Basu Sayan, Hertsenberg Andrew J, Funderburgh Martha L, Burrow Michael K, Mann Mary M, Du Yiqin, Lathrop Kira L, Syed-Picard Fatima N, Adams Sheila M, Birk David E, Funderburgh James L
Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. L V Prasad Eye Institute, Hyderabad 500034, India.
Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
Sci Transl Med. 2014 Dec 10;6(266):266ra172. doi: 10.1126/scitranslmed.3009644.
Conventional allograft therapy for corneal scarring is widespread and successful, but donor tissue is not universally available, and some grafts fail owing to rejection and complications such as endothelial failure. We investigated direct treatment of corneal scarring using autologous stem cells, a therapy that, if successful, could reduce the need for corneal grafts. Mesenchymal cells were expanded from small superficial, clinically replicable limbal biopsies of human cadaveric corneo-scleral rims. Limbal biopsy-derived stromal cells (LBSCs) expanded rapidly in media containing human serum, were highly clonogenic, and could generate spheres expressing stem cell genes (ABCG2, Nestin, NGFR, Oct4, PAX6, and Sox2). Human LBSCs differentiated into keratocytes expressing characteristic marker genes (ALDH3A1, AQP1, KERA, and PTGDS) and organized a thick lamellar stroma-like tissue containing aligned collagen and keratan sulfate proteoglycans when cultured on aligned nanofiber substrata. When engrafted into mouse corneal wounds, LBSCs prevented formation of light-scattering scar tissue containing fibrotic matrix components. The presence of LBSCs induced regeneration of ablated stroma with tissue exhibiting lamellar structure and collagen organization indistinguishable from that of native tissue. Because the limbus can be easily biopsied from either eye of an affected individual and LBSCs capable of corneal stromal remodeling can be expanded under xeno-free autologous conditions, these cells present a potential for autologous stem cell-based treatment of corneal stromal blindness.
传统的角膜瘢痕同种异体移植疗法应用广泛且效果良好，但供体组织并非普遍可得，并且一些移植会因排斥反应和诸如内皮功能衰竭等并发症而失败。我们研究了使用自体干细胞直接治疗角膜瘢痕，这种疗法若取得成功，可减少对角膜移植的需求。间充质细胞从人尸体角膜巩膜缘的小面积浅表、临床可复制的角膜缘活检组织中扩增而来。角膜缘活检来源的基质细胞（LBSCs）在含人血清的培养基中快速扩增，具有高度克隆性，并且能够生成表达干细胞基因（ABCG2、巢蛋白、神经生长因子受体、Oct4、PAX6和Sox2）的球体。人LBSCs分化为表达特征性标记基因（ALDH3A1、水通道蛋白1、角蛋白、前列腺素D合成酶）的角膜细胞，并且当在排列的纳米纤维基质上培养时，会组织形成含有排列的胶原蛋白和硫酸角质素蛋白聚糖的厚层状基质样组织。当植入小鼠角膜伤口时，LBSCs可防止形成含有纤维化基质成分的光散射瘢痕组织。LBSCs的存在诱导了消融基质的再生，再生组织呈现出与天然组织难以区分的层状结构和胶原蛋白排列。由于角膜缘可轻易从受影响个体的任何一只眼睛中进行活检，并且能够进行角膜基质重塑的LBSCs可在无动物源的自体条件下扩增，因此这些细胞为基于自体干细胞的角膜基质盲治疗提供了潜力。
