且这些细胞表现出与体外杆状细胞的形态、蛋白质和基因表达一致。这些结果表明，作为针对视网膜退行性疾病的靶向细胞替代策略的第一步，RSC（一种成体干细胞）可以被富集并定向产生光感受器。
